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5c1ebe9a |
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27-Feb-2024 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Don't initialize idreg debugfs w/ preemption disabled Testing KVM with DEBUG_ATOMIC_SLEEP enabled doesn't get far before hitting the first splat: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 13062, name: vgic_lpi_stress preempt_count: 1, expected: 0 2 locks held by vgic_lpi_stress/13062: #0: ffff080084553240 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xc0/0x13f0 #1: ffff800080485f08 (&kvm->arch.config_lock){+.+.}-{3:3}, at: kvm_arch_vcpu_ioctl+0xd60/0x1788 CPU: 19 PID: 13062 Comm: vgic_lpi_stress Tainted: G W O 6.8.0-dbg-DEV #1 Call trace: dump_backtrace+0xf8/0x148 show_stack+0x20/0x38 dump_stack_lvl+0xb4/0xf8 dump_stack+0x18/0x40 __might_resched+0x248/0x2a0 __might_sleep+0x50/0x88 down_write+0x30/0x150 start_creating+0x90/0x1a0 __debugfs_create_file+0x5c/0x1b0 debugfs_create_file+0x34/0x48 kvm_reset_sys_regs+0x120/0x1e8 kvm_reset_vcpu+0x148/0x270 kvm_arch_vcpu_ioctl+0xddc/0x1788 kvm_vcpu_ioctl+0xb6c/0x13f0 __arm64_sys_ioctl+0x98/0xd8 invoke_syscall+0x48/0x108 el0_svc_common+0xb4/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x54/0x128 el0t_64_sync_handler+0x68/0xc0 el0t_64_sync+0x1a8/0x1b0 kvm_reset_vcpu() disables preemption as it needs to unload vCPU state from the CPU to twiddle with it, which subsequently explodes when taking the parent inode's rwsem while creating the idreg debugfs file. Fix it by moving the initialization to kvm_arch_create_vm_debugfs(). Fixes: 891766581dea ("KVM: arm64: Add debugfs file for guest's ID registers") Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240227094115.1723330-3-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
89176658 |
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14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add debugfs file for guest's ID registers Debugging ID register setup can be a complicated affair. Give the kernel hacker a way to dump that state in an easy to parse way. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240214131827.2856277-27-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
84de212d |
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14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Make FEAT_MOPS UNDEF if not advertised to the guest We unconditionally enable FEAT_MOPS, which is obviously wrong. So let's only do that when it is advertised to the guest. Which means we need to rely on a per-vcpu HCRX_EL2 shadow register. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20240214131827.2856277-25-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
c5bac1ef |
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14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move existing feature disabling over to FGU infrastructure We already trap a bunch of existing features for the purpose of disabling them (MAIR2, POR, ACCDATA, SME...). Let's move them over to our brand new FGU infrastructure. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240214131827.2856277-20-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
2fd8f31c |
|
14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add Fine-Grained UNDEF tracking information In order to efficiently handle system register access being disabled, and this resulting in an UNDEF exception being injected, we introduce the (slightly dubious) concept of Fine-Grained UNDEF, modeled after the architectural Fine-Grained Traps. For each FGT group, we keep a 64 bit word that has the exact same bit assignment as the corresponding FGT register, where a 1 indicates that trapping this register should result in an UNDEF exception being reinjected. So far, nothing populates this information, nor sets the corresponding trap bits. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240214131827.2856277-18-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
19f3e7ea |
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14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Register AArch64 system register entries with the sysreg xarray In order to reduce the number of lookups that we have to perform when handling a sysreg, register each AArch64 sysreg descriptor with the global xarray. The index of the descriptor is stored as a 10 bit field in the data word. Subsequent patches will retrieve and use the stored index. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240214131827.2856277-15-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
888f0880 |
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14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Add sanitising to VNCR-backed sysregs VNCR-backed "registers" are actually only memory. Which means that there is zero control over what the guest can write, and that it is the hypervisor's job to actually sanitise the content of the backing store. Yeah, this is fun. In order to preserve some form of sanity, add a repainting mechanism that makes use of a per-VM set of RES0/RES1 masks, one pair per VNCR register. These masks get applied on access to the backing store via __vcpu_sys_reg(), ensuring that the state that is consumed by KVM is correct. So far, nothing populates these masks, but stay tuned. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20240214131827.2856277-4-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
c62d7a23 |
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14-Feb-2024 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add feature checking helpers In order to make it easier to check whether a particular feature is exposed to a guest, add a new set of helpers, with kvm_has_feat() being the most useful. Let's start making use of them in the PMU code (courtesy of Oliver). Follow-up changes will introduce additional use patterns. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Co-developed--by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240214131827.2856277-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
203f2b95 |
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06-Mar-2024 |
Mark Brown <broonie@kernel.org> |
arm64/fpsimd: Support FEAT_FPMR FEAT_FPMR defines a new EL0 accessible register FPMR use to configure the FP8 related features added to the architecture at the same time. Detect support for this register and context switch it for EL0 when present. Due to the sharing of responsibility for saving floating point state between the host kernel and KVM FP8 support is not yet implemented in KVM and a stub similar to that used for SVCR is provided for FPMR in order to avoid bisection issues. To make it easier to share host state with the hypervisor we store FPMR as a hardened usercopy field in uw (along with some padding). Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20240306-arm64-2023-dpisa-v5-3-c568edc8ed7f@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
fedc6123 |
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17-Dec-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() KVM internally uses accessor functions when reading or writing the guest's system registers. This takes care of accessing either the stored copy or using the "live" EL1 system registers when the host uses VHE. With the introduction of virtual EL2 we add a bunch of EL2 system registers, which now must also be taken care of: - If the guest is running in vEL2, and we access an EL1 sysreg, we must revert to the stored version of that, and not use the CPU's copy. - If the guest is running in vEL1, and we access an EL2 sysreg, we must also use the stored version, since the CPU carries the EL1 copy. - Some EL2 system registers are supposed to affect the current execution of the system, so we need to put them into their respective EL1 counterparts. For this we need to define a mapping between the two. - Some EL2 system registers have a different format than their EL1 counterpart, so we need to translate them before writing them to the CPU. This is done using an (optional) translate function in the map. All of these cases are now wrapped into the existing accessor functions, so KVM users wouldn't need to care whether they access EL2 or EL1 registers and also which state the guest is in. Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Co-developed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
d8bd48e3 |
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26-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Map VNCR-capable registers to a separate page With ARMv8.4-NV, registers that can be directly accessed in memory by the guest have to live at architected offsets in a special page. Let's annotate the sysreg enum to reflect the offset at which they are in this page, whith a little twist: If running on HW that doesn't have the ARMv8.4-NV feature, or even a VM that doesn't use NV, we store all the system registers in the usual sys_regs array. The only difference with the pre-8.4 situation is that VNCR-capable registers are at a "similar" offset as in the VNCR page (we can compute the actual offset at compile time), and that the sys_regs array is both bigger and sparse. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
3ed0b512 |
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12-Nov-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Compute NV view of idregs as a one-off Now that we have a full copy of the idregs for each VM, there is no point in repainting the sysregs on each access. Instead, we can simply perform the transmation as a one-off and be done with it. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
111903d1 |
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13-Nov-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt() A rather common idiom when writing NV code as part of KVM is to have things such has: if (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) { [...] } to check that we are in a hyp-related context. The second part of the conjunction would be enough, but the first one contains a static key that allows the rest of the checkis to be elided when in a non-NV environment. Rewrite is_hyp_ctxt() to directly use vcpu_has_nv(). The result is the same, and the code easier to read. The one occurence of this that is already merged is rewritten in the process. In order to avoid nasty cirtular dependencies between kvm_emulate.h and kvm_nested.h, vcpu_has_feature() is itself hoisted into kvm_host.h, at the cost of some #deferry... Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
676f4823 |
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14-Dec-2023 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Handle HAFGRTR_EL2 trapping in nested virt Add the encodings to fine grain trapping fields for HAFGRTR_EL2 and add the associated handling code in nested virt. Based on DDI0601 2023-09. Add the missing field definitions as well, both to generate the correct RES0 mask and to be able to toggle their FGT bits. Also add the code for handling FGT trapping, reading of the register, to nested virt. Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231214100158.2305400-10-tabba@google.com
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#
f128cf8c |
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27-Oct-2023 |
Sean Christopherson <seanjc@google.com> |
KVM: Convert KVM_ARCH_WANT_MMU_NOTIFIER to CONFIG_KVM_GENERIC_MMU_NOTIFIER Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where appropriate to effectively maintain existing behavior. Using a proper Kconfig will simplify building more functionality on top of KVM's mmu_notifier infrastructure. Add a forward declaration of kvm_gfn_range to kvm_types.h so that including arch/powerpc/include/asm/kvm_ppc.h's with CONFIG_KVM=n doesn't generate warnings due to kvm_gfn_range being undeclared. PPC defines hooks for PR vs. HV without guarding them via #ifdeffery, e.g. bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range); bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range); bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range); bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range); Alternatively, PPC could forward declare kvm_gfn_range, but there's no good reason not to define it in common KVM. Acked-by: Anup Patel <anup@brainfault.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Message-Id: <20231027182217.3615211-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
4d20debf |
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20-Oct-2023 |
Raghavendra Rao Ananta <rananta@google.com> |
KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU The number of PMU event counters is indicated in PMCR_EL0.N. For a vCPU with PMUv3 configured, the value is set to the same value as the current PE on every vCPU reset. Unless the vCPU is pinned to PEs that has the PMU associated to the guest from the initial vCPU reset, the value might be different from the PMU's PMCR_EL0.N on heterogeneous PMU systems. Fix this by setting the vCPU's PMCR_EL0.N to the PMU's PMCR_EL0.N value. Track the PMCR_EL0.N per guest, as only one PMU can be set for the guest (PMCR_EL0.N must be the same for all vCPUs of the guest), and it is convenient for updating the value. To achieve this, the patch introduces a helper, kvm_arm_pmu_get_max_counters(), that reads the maximum number of counters from the arm_pmu associated to the VM. Make the function global as upcoming patches will be interested to know the value while setting the PMCR.N of the guest from userspace. KVM does not yet support userspace modifying PMCR_EL0.N. The following patch will add support for that. Reviewed-by: Sebastian Ott <sebott@redhat.com> Co-developed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-5-rananta@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
fe49fd94 |
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12-Oct-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move VTCR_EL2 into struct s2_mmu We currently have a global VTCR_EL2 value for each guest, even if the guest uses NV. This implies that the guest's own S2 must fit in the host's. This is odd, for multiple reasons: - the PARange values and the number of IPA bits don't necessarily match: you can have 33 bits of IPA space, and yet you can only describe 32 or 36 bits of PARange - When userspace set the IPA space, it creates a contract with the kernel saying "this is the IPA space I'm prepared to handle". At no point does it constraint the guest's own IPA space as long as the guest doesn't try to use a [I]PA outside of the IPA space set by userspace - We don't even try to hide the value of ID_AA64MMFR0_EL1.PARange. And then there is the consequence of the above: if a guest tries to create a S2 that has for input address something that is larger than the IPA space defined by the host, we inject a fatal exception. This is no good. For all intent and purposes, a guest should be able to have the S2 it really wants, as long as the *output* address of that S2 isn't outside of the IPA space. For that, we need to have a per-s2_mmu VTCR_EL2 setting, which allows us to represent the full PARange. Move the vctr field into the s2_mmu structure, which has no impact whatsoever, except for NV. Note that once we are able to override ID_AA64MMFR0_EL1.PARange from userspace, we'll also be able to restrict the size of the shadow S2 that NV uses. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231012205108.3937270-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
27cde4c0 |
|
18-Oct-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Rename helpers for VHE vCPU load/put The names for the helpers we expose to the 'generic' KVM code are a bit imprecise; we switch the EL0 + EL1 sysreg context and setup trap controls that do not need to change for every guest entry/exit. Rename + shuffle things around a bit in preparation for loading the stage-2 MMU context on vcpu_load(). Link: https://lore.kernel.org/r/20231018233212.2888027-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
5eba523e |
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18-Oct-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Reload stage-2 for VMID change on VHE Naturally, a change to the VMID for an MMU implies a new value for VTTBR. Reload on VMID change in anticipation of loading stage-2 on vcpu_load() instead of every guest entry. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231018233212.2888027-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
d8569fba |
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16-Oct-2023 |
Mark Rutland <mark.rutland@arm.com> |
arm64: kvm: Use cpus_have_final_cap() explicitly Much of the arm64 KVM code uses cpus_have_const_cap() to check for cpucaps, but this is unnecessary and it would be preferable to use cpus_have_final_cap(). For historical reasons, cpus_have_const_cap() is more complicated than it needs to be. Before cpucaps are finalized, it will perform a bitmap test of the system_cpucaps bitmap, and once cpucaps are finalized it will use an alternative branch. This used to be necessary to handle some race conditions in the window between cpucap detection and the subsequent patching of alternatives and static branches, where different branches could be out-of-sync with one another (or w.r.t. alternative sequences). Now that we use alternative branches instead of static branches, these are all patched atomically w.r.t. one another, and there are only a handful of cases that need special care in the window between cpucap detection and alternative patching. Due to the above, it would be nice to remove cpus_have_const_cap(), and migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(), or cpus_have_cap() depending on when their requirements. This will remove redundant instructions and improve code generation, and will make it easier to determine how each callsite will behave before, during, and after alternative patching. KVM is initialized after cpucaps have been finalized and alternatives have been patched. Since commit: d86de40decaa14e6 ("arm64: cpufeature: upgrade hyp caps to final") ... use of cpus_have_const_cap() in hyp code is automatically converted to use cpus_have_final_cap(): | static __always_inline bool cpus_have_const_cap(int num) | { | if (is_hyp_code()) | return cpus_have_final_cap(num); | else if (system_capabilities_finalized()) | return __cpus_have_const_cap(num); | else | return cpus_have_cap(num); | } Thus, converting hyp code to use cpus_have_final_cap() directly will not result in any functional change. Non-hyp KVM code is also not executed until cpucaps have been finalized, and it would be preferable to extent the same treatment to this code and use cpus_have_final_cap() directly. This patch converts instances of cpus_have_const_cap() in KVM-only code over to cpus_have_final_cap(). As all of this code runs after cpucaps have been finalized, there should be no functional change as a result of this patch, but the redundant instructions generated by cpus_have_const_cap() will be removed from the non-hyp KVM code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
4202bcac |
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04-Oct-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Use mtree_empty() to determine if SMCCC filter configured The smccc_filter maple tree is only populated if userspace attempted to configure it. Use the state of the maple tree to determine if the filter has been configured, eliminating the VM flag. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231004234947.207507-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
3f9cd0ca |
|
03-Oct-2023 |
Jing Zhang <jingzhangos@google.com> |
KVM: arm64: Allow userspace to get the writable masks for feature ID registers While the Feature ID range is well defined and pretty large, it isn't inconceivable that the architecture will eventually grow some other ranges that will need to similarly be described to userspace. Add a VM ioctl to allow userspace to get writable masks for feature ID registers in below system register space: op0 = 3, op1 = {0, 1, 3}, CRn = 0, CRm = {0 - 7}, op2 = {0 - 7} This is used to support mix-and-match userspace and kernels for writable ID registers, where userspace may want to know upfront whether it can actually tweak the contents of an idreg or not. Add a new capability (KVM_CAP_ARM_SUPPORTED_FEATURE_ID_RANGES) that returns a bitmap of the valid ranges, which can subsequently be retrieved, one at a time by setting the index of the set bit as the range identifier. Suggested-by: Marc Zyngier <maz@kernel.org> Suggested-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jing Zhang <jingzhangos@google.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231003230408.3405722-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
5544750e |
|
27-Sep-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Build MPIDR to vcpu index cache at runtime The MPIDR_EL1 register contains a unique value that identifies the CPU. The only problem with it is that it is stupidly large (32 bits, once the useless stuff is removed). Trying to obtain a vcpu from an MPIDR value is a fairly common, yet costly operation: we iterate over all the vcpus until we find the correct one. While this is cheap for small VMs, it is pretty expensive on large ones, specially if you are trying to get to the one that's at the end of the list... In order to help with this, it is important to realise that the MPIDR values are actually structured, and that implementations tend to use a small number of significant bits in the 32bit space. We can use this fact to our advantage by computing a small hash table that uses the "compression" of the significant MPIDR bits as an index, giving us the vcpu index as a result. Given that the MPIDR values can be supplied by userspace, and that an evil VMM could decide to make *all* bits significant, resulting in a 4G-entry table, we only use this method if the resulting table fits in a single page. Otherwise, we fallback to the good old iterative method. Nothing uses that table just yet, but keep your eyes peeled. Reviewed-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Joey Gouly <joey.gouly@arm.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-9-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
1de10b7d |
|
20-Sep-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Get rid of vCPU-scoped feature bitmap The vCPU-scoped feature bitmap was left in place a couple of releases ago in case the change to VM-scoped vCPU features broke anyone. Nobody has complained and the interop between VM and vCPU bitmaps is pretty gross. Throw it out. Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
3d4b2a4c |
|
20-Sep-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Remove unused return value from kvm_reset_vcpu() Get rid of the return value for kvm_reset_vcpu() as there are no longer any cases where it returns a nonzero value. Link: https://lore.kernel.org/r/20230920195036.1169791-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
b1f778a2 |
|
20-Aug-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: pmu: Resync EL0 state on counter rotation Huang Shijie reports that, when profiling a guest from the host with a number of events that exceeds the number of available counters, the reported counts are wildly inaccurate. Without the counter oversubscription, the reported counts are correct. Their investigation indicates that upon counter rotation (which takes place on the back of a timer interrupt), we fail to re-apply the guest EL0 enabling, leading to the counting of host events instead of guest events. In order to solve this, add yet another hook between the host PMU driver and KVM, re-applying the guest EL0 configuration if the right conditions apply (the host is VHE, we are in interrupt context, and we interrupted a running vcpu). This triggers a new vcpu request which will apply the correct configuration on guest reentry. With this, we have the correct counts, even when the counters are oversubscribed. Reported-by: Huang Shijie <shijie@os.amperecomputing.com> Suggested-by: Oliver Upton <oliver.upton@linux.dev> Tested_by: Huang Shijie <shijie@os.amperecomputing.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230809013953.7692-1-shijie@os.amperecomputing.com Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20230820090108.177817-1-maz@kernel.org
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#
03fb54d0 |
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15-Aug-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Add support for HCRX_EL2 HCRX_EL2 has an interesting effect on HFGITR_EL2, as it conditions the traps of TLBI*nXS. Expand the FGT support to add a new Fine Grained Filter that will get checked when the instruction gets trapped, allowing the shadow register to override the trap as needed. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230815183903.2735724-29-maz@kernel.org
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e58ec47b |
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15-Aug-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Add trap forwarding infrastructure A significant part of what a NV hypervisor needs to do is to decide whether a trap from a L2+ guest has to be forwarded to a L1 guest or handled locally. This is done by checking for the trap bits that the guest hypervisor has set and acting accordingly, as described by the architecture. A previous approach was to sprinkle a bunch of checks in all the system register accessors, but this is pretty error prone and doesn't help getting an overview of what is happening. Instead, implement a set of global tables that describe a trap bit, combinations of trap bits, behaviours on trap, and what bits must be evaluated on a system register trap. Although this is painful to describe, this allows to specify each and every control bit in a static manner. To make it efficient, the table is inserted in an xarray that is global to the system, and checked each time we trap a system register while running a L2 guest. Add the basic infrastructure for now, while additional patches will implement configuration registers. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Jing Zhang <jingzhangos@google.com> Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Link: https://lore.kernel.org/r/20230815183903.2735724-15-maz@kernel.org
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#
50d2fe46 |
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15-Aug-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Add FGT registers Add the 5 registers covering FEAT_FGT. The AMU-related registers are currently left out as we don't have a plan for them. Yet. Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Reviewed-by: Jing Zhang <jingzhangos@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230815183903.2735724-13-maz@kernel.org
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#
c42b6f0b |
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10-Aug-2023 |
Raghavendra Rao Ananta <rananta@google.com> |
KVM: arm64: Implement kvm_arch_flush_remote_tlbs_range() Implement kvm_arch_flush_remote_tlbs_range() for arm64 to invalidate the given range in the TLB. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230811045127.3308641-12-rananta@google.com
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#
32121c81 |
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10-Aug-2023 |
Raghavendra Rao Ananta <rananta@google.com> |
KVM: arm64: Use kvm_arch_flush_remote_tlbs() Stop depending on CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL and opt to standardize on kvm_arch_flush_remote_tlbs() since it avoids duplicating the generic TLB stats across architectures that implement their own remote TLB flush. This adds an extra function call to the ARM64 kvm_flush_remote_tlbs() path, but that is a small cost in comparison to flushing remote TLBs. In addition, instead of just incrementing remote_tlb_flush_requests stat, the generic interface would also increment the remote_tlb_flush stat. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230811045127.3308641-4-rananta@google.com
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#
a6b33d00 |
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14-Aug-2023 |
Yue Haibing <yuehaibing@huawei.com> |
KVM: arm64: Remove unused declarations Commit 53692908b0f5 ("KVM: arm/arm64: vgic: Fix source vcpu issues for GICv2 SGI") removed vgic_v2_set_npie()/vgic_v3_set_npie() but not the declarations. Commit 29eb5a3c57f7 ("KVM: arm64: Handle PtrAuth traps early") left behind kvm_arm_vcpu_ptrauth_trap(), remove it. Commit 2a0c343386ae ("KVM: arm64: Initialize trap registers for protected VMs") declared but never implemented kvm_init_protected_traps() and commit cf5d318865e2 ("arm/arm64: KVM: Turn off vcpus on PSCI shutdown/reboot") declared but never implemented force_vm_exit(). Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230814140636.45988-1-yuehaibing@huawei.com
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#
5346f7e1 |
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10-Jul-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Always return generic v8 as the preferred target Userspace selecting an implementation-specific vCPU target has been completely useless for a very long time. Let's go whole hog and start returning the generic v8 target across all implementations as the preferred target. Uphold the pre-existing behavior by tolerating either the generic target or an implementation-specific target if the vCPU happens to be running on one of the lucky few parts. Acked-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230710193140.1706399-5-oliver.upton@linux.dev
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#
ef984060 |
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10-Jul-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Replace vCPU target with a configuration flag The value of kvm_vcpu_arch::target has been used to determine if a vCPU has actually been initialized. Storing this as an integer is needless at this point, as KVM doesn't do any microarch-specific emulation in the first place. Instead, all we care about is whether or not the vCPU has been initialized. Delete the field in favor of a vCPU configuration flag indicating if KVM_ARM_VCPU_INIT has completed for the vCPU. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230710193140.1706399-4-oliver.upton@linux.dev
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#
b321c31c |
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13-Jul-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemption Xiang reports that VMs occasionally fail to boot on GICv4.1 systems when running a preemptible kernel, as it is possible that a vCPU is blocked without requesting a doorbell interrupt. The issue is that any preemption that occurs between vgic_v4_put() and schedule() on the block path will mark the vPE as nonresident and *not* request a doorbell irq. This occurs because when the vcpu thread is resumed on its way to block, vcpu_load() will make the vPE resident again. Once the vcpu actually blocks, we don't request a doorbell anymore, and the vcpu won't be woken up on interrupt delivery. Fix it by tracking that we're entering WFI, and key the doorbell request on that flag. This allows us not to make the vPE resident when going through a preempt/schedule cycle, meaning we don't lose any state. Cc: stable@vger.kernel.org Fixes: 8e01d9a396e6 ("KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put") Reported-by: Xiang Chen <chenxiang66@hisilicon.com> Suggested-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Co-developed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20230713070657.3873244-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
68667240 |
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09-Jun-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Rip out the vestiges of the 'old' ID register scheme There's no longer a need for the baggage of the old scheme for handling configurable ID register fields. Rip it all out in favor of the generalized infrastructure. Link: https://lore.kernel.org/r/20230609190054.1542113-12-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
47334146 |
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09-Jun-2023 |
Jing Zhang <jingzhangos@google.com> |
KVM: arm64: Save ID registers' sanitized value per guest Initialize the default ID register values upon the first call to KVM_ARM_VCPU_INIT. The vCPU feature flags are finalized at that point, so it is possible to determine the maximum feature set supported by a particular VM configuration. Do nothing with these values for now, as we need to rework the plumbing of what's already writable to be compatible with the generic infrastructure. Co-developed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Jing Zhang <jingzhangos@google.com> Link: https://lore.kernel.org/r/20230609190054.1542113-7-oliver.upton@linux.dev [Oliver: Hoist everything into KVM_ARM_VCPU_INIT time, so the features are final] Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
f90f9360 |
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09-Jun-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Rewrite IMPDEF PMU version as NI KVM allows userspace to write an IMPDEF PMU version to the corresponding 32bit and 64bit ID register fields for the sake of backwards compatibility with kernels that lacked commit 3d0dba5764b9 ("KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation"). Plumbing that IMPDEF PMU version through to the gues is getting in the way of progress, and really doesn't any sense in the first place. Bite the bullet and reinterpret the IMPDEF PMU version as NI (0) for userspace writes. Additionally, spill the dirty details into a comment. Link: https://lore.kernel.org/r/20230609190054.1542113-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
2251e9ff |
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09-Jun-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Make vCPU feature flags consistent VM-wide To date KVM has allowed userspace to construct asymmetric VMs where particular features may only be supported on a subset of vCPUs. This wasn't really the intened usage pattern, and it is a total pain in the ass to keep working in the kernel. What's more, this is at odds with CPU features in host userspace, where asymmetric features are largely hidden or disabled. It's time to put an end to the whole game. Require all vCPUs in the VM to have the same feature set, rejecting deviants in the KVM_ARM_VCPU_INIT ioctl. Preserve some of the vestiges of per-vCPU feature flags in case we need to reinstate the old behavior for some limited configurations. Yes, this is a sign of cowardice around a user-visibile change. Hoist all of the 32-bit limitations into kvm_vcpu_init_check_features() to avoid nested attempts to acquire the config_lock, which won't end well. Link: https://lore.kernel.org/r/20230609190054.1542113-4-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
a7a2c72a |
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09-Jun-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Separate out feature sanitisation and initialisation kvm_vcpu_set_target() iteratively sanitises and copies feature flags in one go. This is rather odd, especially considering the fact that bitmap accessors can do the heavy lifting. A subsequent change will make vCPU features VM-wide, and fitting that into the present implementation is just a chore. Rework the whole thing to use bitmap accessors to sanitise and copy flags. Link: https://lore.kernel.org/r/20230609190054.1542113-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
12bdce4f |
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23-May-2023 |
Will Deacon <will@kernel.org> |
KVM: arm64: Probe FF-A version and host/hyp partition ID during init Probe FF-A during pKVM initialisation so that we can detect any inconsistencies in the version or partition ID early on. Signed-off-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230523101828.7328-3-will@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
2f440b72 |
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26-Apr-2023 |
Ricardo Koller <ricarkol@google.com> |
KVM: arm64: Add KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE Add a capability for userspace to specify the eager split chunk size. The chunk size specifies how many pages to break at a time, using a single allocation. Bigger the chunk size, more pages need to be allocated ahead of time. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Link: https://lore.kernel.org/r/20230426172330.1439644-6-ricarkol@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
187de7c2 |
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23-May-2023 |
Mark Brown <broonie@kernel.org> |
arm64/sysreg: Standardise naming of bitfield constants in OSL[AS]R_EL1 Our standard scheme for naming the constants for bitfields in system registers includes _ELx in the name but not the SYS_, update the constants for OSL[AS]R_EL1 to follow this convention. Reviewed-by: Shaoqin Huang <shahuang@redhat.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20230419-arm64-syreg-gen-v2-3-4c6add1f6257@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
86f9de9d |
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06-Jun-2023 |
Joey Gouly <joey.gouly@arm.com> |
KVM: arm64: Save/restore PIE registers Define the new system registers that PIE introduces and context switch them. The PIE feature is still hidden from the ID register, and not exposed to a VM. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Zenghui Yu <yuzenghui@huawei.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230606145859.697944-10-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
fbff5606 |
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06-Jun-2023 |
Joey Gouly <joey.gouly@arm.com> |
KVM: arm64: Save/restore TCR2_EL1 Define the new system register TCR2_EL1 and context switch it. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Zenghui Yu <yuzenghui@huawei.com> Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230606145859.697944-9-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
0c2f9acf |
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02-Jun-2023 |
Reiji Watanabe <reijiw@google.com> |
KVM: arm64: PMU: Don't overwrite PMUSERENR with vcpu loaded Currently, with VHE, KVM sets ER, CR, SW and EN bits of PMUSERENR_EL0 to 1 on vcpu_load(), and saves and restores the register value for the host on vcpu_load() and vcpu_put(). If the value of those bits are cleared on a pCPU with a vCPU loaded (armv8pmu_start() would do that when PMU counters are programmed for the guest), PMU access from the guest EL0 might be trapped to the guest EL1 directly regardless of the current PMUSERENR_EL0 value of the vCPU. Fix this by not letting armv8pmu_start() overwrite PMUSERENR_EL0 on the pCPU where PMUSERENR_EL0 for the guest is loaded, and instead updating the saved shadow register value for the host so that the value can be restored on vcpu_put() later. While vcpu_{put,load}() are manipulating PMUSERENR_EL0, disable IRQs to prevent a race condition between these processes and IPIs that attempt to update PMUSERENR_EL0 for the host EL0. Suggested-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Marc Zyngier <maz@kernel.org> Fixes: 83a7a4d643d3 ("arm64: perf: Enable PMU counter userspace access for perf event") Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230603025035.3781797-3-reijiw@google.com
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#
fb88707d |
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04-Apr-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Use a maple tree to represent the SMCCC filter Maple tree is an efficient B-tree implementation that is intended for storing non-overlapping intervals. Such a data structure is a good fit for the SMCCC filter as it is desirable to sparsely allocate the 32 bit function ID space. To that end, add a maple tree to kvm_arch and correctly init/teardown along with the VM. Wire in a test against the hypercall filter for HVCs which does nothing until the controls are exposed to userspace. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-8-oliver.upton@linux.dev
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de40bb8a |
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04-Apr-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Add a helper to check if a VM has ran once The test_bit(...) pattern is quite a lot of keystrokes. Replace existing callsites with a helper. No functional change intended. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-3-oliver.upton@linux.dev
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#
81dc9504 |
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30-Mar-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: timers: Support hyp timer emulation Emulating EL2 also means emulating the EL2 timers. To do so, we expand our timer framework to deal with at most 4 timers. At any given time, two timers are using the HW timers, and the two others are purely emulated. The role of deciding which is which at any given time is left to a mapping function which is called every time we need to make such a decision. Reviewed-by: Colton Lewis <coltonlewis@google.com> Co-developed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-18-maz@kernel.org
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#
8a5eb2d2 |
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30-Mar-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data Having the timer IRQs duplicated into each vcpu isn't great, and becomes absolutely awful with NV. So let's move these into the per-VM arch_timer_vm_data structure. This simplifies a lot of code, but requires us to introduce a mutex so that we can reason about userspace trying to change an interrupt number while another vcpu is running, something that wasn't really well handled so far. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-12-maz@kernel.org
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#
30ec7997 |
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30-Mar-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: timers: Allow userspace to set the global counter offset And this is the moment you have all been waiting for: setting the counter offset from userspace. We expose a brand new capability that reports the ability to set the offset for both the virtual and physical sides. In keeping with the architecture, the offset is expressed as a delta that is substracted from the physical counter value. Once this new API is used, there is no going back, and the counters cannot be written to to set the offsets implicitly (the writes are instead ignored). Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-8-maz@kernel.org
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#
96906a91 |
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30-Mar-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM Being able to lock/unlock all vcpus in one go is a feature that only the vgic has enjoyed so far. Let's be brave and expose it to the world. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-7-maz@kernel.org
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#
c43120af |
|
27-Mar-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Avoid lock inversion when setting the VM register width kvm->lock must be taken outside of the vcpu->mutex. Of course, the locking documentation for KVM makes this abundantly clear. Nonetheless, the locking order in KVM/arm64 has been wrong for quite a while; we acquire the kvm->lock while holding the vcpu->mutex all over the shop. All was seemingly fine until commit 42a90008f890 ("KVM: Ensure lockdep knows about kvm->lock vs. vcpu->mutex ordering rule") caught us with our pants down, leading to lockdep barfing: ====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc7+ #19 Not tainted ------------------------------------------------------ qemu-system-aar/859 is trying to acquire lock: ffff5aa69269eba0 (&host_kvm->lock){+.+.}-{3:3}, at: kvm_reset_vcpu+0x34/0x274 but task is already holding lock: ffff5aa68768c0b8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x8c/0xba0 which lock already depends on the new lock. Add a dedicated lock to serialize writes to VM-scoped configuration from the context of a vCPU. Protect the register width flags with the new lock, thus avoiding the need to grab the kvm->lock while holding vcpu->mutex in kvm_reset_vcpu(). Cc: stable@vger.kernel.org Reported-by: Jeremy Linton <jeremy.linton@arm.com> Link: https://lore.kernel.org/kvmarm/f6452cdd-65ff-34b8-bab0-5c06416da5f6@arm.com/ Tested-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230327164747.2466958-3-oliver.upton@linux.dev
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#
0acc7239 |
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27-Mar-2023 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Avoid vcpu->mutex v. kvm->lock inversion in CPU_ON KVM/arm64 had the lock ordering backwards on vcpu->mutex and kvm->lock from the very beginning. One such example is the way vCPU resets are handled: the kvm->lock is acquired while handling a guest CPU_ON PSCI call. Add a dedicated lock to serialize writes to kvm_vcpu_arch::{mp_state, reset_state}. Promote all accessors of mp_state to {READ,WRITE}_ONCE() as readers do not acquire the mp_state_lock. While at it, plug yet another race by taking the mp_state_lock in the KVM_SET_MP_STATE ioctl handler. As changes to MP state are now guarded with a dedicated lock, drop the kvm->lock acquisition from the PSCI CPU_ON path. Similarly, move the reader of reset_state outside of the kvm->lock and instead protect it with the mp_state_lock. Note that writes to reset_state::reset have been demoted to regular stores as both readers and writers acquire the mp_state_lock. While the kvm->lock inversion still exists in kvm_reset_vcpu(), at least now PSCI CPU_ON no longer depends on it for serializing vCPU reset. Cc: stable@vger.kernel.org Tested-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230327164747.2466958-2-oliver.upton@linux.dev
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#
2def950c |
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08-Feb-2023 |
Thomas Huth <thuth@redhat.com> |
KVM: arm64: Limit length in kvm_vm_ioctl_mte_copy_tags() to INT_MAX In case of success, this function returns the amount of handled bytes. However, this does not work for large values: The function is called from kvm_arch_vm_ioctl() (which still returns a long), which in turn is called from kvm_vm_ioctl() in virt/kvm/kvm_main.c. And that function stores the return value in an "int r" variable. So the upper 32-bits of the "long" return value are lost there. KVM ioctl functions should only return "int" values, so let's limit the amount of bytes that can be requested here to INT_MAX to avoid the problem with the truncated return value. We can then also change the return type of the function to "int" to make it clearer that it is not possible to return a "long" here. Fixes: f0376edb1ddc ("KVM: arm64: Add ioctl to fetch/store tags in a guest") Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Steven Price <steven.price@arm.com> Message-Id: <20230208140105.655814-5-thuth@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
35dcb3ac |
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18-Apr-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Make vcpu flag updates non-preemptible Per-vcpu flags are updated using a non-atomic RMW operation. Which means it is possible to get preempted between the read and write operations. Another interesting thing to note is that preemption also updates flags, as we have some flag manipulation in both the load and put operations. It is thus possible to lose information communicated by either load or put, as the preempted flag update will overwrite the flags when the thread is resumed. This is specially critical if either load or put has stored information which depends on the physical CPU the vcpu runs on. This results in really elusive bugs, and kudos must be given to Mostafa for the long hours of debugging, and finally spotting the problem. Fix it by disabling preemption during the RMW operation, which ensures that the state stays consistent. Also upgrade vcpu_get_flag path to use READ_ONCE() to make sure the field is always atomically accessed. Fixes: e87abb73e594 ("KVM: arm64: Add helpers to manipulate vcpu flags among a set") Reported-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230418125737.2327972-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
47053904 |
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24-Feb-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: timers: Convert per-vcpu virtual offset to a global value Having a per-vcpu virtual offset is a pain. It needs to be synchronized on each update, and expands badly to a setup where different timers can have different offsets, or have composite offsets (as with NV). So let's start by replacing the use of the CNTVOFF_EL2 shadow register (which we want to reclaim for NV anyway), and make the virtual timer carry a pointer to a VM-wide offset. This simplifies the code significantly. It also addresses two terrible bugs: - The use of CNTVOFF_EL2 leads to some nice offset corruption when the sysreg gets reset, as reported by Joey. - The kvm mutex is taken from a vcpu ioctl, which goes against the locking rules... Reported-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230224173915.GA17407@e124191.cambridge.arm.com Tested-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20230224191640.3396734-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
d9552fe1 |
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09-Feb-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor We can no longer blindly copy the VCPU's PSTATE into SPSR_EL2 and return to the guest and vice versa when taking an exception to the hypervisor, because we emulate virtual EL2 in EL1 and therefore have to translate the mode field from EL2 to EL1 and vice versa. This requires keeping track of the state we enter the guest, for which we transiently use a dedicated flag. Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230209175820.1939006-15-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
47f3a2fc |
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09-Feb-2023 |
Jintack Lim <jintack.lim@linaro.org> |
KVM: arm64: nv: Support virtual EL2 exceptions Support injecting exceptions and performing exception returns to and from virtual EL2. This must be done entirely in software except when taking an exception from vEL0 to vEL2 when the virtual HCR_EL2.{E2H,TGE} == {1,1} (a VHE guest hypervisor). [maz: switch to common exception injection framework, illegal exeption return handling] Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Signed-off-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230209175820.1939006-10-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
5305cc2c |
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09-Feb-2023 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: nv: Add EL2 system registers to vcpu context Add the minimal set of EL2 system registers to the vcpu context. Nothing uses them just yet. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230209175820.1939006-7-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
675cabc8 |
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09-Feb-2023 |
Jintack Lim <jintack.lim@linaro.org> |
arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Add a new ARM64_HAS_NESTED_VIRT feature to indicate that the CPU has the ARMv8.3 nested virtualization capability, together with the 'kvm-arm.mode=nested' command line option. This will be used to support nested virtualization in KVM. Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jintack Lim <jintack.lim@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> [maz: moved the command-line option to kvm-arm.mode] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230209175820.1939006-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
7af0c253 |
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11-Jan-2023 |
Akihiko Odaki <akihiko.odaki@daynix.com> |
KVM: arm64: Normalize cache configuration Before this change, the cache configuration of the physical CPU was exposed to vcpus. This is problematic because the cache configuration a vcpu sees varies when it migrates between vcpus with different cache configurations. Fabricate cache configuration from the sanitized value, which holds the CTR_EL0 value the userspace sees regardless of which physical CPU it resides on. CLIDR_EL1 and CCSIDR_EL1 are now writable from the userspace so that the VMM can restore the values saved with the old kernel. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Link: https://lore.kernel.org/r/20230112023852.42012-8-akihiko.odaki@daynix.com [ Oliver: Squash Marc's fix for CCSIDR_EL1.LineSize when set from userspace ] Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
cecafc0a |
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05-Jan-2023 |
Yu Zhang <yu.c.zhang@linux.intel.com> |
KVM: MMU: Make the definition of 'INVALID_GPA' common KVM already has a 'GPA_INVALID' defined as (~(gpa_t)0) in kvm_types.h, and it is used by ARM code. We do not need another definition of 'INVALID_GPA' for X86 specifically. Instead of using the common 'GPA_INVALID' for X86, replace it with 'INVALID_GPA', and change the users of 'GPA_INVALID' so that the diff can be smaller. Also because the name 'INVALID_GPA' tells the user we are using an invalid GPA, while the name 'GPA_INVALID' is emphasizing the GPA is an invalid one. No functional change intended. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Reviewed-by: Paul Durrant <paul@xen.org> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20230105130127.866171-1-yu.c.zhang@linux.intel.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
8cc6deda |
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11-Jan-2023 |
Akihiko Odaki <akihiko.odaki@daynix.com> |
KVM: arm64: Always set HCR_TID2 Always set HCR_TID2 to trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1. This saves a few lines of code and allows to employ their access trap handlers for more purposes anticipated by the old condition for setting HCR_TID2. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Link: https://lore.kernel.org/r/20230112023852.42012-6-akihiko.odaki@daynix.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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#
8d20bd63 |
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30-Nov-2022 |
Sean Christopherson <seanjc@google.com> |
KVM: x86: Unify pr_fmt to use module name for all KVM modules Define pr_fmt using KBUILD_MODNAME for all KVM x86 code so that printks use consistent formatting across common x86, Intel, and AMD code. In addition to providing consistent print formatting, using KBUILD_MODNAME, e.g. kvm_amd and kvm_intel, allows referencing SVM and VMX (and SEV and SGX and ...) as technologies without generating weird messages, and without causing naming conflicts with other kernel code, e.g. "SEV: ", "tdx: ", "sgx: " etc.. are all used by the kernel for non-KVM subsystems. Opportunistically move away from printk() for prints that need to be modified anyways, e.g. to drop a manual "kvm: " prefix. Opportunistically convert a few SGX WARNs that are similarly modified to WARN_ONCE; in the very unlikely event that the WARNs fire, odds are good that they would fire repeatedly and spam the kernel log without providing unique information in each print. Note, defining pr_fmt yields undesirable results for code that uses KVM's printk wrappers, e.g. vcpu_unimpl(). But, that's a pre-existing problem as SVM/kvm_amd already defines a pr_fmt, and thankfully use of KVM's wrappers is relatively limited in KVM x86 code. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Paul Durrant <paul@xen.org> Message-Id: <20221130230934.1014142-35-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
63a1bd8a |
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30-Nov-2022 |
Sean Christopherson <seanjc@google.com> |
KVM: Drop arch hardware (un)setup hooks Drop kvm_arch_hardware_setup() and kvm_arch_hardware_unsetup() now that all implementations are nops. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> # s390 Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20221130230934.1014142-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
3d0dba57 |
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13-Nov-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation As further patches will enable the selection of a PMU revision from userspace, sample the supported PMU revision at VM creation time, rather than building each time the ID_AA64DFR0_EL1 register is accessed. This shouldn't result in any change in behaviour. Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221113163832.3154370-11-maz@kernel.org
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#
f41dff4e |
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10-Nov-2022 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Return guest memory from EL2 via dedicated teardown memcache Rather than relying on the host to free the previously-donated pKVM hypervisor VM pages explicitly on teardown, introduce a dedicated teardown memcache which allows the host to reclaim guest memory resources without having to keep track of all of the allocations made by the pKVM hypervisor at EL2. Tested-by: Vincent Donnefort <vdonnefort@google.com> Co-developed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> [maz: dropped __maybe_unused from unmap_donated_memory_noclear()] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110190259.26861-21-will@kernel.org
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#
315775ff |
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10-Nov-2022 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Consolidate stage-2 initialisation into a single function The initialisation of guest stage-2 page-tables is currently split across two functions: kvm_init_stage2_mmu() and kvm_arm_setup_stage2(). That is presumably for historical reasons as kvm_arm_setup_stage2() originates from the (now defunct) KVM port for 32-bit Arm. Simplify this code path by merging both functions into one, taking care to map the 'struct kvm' into the hypervisor stage-1 early on in order to simplify the failure path. Tested-by: Vincent Donnefort <vdonnefort@google.com> Co-developed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110190259.26861-19-will@kernel.org
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#
717a7eeb |
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10-Nov-2022 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Add generic hyp_memcache helpers The host at EL1 and the pKVM hypervisor at EL2 will soon need to exchange memory pages dynamically for creating and destroying VM state. Indeed, the hypervisor will rely on the host to donate memory pages it can use to create guest stage-2 page-tables and to store VM and vCPU metadata. In order to ease this process, introduce a 'struct hyp_memcache' which is essentially a linked list of available pages, indexed by physical addresses so that it can be passed meaningfully between the different virtual address spaces configured at EL1 and EL2. Tested-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110190259.26861-18-will@kernel.org
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#
9d0c063a |
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10-Nov-2022 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Instantiate pKVM hypervisor VM and vCPU structures from EL1 With the pKVM hypervisor at EL2 now offering hypercalls to the host for creating and destroying VM and vCPU structures, plumb these in to the existing arm64 KVM backend to ensure that the hypervisor data structures are allocated and initialised on first vCPU run for a pKVM guest. In the host, 'struct kvm_protected_vm' is introduced to hold the handle of the pKVM VM instance as well as to track references to the memory donated to the hypervisor so that it can be freed back to the host allocator following VM teardown. The stage-2 page-table, hypervisor VM and vCPU structures are allocated separately so as to avoid the need for a large physically-contiguous allocation in the host at run-time. Tested-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110190259.26861-14-will@kernel.org
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#
a1ec5c70 |
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10-Nov-2022 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Add infrastructure to create and track pKVM instances at EL2 Introduce a global table (and lock) to track pKVM instances at EL2, and provide hypercalls that can be used by the untrusted host to create and destroy pKVM VMs and their vCPUs. pKVM VM/vCPU state is directly accessible only by the trusted hypervisor (EL2). Each pKVM VM is directly associated with an untrusted host KVM instance, and is referenced by the host using an opaque handle. Future patches will provide hypercalls to allow the host to initialize/set/get pKVM VM/vCPU state using the opaque handle. Tested-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Fuad Tabba <tabba@google.com> Co-developed-by: Will Deacon <will@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> [maz: silence warning on unmap_donated_memory_noclear()] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110190259.26861-13-will@kernel.org
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#
baa85152 |
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15-Nov-2022 |
Mark Brown <broonie@kernel.org> |
arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE When we save the state for the floating point registers this can be done in the form visible through either the FPSIMD V registers or the SVE Z and P registers. At present we track which format is currently used based on TIF_SVE and the SME streaming mode state but particularly in the SVE case this limits our options for optimising things, especially around syscalls. Introduce a new enum which we place together with saved floating point state in both thread_struct and the KVM guest state which explicitly states which format is active and keep it up to date when we change it. At present we do not use this state except to verify that it has the expected value when loading the state, future patches will introduce functional changes. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221115094640.112848-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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#
370531d1 |
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16-Sep-2022 |
Reiji Watanabe <reijiw@google.com> |
KVM: arm64: Clear PSTATE.SS when the Software Step state was Active-pending While userspace enables single-step, if the Software Step state at the last guest exit was "Active-pending", clear PSTATE.SS on guest entry to restore the state. Currently, KVM sets PSTATE.SS to 1 on every guest entry while userspace enables single-step for the vCPU (with KVM_GUESTDBG_SINGLESTEP). It means KVM always makes the vCPU's Software Step state "Active-not-pending" on the guest entry, which lets the VCPU perform single-step (then Software Step exception is taken). This could cause extra single-step (without returning to userspace) if the Software Step state at the last guest exit was "Active-pending" (i.e. the last exit was triggered by an asynchronous exception after the single-step is performed, but before the Software Step exception is taken. See "Figure D2-3 Software step state machine" and "D2.12.7 Behavior in the active-pending state" in ARM DDI 0487I.a for more info about this behavior). Fix this by clearing PSTATE.SS on guest entry if the Software Step state at the last exit was "Active-pending" so that KVM restore the state (and the exception is taken before further single-step is performed). Fixes: 337b99bf7edf ("KVM: arm64: guest debug, add support for single-step") Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220917010600.532642-3-reijiw@google.com
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34fbdee0 |
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16-Sep-2022 |
Reiji Watanabe <reijiw@google.com> |
KVM: arm64: Preserve PSTATE.SS for the guest while single-step is enabled Preserve the PSTATE.SS value for the guest while userspace enables single-step (i.e. while KVM manipulates the PSTATE.SS) for the vCPU. Currently, while userspace enables single-step for the vCPU (with KVM_GUESTDBG_SINGLESTEP), KVM sets PSTATE.SS to 1 on every guest entry, not saving its original value. When userspace disables single-step, KVM doesn't restore the original value for the subsequent guest entry (use the current value instead). Exception return instructions copy PSTATE.SS from SPSR_ELx.SS only in certain cases when single-step is enabled (and set it to 0 in other cases). So, the value matters only when the guest enables single-step (and when the guest's Software step state isn't affected by single-step enabled by userspace, practically), though. Fix this by preserving the original PSTATE.SS value while userspace enables single-step, and restoring the value once it is disabled. This fix modifies the behavior of GET_ONE_REG/SET_ONE_REG for the PSTATE.SS while single-step is enabled by userspace. Presently, GET_ONE_REG/SET_ONE_REG gets/sets the current PSTATE.SS value, which KVM will override on the next guest entry (i.e. the value userspace gets/sets is not used for the next guest entry). With this patch, GET_ONE_REG/SET_ONE_REG will get/set the guest's preserved value, which KVM will preserve and try to restore after single-step is disabled. Fixes: 337b99bf7edf ("KVM: arm64: guest debug, add support for single-step") Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220917010600.532642-2-reijiw@google.com
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#
f3c6efc7 |
|
16-Aug-2022 |
Oliver Upton <oliver.upton@linux.dev> |
KVM: arm64: Treat PMCR_EL1.LC as RES1 on asymmetric systems KVM does not support AArch32 on asymmetric systems. To that end, enforce AArch64-only behavior on PMCR_EL1.LC when on an asymmetric system. Fixes: 2122a833316f ("arm64: Allow mismatched 32-bit EL0 support") Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220816192554.1455559-2-oliver.upton@linux.dev
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#
c5332898 |
|
04-Jul-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Descope kvm_arm_sys_reg_{get,set}_reg() Having kvm_arm_sys_reg_get_reg and co in kvm_host.h gives the impression that these functions are free to be called from anywhere. Not quite. They really are tied to out internal sysreg handling, and they would be better off in the sys_regs.h header, which is private. kvm_host.h could also get a bit of a diet, so let's just do that. Signed-off-by: Marc Zyngier <maz@kernel.org>
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0fa4a313 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Document why pause cannot be turned into a flag It would be tempting to turn the 'pause' state into a flag. However, this cannot easily be done as it is updated out of context, while all the flags expect to only be updated from the vcpu thread. Turning it into a flag would require to make all flag updates atomic, which isn't necessary desireable. Document this, and take this opportunity to move the field next to the flag sets, filling a hole in the vcpu structure. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
54ddda91 |
|
27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Reduce the size of the vcpu flag members Now that we can detect flags overflowing their container, reduce the size of all flag set members in the vcpu struct, turning them into 8bit quantities. Even with the FP state enum occupying 32bit, the whole of the state that was represented by flags is smaller by one byte. Profit! Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
5a3984f4 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add build-time sanity checks for flags Flags are great, but flags can also be dangerous: it is easy to encode a flag that is bigger than its container (unless the container is a u64), and it is easy to construct a flag value that doesn't fit in the mask that is associated with it. Add a couple of build-time sanity checks that ensure we catch these two cases. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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30b6ab45 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flag The aptly named boolean 'sysregs_loaded_on_cpu' tracks whether some of the vcpu system registers are resident on the physical CPU when running in VHE mode. This is obviously a flag in hidding, so let's convert it to a state flag, since this is solely a host concern (the hypervisor itself always knows which state we're in). Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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781e3ae1 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Kill unused vcpu flags field Horray, we have now sorted all the preexisting flags, and the 'flags' field is now unused. Get rid of it while nobody is looking. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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eebc538d |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move vcpu WFIT flag to the state flag set The host kernel uses the WFIT flag to remember that a vcpu has used this instruction and wake it up as required. Move it to the state set, as nothing in the hypervisor uses this information. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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aff3ccd7 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move vcpu ON_UNSUPPORTED_CPU flag to the state flag set The ON_UNSUPPORTED_CPU flag is only there to track the sad fact that we have ended-up on a CPU where we cannot really run. Since this is only for the host kernel's use, move it to the state set. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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0affa37f |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move vcpu SVE/SME flags to the state flag set The two HOST_{SVE,SME}_ENABLED are only used for the host kernel to track its own state across a vcpu run so that it can be fully restored. Move these flags to the so called state set. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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b1da4908 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag set The three debug flags (which deal with the debug registers, SPE and TRBE) all are input flags to the hypervisor code. Move them into the input set and convert them to the new accessors. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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699bb2e0 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move vcpu PC/Exception flags to the input flag set The PC update flags (which also deal with exception injection) is one of the most complicated use of the flag we have. Make it more fool prof by: - moving it over to the new accessors and assign it to the input flag set - turn the combination of generic ELx flags with another flag indicating the target EL itself into an explicit set of flags for each EL and vector combination - add a new accessor to pend the exception This is otherwise a pretty straightformward conversion. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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4c0680d3 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move vcpu configuration flags into their own set The KVM_ARM64_{GUEST_HAS_SVE,VCPU_SVE_FINALIZED,GUEST_HAS_PTRAUTH} flags are purely configuration flags. Once set, they are never cleared, but evaluated all over the code base. Move these three flags into the configuration set in one go, using the new accessors, and take this opportunity to drop the KVM_ARM64_ prefix which doesn't provide any help. Reviewed-by: Fuad Tabba <tabba@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
690bacb8 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add three sets of flags to the vcpu state It so appears that each of the vcpu flags is really belonging to one of three categories: - a configuration flag, set once and for all - an input flag generated by the kernel for the hypervisor to use - a state flag that is only for the kernel's own bookkeeping As we are going to split all the existing flags into these three sets, introduce all three in one go. No functional change other than a bit of bloat... Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
e87abb73 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add helpers to manipulate vcpu flags among a set Careful analysis of the vcpu flags show that this is a mix of configuration, communication between the host and the hypervisor, as well as anciliary state that has no consistency. It'd be a lot better if we could split these flags into consistent categories. However, even if we split these flags apart, we want to make sure that each flag can only be applied to its own set, and not across sets. To achieve this, use a preprocessor hack so that each flag is always associated with: - the set that contains it, - a mask that describe all the bits that contain it (for a simple flag, this is the same thing as the flag itself, but we will eventually have values that cover multiple bits at once). Each flag is thus a triplet that is not directly usable as a value, but used by three helpers that allow the flag to be set, cleared, and fetched. By mandating the use of such helper, we can easily enforce that a flag can only be used with the set it belongs to. Finally, one last helper "unpacks" the raw value from the triplet that represents a flag, which is useful for multi-bit values that need to be enumerated (in a switch statement, for example). Further patches will start making use of this infrastructure. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
f8077b0d |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move FP state ownership from flag to a tristate The KVM FP code uses a pair of flags to denote three states: - FP_ENABLED set: the guest owns the FP state - FP_HOST set: the host owns the FP state - FP_ENABLED and FP_HOST clear: nobody owns the FP state at all and both flags set is an illegal state, which nothing ever checks for... As it turns out, this isn't really a good match for flags, and we'd be better off if this was a simpler tristate, each state having a name that actually reflect the state: - FP_STATE_FREE - FP_STATE_HOST_OWNED - FP_STATE_GUEST_OWNED Kill the two flags, and move over to an enum encoding these three states. This results in less confusing code, and less risk of ending up in the uncharted territory of a 4th state if we forget to clear one of the two flags. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Reiji Watanabe <reijiw@google.com>
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#
e9ada6c2 |
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27-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop FP_FOREIGN_STATE from the hypervisor code The vcpu KVM_ARM64_FP_FOREIGN_FPSTATE flag tracks the thread's own TIF_FOREIGN_FPSTATE so that we can evaluate just before running the vcpu whether it the FP regs contain something that is owned by the vcpu or not by updating the rest of the FP flags. We do this in the hypervisor code in order to make sure we're in a context where we are not interruptible. But we already have a hook in the run loop to generate this flag. We may as well update the FP flags directly and save the pointless flag tracking. Whilst we're at it, rename update_fp_enabled() to guest_owns_fp_regs() to indicate what the leftover of this helper actually do. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Mark Brown <broonie@kernel.org>
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#
bcbfb588 |
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09-Jun-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop stale comment The layout of 'struct kvm_vcpu_arch' has evolved significantly since the initial port of KVM/arm64, so remove the stale comment suggesting that a prefix of the structure is used exclusively from assembly code. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220609121223.2551-7-will@kernel.org
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#
20492a62 |
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16-May-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: pmu: Restore compilation when HW_PERF_EVENTS isn't selected Moving kvm_pmu_events into the vcpu (and refering to it) broke the somewhat unusual case where the kernel has no support for a PMU at all. In order to solve this, move things around a bit so that we can easily avoid refering to the pmu structure outside of PMU-aware code. As a bonus, pmu.c isn't compiled in when HW_PERF_EVENTS isn't selected. Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/202205161814.KQHpOzsJ-lkp@intel.com
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#
84d751a0 |
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10-May-2022 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Pass pmu events to hyp via vcpu Instead of the host accessing hyp data directly, pass the pmu events of the current cpu to hyp via the vcpu. This adds 64 bits (in two fields) to the vcpu that need to be synced before every vcpu run in nvhe and protected modes. However, it isolates the hypervisor from the host, which allows us to use pmu in protected mode in a subsequent patch. No visible side effects in behavior intended. Signed-off-by: Fuad Tabba <tabba@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220510095710.148178-4-tabba@google.com
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#
f1f0c0cf |
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28-Apr-2022 |
Alexandru Elisei <alexandru.elisei@arm.com> |
KVM: arm64: Don't BUG_ON() if emulated register table is unsorted To emulate a register access, KVM uses a table of registers sorted by register encoding to speed up queries using binary search. When Linux boots, KVM checks that the table is sorted and uses a BUG_ON() statement to let the user know if it's not. The unfortunate side effect is that an unsorted sysreg table brings down the whole kernel, not just KVM, even though the rest of the kernel can function just fine without KVM. To make matters worse, on machines which lack a serial console, the user is left pondering why the machine is taking so long to boot. Improve this situation by returning an error from kvm_arch_init() if the sysreg tables are not in the correct order. The machine is still very much usable for the user, with the exception of virtualization, who can now easily determine what went wrong. A minor typo has also been corrected in the check_sysreg_table() function. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220428103405.70884-2-alexandru.elisei@arm.com
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#
bfbab445 |
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03-May-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Implement PSCI SYSTEM_SUSPEND ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND" describes a PSCI call that allows software to request that a system be placed in the deepest possible low-power state. Effectively, software can use this to suspend itself to RAM. Unfortunately, there really is no good way to implement a system-wide PSCI call in KVM. Any precondition checks done in the kernel will need to be repeated by userspace since there is no good way to protect a critical section that spans an exit to userspace. SYSTEM_RESET and SYSTEM_OFF are equally plagued by this issue, although no users have seemingly cared for the relatively long time these calls have been supported. The solution is to just make the whole implementation userspace's problem. Introduce a new system event, KVM_SYSTEM_EVENT_SUSPEND, that indicates to userspace a calling vCPU has invoked PSCI SYSTEM_SUSPEND. Additionally, add a CAP to get buy-in from userspace for this new exit type. Only advertise the SYSTEM_SUSPEND PSCI call if userspace has opted in. If a vCPU calls SYSTEM_SUSPEND, punt straight to userspace. Provide explicit documentation of userspace's responsibilites for the exit and point to the PSCI specification to describe the actual PSCI call. Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220504032446.4133305-8-oupton@google.com
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#
7b33a09d |
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03-May-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Add support for userspace to suspend a vCPU Introduce a new MP state, KVM_MP_STATE_SUSPENDED, which indicates a vCPU is in a suspended state. In the suspended state the vCPU will block until a wakeup event (pending interrupt) is recognized. Add a new system event type, KVM_SYSTEM_EVENT_WAKEUP, to indicate to userspace that KVM has recognized one such wakeup event. It is the responsibility of userspace to then make the vCPU runnable, or leave it suspended until the next wakeup event. Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220504032446.4133305-7-oupton@google.com
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#
b171f9bb |
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03-May-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Track vCPU power state using MP state values A subsequent change to KVM will add support for additional power states. Store the MP state by value rather than keeping track of it as a boolean. No functional change intended. Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220504032446.4133305-4-oupton@google.com
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#
1e579429 |
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03-May-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Dedupe vCPU power off helpers vcpu_power_off() and kvm_psci_vcpu_off() are equivalent; rename the former and replace all callsites to the latter. No functional change intended. Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220504032446.4133305-3-oupton@google.com
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#
b22216e1 |
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02-May-2022 |
Raghavendra Rao Ananta <rananta@google.com> |
KVM: arm64: Add vendor hypervisor firmware register Introduce the firmware register to hold the vendor specific hypervisor service calls (owner value 6) as a bitmap. The bitmap represents the features that'll be enabled for the guest, as configured by the user-space. Currently, this includes support for KVM-vendor features along with reading the UID, represented by bit-0, and Precision Time Protocol (PTP), represented by bit-1. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> [maz: tidy-up bitmap values] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220502233853.1233742-5-rananta@google.com
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#
428fd678 |
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02-May-2022 |
Raghavendra Rao Ananta <rananta@google.com> |
KVM: arm64: Add standard hypervisor firmware register Introduce the firmware register to hold the standard hypervisor service calls (owner value 5) as a bitmap. The bitmap represents the features that'll be enabled for the guest, as configured by the user-space. Currently, this includes support only for Paravirtualized time, represented by bit-0. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> [maz: tidy-up bitmap values] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220502233853.1233742-4-rananta@google.com
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#
05714cab |
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02-May-2022 |
Raghavendra Rao Ananta <rananta@google.com> |
KVM: arm64: Setup a framework for hypercall bitmap firmware registers KVM regularly introduces new hypercall services to the guests without any consent from the userspace. This means, the guests can observe hypercall services in and out as they migrate across various host kernel versions. This could be a major problem if the guest discovered a hypercall, started using it, and after getting migrated to an older kernel realizes that it's no longer available. Depending on how the guest handles the change, there's a potential chance that the guest would just panic. As a result, there's a need for the userspace to elect the services that it wishes the guest to discover. It can elect these services based on the kernels spread across its (migration) fleet. To remedy this, extend the existing firmware pseudo-registers, such as KVM_REG_ARM_PSCI_VERSION, but by creating a new COPROC register space for all the hypercall services available. These firmware registers are categorized based on the service call owners, but unlike the existing firmware pseudo-registers, they hold the features supported in the form of a bitmap. During the VM initialization, the registers are set to upper-limit of the features supported by the corresponding registers. It's expected that the VMMs discover the features provided by each register via GET_ONE_REG, and write back the desired values using SET_ONE_REG. KVM allows this modification only until the VM has started. Some of the standard features are not mapped to any bits of the registers. But since they can recreate the original problem of making it available without userspace's consent, they need to be explicitly added to the case-list in kvm_hvc_call_default_allowed(). Any function-id that's not enabled via the bitmap, or not listed in kvm_hvc_call_default_allowed, will be returned as SMCCC_RET_NOT_SUPPORTED to the guest. Older userspace code can simply ignore the feature and the hypercall services will be exposed unconditionally to the guests, thus ensuring backward compatibility. In this patch, the framework adds the register only for ARM's standard secure services (owner value 4). Currently, this includes support only for ARM True Random Number Generator (TRNG) service, with bit-0 of the register representing mandatory features of v1.0. Other services are momentarily added in the upcoming patches. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Gavin Shan <gshan@redhat.com> [maz: reduced the scope of some helpers, tidy-up bitmap max values, dropped error-only fast path] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220502233853.1233742-3-rananta@google.com
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#
9369bc5c |
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03-May-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Plumb cp10 ID traps through the AArch64 sysreg handler In order to enable HCR_EL2.TID3 for AArch32 guests KVM needs to handle traps where ESR_EL2.EC=0x8, which corresponds to an attempted VMRS access from an ID group register. Specifically, the MVFR{0-2} registers are accessed this way from AArch32. Conveniently, these registers are architecturally mapped to MVFR{0-2}_EL1 in AArch64. Furthermore, KVM already handles reads to these aliases in AArch64. Plumb VMRS read traps through to the general AArch64 system register handler. Signed-off-by: Oliver Upton <oupton@google.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220503060205.2823727-5-oupton@google.com
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f502cc56 |
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04-Mar-2022 |
Sean Christopherson <seanjc@google.com> |
KVM: Add max_vcpus field in common 'struct kvm' For TDX guests, the maximum number of vcpus needs to be specified when the TDX guest VM is initialized (creating the TDX data corresponding to TDX guest) before creating vcpu. It needs to record the maximum number of vcpus on VM creation (KVM_CREATE_VM) and return error if the number of vcpus exceeds it Because there is already max_vcpu member in arm64 struct kvm_arch, move it to common struct kvm and initialize it to KVM_MAX_VCPUS before kvm_arch_init_vm() instead of adding it to x86 struct kvm_arch. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Message-Id: <e53234cdee6a92357d06c80c03d77c19cdefb804.1646422845.git.isaku.yamahata@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
89f5074c |
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19-Apr-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Handle blocking WFIT instruction When trapping a blocking WFIT instruction, take it into account when computing the deadline of the background timer. The state is tracked with a new vcpu flag, and is gated by a new CPU capability, which isn't currently enabled. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220419182755.601427-6-maz@kernel.org
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#
0b12620f |
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24-Apr-2022 |
Alexandru Elisei <alexandru.elisei@arm.com> |
KVM: arm64: Treat ESR_EL2 as a 64-bit register ESR_EL2 was defined as a 32-bit register in the initial release of the ARM Architecture Manual for Armv8-A, and was later extended to 64 bits, with bits [63:32] RES0. ARMv8.7 introduced FEAT_LS64, which makes use of bits [36:32]. KVM treats ESR_EL1 as a 64-bit register when saving and restoring the guest context, but ESR_EL2 is handled as a 32-bit register. Start treating ESR_EL2 as a 64-bit register to allow KVM to make use of the most significant 32 bits in the future. The type chosen to represent ESR_EL2 is u64, as that is consistent with the notation KVM overwhelmingly uses today (u32), and how the rest of the registers are declared. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220425114444.368693-5-alexandru.elisei@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
861262ab |
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18-Apr-2022 |
Mark Brown <broonie@kernel.org> |
KVM: arm64: Handle SME host state when running guests While we don't currently support SME in guests we do currently support it for the host system so we need to take care of SME's impact, including the floating point register state, when running guests. Simiarly to SVE we need to manage the traps in CPACR_RL1, what is new is the handling of streaming mode and ZA. Normally we defer any handling of the floating point register state until the guest first uses it however if the system is in streaming mode FPSIMD and SVE operations may generate SME traps which we would need to distinguish from actual attempts by the guest to use SME. Rather than do this for the time being if we are in streaming mode when entering the guest we force the floating point state to be saved immediately and exit streaming mode, meaning that the guest won't generate SME traps for supported operations. We could handle ZA in the access trap similarly to the FPSIMD/SVE state without the disruption caused by streaming mode but for simplicity handle it the same way as streaming mode for now. This will be revisited when we support SME for guests (hopefully before SME hardware becomes available), for now it will only incur additional cost on systems with SME and even there only if streaming mode or ZA are enabled. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220419112247.711548-27-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
0033cd93 |
|
18-Apr-2022 |
Mark Brown <broonie@kernel.org> |
arm64/sme: Implement ZA context switching Allocate space for storing ZA on first access to SME and use that to save and restore ZA state when context switching. We do this by using the vector form of the LDR and STR ZA instructions, these do not require streaming mode and have implementation recommendations that they avoid contention issues in shared SMCU implementations. Since ZA is architecturally guaranteed to be zeroed when enabled we do not need to explicitly zero ZA, either we will be restoring from a saved copy or trapping on first use of SME so we know that ZA must be disabled. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20220419112247.711548-16-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
26bf74bd |
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28-Mar-2022 |
Reiji Watanabe <reijiw@google.com> |
KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs KVM allows userspace to configure either all EL1 32bit or 64bit vCPUs for a guest. At vCPU reset, vcpu_allowed_register_width() checks if the vcpu's register width is consistent with all other vCPUs'. Since the checking is done even against vCPUs that are not initialized (KVM_ARM_VCPU_INIT has not been done) yet, the uninitialized vCPUs are erroneously treated as 64bit vCPU, which causes the function to incorrectly detect a mixed-width VM. Introduce KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED bits for kvm->arch.flags. A value of the EL1_32BIT bit indicates that the guest needs to be configured with all 32bit or 64bit vCPUs, and a value of the REG_WIDTH_CONFIGURED bit indicates if a value of the EL1_32BIT bit is valid (already set up). Values in those bits are set at the first KVM_ARM_VCPU_INIT for the guest based on KVM_ARM_VCPU_EL1_32BIT configuration for the vCPU. Check vcpu's register width against those new bits at the vcpu's KVM_ARM_VCPU_INIT (instead of against other vCPUs' register width). Fixes: 66e94d5cafd4 ("KVM: arm64: Prevent mixed-width VM creation") Signed-off-by: Reiji Watanabe <reijiw@google.com> Reviewed-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220329031924.619453-2-reijiw@google.com
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#
06394531 |
|
11-Mar-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Generalise VM features into a set of flags We currently deal with a set of booleans for VM features, while they could be better represented as set of flags contained in an unsigned long, similarily to what we are doing on the CPU side. Signed-off-by: Marc Zyngier <maz@kernel.org> [Oliver: Flag-ify the 'ran_once' boolean] Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220311174001.605719-2-oupton@google.com
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#
583cda1b |
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27-Jan-2022 |
Alexandru Elisei <alexandru.elisei@arm.com> |
KVM: arm64: Refuse to run VCPU if the PMU doesn't match the physical CPU Userspace can assign a PMU to a VCPU with the KVM_ARM_VCPU_PMU_V3_SET_PMU device ioctl. If the VCPU is scheduled on a physical CPU which has a different PMU, the perf events needed to emulate a guest PMU won't be scheduled in and the guest performance counters will stop counting. Treat it as an userspace error and refuse to run the VCPU in this situation. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220127161759.53553-7-alexandru.elisei@arm.com
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#
46b18782 |
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27-Jan-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Keep a per-VM pointer to the default PMU As we are about to allow selection of the PMU exposed to a guest, start by keeping track of the default one instead of only the PMU version. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Link: https://lore.kernel.org/r/20220127161759.53553-4-alexandru.elisei@arm.com
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#
5177fe91 |
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27-Jan-2022 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Do not change the PMU event filter after a VCPU has run Userspace can specify which events a guest is allowed to use with the KVM_ARM_VCPU_PMU_V3_FILTER attribute. The list of allowed events can be identified by a guest from reading the PMCEID{0,1}_EL0 registers. Changing the PMU event filter after a VCPU has run can cause reads of the registers performed before the filter is changed to return different values than reads performed with the new event filter in place. The architecture defines the two registers as read-only, and this behaviour contradicts that. Keep track when the first VCPU has run and deny changes to the PMU event filter to prevent this from happening. Signed-off-by: Marc Zyngier <maz@kernel.org> [ Alexandru E: Added commit message, updated ioctl documentation ] Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220127161759.53553-2-alexandru.elisei@arm.com
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#
100b4f09 |
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21-Nov-2021 |
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> |
KVM: arm64: Make active_vmids invalid on vCPU schedule out Like ASID allocator, we copy the active_vmids into the reserved_vmids on a rollover. But it's unlikely that every CPU will have a vCPU as current task and we may end up unnecessarily reserving the VMID space. Hence, set active_vmids to an invalid one when scheduling out a vCPU. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211122121844.867-5-shameerali.kolothum.thodi@huawei.com
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#
3248136b |
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21-Nov-2021 |
Julien Grall <julien.grall@arm.com> |
KVM: arm64: Align the VMID allocation with the arm64 ASID At the moment, the VMID algorithm will send an SGI to all the CPUs to force an exit and then broadcast a full TLB flush and I-Cache invalidation. This patch uses the new VMID allocator. The benefits are: - Aligns with arm64 ASID algorithm. - CPUs are not forced to exit at roll-over. Instead, the VMID will be marked reserved and context invalidation is broadcasted. This will reduce the IPIs traffic. - More flexible to add support for pinned KVM VMIDs in the future. With the new algo, the code is now adapted: - The call to update_vmid() will be done with preemption disabled as the new algo requires to store information per-CPU. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211122121844.867-4-shameerali.kolothum.thodi@huawei.com
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#
f8051e96 |
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21-Nov-2021 |
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> |
KVM: arm64: Make VMID bits accessible outside of allocator Since we already set the kvm_arm_vmid_bits in the VMID allocator init function, make it accessible outside as well so that it can be used in the subsequent patch. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211122121844.867-3-shameerali.kolothum.thodi@huawei.com
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#
41783839 |
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21-Nov-2021 |
Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> |
KVM: arm64: Introduce a new VMID allocator for KVM A new VMID allocator for arm64 KVM use. This is based on arm64 ASID allocator algorithm. One major deviation from the ASID allocator is the way we flush the context. Unlike ASID allocator, we expect less frequent rollover in the case of VMIDs. Hence, instead of marking the CPU as flush_pending and issuing a local context invalidation on the next context switch, we broadcast TLB flush + I-cache invalidation over the inner shareable domain on rollover. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211122121844.867-2-shameerali.kolothum.thodi@huawei.com
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#
fcc5bf89 |
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17-Jan-2022 |
Jing Zhang <jingzhangos@google.com> |
KVM: arm64: Use read/write spin lock for MMU protection Replace MMU spinlock with rwlock and update all instances of the lock being acquired with a write lock acquisition. Future commit will add a fast path for permission relaxation during dirty logging under a read lock. Signed-off-by: Jing Zhang <jingzhangos@google.com> Tested-by: Fuad Tabba <tabba@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220118015703.3630552-2-jingzhangos@google.com
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#
7dabf02f |
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03-Feb-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Emulate the OS Lock The OS lock blocks all debug exceptions at every EL. To date, KVM has not implemented the OS lock for its guests, despite the fact that it is mandatory per the architecture. Simple context switching between the guest and host is not appropriate, as its effects are not constrained to the guest context. Emulate the OS Lock by clearing MDE and SS in MDSCR_EL1, thereby blocking all but software breakpoint instructions. Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220203174159.2887882-5-oupton@google.com
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#
d42e2671 |
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03-Feb-2022 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Stash OSLSR_EL1 in the cpu context An upcoming change to KVM will emulate the OS Lock from the PoV of the guest. Add OSLSR_EL1 to the cpu context and handle reads using the stored value. Define some mnemonics for for handling the OSLM field and use them to make the reset value of OSLSR_EL1 more readable. Wire up a custom handler for writes from userspace and prevent any of the invariant bits from changing. Note that the OSLK bit is not invariant and will be made writable by the aforementioned change. Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220203174159.2887882-3-oupton@google.com
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#
5bdf3437 |
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16-Nov-2021 |
James Morse <james.morse@arm.com> |
KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A CPUs vulnerable to Spectre-BHB either need to make an SMC-CC firmware call from the vectors, or run a sequence of branches. This gets added to the hyp vectors. If there is no support for arch-workaround-1 in firmware, the indirect vector will be used. kvm_init_vector_slots() only initialises the two indirect slots if the platform is vulnerable to Spectre-v3a. pKVM's hyp_map_vectors() only initialises __hyp_bp_vect_base if the platform is vulnerable to Spectre-v3a. As there are about to more users of the indirect vectors, ensure their entries in hyp_spectre_vector_selector[] are always initialised, and __hyp_bp_vect_base defaults to the regular VA mapping. The Spectre-v3a check is moved to a helper kvm_system_needs_idmapped_vectors(), and merged with the code that creates the hyp mappings. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
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#
52b28657 |
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15-Dec-2021 |
Quentin Perret <qperret@google.com> |
KVM: arm64: pkvm: Unshare guest structs during teardown Make use of the newly introduced unshare hypercall during guest teardown to unmap guest-related data structures from the hyp stage-1. Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211215161232.1480836-15-qperret@google.com
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#
142ff9bd |
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08-Dec-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop unused workaround_flags vcpu field workaround_flags is a leftover from our earlier Spectre-v4 workaround implementation, and now serves no purpose. Get rid of the field and the corresponding asm-offset definition. Fixes: 29e8910a566a ("KVM: arm64: Simplify handling of ARCH_WORKAROUND_2") Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
005467e0 |
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08-Oct-2021 |
Sean Christopherson <seanjc@google.com> |
KVM: Drop obsolete kvm_arch_vcpu_block_finish() Drop kvm_arch_vcpu_block_finish() now that all arch implementations are nops. No functional change intended. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
cc5705fb |
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13-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop vcpu->arch.has_run_once for vcpu->pid With the transition to kvm_arch_vcpu_run_pid_change() to handle the "run once" activities, it becomes obvious that has_run_once is now an exact shadow of vcpu->pid. Replace vcpu->arch.has_run_once with a new vcpu_has_run_once() helper that directly checks for vcpu->pid, and get rid of the now unused field. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
052f064d |
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14-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move kvm_arch_vcpu_run_pid_change() out of line Having kvm_arch_vcpu_run_pid_change() inline doesn't bring anything to the table. Move it next to kvm_vcpu_first_run_init(), which will be convenient for what is next to come. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
bee14bca |
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21-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Stop mapping current thread_info at EL2 Now that we can track an equivalent of TIF_FOREIGN_FPSTATE, drop the mapping of current's thread_info at EL2. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
af9a0e21 |
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21-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE We currently have to maintain a mapping the thread_info structure at EL2 in order to be able to check the TIF_FOREIGN_FPSTATE flag. In order to eventually get rid of this, start with a vcpu flag that shadows the thread flag on each entry into the hypervisor. Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
8383741a |
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27-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Get rid of host SVE tracking/saving The SVE host tracking in KVM is pretty involved. It relies on a set of flags tracking the ownership of the SVE register, as well as that of the EL0 access. It is also pretty scary: __hyp_sve_save_host() computes a thread_struct pointer and obtains a sve_state which gets directly accessed without further ado, even on nVHE. How can this even work? The answer to that is that it doesn't, and that this is mostly dead code. Closer examination shows that on executing a syscall, userspace loses its SVE state entirely. This is part of the ABI. Another thing to notice is that although the kernel provides helpers such as kernel_neon_begin()/end(), they only deal with the FP/NEON state, and not SVE. Given that you can only execute a guest as the result of a syscall, and that the kernel cannot use SVE by itself, it becomes pretty obvious that there is never any host SVE state to save, and that this code is only there to increase confusion. Get rid of the TIF_SVE tracking and host save infrastructure altogether. Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
892fd259 |
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21-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Reorder vcpu flag definitions The vcpu arch flags are in an interesting, semi random order. As I have made the mistake of reusing a flag once, let's rework this in an order that I find a bit less confusing. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
17ed14eb |
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10-Nov-2021 |
Sean Christopherson <seanjc@google.com> |
KVM: arm64: Drop perf.c and fold its tiny bits of code into arm.c Call KVM's (un)register perf callbacks helpers directly from arm.c and delete perf.c No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20211111020738.2512932-17-seanjc@google.com
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#
e1bfc245 |
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10-Nov-2021 |
Sean Christopherson <seanjc@google.com> |
KVM: Move x86's perf guest info callbacks to generic KVM Move x86's perf guest callbacks into common KVM, as they are semantically identical to arm64's callbacks (the only other such KVM callbacks). arm64 will convert to the common versions in a future patch. Implement the necessary arm64 arch hooks now to avoid having to provide stubs or a temporary #define (from x86) to avoid arm64 compilation errors when CONFIG_GUEST_PERF_EVENTS=y. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211111020738.2512932-13-seanjc@google.com
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#
2934e3d0 |
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10-Nov-2021 |
Sean Christopherson <seanjc@google.com> |
perf: Stop pretending that perf can handle multiple guest callbacks Drop the 'int' return value from the perf (un)register callbacks helpers and stop pretending perf can support multiple callbacks. The 'int' returns are not future proofing anything as none of the callers take action on an error. It's also not obvious that there will ever be co-tenant hypervisors, and if there are, that allowing multiple callbacks to be registered is desirable or even correct. Opportunistically rename callbacks=>cbs in the affected declarations to match their definitions. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20211111020738.2512932-5-seanjc@google.com
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#
08e873cb |
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04-Nov-2021 |
YueHaibing <yuehaibing@huawei.com> |
KVM: arm64: Change the return type of kvm_vcpu_preferred_target() kvm_vcpu_preferred_target() always return 0 because kvm_target_cpu() never returns a negative error code. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211105011500.16280-1-yuehaibing@huawei.com
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#
2a0c3433 |
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10-Oct-2021 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Initialize trap registers for protected VMs Protected VMs have more restricted features that need to be trapped. Moreover, the host should not be trusted to set the appropriate trapping registers and their values. Initialize the trapping registers, i.e., hcr_el2, mdcr_el2, and cptr_el2 at EL2 for protected guests, based on the values of the guest's feature id registers. No functional change intended as trap handlers introduced in the previous patch are still not hooked in to the guest exit handlers. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211010145636.1950948-9-tabba@google.com
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#
b6a68b97 |
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01-Oct-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Allow KVM to be disabled from the command line Although KVM can be compiled out of the kernel, it cannot be disabled at runtime. Allow this possibility by introducing a new mode that will prevent KVM from initialising. This is useful in the (limited) circumstances where you don't want KVM to be available (what is wrong with you?), or when you want to install another hypervisor instead (good luck with that). Reviewed-by: David Brazdil <dbrazdil@google.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Andrew Scull <ascull@google.com> Link: https://lore.kernel.org/r/20211001170553.3062988-1-maz@kernel.org
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78b497f2 |
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03-Sep-2021 |
Juergen Gross <jgross@suse.com> |
kvm: use kvfree() in kvm_arch_free_vm() By switching from kfree() to kvfree() in kvm_arch_free_vm() Arm64 can use the common variant. This can be accomplished by adding another macro __KVM_HAVE_ARCH_VM_FREE, which will be used only by x86 for now. Further simplification can be achieved by adding __kvm_arch_free_vm() doing the common part. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Juergen Gross <jgross@suse.com> Message-Id: <20210903130808.30142-5-jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
cd496228 |
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17-Aug-2021 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Track value of cptr_el2 in struct kvm_vcpu_arch Track the baseline guest value for cptr_el2 in struct kvm_vcpu_arch, similar to the other registers that control traps. Use this value when setting cptr_el2 for the guest. Currently this value is unchanged (CPTR_EL2_DEFAULT), but future patches will set trapping bits based on features supported for the guest. No functional change intended. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-9-tabba@google.com
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#
1460b4b2 |
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17-Aug-2021 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: Restore mdcr_el2 from vcpu On deactivating traps, restore the value of mdcr_el2 from the newly created and preserved host value vcpu context, rather than directly reading the hardware register. Up until and including this patch the two values are the same, i.e., the hardware register and the vcpu one. A future patch will be changing the value of mdcr_el2 on activating traps, and this ensures that its value will be restored. No functional change intended. Signed-off-by: Fuad Tabba <tabba@google.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-7-tabba@google.com
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d6c850dd |
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17-Aug-2021 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: MDCR_EL2 is a 64-bit register Fix the places in KVM that treat MDCR_EL2 as a 32-bit register. More recent features (e.g., FEAT_SPEv1p2) use bits above 31. No functional change intended. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210817081134.2918285-4-tabba@google.com
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2ea7f655 |
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17-Aug-2021 |
Fuad Tabba <tabba@google.com> |
KVM: arm64: placeholder to check if VM is protected Add a function to check whether a VM is protected (under pKVM). Since the creation of protected VMs isn't enabled yet, this is a placeholder that always returns false. The intention is for this to become a check for protected VMs in the future (see Will's RFC). No functional change intended. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/kvmarm/20210603183347.1695-1-will@kernel.org/ Link: https://lore.kernel.org/r/20210817081134.2918285-2-tabba@google.com
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#
fe5161d2 |
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02-Aug-2021 |
Oliver Upton <oupton@google.com> |
KVM: arm64: Record number of signal exits as a vCPU stat Most other architectures that implement KVM record a statistic indicating the number of times a vCPU has exited due to a pending signal. Add support for that stat to arm64. Reviewed-by: Jing Zhang <jingzhangos@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210802192809.1851010-2-oupton@google.com
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#
6b7982fe |
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11-Aug-2021 |
Anshuman Khandual <anshuman.khandual@arm.com> |
KVM: arm64: Drop check_kvm_target_cpu() based percpu probe kvm_target_cpu() never returns a negative error code, so check_kvm_target() would never have 'ret' filled with a negative error code. Hence the percpu probe via check_kvm_target_cpu() does not make sense as its never going to find an unsupported CPU, forcing kvm_arch_init() to exit early. Hence lets just drop this percpu probe (and also check_kvm_target_cpu()) altogether. While here, this also changes kvm_target_cpu() return type to a u32, making it explicit that an error code will not be returned from this function. Cc: Marc Zyngier <maz@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Alexandru Elisei <alexandru.elisei@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/1628744994-16623-5-git-send-email-anshuman.khandual@arm.com
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#
7a3ba309 |
|
19-Jul-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Remove PMSWINC_EL0 shadow register We keep an entry for the PMSWINC_EL0 register in the vcpu structure, while *never* writing anything there outside of reset. Given that the register is defined as write-only, that we always trap when this register is accessed, there is little point in saving anything anyway. Get rid of the entry, and save a mighty 8 bytes per vcpu structure. We still need to keep it exposed to userspace in order to preserve backward compatibility with previously saved VMs. Since userspace cannot expect any effect of writing to PMSWINC_EL0, treat the register as RAZ/WI for the purpose of userspace access. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210719123902.1493805-5-maz@kernel.org
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#
0193cc90 |
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18-Jun-2021 |
Jing Zhang <jingzhangos@google.com> |
KVM: stats: Separate generic stats from architecture specific ones Generic KVM stats are those collected in architecture independent code or those supported by all architectures; put all generic statistics in a separate structure. This ensures that they are defined the same way in the statistics API which is being added, removing duplication among different architectures in the declaration of the descriptors. No functional change intended. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-2-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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f0376edb |
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20-Jun-2021 |
Steven Price <steven.price@arm.com> |
KVM: arm64: Add ioctl to fetch/store tags in a guest The VMM may not wish to have it's own mapping of guest memory mapped with PROT_MTE because this causes problems if the VMM has tag checking enabled (the guest controls the tags in physical RAM and it's unlikely the tags are correct for the VMM). Instead add a new ioctl which allows the VMM to easily read/write the tags from guest memory, allowing the VMM's mapping to be non-PROT_MTE while the VMM can still read/write the tags for the purpose of migration. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210621111716.37157-6-steven.price@arm.com
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e1f358b5 |
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20-Jun-2021 |
Steven Price <steven.price@arm.com> |
KVM: arm64: Save/restore MTE registers Define the new system registers that MTE introduces and context switch them. The MTE feature is still hidden from the ID register as it isn't supported in a VM yet. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210621111716.37157-4-steven.price@arm.com
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ea7fc1bb |
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20-Jun-2021 |
Steven Price <steven.price@arm.com> |
KVM: arm64: Introduce MTE VM feature Add a new VM feature 'KVM_ARM_CAP_MTE' which enables memory tagging for a VM. This will expose the feature to the guest and automatically tag memory pages touched by the VM as PG_mte_tagged (and clear the tag storage) to ensure that the guest cannot see stale tags, and so that the tags are correctly saved/restored across swap. Actually exposing the new capability to user space happens in a later patch. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> [maz: move VM_SHARED sampling into the critical section] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210621111716.37157-3-steven.price@arm.com
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d0c94c49 |
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03-Jun-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Restore PMU configuration on first run Restoring a guest with an active virtual PMU results in no perf counters being instanciated on the host side. Not quite what you'd expect from a restore. In order to fix this, force a writeback of PMCR_EL0 on the first run of a vcpu (using a new request so that it happens once the vcpu has been loaded). This will in turn create all the host-side counters that were missing. Reported-by: Jinank Jain <jinankj@amazon.de> Tested-by: Jinank Jain <jinankj@amazon.de> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/87wnrbylxv.wl-maz@kernel.org Link: https://lore.kernel.org/r/b53dfcf9bbc4db7f96154b1cd5188d72b9766358.camel@amazon.de
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#
e3cb6fa0 |
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09-Jun-2021 |
Paolo Bonzini <pbonzini@redhat.com> |
KVM: switch per-VM stats to u64 Make them the same type as vCPU stats. There is no reason to limit the counters to unsigned long. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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b4c5936c |
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01-Apr-2021 |
Sean Christopherson <seanjc@google.com> |
KVM: Kill off the old hva-based MMU notifier callbacks Yank out the hva-based MMU notifier APIs now that all architectures that use the notifiers have moved to the gfn-based APIs. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-7-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
cd4c7183 |
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01-Apr-2021 |
Sean Christopherson <seanjc@google.com> |
KVM: arm64: Convert to the gfn-based MMU notifier callbacks Move arm64 to the gfn-base MMU notifier APIs, which do the hva->gfn lookup in common code. No meaningful functional change intended, though the exact order of operations is slightly different since the memslot lookups occur before calling into arch code. Reviewed-by: Marc Zyngier <maz@kernel.org> Tested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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fa18aca9 |
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01-Apr-2021 |
Maxim Levitsky <mlevitsk@redhat.com> |
KVM: aarch64: implement KVM_CAP_SET_GUEST_DEBUG2 Move KVM_GUESTDBG_VALID_MASK to kvm_host.h and use it to return the value of this capability. Compile tested only. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210401135451.1004564-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
5f7c292b |
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25-Mar-2021 |
Sean Christopherson <seanjc@google.com> |
KVM: Move prototypes for MMU notifier callbacks to generic code Move the prototypes for the MMU notifier callbacks out of arch code and into common code. There is no benefit to having each arch replicate the prototypes since any deviation from the invocation in common code will explode. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210326021957.1424875-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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263d6287 |
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07-Apr-2021 |
Alexandru Elisei <alexandru.elisei@arm.com> |
KVM: arm64: Initialize VCPU mdcr_el2 before loading it When a VCPU is created, the kvm_vcpu struct is initialized to zero in kvm_vm_ioctl_create_vcpu(). On VHE systems, the first time vcpu.arch.mdcr_el2 is loaded on hardware is in vcpu_load(), before it is set to a sensible value in kvm_arm_setup_debug() later in the run loop. The result is that KVM executes for a short time with MDCR_EL2 set to zero. This has several unintended consequences: * Setting MDCR_EL2.HPMN to 0 is constrained unpredictable according to ARM DDI 0487G.a, page D13-3820. The behavior specified by the architecture in this case is for the PE to behave as if MDCR_EL2.HPMN is set to a value less than or equal to PMCR_EL0.N, which means that an unknown number of counters are now disabled by MDCR_EL2.HPME, which is zero. * The host configuration for the other debug features controlled by MDCR_EL2 is temporarily lost. This has been harmless so far, as Linux doesn't use the other fields, but that might change in the future. Let's avoid both issues by initializing the VCPU's mdcr_el2 field in kvm_vcpu_vcpu_first_run_init(), thus making sure that the MDCR_EL2 register has a consistent value after each vcpu_load(). Fixes: d5a21bcc2995 ("KVM: arm64: Move common VHE/non-VHE trap config in separate functions") Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210407144857.199746-3-alexandru.elisei@arm.com
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eab62148 |
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15-Mar-2021 |
Gavin Shan <gshan@redhat.com> |
KVM: arm64: Hide kvm_mmu_wp_memory_region() We needn't expose the function as it's only used by mmu.c since it was introduced by commit c64735554c0a ("KVM: arm: Add initial dirty page locking support"). Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210316041126.81860-2-gshan@redhat.com
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a1319260 |
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05-Apr-2021 |
Suzuki K Poulose <suzuki.poulose@arm.com> |
arm64: KVM: Enable access to TRBE support for host For a nvhe host, the EL2 must allow the EL1&0 translation regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must be saved/restored over a trip to the guest. Also, before entering the guest, we must flush any trace data if the TRBE was enabled. And we must prohibit the generation of trace while we are in EL1 by clearing the TRFCR_EL1. For vhe, the EL2 must prevent the EL1 access to the Trace Buffer. The MDCR_EL2 bit definitions for TRBE are available here : https://developer.arm.com/documentation/ddi0601/2020-12/AArch64-Registers/ Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405164307.1720226-8-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
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#
d2602bb4 |
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05-Apr-2021 |
Suzuki K Poulose <suzuki.poulose@arm.com> |
KVM: arm64: Move SPE availability check to VCPU load At the moment, we check the availability of SPE on the given CPU (i.e, SPE is implemented and is allowed at the host) during every guest entry. This can be optimized a bit by moving the check to vcpu_load time and recording the availability of the feature on the current CPU via a new flag. This will also be useful for adding the TRBE support. Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Alexandru Elisei <Alexandru.Elisei@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405164307.1720226-7-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
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#
7c419937 |
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22-Mar-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop the CPU_FTR_REG_HYP_COPY infrastructure Now that the read_ctr macro has been specialised for nVHE, the whole CPU_FTR_REG_HYP_COPY infrastrcture looks completely overengineered. Simplify it by populating the two u64 quantities (MMFR0 and 1) that the hypervisor need. Reviewed-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
cfb1a98d |
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19-Mar-2021 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Use kvm_arch in kvm_s2_mmu In order to make use of the stage 2 pgtable code for the host stage 2, change kvm_s2_mmu to use a kvm_arch pointer in lieu of the kvm pointer, as the host will have the former but not the latter. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-21-qperret@google.com
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f320bc74 |
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19-Mar-2021 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Prepare the creation of s1 mappings at EL2 When memory protection is enabled, the EL2 code needs the ability to create and manage its own page-table. To do so, introduce a new set of hypercalls to bootstrap a memory management system at EL2. This leads to the following boot flow in nVHE Protected mode: 1. the host allocates memory for the hypervisor very early on, using the memblock API; 2. the host creates a set of stage 1 page-table for EL2, installs the EL2 vectors, and issues the __pkvm_init hypercall; 3. during __pkvm_init, the hypervisor re-creates its stage 1 page-table and stores it in the memory pool provided by the host; 4. the hypervisor then extends its stage 1 mappings to include a vmemmap in the EL2 VA space, hence allowing to use the buddy allocator introduced in a previous patch; 5. the hypervisor jumps back in the idmap page, switches from the host-provided page-table to the new one, and wraps up its initialization by enabling the new allocator, before returning to the host. 6. the host can free the now unused page-table created for EL2, and will now need to issue hypercalls to make changes to the EL2 stage 1 mappings instead of modifying them directly. Note that for the sake of simplifying the review, this patch focuses on the hypervisor side of things. In other words, this only implements the new hypercalls, but does not make use of them from the host yet. The host-side changes will follow in a subsequent patch. Credits to Will for __pkvm_init_switch_pgd. Acked-by: Will Deacon <will@kernel.org> Co-authored-by: Will Deacon <will@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-18-qperret@google.com
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#
7a440cc7 |
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19-Mar-2021 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Enable access to sanitized CPU features at EL2 Introduce the infrastructure in KVM enabling to copy CPU feature registers into EL2-owned data-structures, to allow reading sanitised values directly at EL2 in nVHE. Given that only a subset of these features are being read by the hypervisor, the ones that need to be copied are to be listed under <asm/kvm_cpufeature.h> together with the name of the nVHE variable that will hold the copy. This introduces only the infrastructure enabling this copy. The first users will follow shortly. Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-14-qperret@google.com
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40a50853 |
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19-Mar-2021 |
Quentin Perret <qperret@google.com> |
KVM: arm64: Make kvm_call_hyp() a function call at Hyp kvm_call_hyp() has some logic to issue a function call or a hypercall depending on the EL at which the kernel is running. However, all the code compiled under __KVM_NVHE_HYPERVISOR__ is guaranteed to only run at EL2 which allows us to simplify. Add ifdefery to kvm_host.h to simplify kvm_call_hyp() in .hyp.text. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210319100146.1149909-9-qperret@google.com
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6e94095c |
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11-Mar-2021 |
Daniel Kiss <daniel.kiss@arm.com> |
KVM: arm64: Enable SVE support for nVHE Now that KVM is equipped to deal with SVE on nVHE, remove the code preventing it from being used as well as the bits of documentation that were mentioning the incompatibility. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Daniel Kiss <daniel.kiss@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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468f3477 |
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12-Mar-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Introduce vcpu_sve_vq() helper The KVM code contains a number of "sve_vq_from_vl(vcpu->arch.sve_max_vl)" instances, and we are about to add more. Introduce vcpu_sve_vq() as a shorthand for this expression. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
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985d3a1b |
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11-Mar-2021 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Let vcpu_sve_pffr() handle HYP VAs The vcpu_sve_pffr() returns a pointer, which can be an interesting thing to do on nVHE. Wrap the pointer with kern_hyp_va(), and take this opportunity to remove the unnecessary casts (sve_state being a void *). Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
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4fc096a9 |
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28-Jan-2021 |
Vitaly Kuznetsov <vkuznets@redhat.com> |
KVM: Raise the maximum number of user memslots Current KVM_USER_MEM_SLOTS limits are arch specific (512 on Power, 509 on x86, 32 on s390, 16 on MIPS) but they don't really need to be. Memory slots are allocated dynamically in KVM when added so the only real limitation is 'id_to_index' array which is 'short'. We don't have any other KVM_MEM_SLOTS_NUM/KVM_USER_MEM_SLOTS-sized statically defined structures. Low KVM_USER_MEM_SLOTS can be a limiting factor for some configurations. In particular, when QEMU tries to start a Windows guest with Hyper-V SynIC enabled and e.g. 256 vCPUs the limit is hit as SynIC requires two pages per vCPU and the guest is free to pick any GFN for each of them, this fragments memslots as QEMU wants to have a separate memslot for each of these pages (which are supposed to act as 'overlay' pages). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210127175731.2020089-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
a8e190cd |
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06-Jan-2021 |
Ard Biesheuvel <ardb@kernel.org> |
KVM: arm64: Implement the TRNG hypervisor call Provide a hypervisor implementation of the ARM architected TRNG firmware interface described in ARM spec DEN0098. All function IDs are implemented, including both 32-bit and 64-bit versions of the TRNG_RND service, which is the centerpiece of the API. The API is backed by the kernel's entropy pool only, to avoid guests draining more precious direct entropy sources. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> [Andre: minor fixes, drop arch_get_random() usage] Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210106103453.152275-6-andre.przywara@arm.com
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767c973f |
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21-Dec-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Declutter host PSCI 0.1 handling Although there is nothing wrong with the current host PSCI relay implementation, we can clean it up and remove some of the helpers that do not improve the overall readability of the legacy PSCI 0.1 handling. Opportunity is taken to turn the bitmap into a set of booleans, and creative use of preprocessor macros make init and check more concise/readable. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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61fe0c37 |
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08-Dec-2020 |
David Brazdil <dbrazdil@google.com> |
KVM: arm64: Minor cleanup of hyp variables used in host Small cleanup moving declarations of hyp-exported variables to kvm_host.h and using macros to avoid having to refer to them with kvm_nvhe_sym() in host. No functional change intended. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201208142452.87237-5-dbrazdil@google.com
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ff367fe4 |
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08-Dec-2020 |
David Brazdil <dbrazdil@google.com> |
KVM: arm64: Prevent use of invalid PSCI v0.1 function IDs PSCI driver exposes a struct containing the PSCI v0.1 function IDs configured in the DT. However, the struct does not convey the information whether these were set from DT or contain the default value zero. This could be a problem for PSCI proxy in KVM protected mode. Extend config passed to KVM with a bit mask with individual bits set depending on whether the corresponding function pointer in psci_ops is set, eg. set bit for PSCI_CPU_SUSPEND if psci_ops.cpu_suspend != NULL. Previously config was split into multiple global variables. Put everything into a single struct for convenience. Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201208142452.87237-2-dbrazdil@google.com
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3eb681fb |
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02-Dec-2020 |
David Brazdil <dbrazdil@google.com> |
KVM: arm64: Add ARM64_KVM_PROTECTED_MODE CPU capability Expose the boolean value whether the system is running with KVM in protected mode (nVHE + kernel param). CPU capability was selected over a global variable to allow use in alternatives. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-3-dbrazdil@google.com
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d8b369c4 |
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02-Dec-2020 |
David Brazdil <dbrazdil@google.com> |
KVM: arm64: Add kvm-arm.mode early kernel parameter Add an early parameter that allows users to select the mode of operation for KVM/arm64. For now, the only supported value is "protected". By passing this flag users opt into the hypervisor placing additional restrictions on the host kernel. These allow the hypervisor to spawn guests whose state is kept private from the host. Restrictions will include stage-2 address translation to prevent host from accessing guest memory, filtering its SMC calls, etc. Without this parameter, the default behaviour remains selecting VHE/nVHE based on hardware support and CONFIG_ARM64_VHE. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201202184122.26046-2-dbrazdil@google.com
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4f1df628 |
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26-Nov-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Advertise ID_AA64PFR0_EL1.CSV3=1 if the CPUs are Meltdown-safe Cores that predate the introduction of ID_AA64PFR0_EL1.CSV3 to the ARMv8 architecture have this field set to 0, even of some of them are not affected by the vulnerability. The kernel maintains a list of unaffected cores (A53, A55 and a few others) so that it doesn't impose an expensive mitigation uncessarily. As we do for CSV2, let's expose the CSV3 property to guests that run on HW that is effectively not vulnerable. This can be reset to zero by writing to the ID register from userspace, ensuring that VMs can be migrated despite the new property being set. Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
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bf118a5c |
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18-Nov-2020 |
Will Deacon <will@kernel.org> |
KVM: arm64: Remove unused __extended_idmap_trampoline() prototype __extended_idmap_trampoline() was removed a long time ago by 3421e9d88d7a ("arm64: KVM: Simplify HYP init/teardown") so remove the unused function prototype. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201118194402.2892-4-will@kernel.org
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36fb4cd5 |
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18-Nov-2020 |
Will Deacon <will@kernel.org> |
KVM: arm64: Remove kvm_arch_vm_ioctl_check_extension() kvm_arch_vm_ioctl_check_extension() is only called from kvm_vm_ioctl_check_extension(), so we can inline it and remove the extra function. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201118194402.2892-3-will@kernel.org
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#
8d14797b |
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18-Nov-2020 |
Will Deacon <will@kernel.org> |
KVM: arm64: Move 'struct kvm_arch_memory_slot' out of uapi/ 'struct kvm_arch_memory_slot' isn't part of the user ABI, so move it out of the uapi/ headers in case we start using it in future and accidentally back ourselves into a corner. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201118194402.2892-2-will@kernel.org
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14bda7a9 |
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13-Nov-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add kvm_vcpu_has_pmu() helper There are a number of places where we check for the KVM_ARM_VCPU_PMU_V3 feature. Wrap this check into a new kvm_vcpu_has_pmu(), and use it at the existing locations. No functional change. Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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23711a5e |
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10-Nov-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Allow setting of ID_AA64PFR0_EL1.CSV2 from userspace We now expose ID_AA64PFR0_EL1.CSV2=1 to guests running on hosts that are immune to Spectre-v2, but that don't have this field set, most likely because they predate the specification. However, this prevents the migration of guests that have started on a host the doesn't fake this CSV2 setting to one that does, as KVM rejects the write to ID_AA64PFR0_EL2 on the grounds that it isn't what is already there. In order to fix this, allow userspace to set this field as long as this doesn't result in a promising more than what is already there (setting CSV2 to 0 is acceptable, but setting it to 1 when it is already set to 0 isn't). Fixes: e1026237f9067 ("KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2") Reported-by: Peng Liang <liangpeng10@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20201110141308.451654-2-maz@kernel.org
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#
6ac4a5ac |
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02-Nov-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop kvm_coproc.h kvm_coproc.h used to serve as a compatibility layer for the files shared between the 32 and 64 bit ports. Another one bites the dust... Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
5f7e02ae |
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29-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop legacy copro shadow register Finally remove one of the biggest 32bit legacy: the copro shadow mapping. We won't missit. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
1da42c34 |
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29-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Map AArch32 cp14 register to AArch64 sysregs Similarly to what has been done on the cp15 front, repaint the debug registers to use their AArch64 counterparts. This results in some simplification as we can remove the 32bit-specific accessors. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
4ff3fc31 |
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27-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move AArch32 exceptions over to AArch64 sysregs The use of the AArch32-specific accessors have always been a bit annoying on 64bit, and it is time for a change. Let's move the AArch32 exception injection over to the AArch64 encoding, which requires us to split the two halves of FAR_EL1 into DFAR and IFAR. This enables us to drop the preempt_disable() games on VHE, and to kill the last user of the vcpu_cp15() macro. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
ca4e5147 |
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10-Nov-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Introduce handling of AArch32 TTBCR2 traps ARMv8.2 introduced TTBCR2, which shares TCR_EL1 with TTBCR. Gracefully handle traps to this register when HCR_EL2.TVM is set. Cc: stable@vger.kernel.org Reported-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
e650b64f |
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14-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add basic hooks for injecting exceptions from EL2 Add the basic infrastructure to describe injection of exceptions into a guest. So far, nothing uses this code path. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
21c81001 |
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14-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move VHE direct sysreg accessors into kvm_host.h As we are about to need to access system registers from the HYP code based on their internal encoding, move the direct sysreg accessors to a common include file, with a VHE-specific guard. No functionnal change. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
cdb5e02e |
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14-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Make kvm_skip_instr() and co private to HYP In an effort to remove the vcpu PC manipulations from EL1 on nVHE systems, move kvm_skip_instr() to be HYP-specific. EL1's intent to increment PC post emulation is now signalled via a flag in the vcpu structure. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
4a1c2c7f |
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29-Oct-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR The DBGD{CCINT,SCRext} and DBGVCR register entries in the cp14 array are missing their target register, resulting in all accesses being targetted at the guard sysreg (indexed by __INVALID_SYSREG__). Point the emulation code at the actual register entries. Fixes: bdfb4b389c8d ("arm64: KVM: add trap handlers for AArch32 debug registers") Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201029172409.2768336-1-maz@kernel.org
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#
2a1198c9 |
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22-Sep-2020 |
David Brazdil <dbrazdil@google.com> |
kvm: arm64: Create separate instances of kvm_host_data for VHE/nVHE Host CPU context is stored in a global per-cpu variable `kvm_host_data`. In preparation for introducing independent per-CPU region for nVHE hyp, create two separate instances of `kvm_host_data`, one for VHE and one for nVHE. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200922204910.7265-9-dbrazdil@google.com
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#
73114677 |
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18-Sep-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Get rid of kvm_arm_have_ssbd() kvm_arm_have_ssbd() is now completely unused, get rid of it. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
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#
d4647f0a |
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15-Sep-2020 |
Will Deacon <will@kernel.org> |
arm64: Rewrite Spectre-v2 mitigation code The Spectre-v2 mitigation code is pretty unwieldy and hard to maintain. This is largely due to it being written hastily, without much clue as to how things would pan out, and also because it ends up mixing policy and state in such a way that it is very difficult to figure out what's going on. Rewrite the Spectre-v2 mitigation so that it clearly separates state from policy and follows a more structured approach to handling the mitigation. Signed-off-by: Will Deacon <will@kernel.org>
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#
d7eec236 |
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12-Feb-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Add PMU event filtering infrastructure It can be desirable to expose a PMU to a guest, and yet not want the guest to be able to count some of the implemented events (because this would give information on shared resources, for example. For this, let's extend the PMUv3 device API, and offer a way to setup a bitmap of the allowed events (the default being no bitmap, and thus no filtering). Userspace can thus allow/deny ranges of event. The default policy depends on the "polarity" of the first filter setup (default deny if the filter allows events, and default allow if the filter denies events). This allows to setup exactly what is allowed for a given guest. Note that although the ioctl is per-vcpu, the map of allowed events is global to the VM (it can be setup from any vcpu until the vcpu PMU is initialized). Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
fd65a3b5 |
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17-Mar-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Use event mask matching architecture revision The PMU code suffers from a small defect where we assume that the event number provided by the guest is always 16 bit wide, even if the CPU only implements the ARMv8.0 architecture. This isn't really problematic in the sense that the event number ends up in a system register, cropping it to the right width, but still this needs fixing. In order to make it work, let's probe the version of the PMU that the guest is going to use. This is done by temporarily creating a kernel event and looking at the PMUVer field that has been saved at probe time in the associated arm_pmu structure. This in turn gets saved in the kvm structure, and subsequently used to compute the event mask that gets used throughout the PMU code. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
04e4caa8 |
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15-Sep-2020 |
Andrew Scull <ascull@google.com> |
KVM: arm64: nVHE: Migrate hyp-init to SMCCC To complete the transition to SMCCC, the hyp initialization is given a function ID. This looks neater than comparing the hyp stub function IDs to the page table physical address. Some care is taken to only clobber x0-3 before the host context is saved as only those registers can be clobbered accoring to SMCCC. Fortunately, only a few acrobatics are needed. The possible new tpidr_el2 is moved to the argument in x2 so that it can be stashed in tpidr_el2 early to free up a scratch register. The page table configuration then makes use of x0-2. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-19-ascull@google.com
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#
05469831 |
|
15-Sep-2020 |
Andrew Scull <ascull@google.com> |
KVM: arm64: nVHE: Migrate hyp interface to SMCCC Rather than passing arbitrary function pointers to run at hyp, define and equivalent set of SMCCC functions. Since the SMCCC functions are strongly tied to the original function prototypes, it is not expected for the host to ever call an invalid ID but a warning is raised if this does ever occur. As __kvm_vcpu_run is used for every switch between the host and a guest, it is explicitly singled out to be identified before the other function IDs to improve the performance of the hot path. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-18-ascull@google.com
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#
d7ca1079 |
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15-Sep-2020 |
Andrew Scull <ascull@google.com> |
KVM: arm64: Remove kvm_host_data_t typedef The kvm_host_data_t typedef is used inconsistently and goes against the kernel's coding style. Remove it in favour of the full struct specifier. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200915104643.2543892-4-ascull@google.com
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#
74cfa7ea |
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11-Sep-2020 |
Will Deacon <will@kernel.org> |
KVM: arm64: Remove unused 'pgd' field from 'struct kvm_s2_mmu' The stage-2 page-tables are entirely encapsulated by the 'pgt' field of 'struct kvm_s2_mmu', so remove the unused 'pgd' field. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20200911132529.19844-21-will@kernel.org
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#
71233d05 |
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11-Sep-2020 |
Will Deacon <will@kernel.org> |
KVM: arm64: Add support for creating kernel-agnostic stage-2 page tables Introduce alloc() and free() functions to the generic page-table code for guest stage-2 page-tables and plumb these into the existing KVM page-table allocator. Subsequent patches will convert other operations within the KVM allocator over to the generic code. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Link: https://lore.kernel.org/r/20200911132529.19844-6-will@kernel.org
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#
fdfe7cbd |
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11-Aug-2020 |
Will Deacon <will@kernel.org> |
KVM: Pass MMU notifier range flags to kvm_unmap_hva_range() The 'flags' field of 'struct mmu_notifier_range' is used to indicate whether invalidate_range_{start,end}() are permitted to block. In the case of kvm_mmu_notifier_invalidate_range_start(), this field is not forwarded on to the architecture-specific implementation of kvm_unmap_hva_range() and therefore the backend cannot sensibly decide whether or not to block. Add an extra 'flags' parameter to kvm_unmap_hva_range() so that architectures are aware as to whether or not they are permitted to block. Cc: <stable@vger.kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Message-Id: <20200811102725.7121-2-will@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
004a0124 |
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04-Aug-2020 |
Andrew Jones <drjones@redhat.com> |
arm64/x86: KVM: Introduce steal-time cap arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe support for steal-time. However this is unnecessary, as only a KVM fd is required, and it complicates userspace (userspace may prefer delaying vcpu creation until after feature probing). Introduce a cap that can be checked instead. While x86 can already probe steal-time support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there too for consistency. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200804170604.42662-7-drjones@redhat.com
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#
53f98558 |
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04-Aug-2020 |
Andrew Jones <drjones@redhat.com> |
KVM: arm64: pvtime: Fix stolen time accounting across migration When updating the stolen time we should always read the current stolen time from the user provided memory, not from a kernel cache. If we use a cache then we'll end up resetting stolen time to zero on the first update after migration. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200804170604.42662-5-drjones@redhat.com
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#
bf4086b1 |
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22-Jul-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Prevent vcpu_has_ptrauth from generating OOL functions So far, vcpu_has_ptrauth() is implemented in terms of system_supports_*_auth() calls, which are declared "inline". In some specific conditions (clang and SCS), the "inline" very much turns into an "out of line", which leads to a fireworks when this predicate is evaluated on a non-VHE system (right at the beginning of __hyp_handle_ptrauth). Instead, make sure vcpu_has_ptrauth gets expanded inline by directly using the cpus_have_final_cap() helpers, which are __always_inline, generate much better code, and are the only thing that make sense when running at EL2 on a nVHE system. Fixes: 29eb5a3c57f7 ("KVM: arm64: Handle PtrAuth traps early") Reported-by: Nathan Chancellor <natechancellor@gmail.com> Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lore.kernel.org/r/20200722162231.3689767-1-maz@kernel.org
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#
74cc7e0c |
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23-Jun-2020 |
Tianjia Zhang <tianjia.zhang@linux.alibaba.com> |
KVM: arm64: clean up redundant 'kvm_run' parameters In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu' structure. For historical reasons, many kvm-related function parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time. This patch does a unified cleanup of these remaining redundant parameters. Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200623131418.31473-3-tianjia.zhang@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
c1a33aeb |
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02-Jul-2020 |
Sean Christopherson <seanjc@google.com> |
KVM: arm64: Use common KVM implementation of MMU memory caches Move to the common MMU memory cache implementation now that the common code and arm64's existing code are semantically compatible. No functional change intended. Cc: Marc Zyngier <maz@kernel.org> Suggested-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200703023545.8771-19-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
e539451b |
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02-Jul-2020 |
Sean Christopherson <seanjc@google.com> |
KVM: arm64: Use common code's approach for __GFP_ZERO with memory caches Add a "gfp_zero" member to arm64's 'struct kvm_mmu_memory_cache' to make the struct and its usage compatible with the common 'struct kvm_mmu_memory_cache' in linux/kvm_host.h. This will minimize code churn when arm64 moves to the common implementation in a future patch, at the cost of temporarily having somewhat silly code. Note, GFP_PGTABLE_USER is equivalent to GFP_KERNEL_ACCOUNT | GFP_ZERO: #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT) | -> #define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO) == GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO versus #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT) with __GFP_ZERO explicitly OR'd in == GFP_KERNEL | __GFP_ACCOUNT | __GFP_ZERO No functional change intended. Tested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200703023545.8771-18-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
41ce82f6 |
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28-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: timers: Move timer registers to the sys_regs file Move the timer gsisters to the sysreg file. This will further help when they are directly changed by a nesting hypervisor in the VNCR page. This requires moving the initialisation of the timer struct so that some of the helpers (such as arch_timer_ctx_index) can work correctly at an early stage. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
710f1982 |
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28-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move SPSR_EL1 to the system register array SPSR_EL1 being a VNCR-capable register with ARMv8.4-NV, move it to the sysregs array and update the accessors. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
fd85b667 |
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28-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Disintegrate SPSR array As we're about to move SPSR_EL1 into the VNCR page, we need to disassociate it from the rest of the 32bit cruft. Let's break the array into individual fields. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
1bded23e |
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28-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move SP_EL1 to the system register array SP_EL1 being a VNCR-capable register with ARMv8.4-NV, move it to the system register array and update the accessors. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
98909e6d |
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28-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Move ELR_EL1 to the system register array As ELR-EL1 is a VNCR-capable register with ARMv8.4-NV, let's move it to the sys_regs array and repaint the accessors. While we're at it, let's kill the now useless accessors used only on the fault injection path. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
e47c2055 |
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28-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Make struct kvm_regs userspace-only struct kvm_regs is used by userspace to indicate which register gets accessed by the {GET,SET}_ONE_REG API. But as we're about to refactor the layout of the in-kernel register structures, we need the kernel to move away from it. Let's make kvm_regs userspace only, and let the kernel map it to its own internal representation. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
71071acf |
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12-Apr-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: hyp: Use ctxt_sys_reg/__vcpu_sys_reg instead of raw sys_regs access Switch the hypervisor code to using ctxt_sys_reg/__vcpu_sys_reg instead of raw sys_regs accesses. No intended functionnal change. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
1b422dd7 |
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26-Jun-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Introduce accessor for ctxt->sys_reg In order to allow the disintegration of the per-vcpu sysreg array, let's introduce a new helper (ctxt_sys_reg()) that returns the in-memory copy of a system register, picked from a given context. __vcpu_sys_reg() is rewritten to use this helper. Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
a0e50aa3 |
|
04-Jan-2019 |
Christoffer Dall <christoffer.dall@arm.com> |
KVM: arm64: Factor out stage 2 page table data from struct kvm As we are about to reuse our stage 2 page table manipulation code for shadow stage 2 page tables in the context of nested virtualization, we are going to manage multiple stage 2 page tables for a single VM. This requires some pretty invasive changes to our data structures, which moves the vmid and pgd pointers into a separate structure and change pretty much all of our mmu code to operate on this structure instead. The new structure is called struct kvm_s2_mmu. There is no intended functional change by this patch alone. Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> [Designed data structure layout in collaboration] Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Co-developed-by: Marc Zyngier <maz@kernel.org> [maz: Moved the last_vcpu_ran down to the S2 MMU structure as well] Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
13aeb9b4 |
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25-Jun-2020 |
David Brazdil <dbrazdil@google.com> |
KVM: arm64: Split hyp/sysreg-sr.c to VHE/nVHE sysreg-sr.c contains KVM's code for saving/restoring system registers, with some code shared between VHE/nVHE. These common routines are moved to a header file, VHE-specific code is moved to vhe/sysreg-sr.c and nVHE-specific code to nvhe/sysreg-sr.c. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-12-dbrazdil@google.com
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#
f50b6f6a |
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25-Jun-2020 |
Andrew Scull <ascull@google.com> |
KVM: arm64: Handle calls to prefixed hyp functions Once hyp functions are moved to a hyp object, they will have prefixed symbols. This change declares and gets the address of the prefixed version for calls to the hyp functions. To aid migration, the hyp functions that have not yet moved have their prefixed versions aliased to their non-prefixed version. This begins with all the hyp functions being listed and will reduce to none of them once the migration is complete. Signed-off-by: Andrew Scull <ascull@google.com> [David: Extracted kvm_call_hyp nVHE branches into own helper macros, added comments around symbol aliases.] Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-6-dbrazdil@google.com
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#
3204be41 |
|
09-Jun-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts AArch32 CP1x registers are overlayed on their AArch64 counterparts in the vcpu struct. This leads to an interesting problem as they are stored in their CPU-local format, and thus a CP1x register doesn't "hit" the lower 32bit portion of the AArch64 register on a BE host. To workaround this unfortunate situation, introduce a bias trick in the vcpu_cp1x() accessors which picks the correct half of the 64bit register. Cc: stable@vger.kernel.org Reported-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Acked-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
07da1ffa |
|
05-Jun-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Remove host_cpu_context member from vcpu structure For very long, we have kept this pointer back to the per-cpu host state, despite having working per-cpu accessors at EL2 for some time now. Recent investigations have shown that this pointer is easy to abuse in preemptible context, which is a sure sign that it would better be gone. Not to mention that a per-cpu pointer is faster to access at all times. Reported-by: Andrew Scull <ascull@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com Reviewed-by: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
b130a8f7 |
|
28-May-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Check advertised Stage-2 page size capability With ARMv8.5-GTG, the hardware (or more likely a hypervisor) can advertise the supported Stage-2 page sizes. Let's check this at boot time. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Will Deacon <will@kernel.org>
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#
8f7f4fe7 |
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27-May-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Drop obsolete comment about sys_reg ordering The general comment about keeping the enum order in sync with the save/restore code has been obsolete for many years now. Just drop it. Note that there are other ordering requirements in the enum, such as the PtrAuth and PMU registers, which are still valid. Reported-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
71b3ec5f |
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15-May-2020 |
David Brazdil <dbrazdil@google.com> |
KVM: arm64: Clean up cpu_init_hyp_mode() Pull bits of code to the only place where it is used. Remove empty function __cpu_init_stage2(). Remove redundant has_vhe() check since this function is nVHE-only. No functional changes intended. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200515152056.83158-1-dbrazdil@google.com
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#
c862626e |
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13-Apr-2020 |
Keqian Zhu <zhukeqian1@huawei.com> |
KVM: arm64: Support enabling dirty log gradually in small chunks There is already support of enabling dirty log gradually in small chunks for x86 in commit 3c9bd4006bfc ("KVM: x86: enable dirty log gradually in small chunks"). This adds support for arm64. x86 still writes protect all huge pages when DIRTY_LOG_INITIALLY_ALL_SET is enabled. However, for arm64, both huge pages and normal pages can be write protected gradually by userspace. Under the Huawei Kunpeng 920 2.6GHz platform, I did some tests on 128G Linux VMs with different page size. The memory pressure is 127G in each case. The time taken of memory_global_dirty_log_start in QEMU is listed below: Page Size Before After Optimization 4K 650ms 1.8ms 2M 4ms 1.8ms 1G 2ms 1.8ms Besides the time reduction, the biggest improvement is that we will minimize the performance side effect (because of dissolving huge pages and marking memslots dirty) on guest after enabling dirty log. Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200413122023.52583-1-zhukeqian1@huawei.com
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#
cb953129 |
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08-May-2020 |
David Matlack <dmatlack@google.com> |
kvm: add halt-polling cpu usage stats Two new stats for exposing halt-polling cpu usage: halt_poll_success_ns halt_poll_fail_ns Thus sum of these 2 stats is the total cpu time spent polling. "success" means the VCPU polled until a virtual interrupt was delivered. "fail" means the VCPU had to schedule out (either because the maximum poll time was reached or it needed to yield the CPU). To avoid touching every arch's kvm_vcpu_stat struct, only update and export halt-polling cpu usage stats if we're on x86. Exporting cpu usage as a u64 and in nanoseconds means we will overflow at ~500 years, which seems reasonably large. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Jon Cargille <jcargill@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20200508182240.68440-1-jcargill@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
02ab1f50 |
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04-May-2020 |
Andrew Scull <ascull@google.com> |
arm64: Unify WORKAROUND_SPECULATIVE_AT_{NVHE,VHE} Errata 1165522, 1319367 and 1530923 each allow TLB entries to be allocated as a result of a speculative AT instruction. In order to avoid mandating VHE on certain affected CPUs, apply the workaround to both the nVHE and the VHE case for all affected CPUs. Signed-off-by: Andrew Scull <ascull@google.com> Acked-by: Will Deacon <will@kernel.org> CC: Marc Zyngier <maz@kernel.org> CC: James Morse <james.morse@arm.com> CC: Suzuki K Poulose <suzuki.poulose@arm.com> CC: Will Deacon <will@kernel.org> CC: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200504094858.108917-1-ascull@google.com Signed-off-by: Will Deacon <will@kernel.org>
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#
d9c3872c |
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04-Mar-2020 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: GICv4.1: Reload VLPI configuration on distributor enable/disable Each time a Group-enable bit gets flipped, the state of these bits needs to be forwarded to the hardware. This is a pretty heavy handed operation, requiring all vcpus to reload their GICv4 configuration. It is thus implemented as a new request type. These enable bits are programmed into the HW by setting the VGrp{0,1}En fields of GICR_VPENDBASER when the vPEs are made resident again. Of course, we only support Group-1 for now... Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20200304203330.4967-22-maz@kernel.org
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#
b3f15ec3 |
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10-Feb-2020 |
Mark Rutland <mark.rutland@arm.com> |
kvm: arm/arm64: Fold VHE entry/exit work into kvm_vcpu_run_vhe() With VHE, running a vCPU always requires the sequence: 1. kvm_arm_vhe_guest_enter(); 2. kvm_vcpu_run_vhe(); 3. kvm_arm_vhe_guest_exit() ... and as we invoke this from the shared arm/arm64 KVM code, 32-bit arm has to provide stubs for all three functions. To simplify the common code, and make it easier to make further modifications to the arm64-specific portions in the near future, let's fold kvm_arm_vhe_guest_enter() and kvm_arm_vhe_guest_exit() into kvm_vcpu_run_vhe(). The 32-bit stubs for kvm_arm_vhe_guest_enter() and kvm_arm_vhe_guest_exit() are removed, as they are no longer used. The 32-bit stub for kvm_vcpu_run_vhe() is left as-is. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200210114757.2889-1-mark.rutland@arm.com
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#
7495e22b |
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09-Jan-2020 |
Paolo Bonzini <pbonzini@redhat.com> |
KVM: Move running VCPU from ARM to common code For ring-based dirty log tracking, it will be more efficient to account writes during schedule-out or schedule-in to the currently running VCPU. We would like to do it even if the write doesn't use the current VCPU's address space, as is the case for cached writes (see commit 4e335d9e7ddb, "Revert "KVM: Support vCPU-based gfn->hva cache"", 2017-05-02). Therefore, add a mechanism to track the currently-loaded kvm_vcpu struct. There is already something similar in KVM/ARM; one important difference is that kvm_arch_vcpu_{load,put} have two callers in virt/kvm/kvm_main.c: we have to update both the architecture-independent vcpu_{load,put} and the preempt notifiers. Another change made in the process is to allow using kvm_get_running_vcpu() in preemptible code. This is allowed because preempt notifiers ensure that the value does not change even after the VCPU thread is migrated. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
ddd259c9 |
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18-Dec-2019 |
Sean Christopherson <seanjc@google.com> |
KVM: Drop kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() Remove kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() now that all arch specific implementations are nops. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
19bcc89e |
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18-Dec-2019 |
Sean Christopherson <seanjc@google.com> |
KVM: arm64: Free sve_state via arm specific hook Add an arm specific hook to free the arm64-only sve_state. Doing so eliminates the last functional code from kvm_arch_vcpu_uninit() across all architectures and paves the way for removing kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() entirely. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
0e20f5e2 |
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13-Dec-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm/arm64: Cleanup MMIO handling Our MMIO handling is a bit odd, in the sense that it uses an intermediate per-vcpu structure to store the various decoded information that describe the access. But the same information is readily available in the HSR/ESR_EL2 field, and we actually use this field to populate the structure. Let's simplify the whole thing by getting rid of the superfluous structure and save a (tiny) bit of space in the vcpu structure. [32bit fix courtesy of Olof Johansson <olof@lixom.net>] Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
e85d68fa |
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16-Dec-2019 |
Steven Price <steven.price@arm.com> |
arm64: Rename WORKAROUND_1165522 to SPECULATIVE_AT_VHE Cortex-A55 is affected by a similar erratum, so rename the existing workaround for errarum 1165522 so it can be used for both errata. Acked-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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#
b51c6ac2 |
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13-Jan-2020 |
Suzuki K Poulose <suzuki.poulose@arm.com> |
arm64: Introduce system_capabilities_finalized() marker We finalize the system wide capabilities after the SMP CPUs are booted by the kernel. This is used as a marker for deciding various checks in the kernel. e.g, sanity check the hotplugged CPUs for missing mandatory features. However there is no explicit helper available for this in the kernel. There is sys_caps_initialised, which is not exposed. The other closest one we have is the jump_label arm64_const_caps_ready which denotes that the capabilities are set and the capability checks could use the individual jump_labels for fast path. This is performed before setting the ELF Hwcaps, which must be checked against the new CPUs. We also perform some of the other initialization e.g, SVE setup, which is important for the use of FP/SIMD where SVE is supported. Normally userspace doesn't get to run before we finish this. However the in-kernel users may potentially start using the neon mode. So, we need to reject uses of neon mode before we are set. Instead of defining a new marker for the completion of SVE setup, we could simply reuse the arm64_const_caps_ready and enable it once we have finished all the setup. Also we could expose this to the various users as "system_capabilities_finalized()" to make it more meaningful than "const_caps_ready". Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
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#
58772e9a |
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21-Oct-2019 |
Steven Price <steven.price@arm.com> |
KVM: arm64: Provide VCPU attributes for stolen time Allow user space to inform the KVM host where in the physical memory map the paravirtualized time structures should be located. User space can set an attribute on the VCPU providing the IPA base address of the stolen time structure for that VCPU. This must be repeated for every VCPU in the VM. The address is given in terms of the physical address visible to the guest and must be 64 byte aligned. The guest will discover the address via a hypercall. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
8564d637 |
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21-Oct-2019 |
Steven Price <steven.price@arm.com> |
KVM: arm64: Support stolen time reporting via shared structure Implement the service call for configuring a shared structure between a VCPU and the hypervisor in which the hypervisor can write the time stolen from the VCPU's execution time by other tasks on the host. User space allocates memory which is placed at an IPA also chosen by user space. The hypervisor then updates the shared structure using kvm_put_guest() to ensure single copy atomicity of the 64-bit value reporting the stolen time in nanoseconds. Whenever stolen time is enabled by the guest, the stolen time counter is reset. The stolen time itself is retrieved from the sched_info structure maintained by the Linux scheduler code. We enable SCHEDSTATS when selecting KVM Kconfig to ensure this value is meaningful. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
b48c1a45 |
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21-Oct-2019 |
Steven Price <steven.price@arm.com> |
KVM: arm64: Implement PV_TIME_FEATURES call This provides a mechanism for querying which paravirtualized time features are available in this hypervisor. Also add the header file which defines the ABI for the paravirtualized time features we're about to add. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
c726200d |
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11-Oct-2019 |
Christoffer Dall <christoffer.dall@arm.com> |
KVM: arm/arm64: Allow reporting non-ISV data aborts to userspace For a long time, if a guest accessed memory outside of a memslot using any of the load/store instructions in the architecture which doesn't supply decoding information in the ESR_EL2 (the ISV bit is not set), the kernel would print the following message and terminate the VM as a result of returning -ENOSYS to userspace: load/store instruction decoding not implemented The reason behind this message is that KVM assumes that all accesses outside a memslot is an MMIO access which should be handled by userspace, and we originally expected to eventually implement some sort of decoding of load/store instructions where the ISV bit was not set. However, it turns out that many of the instructions which don't provide decoding information on abort are not safe to use for MMIO accesses, and the remaining few that would potentially make sense to use on MMIO accesses, such as those with register writeback, are not used in practice. It also turns out that fetching an instruction from guest memory can be a pretty horrible affair, involving stopping all CPUs on SMP systems, handling multiple corner cases of address translation in software, and more. It doesn't appear likely that we'll ever implement this in the kernel. What is much more common is that a user has misconfigured his/her guest and is actually not accessing an MMIO region, but just hitting some random hole in the IPA space. In this scenario, the error message above is almost misleading and has led to a great deal of confusion over the years. It is, nevertheless, ABI to userspace, and we therefore need to introduce a new capability that userspace explicitly enables to change behavior. This patch introduces KVM_CAP_ARM_NISV_TO_USER (NISV meaning Non-ISV) which does exactly that, and introduces a new exit reason to report the event to userspace. User space can then emulate an exception to the guest, restart the guest, suspend the guest, or take any other appropriate action as per the policy of the running system. Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Alexander Graf <graf@amazon.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
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#
f2266504 |
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02-Oct-2019 |
Marc Zyngier <maz@kernel.org> |
arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear The GICv3 architecture specification is incredibly misleading when it comes to PMR and the requirement for a DSB. It turns out that this DSB is only required if the CPU interface sends an Upstream Control message to the redistributor in order to update the RD's view of PMR. This message is only sent when ICC_CTLR_EL1.PMHE is set, which isn't the case in Linux. It can still be set from EL3, so some special care is required. But the upshot is that in the (hopefuly large) majority of the cases, we can drop the DSB altogether. This relies on a new static key being set if the boot CPU has PMHE set. The drawback is that this static key has to be exported to modules. Cc: Will Deacon <will@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
1e0cf16c |
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05-Jul-2019 |
Marc Zyngier <maz@kernel.org> |
KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register As part of setting up the host context, we populate its MPIDR by using cpu_logical_map(). It turns out that contrary to arm64, cpu_logical_map() on 32bit ARM doesn't return the *full* MPIDR, but a truncated version. This leaves the host MPIDR slightly corrupted after the first run of a VM, since we won't correctly restore the MPIDR on exit. Oops. Since we cannot trust cpu_logical_map(), let's adopt a different strategy. We move the initialization of the host CPU context as part of the per-CPU initialization (which, in retrospect, makes a lot of sense), and directly read the MPIDR from the HW. This is guaranteed to work on both arm and arm64. Reported-by: Andre Przywara <Andre.Przywara@arm.com> Tested-by: Andre Przywara <Andre.Przywara@arm.com> Fixes: 32f139551954 ("arm/arm64: KVM: Statically configure the host's view of MPIDR") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
c118bbb5 |
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03-May-2019 |
Andre Przywara <andre.przywara@arm.com> |
arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests Recent commits added the explicit notion of "workaround not required" to the state of the Spectre v2 (aka. BP_HARDENING) workaround, where we just had "needed" and "unknown" before. Export this knowledge to the rest of the kernel and enhance the existing kvm_arm_harden_branch_predictor() to report this new state as well. Export this new state to guests when they use KVM's firmware interface emulation. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
bd82d4bd |
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11-Jun-2019 |
Julien Thierry <julien.thierry.kdev@gmail.com> |
arm64: Fix incorrect irqflag restore for priority masking When using IRQ priority masking to disable interrupts, in order to deal with the PSR.I state, local_irq_save() would convert the I bit into a PMR value (GIC_PRIO_IRQOFF). This resulted in local_irq_restore() potentially modifying the value of PMR in undesired location due to the state of PSR.I upon flag saving [1]. In an attempt to solve this issue in a less hackish manner, introduce a bit (GIC_PRIO_IGNORE_PMR) for the PMR values that can represent whether PSR.I is being used to disable interrupts, in which case it takes precedence of the status of interrupt masking via PMR. GIC_PRIO_PSR_I_SET is chosen such that (<pmr_value> | GIC_PRIO_PSR_I_SET) does not mask more interrupts than <pmr_value> as some sections (e.g. arch_cpu_idle(), interrupt acknowledge path) requires PMR not to mask interrupts that could be signaled to the CPU when using only PSR.I. [1] https://www.spinics.net/lists/arm-kernel/msg716956.html Fixes: 4a503217ce37 ("arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking") Cc: <stable@vger.kernel.org> # 5.1.x- Reported-by: Zenghui Yu <yuzenghui@huawei.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Li <liwei391@huawei.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Suzuki K Pouloze <suzuki.poulose@arm.com> Cc: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
caab277b |
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02-Jun-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
b7c50fab |
|
22-May-2019 |
James Morse <james.morse@arm.com> |
KVM: arm64: Move pmu hyp code under hyp's Makefile to avoid instrumentation KVM's pmu.c contains the __hyp_text needed to switch the pmu registers between host and guest. Because this isn't covered by the 'hyp' Makefile, it can be built with kasan and friends when these are enabled in Kconfig. When starting a guest, this results in: | Kernel panic - not syncing: HYP panic: | PS:a00003c9 PC:000083000028ada0 ESR:86000007 | FAR:000083000028ada0 HPFAR:0000000029df5300 PAR:0000000000000000 | VCPU:000000004e10b7d6 | CPU: 0 PID: 3088 Comm: qemu-system-aar Not tainted 5.2.0-rc1 #11026 | Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Plat | Call trace: | dump_backtrace+0x0/0x200 | show_stack+0x20/0x30 | dump_stack+0xec/0x158 | panic+0x1ec/0x420 | panic+0x0/0x420 | SMP: stopping secondary CPUs | Kernel Offset: disabled | CPU features: 0x002,25006082 | Memory Limit: none | ---[ end Kernel panic - not syncing: HYP panic: This is caused by functions in pmu.c calling the instrumented code, which isn't mapped to hyp. From objdump -r: | RELOCATION RECORDS FOR [.hyp.text]: | OFFSET TYPE VALUE | 0000000000000010 R_AARCH64_CALL26 __sanitizer_cov_trace_pc | 0000000000000018 R_AARCH64_CALL26 __asan_load4_noabort | 0000000000000024 R_AARCH64_CALL26 __asan_load4_noabort Move the affected code to a new file under 'hyp's Makefile. Fixes: 3d91befbb3a0 ("arm64: KVM: Enable !VHE support for :G/:H perf event modifiers") Cc: Andrew Murray <Andrew.Murray@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
435e53fb |
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09-Apr-2019 |
Andrew Murray <amurray@thegoodpenguin.co.uk> |
arm64: KVM: Enable VHE support for :G/:H perf event modifiers With VHE different exception levels are used between the host (EL2) and guest (EL1) with a shared exception level for userpace (EL0). We can take advantage of this and use the PMU's exception level filtering to avoid enabling/disabling counters in the world-switch code. Instead we just modify the counter type to include or exclude EL0 at vcpu_{load,put} time. We also ensure that trapped PMU system register writes do not re-enable EL0 when reconfiguring the backing perf events. This approach completely avoids blackout windows seen with !VHE. Suggested-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Andrew Murray <andrew.murray@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3d91befb |
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09-Apr-2019 |
Andrew Murray <amurray@thegoodpenguin.co.uk> |
arm64: KVM: Enable !VHE support for :G/:H perf event modifiers Enable/disable event counters as appropriate when entering and exiting the guest to enable support for guest or host only event counting. For both VHE and non-VHE we switch the counters between host/guest at EL2. The PMU may be on when we change which counters are enabled however we avoid adding an isb as we instead rely on existing context synchronisation events: the eret to enter the guest (__guest_enter) and eret in kvm_call_hyp for __kvm_vcpu_run_nvhe on returning. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
eb41238c |
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09-Apr-2019 |
Andrew Murray <amurray@thegoodpenguin.co.uk> |
arm64: KVM: Add accessors to track guest/host only counters In order to effeciently switch events_{guest,host} perf counters at guest entry/exit we add bitfields to kvm_cpu_context for guest and host events as well as accessors for updating them. A function is also provided which allows the PMU driver to determine if a counter should start counting when it is enabled. With exclude_host, we may only start counting when entering the guest. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
630a1685 |
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09-Apr-2019 |
Andrew Murray <amurray@thegoodpenguin.co.uk> |
arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_data The virt/arm core allocates a kvm_cpu_context_t percpu, at present this is a typedef to kvm_cpu_context and is used to store host cpu context. The kvm_cpu_context structure is also used elsewhere to hold vcpu context. In order to use the percpu to hold additional future host information we encapsulate kvm_cpu_context in a new structure and rename the typedef and percpu to match. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
a22fa321 |
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22-Apr-2019 |
Amit Daniel Kachhap <amit.kachhap@arm.com> |
KVM: arm64: Add userspace flag to enable pointer authentication Now that the building blocks of pointer authentication are present, lets add userspace flags KVM_ARM_VCPU_PTRAUTH_ADDRESS and KVM_ARM_VCPU_PTRAUTH_GENERIC. These flags will enable pointer authentication for the KVM guest on a per-vcpu basis through the ioctl KVM_ARM_VCPU_INIT. This features will allow the KVM guest to allow the handling of pointer authentication instructions or to treat them as undefined if not set. Necessary documentations are added to reflect the changes done. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
384b40ca |
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22-Apr-2019 |
Mark Rutland <mark.rutland@arm.com> |
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
b890d75c |
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22-Apr-2019 |
Amit Daniel Kachhap <amit.kachhap@arm.com> |
KVM: arm64: Add a vcpu flag to control ptrauth for guest A per vcpu flag is added to check if pointer authentication is enabled for the vcpu or not. This flag may be enabled according to the necessary user policies and host capabilities. This patch also adds a helper to check the flag. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
92e68b2b |
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10-Apr-2019 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm/arm64: Clean up vcpu finalization function parameter naming Currently, the internal vcpu finalization functions use a different name ("what") for the feature parameter than the name ("feature") used in the documentation. To avoid future confusion, this patch converts everything to use the name "feature" consistently. No functional change. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
a3be836d |
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12-Apr-2019 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm/arm64: Demote kvm_arm_init_arch_resources() to just set up SVE The introduction of kvm_arm_init_arch_resources() looks like premature factoring, since nothing else uses this hook yet and it is not clear what will use it in the future. For now, let's not pretend that this is a general thing: This patch simply renames the function to kvm_arm_init_sve(), retaining the arm stub version under the new name. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
9a3cdf26 |
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28-Feb-2019 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64/sve: Allow userspace to enable SVE for vcpus Now that all the pieces are in place, this patch offers a new flag KVM_ARM_VCPU_SVE that userspace can pass to KVM_ARM_VCPU_INIT to turn on SVE for the guest, on a per-vcpu basis. As part of this, support for initialisation and reset of the SVE vector length set and registers is added in the appropriate places, as well as finally setting the KVM_ARM64_GUEST_HAS_SVE vcpu flag, to turn on the SVE support code. Allocation of the SVE register storage in vcpu->arch.sve_state is deferred until the SVE configuration is finalized, by which time the size of the registers is known. Setting the vector lengths supported by the vcpu is considered configuration of the emulated hardware rather than runtime configuration, so no support is offered for changing the vector lengths available to an existing vcpu across reset. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
9033bba4 |
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28-Feb-2019 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64/sve: Add pseudo-register for the guest's vector lengths This patch adds a new pseudo-register KVM_REG_ARM64_SVE_VLS to allow userspace to set and query the set of vector lengths visible to the guest. In the future, multiple register slices per SVE register may be visible through the ioctl interface. Once the set of slices has been determined we would not be able to allow the vector length set to be changed any more, in order to avoid userspace seeing inconsistent sets of registers. For this reason, this patch adds support for explicit finalization of the SVE configuration via the KVM_ARM_VCPU_FINALIZE ioctl. Finalization is the proper place to allocate the SVE register state storage in vcpu->arch.sve_state, so this patch adds that as appropriate. The data is freed via kvm_arch_vcpu_uninit(), which was previously a no-op on arm64. To simplify the logic for determining what vector lengths can be supported, some code is added to KVM init to work this out, in the kvm_arm_init_arch_resources() hook. The KVM_REG_ARM64_SVE_VLS pseudo-register is not exposed yet. Subsequent patches will allow SVE to be turned on for guest vcpus, making it visible. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
7dd32a0d |
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19-Dec-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm/arm64: Add KVM_ARM_VCPU_FINALIZE ioctl Some aspects of vcpu configuration may be too complex to be completed inside KVM_ARM_VCPU_INIT. Thus, there may be a requirement for userspace to do some additional configuration before various other ioctls will work in a consistent way. In particular this will be the case for SVE, where userspace will need to negotiate the set of vector lengths to be made available to the guest before the vcpu becomes fully usable. In order to provide an explicit way for userspace to confirm that it has finished setting up a particular vcpu feature, this patch adds a new ioctl KVM_ARM_VCPU_FINALIZE. When userspace has opted into a feature that requires finalization, typically by means of a feature flag passed to KVM_ARM_VCPU_INIT, a matching call to KVM_ARM_VCPU_FINALIZE is now required before KVM_RUN or KVM_GET_REG_LIST is allowed. Individual features may impose additional restrictions where appropriate. No existing vcpu features are affected by this, so current userspace implementations will continue to work exactly as before, with no need to issue KVM_ARM_VCPU_FINALIZE. As implemented in this patch, KVM_ARM_VCPU_FINALIZE is currently a placeholder: no finalizable features exist yet, so ioctl is not required and will always yield EINVAL. Subsequent patches will add the finalization logic to make use of this ioctl for SVE. No functional change for existing userspace. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
0f062bfe |
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28-Feb-2019 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm/arm64: Add hook for arch-specific KVM initialisation This patch adds a kvm_arm_init_arch_resources() hook to perform subarch-specific initialisation when starting up KVM. This will be used in a subsequent patch for global SVE-related setup on arm64. No functional change. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
e1c9c983 |
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28-Sep-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64/sve: Add SVE support to register access ioctl interface This patch adds the following registers for access via the KVM_{GET,SET}_ONE_REG interface: * KVM_REG_ARM64_SVE_ZREG(n, i) (n = 0..31) (in 2048-bit slices) * KVM_REG_ARM64_SVE_PREG(n, i) (n = 0..15) (in 256-bit slices) * KVM_REG_ARM64_SVE_FFR(i) (in 256-bit slices) In order to adapt gracefully to future architectural extensions, the registers are logically divided up into slices as noted above: the i parameter denotes the slice index. This allows us to reserve space in the ABI for future expansion of these registers. However, as of today the architecture does not permit registers to be larger than a single slice, so no code is needed in the kernel to expose additional slices, for now. The code can be extended later as needed to expose them up to a maximum of 32 slices (as carved out in the architecture itself) if they really exist someday. The registers are only visible for vcpus that have SVE enabled. They are not enumerated by KVM_GET_REG_LIST on vcpus that do not have SVE. Accesses to the FPSIMD registers via KVM_REG_ARM_CORE is not allowed for SVE-enabled vcpus: SVE-aware userspace can use the KVM_REG_ARM64_SVE_ZREG() interface instead to access the same register state. This avoids some complex and pointless emulation in the kernel to convert between the two views of these aliased registers. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
b43b5dd9 |
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28-Sep-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64/sve: Context switch the SVE registers In order to give each vcpu its own view of the SVE registers, this patch adds context storage via a new sve_state pointer in struct vcpu_arch. An additional member sve_max_vl is also added for each vcpu, to determine the maximum vector length visible to the guest and thus the value to be configured in ZCR_EL2.LEN while the vcpu is active. This also determines the layout and size of the storage in sve_state, which is read and written by the same backend functions that are used for context-switching the SVE state for host tasks. On SVE-enabled vcpus, SVE access traps are now handled by switching in the vcpu's SVE context and disabling the trap before returning to the guest. On other vcpus, the trap is not handled and an exit back to the host occurs, where the handle_sve() fallback path reflects an undefined instruction exception back to the guest, consistently with the behaviour of non-SVE-capable hardware (as was done unconditionally prior to this patch). No SVE handling is added on non-VHE-only paths, since VHE is an architectural and Kconfig prerequisite of SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
73433762 |
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28-Sep-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64/sve: System register context switch and access support This patch adds the necessary support for context switching ZCR_EL1 for each vcpu. ZCR_EL1 is trapped alongside the FPSIMD/SVE registers, so it makes sense for it to be handled as part of the guest FPSIMD/SVE context for context switch purposes instead of handling it as a general system register. This means that it can be switched in lazily at the appropriate time. No effort is made to track host context for this register, since SVE requires VHE: thus the hosts's value for this register lives permanently in ZCR_EL2 and does not alias the guest's value at any time. The Hyp switch and fpsimd context handling code is extended appropriately. Accessors are added in sys_regs.c to expose the SVE system registers and ID register fields. Because these need to be conditionally visible based on the guest configuration, they are implemented separately for now rather than by use of the generic system register helpers. This may be abstracted better later on when/if there are more features requiring this model. ID_AA64ZFR0_EL1 is RO-RAZ for MRS/MSR when SVE is disabled for the guest, but for compatibility with non-SVE aware KVM implementations the register should not be enumerated at all for KVM_GET_REG_LIST in this case. For consistency we also reject ioctl access to the register. This ensures that a non-SVE-enabled guest looks the same to userspace, irrespective of whether the kernel KVM implementation supports SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
1765edba |
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28-Sep-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64: Add a vcpu flag to control SVE visibility for the guest Since SVE will be enabled or disabled on a per-vcpu basis, a flag is needed in order to track which vcpus have it enabled. This patch adds a suitable flag and a helper for checking it. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3f61f409 |
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28-Sep-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64: Add missing #includes to kvm_host.h kvm_host.h uses some declarations from other headers that are currently included by accident, without an explicit #include. This patch adds a few #includes that are clearly missing. Although the header builds without them today, this should help to avoid future surprises. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
e329fb75 |
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11-Dec-2018 |
Christoffer Dall <christoffer.dall@arm.com> |
KVM: arm/arm64: Factor out VMID into struct kvm_vmid In preparation for nested virtualization where we are going to have more than a single VMID per VM, let's factor out the VMID data into a separate VMID data structure and change the VMID allocator to operate on this new structure instead of using a struct kvm. This also means that udate_vttbr now becomes update_vmid, and that the vttbr itself is generated on the fly based on the stage 2 page table base address and the vmid. We cache the physical address of the pgd when allocating the pgd to avoid doing the calculation on every entry to the guest and to avoid calling into potentially non-hyp-mapped code from hyp/EL2. If we wanted to merge the VMID allocator with the arm64 ASID allocator at some point in the future, it should actually become easier to do that after this patch. Note that to avoid mapping the kvm_vmid_bits variable into hyp, we simply forego the masking of the vmid value in kvm_get_vttbr and rely on update_vmid to always assign a valid vmid value (within the supported range). Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> [maz: minor cleanups] Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
32f13955 |
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19-Jan-2019 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Statically configure the host's view of MPIDR We currently eagerly save/restore MPIDR. It turns out to be slightly pointless: - On the host, this value is known as soon as we're scheduled on a physical CPU - In the guest, this value cannot change, as it is set by KVM (and this is a read-only register) The result of the above is that we can perfectly avoid the eager saving of MPIDR_EL1, and only keep the restore. We just have to setup the host contexts appropriately at boot time. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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#
18fc7bf8 |
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05-Jan-2019 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Allow for direct call of HYP functions when using VHE When running VHE, there is no need to jump via some stub to perform a "HYP" function call, as there is a single address space. Let's thus change kvm_call_hyp() and co to perform a direct call in this case. Although this results in a bit of code expansion, it allows the compiler to check for type compatibility, something that we are missing so far. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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#
7aa8d146 |
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05-Jan-2019 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Introduce kvm_call_hyp_ret() Until now, we haven't differentiated between HYP calls that have a return value and those who don't. As we're about to change this, introduce kvm_call_hyp_ret(), and change all call sites that actually make use of a return value. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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#
358b28f0 |
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20-Dec-2018 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Allow a VCPU to fully reset itself The current kvm_psci_vcpu_on implementation will directly try to manipulate the state of the VCPU to reset it. However, since this is not done on the thread that runs the VCPU, we can end up in a strangely corrupted state when the source and target VCPUs are running at the same time. Fix this by factoring out all reset logic from the PSCI implementation and forwarding the required information along with a request to the target VCPU. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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#
85738e05 |
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31-Jan-2019 |
Julien Thierry <julien.thierry.kdev@gmail.com> |
arm64: kvm: Unmask PMR before entering guest Interrupts masked by ICC_PMR_EL1 will not be signaled to the CPU. This means that hypervisor will not receive masked interrupts while running a guest. We need to make sure that all maskable interrupts are masked from the time we call local_irq_disable() in the main run loop, and remain so until we call local_irq_enable() after returning from the guest, and we need to ensure that we see no interrupts at all (including pseudo-NMIs) in the middle of the VM world-switch, while at the same time we need to ensure we exit the guest when there are interrupts for the host. We can accomplish this with pseudo-NMIs enabled by: (1) local_irq_disable: set the priority mask (2) enter guest: set PSTATE.I (3) clear the priority mask (4) eret to guest (5) exit guest: set the priotiy mask clear PSTATE.I (and restore other host PSTATE bits) (6) local_irq_enable: clear the priority mask. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
748c0e31 |
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06-Dec-2018 |
Lan Tianyu <Tianyu.Lan@microsoft.com> |
KVM: Make kvm_set_spte_hva() return int The patch is to make kvm_set_spte_hva() return int and caller can check return value to determine flush tlb or not. Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com> Acked-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
da6f1666 |
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28-Nov-2018 |
Christoffer Dall <christoffer.dall@arm.com> |
KVM: arm64: Make vcpu const in vcpu_read_sys_reg vcpu_read_sys_reg should not be modifying the VCPU structure. Eventually, to handle EL2 sysregs for nested virtualization, we will call vcpu_read_sys_reg from places that have a const vcpu pointer, which will complain about the lack of the const modifier on the read path. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
bd7d95ca |
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09-Nov-2018 |
Mark Rutland <mark.rutland@arm.com> |
arm64: KVM: Consistently advance singlestep when emulating instructions When we emulate a guest instruction, we don't advance the hardware singlestep state machine, and thus the guest will receive a software step exception after a next instruction which is not emulated by the host. We bodge around this in an ad-hoc fashion. Sometimes we explicitly check whether userspace requested a single step, and fake a debug exception from within the kernel. Other times, we advance the HW singlestep state rely on the HW to generate the exception for us. Thus, the observed step behaviour differs for host and guest. Let's make this simpler and consistent by always advancing the HW singlestep state machine when we skip an instruction. Thus we can rely on the hardware to generate the singlestep exception for us, and never need to explicitly check for an active-pending step, nor do we need to fake a debug exception from the guest. Cc: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
8b2cca9a |
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06-Dec-2018 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Force VHE for systems affected by erratum 1165522 In order to easily mitigate ARM erratum 1165522, we need to force affected CPUs to run in VHE mode if using KVM. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
33e5f4e5 |
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06-Dec-2018 |
Marc Zyngier <maz@kernel.org> |
KVM: arm64: Rework detection of SVE, !VHE systems An SVE system is so far the only case where we mandate VHE. As we're starting to grow this requirements, let's slightly rework the way we deal with that situation, allowing for easy extension of this check. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
375bdd3b |
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12-Oct-2018 |
Dongjiu Geng <gengdongjiu@huawei.com> |
arm/arm64: KVM: Rename function kvm_arch_dev_ioctl_check_extension() Rename kvm_arch_dev_ioctl_check_extension() to kvm_arch_vm_ioctl_check_extension(), because it does not have any relationship with device. Renaming this function can make code readable. Cc: James Morse <james.morse@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
bca607eb |
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01-Oct-2018 |
Marc Zyngier <maz@kernel.org> |
KVM: arm/arm64: Rename kvm_arm_config_vm to kvm_arm_setup_stage2 VM tends to be a very overloaded term in KVM, so let's keep it to describe the virtual machine. For the virtual memory setup, let's use the "stage2" suffix. Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
0f62f0e9 |
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26-Sep-2018 |
Suzuki K Poulose <suzuki.poulose@arm.com> |
kvm: arm64: Set a limit on the IPA size So far we have restricted the IPA size of the VM to the default value (40bits). Now that we can manage the IPA size per VM and support dynamic stage2 page tables, we can allow VMs to have larger IPA. This patch introduces a the maximum IPA size supported on the host. This is decided by the following factors : 1) Maximum PARange supported by the CPUs - This can be inferred from the system wide safe value. 2) Maximum PA size supported by the host kernel (48 vs 52) 3) Number of levels in the host page table (as we base our stage2 tables on the host table helpers). Since the stage2 page table code is dependent on the stage1 page table, we always ensure that : Number of Levels at Stage1 >= Number of Levels at Stage2 So we limit the IPA to make sure that the above condition is satisfied. This will affect the following combinations of VA_BITS and IPA for different page sizes. Host configuration | Unsupported IPA ranges 39bit VA, 4K | [44, 48] 36bit VA, 16K | [41, 48] 42bit VA, 64K | [47, 52] Supporting the above combinations need independent stage2 page table manipulation code, which would need substantial changes. We could purse the solution independently and switch the page table code once we have it ready. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
7665f3a8 |
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26-Sep-2018 |
Suzuki K Poulose <suzuki.poulose@arm.com> |
kvm: arm64: Configure VTCR_EL2 per VM Add support for setting the VTCR_EL2 per VM, rather than hard coding a value at boot time per CPU. This would allow us to tune the stage2 page table parameters per VM in the later changes. We compute the VTCR fields based on the system wide sanitised feature registers, except for the hardware management of Access Flags (VTCR_EL2.HA). It is fine to run a system with a mix of CPUs that may or may not update the page table Access Flags. Since the bit is RES0 on CPUs that don't support it, the bit should be ignored on them. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
5b6c6742 |
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26-Sep-2018 |
Suzuki K Poulose <suzuki.poulose@arm.com> |
kvm: arm/arm64: Allow arch specific configurations for VM Allow the arch backends to perform VM specific initialisation. This will be later used to handle IPA size configuration and per-VM VTCR configuration on arm64. Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@kernel.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
7c36447a |
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08-Aug-2018 |
Will Deacon <will@kernel.org> |
KVM: arm64: Set SCTLR_EL2.DSSBS if SSBD is forcefully disabled and !vhe When running without VHE, it is necessary to set SCTLR_EL2.DSSBS if SSBD has been forcefully disabled on the kernel command-line. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
df3190e2 |
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13-Aug-2018 |
Steven Price <steven.price@arm.com> |
arm64: KVM: Remove pgd_lock The lock has never been used and the page tables are protected by mmu_lock in struct kvm. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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#
a35381e1 |
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23-Aug-2018 |
Marc Zyngier <maz@kernel.org> |
KVM: Remove obsolete kvm_unmap_hva notifier backend kvm_unmap_hva is long gone, and we only have kvm_unmap_hva_range to deal with. Drop the now obsolete code. Fixes: fb1522e099f0 ("KVM: update to new mmu_notifier semantic v2") Cc: James Hogan <jhogan@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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#
539aee0e |
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19-Jul-2018 |
James Morse <james.morse@arm.com> |
KVM: arm64: Share the parts of get/set events useful to 32bit The get/set events helpers to do some work to check reserved and padding fields are zero. This is useful on 32bit too. Move this code into virt/kvm/arm/arm.c, and give the arch code some underscores. This is temporarily hidden behind __KVM_HAVE_VCPU_EVENTS until 32bit is wired up. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Dongjiu Geng <gengdongjiu@huawei.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
b7b27fac |
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19-Jul-2018 |
Dongjiu Geng <gengdongjiu@huawei.com> |
arm/arm64: KVM: Add KVM_GET/SET_VCPU_EVENTS For the migrating VMs, user space may need to know the exception state. For example, in the machine A, KVM make an SError pending, when migrate to B, KVM also needs to pend an SError. This new IOCTL exports user-invisible states related to SError. Together with appropriate user space changes, user space can get/set the SError exception state to do migrate/snapshot/suspend. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: James Morse <james.morse@arm.com> [expanded documentation wording] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
9bc03f1d |
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10-Jul-2018 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Cleanup tpidr_el2 init on non-VHE When running on a non-VHE system, we initialize tpidr_el2 to contain the per-CPU offset required to reach per-cpu variables. Actually, we initialize it twice: the first time as part of the EL2 initialization, by copying tpidr_el1 into its el2 counterpart, and another time by calling into __kvm_set_tpidr_el2. It turns out that the first part is wrong, as it includes the distance between the kernel mapping and the linear mapping, while EL2 only cares about the linear mapping. This was the last vestige of the first per-cpu use of tpidr_el2 that came in with SDEI. The only caller then was hyp_panic(), and its now using the pc-relative get_host_ctxt() stuff, instead of kimage addresses from the literal pool. It is not a big deal, as we override it straight away, but it is slightly confusing. In order to clear said confusion, let's set this directly as part of the hyp-init code, and drop the ad-hoc HYP helper. Reviewed-by: James Morse <james.morse@arm.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
b3eb56b6 |
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15-Jun-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64/sve: Fix SVE trap restoration for non-current tasks Commit e6b673b ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing") attempts to restore the configuration of userspace SVE trapping via a call to fpsimd_bind_task_to_cpu(), but the logic for determining when to do this is not correct. The patch makes the errnoenous assumption that the only task that may try to enter userspace with the currently loaded FPSIMD/SVE register content is current. This may not be the case however: if some other user task T is scheduled on the CPU during the execution of the KVM run loop, and the vcpu does not try to use the registers in the meantime, then T's state may be left there intact. If T happens to be the next task to enter userspace on this CPU then the hooks for reloading the register state and configuring traps will be skipped. (Also, current never has SVE state at this point anyway and should always have the trap enabled, as a side-effect of the ioctl() syscall needed to reach the KVM run loop in the first place.) This patch instead restores the state of the EL0 trap from the state observed at the most recent vcpu_load(), ensuring that the trap is set correctly for the loaded context (if any). Fixes: e6b673b741ea ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
d1e5b0e9 |
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15-May-2018 |
Marc Orr <marcorr@google.com> |
kvm: Make VM ioctl do valloc for some archs The kvm struct has been bloating. For example, it's tens of kilo-bytes for x86, which turns out to be a large amount of memory to allocate contiguously via kzalloc. Thus, this patch does the following: 1. Uses architecture-specific routines to allocate the kvm struct via vzalloc for x86. 2. Switches arm to __KVM_HAVE_ARCH_VM_ALLOC so that it can use vzalloc when has_vhe() is true. Other architectures continue to default to kalloc, as they have a dependency on kalloc or have a small-enough struct kvm. Signed-off-by: Marc Orr <marcorr@google.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
5d81f7dc |
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29-May-2018 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID Now that all our infrastructure is in place, let's expose the availability of ARCH_WORKAROUND_2 to guests. We take this opportunity to tidy up a couple of SMCCC constants. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
55e3748e |
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29-May-2018 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Add ARCH_WORKAROUND_2 support for guests In order to offer ARCH_WORKAROUND_2 support to guests, we need a bit of infrastructure. Let's add a flag indicating whether or not the guest uses SSBD mitigation. Depending on the state of this flag, allow KVM to disable ARCH_WORKAROUND_2 before entering the guest, and enable it when exiting it. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
21cdd7fd |
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20-Apr-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64: Remove eager host SVE state saving Now that the host SVE context can be saved on demand from Hyp, there is no longer any need to save this state in advance before entering the guest. This patch removes the relevant call to kvm_fpsimd_flush_cpu_state(). Since the problem that function was intended to solve now no longer exists, the function and its dependencies are also deleted. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
85acda3b |
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20-Apr-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64: Save host SVE context as appropriate This patch adds SVE context saving to the hyp FPSIMD context switch path. This means that it is no longer necessary to save the host SVE state in advance of entering the guest, when in use. In order to avoid adding pointless complexity to the code, VHE is assumed if SVE is in use. VHE is an architectural prerequisite for SVE, so there is no good reason to turn CONFIG_ARM64_VHE off in kernels that support both SVE and KVM. Historically, software models exist that can expose the architecturally invalid configuration of SVE without VHE, so if this situation is detected at kvm_init() time then KVM will be disabled. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
e6b673b7 |
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06-Apr-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing This patch refactors KVM to align the host and guest FPSIMD save/restore logic with each other for arm64. This reduces the number of redundant save/restore operations that must occur, and reduces the common-case IRQ blackout time during guest exit storms by saving the host state lazily and optimising away the need to restore the host state before returning to the run loop. Four hooks are defined in order to enable this: * kvm_arch_vcpu_run_map_fp(): Called on PID change to map necessary bits of current to Hyp. * kvm_arch_vcpu_load_fp(): Set up FP/SIMD for entering the KVM run loop (parse as "vcpu_load fp"). * kvm_arch_vcpu_ctxsync_fp(): Get FP/SIMD into a safe state for re-enabling interrupts after a guest exit back to the run loop. For arm64 specifically, this involves updating the host kernel's FPSIMD context tracking metadata so that kernel-mode NEON use will cause the vcpu's FPSIMD state to be saved back correctly into the vcpu struct. This must be done before re-enabling interrupts because kernel-mode NEON may be used by softirqs. * kvm_arch_vcpu_put_fp(): Save guest FP/SIMD state back to memory and dissociate from the CPU ("vcpu_put fp"). Also, the arm64 FPSIMD context switch code is updated to enable it to save back FPSIMD state for a vcpu, not just current. A few helpers drive this: * fpsimd_bind_state_to_cpu(struct user_fpsimd_state *fp): mark this CPU as having context fp (which may belong to a vcpu) currently loaded in its registers. This is the non-task equivalent of the static function fpsimd_bind_to_cpu() in fpsimd.c. * task_fpsimd_save(): exported to allow KVM to save the guest's FPSIMD state back to memory on exit from the run loop. * fpsimd_flush_state(): invalidate any context's FPSIMD state that is currently loaded. Used to disassociate the vcpu from the CPU regs on run loop exit. These changes allow the run loop to enable interrupts (and thus softirqs that may use kernel-mode NEON) without having to save the guest's FPSIMD state eagerly. Some new vcpu_arch fields are added to make all this work. Because host FPSIMD state can now be saved back directly into current's thread_struct as appropriate, host_cpu_context is no longer used for preserving the FPSIMD state. However, it is still needed for preserving other things such as the host's system registers. To avoid ABI churn, the redundant storage space in host_cpu_context is not removed for now. arch/arm is not addressed by this patch and continues to use its current save/restore logic. It could provide implementations of the helpers later if desired. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
fa89d31c |
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08-May-2018 |
Dave Martin <Dave.Martin@arm.com> |
KVM: arm64: Repurpose vcpu_arch.debug_flags for general-purpose flags In struct vcpu_arch, the debug_flags field is used to store debug-related flags about the vcpu state. Since we are about to add some more flags related to FPSIMD and SVE, it makes sense to add them to the existing flags field rather than adding new fields. Since there is only one debug_flags flag defined so far, there is plenty of free space for expansion. In preparation for adding more flags, this patch renames the debug_flags field to simply "flags", and updates comments appropriately. The flag definitions are also moved to <asm/kvm_host.h>, since their presence in <asm/kvm_asm.h> was for purely historical reasons: these definitions are not used from asm any more, and not very likely to be as more Hyp asm is migrated to C. KVM_ARM64_DEBUG_DIRTY_SHIFT has not been used since commit 1ea66d27e7b0 ("arm64: KVM: Move away from the assembly version of the world switch"), so this patch gets rid of that too. No functional change. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@arm.com> [maz: fixed minor conflict] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
85bd0ba1 |
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21-Jan-2018 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Add PSCI version selection API Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1 or 1.0 to a guest, defaulting to the latest version of the PSCI implementation that is compatible with the requested version. This is no different from doing a firmware upgrade on KVM. But in order to give a chance to hypothetical badly implemented guests that would have a fit by discovering something other than PSCI 0.2, let's provide a new API that allows userspace to pick one particular version of the API. This is implemented as a new class of "firmware" registers, where we expose the PSCI version. This allows the PSCI version to be save/restored as part of a guest migration, and also set to any supported version if the guest requires it. Cc: stable@vger.kernel.org #4.16 Reviewed-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
d47533da |
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23-Dec-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm64: Introduce framework for accessing deferred sysregs We are about to defer saving and restoring some groups of system registers to vcpu_put and vcpu_load on supported systems. This means that we need some infrastructure to access system registes which supports either accessing the memory backing of the register or directly accessing the system registers, depending on the state of the system when we access the register. We do this by defining read/write accessor functions, which can handle both "immediate" and "deferrable" system registers. Immediate registers are always saved/restored in the world-switch path, but deferrable registers are only saved/restored in vcpu_put/vcpu_load when supported and sysregs_loaded_on_cpu will be set in that case. Note that we don't use the deferred mechanism yet in this patch, but only introduce infrastructure. This is to improve convenience of review in the subsequent patches where it is clear which registers become deferred. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
8d404c4c |
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16-Mar-2016 |
Christoffer Dall <cdall@cs.columbia.edu> |
KVM: arm64: Rewrite system register accessors to read/write functions Currently we access the system registers array via the vcpu_sys_reg() macro. However, we are about to change the behavior to some times modify the register file directly, so let's change this to two primitives: * Accessor macros vcpu_write_sys_reg() and vcpu_read_sys_reg() * Direct array access macro __vcpu_sys_reg() The accessor macros should be used in places where the code needs to access the currently loaded VCPU's state as observed by the guest. For example, when trapping on cache related registers, a write to a system register should go directly to the VCPU version of the register. The direct array access macro can be used in places where the VCPU is known to never be running (for example userspace access) or for registers which are never context switched (for example all the PMU system registers). This rewrites all users of vcpu_sys_regs to one of the macros described above. No functional change. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
52f6c4f0 |
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11-Oct-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm64: Change 32-bit handling of VM system registers We currently handle 32-bit accesses to trapped VM system registers using the 32-bit index into the coproc array on the vcpu structure, which is a union of the coproc array and the sysreg array. Since all the 32-bit coproc indices are created to correspond to the architectural mapping between 64-bit system registers and 32-bit coprocessor registers, and because the AArch64 system registers are the double in size of the AArch32 coprocessor registers, we can always find the system register entry that we must update by dividing the 32-bit coproc index by 2. This is going to make our lives much easier when we have to start accessing system registers that use deferred save/restore and might have to be read directly from the physical CPU. Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3f5c90b8 |
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03-Oct-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm64: Introduce VHE-specific kvm_vcpu_run So far this is mostly (see below) a copy of the legacy non-VHE switch function, but we will start reworking these functions in separate directions to work on VHE and non-VHE in the most optimal way in later patches. The only difference after this patch between the VHE and non-VHE run functions is that we omit the branch-predictor variant-2 hardening for QC Falkor CPUs, because this workaround is specific to a series of non-VHE ARMv8.0 CPUs. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
bc192cee |
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10-Oct-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm/arm64: Add kvm_vcpu_load_sysregs and kvm_vcpu_put_sysregs As we are about to move a bunch of save/restore logic for VHE kernels to the load and put functions, we need some infrastructure to do this. Reviewed-by: Andrew Jones <drjones@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3df59d8d |
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02-Aug-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm/arm64: Get rid of vcpu->arch.irq_lines We currently have a separate read-modify-write of the HCR_EL2 on entry to the guest for the sole purpose of setting the VF and VI bits, if set. Since this is most rarely the case (only when using userspace IRQ chip and interrupts are in flight), let's get rid of this operation and instead modify the bits in the vcpu->arch.hcr[_el2] directly when needed. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
4464e210 |
|
08-Oct-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm64: Avoid storing the vcpu pointer on the stack We already have the percpu area for the host cpu state, which points to the VCPU, so there's no need to store the VCPU pointer on the stack on every context switch. We can be a little more clever and just use tpidr_el2 for the percpu offset and load the VCPU pointer from the host context. This has the benefit of being able to retrieve the host context even when our stack is corrupted, and it has a potential performance benefit because we trade a store plus a load for an mrs and a load on a round trip to the guest. This does require us to calculate the percpu offset without including the offset from the kernel mapping of the percpu array to the linear mapping of the array (which is what we store in tpidr_el1), because a PC-relative generated address in EL2 is already giving us the hyp alias of the linear mapping of a kernel address. We do this in __cpu_init_hyp_mode() by using kvm_ksym_ref(). The code that accesses ESR_EL2 was previously using an alternative to use the _EL1 accessor on VHE systems, but this was actually unnecessary as the _EL1 accessor aliases the ESR_EL2 register on VHE, and the _EL2 accessor does the same thing on both systems. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
6167ec5c |
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06-Feb-2018 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support A new feature of SMCCC 1.1 is that it offers firmware-based CPU workarounds. In particular, SMCCC_ARCH_WORKAROUND_1 provides BP hardening for CVE-2017-5715. If the host has some mitigation for this issue, report that we deal with it using SMCCC_ARCH_WORKAROUND_1, as we apply the host workaround on every guest exit. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
0067df41 |
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15-Jan-2018 |
James Morse <james.morse@arm.com> |
KVM: arm64: Handle RAS SErrors from EL2 on guest exit We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. The current SError from EL2 code unmasks SError and tries to fence any pending SError into a single instruction window. It then leaves SError unmasked. With the v8.2 RAS Extensions we may take an SError for a 'corrected' error, but KVM is only able to handle SError from EL2 if they occur during this single instruction window... The RAS Extensions give us a new instruction to synchronise and consume SErrors. The RAS Extensions document (ARM DDI0587), '2.4.1 ESB and Unrecoverable errors' describes ESB as synchronising SError interrupts generated by 'instructions, translation table walks, hardware updates to the translation tables, and instruction fetches on the same PE'. This makes ESB equivalent to KVMs existing 'dsb, mrs-daifclr, isb' sequence. Use the alternatives to synchronise and consume any SError using ESB instead of unmasking and taking the SError. Set ARM_EXIT_WITH_SERROR_BIT in the exit_code so that we can restart the vcpu if it turns out this SError has no impact on the vcpu. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
3368bd80 |
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15-Jan-2018 |
James Morse <james.morse@arm.com> |
KVM: arm64: Handle RAS SErrors from EL1 on guest exit We expect to have firmware-first handling of RAS SErrors, with errors notified via an APEI method. For systems without firmware-first, add some minimal handling to KVM. There are two ways KVM can take an SError due to a guest, either may be a RAS error: we exit the guest due to an SError routed to EL2 by HCR_EL2.AMO, or we take an SError from EL2 when we unmask PSTATE.A from __guest_exit. For SError that interrupt a guest and are routed to EL2 the existing behaviour is to inject an impdef SError into the guest. Add code to handle RAS SError based on the ESR. For uncontained and uncategorized errors arm64_is_fatal_ras_serror() will panic(), these errors compromise the host too. All other error types are contained: For the fatal errors the vCPU can't make progress, so we inject a virtual SError. We ignore contained errors where we can make progress as if we're lucky, we may not hit them again. If only some of the CPUs support RAS the guest will see the cpufeature sanitised version of the id registers, but we may still take RAS SError on this CPU. Move the SError handling out of handle_exit() into a new handler that runs before we can be preempted. This allows us to use this_cpu_has_cap(), via arm64_is_ras_serror(). Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
c773ae2b |
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15-Jan-2018 |
James Morse <james.morse@arm.com> |
KVM: arm64: Save/Restore guest DISR_EL1 If we deliver a virtual SError to the guest, the guest may defer it with an ESB instruction. The guest reads the deferred value via DISR_EL1, but the guests view of DISR_EL1 is re-mapped to VDISR_EL2 when HCR_EL2.AMO is set. Add the KVM code to save/restore VDISR_EL2, and make it accessible to userspace as DISR_EL1. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
4715c14b |
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15-Jan-2018 |
James Morse <james.morse@arm.com> |
KVM: arm64: Set an impdef ESR for Virtual-SError using VSESR_EL2. Prior to v8.2's RAS Extensions, the HCR_EL2.VSE 'virtual SError' feature generated an SError with an implementation defined ESR_EL1.ISS, because we had no mechanism to specify the ESR value. On Juno this generates an all-zero ESR, the most significant bit 'ISV' is clear indicating the remainder of the ISS field is invalid. With the RAS Extensions we have a mechanism to specify this value, and the most significant bit has a new meaning: 'IDS - Implementation Defined Syndrome'. An all-zero SError ESR now means: 'RAS error: Uncategorized' instead of 'no valid ISS'. Add KVM support for the VSESR_EL2 register to specify an ESR value when HCR_EL2.VSE generates a virtual SError. Change kvm_inject_vabt() to specify an implementation-defined value. We only need to restore the VSESR_EL2 value when HCR_EL2.VSE is set, KVM save/restores this bit during __{,de}activate_traps() and hardware clears the bit once the guest has consumed the virtual-SError. Future patches may add an API (or KVM CAP) to pend a virtual SError with a specified ESR. Cc: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
4f5abad9 |
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15-Jan-2018 |
James Morse <james.morse@arm.com> |
KVM: arm/arm64: mask/unmask daif around VHE guests Non-VHE systems take an exception to EL2 in order to world-switch into the guest. When returning from the guest KVM implicitly restores the DAIF flags when it returns to the kernel at EL1. With VHE none of this exception-level jumping happens, so KVMs world-switch code is exposed to the host kernel's DAIF values, and KVM spills the guest-exit DAIF values back into the host kernel. On entry to a guest we have Debug and SError exceptions unmasked, KVM has switched VBAR but isn't prepared to handle these. On guest exit Debug exceptions are left disabled once we return to the host and will stay this way until we enter user space. Add a helper to mask/unmask DAIF around VHE guests. The unmask can only happen after the hosts VBAR value has been synchronised by the isb in __vhe_hyp_call (via kvm_call_hyp()). Masking could be as late as setting KVMs VBAR value, but is kept here for symmetry. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
c97e166e |
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08-Jan-2018 |
James Morse <james.morse@arm.com> |
KVM: arm64: Change hyp_panic()s dependency on tpidr_el2 Make tpidr_el2 a cpu-offset for per-cpu variables in the same way the host uses tpidr_el1. This lets tpidr_el{1,2} have the same value, and on VHE they can be the same register. KVM calls hyp_panic() when anything unexpected happens. This may occur while a guest owns the EL1 registers. KVM stashes the vcpu pointer in tpidr_el2, which it uses to find the host context in order to restore the host EL1 registers before parachuting into the host's panic(). The host context is a struct kvm_cpu_context allocated in the per-cpu area, and mapped to hyp. Given the per-cpu offset for this CPU, this is easy to find. Change hyp_panic() to take a pointer to the struct kvm_cpu_context. Wrap these calls with an asm function that retrieves the struct kvm_cpu_context from the host's per-cpu area. Copy the per-cpu offset from the hosts tpidr_el1 into tpidr_el2 during kvm init. (Later patches will make this unnecessary for VHE hosts) We print out the vcpu pointer as part of the panic message. Add a back reference to the 'running vcpu' in the host cpu context to preserve this. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
61bbe380 |
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27-Oct-2017 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm/arm64: Avoid work when userspace iqchips are not used We currently check if the VM has a userspace irqchip in several places along the critical path, and if so, we do some work which is only required for having an irqchip in userspace. This is unfortunate, as we could avoid doing any work entirely, if we didn't have to support irqchip in userspace. Realizing the userspace irqchip on ARM is mostly a developer or hobby feature, and is unlikely to be used in servers or other scenarios where performance is a priority, we can use a refcounted static key to only check the irqchip configuration when we have at least one VM that uses an irqchip in userspace. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
696673d1 |
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16-Nov-2017 |
Alex Bennée <alex.bennee@linaro.org> |
KVM: arm/arm64: debug: Introduce helper for single-step After emulating instructions we may want return to user-space to handle single-step debugging. Introduce a helper function, which, if single-step is enabled, sets the run structure for return and returns true. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
17eed27b |
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31-Oct-2017 |
Dave Martin <Dave.Martin@arm.com> |
arm64/sve: KVM: Prevent guests from using SVE Until KVM has full SVE support, guests must not be allowed to execute SVE instructions. This patch enables the necessary traps, and also ensures that the traps are disabled again on exit from the guest so that the host can still use SVE if it wants to. On guest exit, high bits of the SVE Zn registers may have been clobbered as a side-effect the execution of FPSIMD instructions in the guest. The existing KVM host FPSIMD restore code is not sufficient to restore these bits, so this patch explicitly marks the CPU as not containing cached vector state for any task, thus forcing a reload on the next return to userspace. This is an interim measure, in advance of adding full SVE awareness to KVM. This marking of cached vector state in the CPU as invalid is done using __this_cpu_write(fpsimd_last_state, NULL) in fpsimd.c. Due to the repeated use of this rather obscure operation, it makes sense to factor it out as a separate helper with a clearer name. This patch factors it out as fpsimd_flush_cpu_state(), and ports all callers to use it. As a side effect of this refactoring, a this_cpu_write() in fpsimd_cpu_pm_notifier() is changed to __this_cpu_write(). This should be fine, since cpu_pm_enter() is supposed to be called only with interrupts disabled. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
fb1522e0 |
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31-Aug-2017 |
Jérôme Glisse <jglisse@redhat.com> |
KVM: update to new mmu_notifier semantic v2 Calls to mmu_notifier_invalidate_page() were replaced by calls to mmu_notifier_invalidate_range() and are now bracketed by calls to mmu_notifier_invalidate_range_start()/end() Remove now useless invalidate_page callback. Changed since v1 (Linus Torvalds) - remove now useless kvm_arch_mmu_notifier_invalidate_page() Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Tested-by: Mike Galbraith <efault@gmx.de> Tested-by: Adam Borowski <kilobyte@angband.pl> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
325f9c64 |
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04-Jun-2017 |
Andrew Jones <drjones@redhat.com> |
KVM: arm/arm64: use vcpu requests for irq injection Don't use request-less VCPU kicks when injecting IRQs, as a VCPU kick meant to trigger the interrupt injection could be sent while the VCPU is outside guest mode, which means no IPI is sent, and after it has called kvm_vgic_flush_hwstate(), meaning it won't see the updated GIC state until its next exit some time later for some other reason. The receiving VCPU only needs to check this request in VCPU RUN to handle it. By checking it, if it's pending, a memory barrier will be issued that ensures all state is visible. See "Ensuring Requests Are Seen" of Documentation/virtual/kvm/vcpu-requests.rst Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
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#
7b244e2b |
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04-Jun-2017 |
Andrew Jones <drjones@redhat.com> |
KVM: arm/arm64: change exit request to sleep request A request called EXIT is too generic. All requests are meant to cause exits, but different requests have different flags. Let's not make it difficult to decide if the EXIT request is correct for some case by just always providing unique requests for each case. This patch changes EXIT to SLEEP, because that's what the request is asking the VCPU to do. Signed-off-by: Andrew Jones <drjones@redhat.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
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#
2387149e |
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04-Jun-2017 |
Andrew Jones <drjones@redhat.com> |
KVM: improve arch vcpu request defining Marc Zyngier suggested that we define the arch specific VCPU request base, rather than requiring each arch to remember to start from 8. That suggestion, along with Radim Krcmar's recent VCPU request flag addition, snowballed into defining something of an arch VCPU request defining API. No functional change. (Looks like x86 is running out of arch VCPU request bits. Maybe someday we'll need to extend to 64.) Signed-off-by: Andrew Jones <drjones@redhat.com> Acked-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
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#
abd72296 |
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06-May-2017 |
Christoffer Dall <cdall@linaro.org> |
KVM: arm/arm64: Simplify active_change_prepare and plug race We don't need to stop a specific VCPU when changing the active state, because private IRQs can only be modified by a running VCPU for the VCPU itself and it is therefore already stopped. However, it is also possible for two VCPUs to be modifying the active state of SPIs at the same time, which can cause the thread being stuck in the loop that checks other VCPU threads for a potentially very long time, or to modify the active state of a running VCPU. Fix this by serializing all accesses to setting and clearing the active state of interrupts using the KVM mutex. Reported-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
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#
63a1e1c9 |
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16-May-2017 |
Mark Rutland <mark.rutland@arm.com> |
arm64/cpufeature: don't use mutex in bringup path Currently, cpus_set_cap() calls static_branch_enable_cpuslocked(), which must take the jump_label mutex. We call cpus_set_cap() in the secondary bringup path, from the idle thread where interrupts are disabled. Taking a mutex in this path "is a NONO" regardless of whether it's contended, and something we must avoid. We didn't spot this until recently, as ___might_sleep() won't warn for this case until all CPUs have been brought up. This patch avoids taking the mutex in the secondary bringup path. The poking of static keys is deferred until enable_cpu_capabilities(), which runs in a suitable context on the boot CPU. To account for the static keys being set later, cpus_have_const_cap() is updated to use another static key to check whether the const cap keys have been initialised, falling back to the caps bitmap until this is the case. This means that users of cpus_have_const_cap() gain should only gain a single additional NOP in the fast path once the const caps are initialised, but should always see the current cap value. The hyp code should never dereference the caps array, since the caps are initialized before we run the module initcall to initialise hyp. A check is added to the hyp init code to document this requirement. This change will sidestep a number of issues when the upcoming hotplug locking rework is merged. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyniger <marc.zyngier@arm.com> Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Sewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
7a97cec2 |
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27-Apr-2017 |
Paolo Bonzini <pbonzini@redhat.com> |
KVM: mark requests that need synchronization kvm_make_all_requests() provides a synchronization that waits until all kicked VCPUs have acknowledged the kick. This is important for KVM_REQ_MMU_RELOAD as it prevents freeing while lockless paging is underway. This patch adds the synchronization property into all requests that are currently being used with kvm_make_all_requests() in order to preserve the current behavior and only introduce a new framework. Removing it from requests where it is not necessary is left for future patches. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
930f7fd6 |
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26-Apr-2017 |
Radim Krčmář <rkrcmar@redhat.com> |
KVM: mark requests that do not need a wakeup Some operations must ensure that the guest is not running with stale data, but if the guest is halted, then the update can wait until another event happens. kvm_make_all_requests() currently doesn't wake up, so we can mark all requests used with it. First 8 bits were arbitrarily reserved for request numbers. Most uses of requests have the request type as a constant, so a compiler will optimize the '&'. An alternative would be to have an inline function that would return whether the request needs a wake-up or not, but I like this one better even though it might produce worse assembly. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
0fb26593 |
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03-Apr-2017 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Use __hyp_reset_vectors() directly __cpu_reset_hyp_mode doesn't need to be passed any argument now, as the hyp-stub implementations are self-contained, and is now reduced to just calling __hyp_reset_vectors(). Let's drop the wrapper and use the stub hypercall directly. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
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#
4adb1341 |
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03-Apr-2017 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Convert __cpu_reset_hyp_mode to using __hyp_reset_vectors We are now able to use the hyp stub to reset HYP mode. Time to kiss __kvm_hyp_reset goodbye, and use __hyp_reset_vectors. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
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#
4b4357e0 |
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31-Mar-2017 |
Paolo Bonzini <pbonzini@redhat.com> |
kvm: make KVM_COALESCED_MMIO_PAGE_OFFSET public Its value has never changed; we might as well make it part of the ABI instead of using the return value of KVM_CHECK_EXTENSION(KVM_CAP_COALESCED_MMIO). Because PPC does not always make MMIO available, the code has to be made dependent on CONFIG_KVM_MMIO rather than KVM_COALESCED_MMIO_PAGE_OFFSET. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
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#
955a3fc6 |
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07-Mar-2017 |
Linu Cherian <linu.cherian@cavium.com> |
KVM: arm64: Increase number of user memslots to 512 Having only 32 memslots is a real constraint for the maximum number of PCI devices that can be assigned to a single guest. Assuming each PCI device/virtual function having two memory BAR regions, we could assign only 15 devices/virtual functions to a guest. Hence increase KVM_USER_MEM_SLOTS to 512 as done in other archs like powerpc. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Linu Cherian <linu.cherian@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3e92f94a |
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07-Mar-2017 |
Linu Cherian <linu.cherian@cavium.com> |
KVM: arm/arm64: Remove KVM_PRIVATE_MEM_SLOTS definition that are unused arm/arm64 architecture doesnt use private memslots, hence removing KVM_PRIVATE_MEM_SLOTS macro definition. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Linu Cherian <linu.cherian@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
90de943a |
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03-Feb-2017 |
Jintack Lim <jintack@cs.columbia.edu> |
KVM: arm/arm64: Move cntvoff to each timer context Make cntvoff per each timer context. This is helpful to abstract kvm timer functions to work with timer context without considering timer types (e.g. physical timer or virtual timer). This also would pave the way for ever doing adjustments of the cntvoff on a per-CPU basis if that should ever make sense. Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
f85279b4 |
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22-Sep-2016 |
Will Deacon <will@kernel.org> |
arm64: KVM: Save/restore the host SPE state when entering/leaving a VM The SPE buffer is virtually addressed, using the page tables of the CPU MMU. Unusually, this means that the EL0/1 page table may be live whilst we're executing at EL2 on non-VHE configurations. When VHE is in use, we can use the same property to profile the guest behind its back. This patch adds the relevant disabling and flushing code to KVM so that the host can make use of SPE without corrupting guest memory, and any attempts by a guest to use SPE will result in a trap. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
94d0e598 |
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18-Oct-2016 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a single CPU Architecturally, TLBs are private to the (physical) CPU they're associated with. But when multiple vcpus from the same VM are being multiplexed on the same CPU, the TLBs are not private to the vcpus (and are actually shared across the VMID). Let's consider the following scenario: - vcpu-0 maps PA to VA - vcpu-1 maps PA' to VA If run on the same physical CPU, vcpu-1 can hit TLB entries generated by vcpu-0 accesses, and access the wrong physical page. The solution to this is to keep a per-VM map of which vcpu ran last on each given physical CPU, and invalidate local TLBs when switching to a different vcpu from the same VM. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
8a7e75d4 |
|
01-Aug-2016 |
Suraj Jitindar Singh <sjitindarsingh@gmail.com> |
KVM: Add provisioning for ulong vm stats and u64 vcpu stats vms and vcpus have statistics associated with them which can be viewed within the debugfs. Currently it is assumed within the vcpu_stat_get() and vm_stat_get() functions that all of these statistics are represented as u32s, however the next patch adds some u64 vcpu statistics. Change all vcpu statistics to u64 and modify vcpu_stat_get() accordingly. Since vcpu statistics are per vcpu, they will only be updated by a single vcpu at a time so this shouldn't present a problem on 32-bit machines which can't atomically increment 64-bit numbers. However vm statistics could potentially be updated by multiple vcpus from that vm at a time. To avoid the overhead of atomics make all vm statistics ulong such that they are 64-bit on 64-bit systems where they can be atomically incremented and are 32-bit on 32-bit systems which may not be able to atomically increment 64-bit numbers. Modify vm_stat_get() to expect ulongs. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: David Matlack <dmatlack@google.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
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#
b46f01ce |
|
14-Jul-2016 |
Andre Przywara <andre.przywara@arm.com> |
KVM: arm/arm64: Extend arch CAP checks to allow per-VM capabilities KVM capabilities can be a per-VM property, though ARM/ARM64 currently does not pass on the VM pointer to the architecture specific capability handlers. Add a "struct kvm*" parameter to those function to later allow proper per-VM capability reporting. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
e537ecd7 |
|
30-Jun-2016 |
Marc Zyngier <maz@kernel.org> |
arm: KVM: Allow hyp teardown So far, KVM was getting in the way of kexec on 32bit (and the arm64 kexec hackers couldn't be bothered to fix it on 32bit...). With simpler page tables, tearing KVM down becomes very easy, so let's just do it. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
12fda812 |
|
30-Jun-2016 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Drop boot_pgd Since we now only have one set of page tables, the concept of boot_pgd is useless and can be removed. We still keep it as an element of the "extended idmap" thing. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
3421e9d8 |
|
30-Jun-2016 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Simplify HYP init/teardown Now that we only have the "merged page tables" case to deal with, there is a bunch of things we can simplify in the HYP code (both at init and teardown time). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
35a2d585 |
|
20-May-2016 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm/arm64: vgic-new: Synchronize changes to active state When modifying the active state of an interrupt via the MMIO interface, we should ensure that the write has the intended effect. If a guest sets an interrupt to active, but that interrupt is already flushed into a list register on a running VCPU, then that VCPU will write the active state back into the struct vgic_irq upon returning from the guest and syncing its state. This is a non-benign race, because the guest can observe that an interrupt is not active, and it can have a reasonable expectations that other VCPUs will not ack any IRQs, and then set the state to active, and expect it to stay that way. Currently we are not honoring this case. Thefore, change both the SACTIVE and CACTIVE mmio handlers to stop the world, change the irq state, potentially queue the irq if we're setting it to active, and then continue. We take this chance to slightly optimize these functions by not stopping the world when touching private interrupts where there is inherently no possible race. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
b13216cf |
|
27-Apr-2016 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm/arm64: Provide functionality to pause and resume a guest For some rare corner cases in our VGIC emulation later we have to stop the guest to make sure the VGIC state is consistent. Provide the necessary framework to pause and resume a guest. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
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#
3491caf2 |
|
12-May-2016 |
Christian Borntraeger <borntraeger@de.ibm.com> |
KVM: halt_polling: provide a way to qualify wakeups during poll Some wakeups should not be considered a sucessful poll. For example on s390 I/O interrupts are usually floating, which means that _ALL_ CPUs would be considered runnable - letting all vCPUs poll all the time for transactional like workload, even if one vCPU would be enough. This can result in huge CPU usage for large guests. This patch lets architectures provide a way to qualify wakeups if they should be considered a good/bad wakeups in regard to polls. For s390 the implementation will fence of halt polling for anything but known good, single vCPU events. The s390 implementation for floating interrupts does a wakeup for one vCPU, but the interrupt will be delivered by whatever CPU checks first for a pending interrupt. We prefer the woken up CPU by marking the poll of this CPU as "good" poll. This code will also mark several other wakeup reasons like IPI or expired timers as "good". This will of course also mark some events as not sucessful. As KVM on z runs always as a 2nd level hypervisor, we prefer to not poll, unless we are really sure, though. This patch successfully limits the CPU usage for cases like uperf 1byte transactional ping pong workload or wakeup heavy workload like OLTP while still providing a proper speedup. This also introduced a new vcpu stat "halt_poll_no_tuning" that marks wakeups that are considered not good for polling. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version) Cc: David Matlack <dmatlack@google.com> Cc: Wanpeng Li <kernellwp@gmail.com> [Rename config symbol. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
c612505f |
|
29-Apr-2016 |
James Morse <james.morse@arm.com> |
arm64: kvm: Fix kvm teardown for systems using the extended idmap If memory is located above 1<<VA_BITS, kvm adds an extra level to its page tables, merging the runtime tables and boot tables that contain the idmap. This lets us avoid the trampoline dance during initialisation. This also means there is no trampoline page mapped, so __cpu_reset_hyp_mode() can't call __kvm_hyp_reset() in this page. The good news is the idmap is still mapped, so we don't need the trampoline page. The bad news is we can't call it directly as the idmap is above HYP_PAGE_OFFSET, so its address is masked by kvm_call_hyp. Add a function __extended_idmap_trampoline which will branch into __kvm_hyp_reset in the idmap, change kvm_hyp_reset_entry() to return this address if __kvm_cpu_uses_extended_idmap(). In this case __kvm_hyp_reset() will still switch to the boot tables (which are the merged tables that were already in use), and branch into the idmap (where it already was). This fixes boot failures on these systems, where we fail to execute the missing trampoline page when tearing down kvm in init_subsystems(): [ 2.508922] kvm [1]: 8-bit VMID [ 2.512057] kvm [1]: Hyp mode initialized successfully [ 2.517242] kvm [1]: interrupt-controller@e1140000 IRQ13 [ 2.522622] kvm [1]: timer IRQ3 [ 2.525783] Kernel panic - not syncing: HYP panic: [ 2.525783] PS:200003c9 PC:0000007ffffff820 ESR:86000005 [ 2.525783] FAR:0000007ffffff820 HPFAR:00000000003ffff0 PAR:0000000000000000 [ 2.525783] VCPU: (null) [ 2.525783] [ 2.547667] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.6.0-rc5+ #1 [ 2.555137] Hardware name: Default string Default string/Default string, BIOS ROD0084E 09/03/2015 [ 2.563994] Call trace: [ 2.566432] [<ffffff80080888d0>] dump_backtrace+0x0/0x240 [ 2.571818] [<ffffff8008088b24>] show_stack+0x14/0x20 [ 2.576858] [<ffffff80083423ac>] dump_stack+0x94/0xb8 [ 2.581899] [<ffffff8008152130>] panic+0x10c/0x250 [ 2.586677] [<ffffff8008152024>] panic+0x0/0x250 [ 2.591281] SMP: stopping secondary CPUs [ 3.649692] SMP: failed to stop secondary CPUs 0-2,4-7 [ 3.654818] Kernel Offset: disabled [ 3.658293] Memory Limit: none [ 3.661337] ---[ end Kernel panic - not syncing: HYP panic: [ 3.661337] PS:200003c9 PC:0000007ffffff820 ESR:86000005 [ 3.661337] FAR:0000007ffffff820 HPFAR:00000000003ffff0 PAR:0000000000000000 [ 3.661337] VCPU: (null) [ 3.661337] Reported-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
67f69197 |
|
27-Apr-2016 |
AKASHI Takahiro <takahiro.akashi@linaro.org> |
arm64: kvm: allows kvm cpu hotplug The current kvm implementation on arm64 does cpu-specific initialization at system boot, and has no way to gracefully shutdown a core in terms of kvm. This prevents kexec from rebooting the system at EL2. This patch adds a cpu tear-down function and also puts an existing cpu-init code into a separate function, kvm_arch_hardware_disable() and kvm_arch_hardware_enable() respectively. We don't need the arm64 specific cpu hotplug hook any more. Since this patch modifies common code between arm and arm64, one stub definition, __cpu_reset_hyp_mode(), is added on arm side to avoid compilation errors. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [Rebase, added separate VHE init/exit path, changed resets use of kvm_call_hyp() to the __version, en/disabled hardware in init_subsystems(), added icache maintenance to __kvm_hyp_reset() and removed lr restore, removed guest-enter after teardown handling] Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
6141570c |
|
05-Apr-2016 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Warn when PARange is less than 40 bits We always thought that 40bits of PA range would be the minimum people would actually build. Anything less is terrifyingly small. Turns out that we were both right and wrong. Nobody has ever built such a system, but the ARM Foundation Model has a PARange set to 36bits. Just because we can. Oh well. Now, the KVM API explicitely says that we offer a 40bit PA space to the VM, so we shouldn't run KVM on the Foundation Model at all. That being said, this patch offers a less agressive alternative, and loudly warns about the configuration being unsupported. You'll still be able to run VMs (at your own risks, though). This is just a workaround until we have a proper userspace API where we report the PARange to userspace. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
b8cfadfc |
|
24-Mar-2016 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: perf: Move PMU register related defines to asm/perf_event.h To use the ARMv8 PMU related register defines from the KVM code, we move the relevant definitions to asm/perf_event.h header file and rename them with prefix ARMV8_PMU_. This allows us to get rid of kvm_perf_event.h. Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
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#
ef769e32 |
|
24-Feb-2016 |
Adam Buchbinder <adam.buchbinder@gmail.com> |
arm64: Fix misspellings in comments. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
22b39ca3 |
|
01-Mar-2016 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Move kvm_call_hyp back to its original localtion In order to reduce the risk of a bad merge, let's move the new kvm_call_hyp back to its original location in the file. This has zero impact from a code point of view. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
bb0c70bc |
|
11-Jan-2016 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add a new vcpu device control group for PMUv3 To configure the virtual PMUv3 overflow interrupt number, we use the vcpu kvm_device ioctl, encapsulating the KVM_ARM_VCPU_PMU_V3_IRQ attribute within the KVM_ARM_VCPU_PMU_V3_CTRL group. After configuring the PMUv3, call the vcpu ioctl with attribute KVM_ARM_VCPU_PMU_V3_INIT to initialize the PMUv3. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
808e7381 |
|
11-Jan-2016 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add a new feature bit for PMUv3 To support guest PMUv3, use one bit of the VCPU INIT feature array. Initialize the PMU when initialzing the vcpu with that bit and PMU overflow interrupt set. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
d692b8ad |
|
08-Sep-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMUSERENR register This register resets as unknown in 64bit mode while it resets as zero in 32bit mode. Here we choose to reset it as zero for consistency. PMUSERENR_EL0 holds some bits which decide whether PMU registers can be accessed from EL0. Add some check helpers to handle the access from EL0. When these bits are zero, only reading PMUSERENR will trap to EL2 and writing PMUSERENR or reading/writing other PMU registers will trap to EL1 other than EL2 when HCR.TGE==0. To current KVM configuration (HCR.TGE==0) there is no way to get these traps. Here we write 0xf to physical PMUSERENR register on VM entry, so that it will trap PMU access from EL0 to EL2. Within the register access handler we check the real value of guest PMUSERENR register to decide whether this access is allowed. If not allowed, return false to inject UND to guest. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
7a0adc70 |
|
08-Sep-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMSWINC register Add access handler which emulates writing and reading PMSWINC register and add support for creating software increment event. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
76d883c4 |
|
08-Sep-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register Since the reset value of PMOVSSET and PMOVSCLR is UNKNOWN, use reset_unknown for its reset handler. Add a handler to emulate writing PMOVSSET or PMOVSCLR register. When writing non-zero value to PMOVSSET, the counter and its interrupt is enabled, kick this vcpu to sync PMU interrupt. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
9db52c78 |
|
08-Sep-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMINTENSET and PMINTENCLR register Since the reset value of PMINTENSET and PMINTENCLR is UNKNOWN, use reset_unknown for its reset handler. Add a handler to emulate writing PMINTENSET or PMINTENCLR register. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
9feb21ac |
|
22-Feb-2016 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for event type register These kind of registers include PMEVTYPERn, PMCCFILTR and PMXEVTYPER which is mapped to PMEVTYPERn or PMCCFILTR. The access handler translates all aarch32 register offsets to aarch64 ones and uses vcpu_sys_reg() to access their values to avoid taking care of big endian. When writing to these registers, create a perf_event for the selected event type. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
96b0eebc |
|
07-Sep-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMCNTENSET and PMCNTENCLR register Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use reset_unknown for its reset handler. Add a handler to emulate writing PMCNTENSET or PMCNTENCLR register. When writing to PMCNTENSET, call perf_event_enable to enable the perf event. When writing to PMCNTENCLR, call perf_event_disable to disable the perf event. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
051ff581 |
|
08-Dec-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for event counter register These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which is mapped to PMEVCNTRn. The access handler translates all aarch32 register offsets to aarch64 ones and uses vcpu_sys_reg() to access their values to avoid taking care of big endian. When reading these registers, return the sum of register value and the value perf event counts. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3965c3ce |
|
31-Aug-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMSELR register Since the reset value of PMSELR_EL0 is UNKNOWN, use reset_unknown for its reset handler. When reading PMSELR, return the PMSELR.SEL field to guest. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
ab946834 |
|
18-Jun-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Add access handler for PMCR register Add reset handler which gets host value of PMCR_EL0 and make writable bits architecturally UNKNOWN except PMCR.E which is zero. Add an access handler for PMCR. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
04fe4726 |
|
10-Sep-2015 |
Shannon Zhao <shannon.zhao@linaro.org> |
arm64: KVM: Define PMU data structure for each vcpu Here we plan to support virtual PMU for guest by full software emulation, so define some basic structs and functions preparing for futher steps. Define struct kvm_pmc for performance monitor counter and struct kvm_pmu for performance monitor unit for each vcpu. According to ARMv8 spec, the PMU contains at most 32(ARMV8_PMU_MAX_COUNTERS) counters. Since this only supports ARM64 (or PMUv3), add a separate config symbol for it. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
ad882137 |
|
29-Feb-2016 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Add temporary kvm_perf_event.h In order to merge the KVM/ARM PMU patches without creating a conflict mess, let's have a temporary include file that won't conflict with anything. Subsequent patches will clean that up. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
21a4179c |
|
22-Feb-2016 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Move __cpu_init_stage2 after kvm_call_hyp In order to ease the merge with the rest of the arm64 tree, move the definition of __cpu_init_stage2() after what will be the new kvm_call_hyp. Hopefully the resolution of the merge conflict will be obvious. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
3a3604bc |
|
29-Jan-2015 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Switch to C-based stage2 init There is no real need to leave the stage2 initialization as part of the early HYP bootstrap, and we can easily postpone it to the point where we can safely run C code. This will help VHE, which doesn't need any of this bootstrap. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
35a2491a |
|
01-Feb-2016 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Add hook for C-based stage2 init As we're about to move the stage2 init to C code, introduce some C hooks that will later be populated with arch-specific implementations. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
a0bf9776 |
|
16-Feb-2016 |
Ard Biesheuvel <ardb@kernel.org> |
arm64: kvm: deal with kernel symbols outside of linear mapping KVM on arm64 uses a fixed offset between the linear mapping at EL1 and the HYP mapping at EL2. Before we can move the kernel virtual mapping out of the linear mapping, we have to make sure that references to kernel symbols that are accessed via the HYP mapping are translated to their linear equivalent. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
9d8415d6 |
|
25-Oct-2015 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Turn system register numbers to an enum Having the system register numbers as #defines has been a pain since day one, as the ordering is pretty fragile, and moving things around leads to renumbering and epic conflict resolutions. Now that we're mostly acessing the sysreg file in C, an enum is a much better type to use, and we can clean things up a bit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
b19e6892 |
|
26-Nov-2015 |
Amit Tomar <amittomer25@gmail.com> |
KVM: arm/arm64: Count guest exit due to various reasons It would add guest exit statistics to debugfs, this can be helpful while measuring KVM performance. [ Renamed some of the field names - Christoffer ] Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
3b92830a |
|
25-Sep-2015 |
Eric Auger <eric.auger@linaro.org> |
KVM: arm/arm64: implement kvm_arm_[halt,resume]_guest We introduce kvm_arm_halt_guest and resume functions. They will be used for IRQ forward state change. Halt is synchronous and prevents the guest from being re-entered. We use the same mechanism put in place for PSCI former pause, now renamed power_off. A new flag is introduced in arch vcpu state, pause, only meant to be used by those functions. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
3781528e |
|
25-Sep-2015 |
Eric Auger <eric.auger@linaro.org> |
KVM: arm/arm64: rename pause into power_off The kvm_vcpu_arch pause field is renamed into power_off to prepare for the introduction of a new pause field. Also vcpu_pause is renamed into vcpu_sleep since we will sleep until both power_off and pause are false. Signed-off-by: Eric Auger <eric.auger@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
d35268da |
|
25-Aug-2015 |
Christoffer Dall <christoffer.dall@linaro.org> |
arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_block We currently schedule a soft timer every time we exit the guest if the timer did not expire while running the guest. This is really not necessary, because the only work we do in the timer work function is to kick the vcpu. Kicking the vcpu does two things: (1) If the vpcu thread is on a waitqueue, make it runnable and remove it from the waitqueue. (2) If the vcpu is running on a different physical CPU from the one doing the kick, it sends a reschedule IPI. The second case cannot happen, because the soft timer is only ever scheduled when the vcpu is not running. The first case is only relevant when the vcpu thread is on a waitqueue, which is only the case when the vcpu thread has called kvm_vcpu_block(). Therefore, we only need to make sure a timer is scheduled for kvm_vcpu_block(), which we do by encapsulating all calls to kvm_vcpu_block() with kvm_timer_{un}schedule calls. Additionally, we only schedule a soft timer if the timer is enabled and unmasked, since it is useless otherwise. Note that theoretically userspace can use the SET_ONE_REG interface to change registers that should cause the timer to fire, even if the vcpu is blocked without a scheduled timer, but this case was not supported before this patch and we leave it for future work for now. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
3217f7c2 |
|
27-Aug-2015 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: Add kvm_arch_vcpu_{un}blocking callbacks Some times it is useful for architecture implementations of KVM to know when the VCPU thread is about to block or when it comes back from blocking (arm/arm64 needs to know this to properly implement timers, for example). Therefore provide a generic architecture callback function in line with what we do elsewhere for KVM generic-arch interactions. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
|
#
920552b2 |
|
17-Sep-2015 |
David Hildenbrand <dahi@linux.vnet.ibm.com> |
KVM: disable halt_poll_ns as default for s390x We observed some performance degradation on s390x with dynamic halt polling. Until we can provide a proper fix, let's enable halt_poll_ns as default only for supported architectures. Architectures are now free to set their own halt_poll_ns default value. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
ef748917 |
|
02-Sep-2015 |
Ming Lei <ming.lei@canonical.com> |
arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS' This patch removes config option of KVM_ARM_MAX_VCPUS, and like other ARCHs, just choose the maximum allowed value from hardware, and follows the reasons: 1) from distribution view, the option has to be defined as the max allowed value because it need to meet all kinds of virtulization applications and need to support most of SoCs; 2) using a bigger value doesn't introduce extra memory consumption, and the help text in Kconfig isn't accurate because kvm_vpu structure isn't allocated until request of creating VCPU is sent from QEMU; 3) the main effect is that the field of vcpus[] in 'struct kvm' becomes a bit bigger(sizeof(void *) per vcpu) and need more cache lines to hold the structure, but 'struct kvm' is one generic struct, and it has worked well on other ARCHs already in this way. Also, the world switch frequecy is often low, for example, it is ~2000 when running kernel building load in VM from APM xgene KVM host, so the effect is very small, and the difference can't be observed in my test at all. Cc: Dann Frazier <dann.frazier@canonical.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
62bea5bf |
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15-Sep-2015 |
Paolo Bonzini <pbonzini@redhat.com> |
KVM: add halt_attempted_poll to VCPU stats This new statistic can help diagnosing VCPUs that, for any reason, trigger bad behavior of halt_poll_ns autotuning. For example, say halt_poll_ns = 480000, and wakeups are spaced exactly like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes 10+20+40+80+160+320+480 = 1110 microseconds out of every 479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then is consuming about 30% more CPU than it would use without polling. This would show as an abnormally high number of attempted polling compared to the successful polls. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com< Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
48f8bd57 |
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28-Jul-2015 |
Vladimir Murzin <Vladimir.Murzin@arm.com> |
arm64: KVM: remove remaining reference to vgic_sr_vectors Since commit 8a14849 (arm64: KVM: Switch vgic save/restore to alternative_insn) vgic_sr_vectors is not used anymore, so remove remaining leftovers and kill the structure. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
834bf887 |
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07-Jul-2015 |
Alex Bennée <alex.bennee@linaro.org> |
KVM: arm64: enable KVM_CAP_SET_GUEST_DEBUG Finally advertise the KVM capability for SET_GUEST_DEBUG. Once arm support is added this check can be moved to the common kvm_vm_ioctl_check_extension() code. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
84e690bf |
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07-Jul-2015 |
Alex Bennée <alex.bennee@linaro.org> |
KVM: arm64: introduce vcpu->arch.debug_ptr This introduces a level of indirection for the debug registers. Instead of using the sys_regs[] directly we store registers in a structure in the vcpu. The new kvm_arm_reset_debug_ptr() sets the debug ptr to the guest context. Because we no longer give the sys_regs offset for the sys_reg_desc->reg field, but instead the index into a debug-specific struct we need to add a number of additional trap functions for each register. Also as the generic generic user-space access code no longer works we have introduced a new pair of function pointers to the sys_reg_desc structure to override the generic code when needed. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
337b99bf |
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07-Jul-2015 |
Alex Bennée <alex.bennee@linaro.org> |
KVM: arm64: guest debug, add support for single-step This adds support for single-stepping the guest. To do this we need to manipulate the guests PSTATE.SS and MDSCR_EL1.SS bits to trigger stepping. We take care to preserve MDSCR_EL1 and trap access to it to ensure we don't affect the apparent state of the guest. As we have to enable trapping of all software debug exceptions we suppress the ability of the guest to single-step itself. If we didn't we would have to deal with the exception arriving while the guest was in kernelspace when the guest is expecting to single-step userspace. This is something we don't want to unwind in the kernel. Once the host is no longer debugging the guest its ability to single-step userspace is restored. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
56c7f5e7 |
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07-Jul-2015 |
Alex Bennée <alex.bennee@linaro.org> |
KVM: arm: introduce kvm_arm_init/setup/clear_debug This is a precursor for later patches which will need to do more to setup debug state before entering the hyp.S switch code. The existing functionality for setting mdcr_el2 has been moved out of hyp.S and now uses the value kept in vcpu->arch.mdcr_el2. As the assembler used to previously mask and preserve MDCR_EL2.HPMN I've had to add a mechanism to save the value of mdcr_el2 as a per-cpu variable during the initialisation code. The kernel never sets this number so we are assuming the bootcode has set up the correct value here. This also moves the conditional setting of the TDA bit from the hyp code into the C code which is currently used for the lazy debug register context switch code. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
8a14849b |
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11-Jun-2015 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: Switch vgic save/restore to alternative_insn So far, we configured the world-switch by having a small array of pointers to the save and restore functions, depending on the GIC used on the platform. Loading these values each time is a bit silly (they never change), and it makes sense to rely on the instruction patching instead. This leads to a nice cleanup of the code. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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#
35307b9a |
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12-Mar-2015 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Implement Stage-2 page aging Until now, KVM/arm didn't care much for page aging (who was swapping anyway?), and simply provided empty hooks to the core KVM code. With server-type systems now being available, things are quite different. This patch implements very simple support for page aging, by clearing the Access flag in the Stage-2 page tables. On access fault, the current fault handling will write the PTE or PMD again, putting the Access flag back on. It should be possible to implement a much faster handling for Access faults, but that's left for a later patch. With this in place, performance in VMs is degraded much more gracefully. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
c1426e4c |
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04-Mar-2015 |
Eric Auger <eric.auger@linaro.org> |
KVM: arm/arm64: implement kvm_arch_intc_initialized On arm/arm64 the VGIC is dynamically instantiated and it is useful to expose its state, especially for irqfd setup. This patch defines __KVM_HAVE_ARCH_INTC_INITIALIZED and implements kvm_arch_intc_initialized. Signed-off-by: Eric Auger <eric.auger@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
f7819512 |
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04-Feb-2015 |
Paolo Bonzini <pbonzini@redhat.com> |
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
3c1e7165 |
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19-Dec-2014 |
Marc Zyngier <maz@kernel.org> |
arm/arm64: KVM: Use set/way op trapping to track the state of the caches Trying to emulate the behaviour of set/way cache ops is fairly pointless, as there are too many ways we can end-up missing stuff. Also, there is some system caches out there that simply ignore set/way operations. So instead of trying to implement them, let's convert it to VA ops, and use them as a way to re-enable the trapping of VM ops. That way, we can detect the point when the MMU/caches are turned off, and do a full VM flush (which is what the guest was trying to do anyway). This allows a 32bit zImage to boot on the APM thingy, and will probably help bootloaders in general. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
3caa2d8c |
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02-Jun-2014 |
Andre Przywara <andre.przywara@arm.com> |
arm/arm64: KVM: make the maximum number of vCPUs a per-VM value Currently the maximum number of vCPUs supported is a global value limited by the used GIC model. GICv3 will lift this limit, but we still need to observe it for guests using GICv2. So the maximum number of vCPUs is per-VM value, depending on the GIC model the guest uses. Store and check the value in struct kvm_arch, but keep it down to 8 for now. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
4429fc64 |
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02-Jun-2014 |
Andre Przywara <andre.przywara@arm.com> |
arm/arm64: KVM: rework MPIDR assignment and add accessors The virtual MPIDR registers (containing topology information) for the guest are currently mapped linearily to the vcpu_id. Improve this mapping for arm64 by using three levels to not artificially limit the number of vCPUs. To help this, change and rename the kvm_vcpu_get_mpidr() function to mask off the non-affinity bits in the MPIDR register. Also add an accessor to later allow easier access to a vCPU with a given MPIDR. Use this new accessor in the PSCI emulation. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
8199ed0e |
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15-Jan-2015 |
Mario Smarduch <m.smarduch@samsung.com> |
KVM: arm64: ARMv8 header changes for page logging This patch adds arm64 helpers to write protect pmds/ptes and retrieve permissions while logging dirty pages. Also adds prototype to write protect a memory slot and adds a pmd define to check for read-only pmds. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
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#
cf5d3188 |
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16-Oct-2014 |
Christoffer Dall <christoffer.dall@linaro.org> |
arm/arm64: KVM: Turn off vcpus on PSCI shutdown/reboot When a vcpu calls SYSTEM_OFF or SYSTEM_RESET with PSCI v0.2, the vcpus should really be turned off for the VM adhering to the suggestions in the PSCI spec, and it's the sane thing to do. Also, clarify the behavior and expectations for exits to user space with the KVM_EXIT_SYSTEM_EVENT case. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
f7fa034d |
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16-Oct-2014 |
Christoffer Dall <christoffer.dall@linaro.org> |
arm/arm64: KVM: Clarify KVM_ARM_VCPU_INIT ABI It is not clear that this ioctl can be called multiple times for a given vcpu. Userspace already does this, so clarify the ABI. Also specify that userspace is expected to always make secondary and subsequent calls to the ioctl with the same parameters for the VCPU as the initial call (which userspace also already does). Add code to check that userspace doesn't violate that ABI in the future, and move the kvm_vcpu_set_target() function which is currently duplicated between the 32-bit and 64-bit versions in guest.c to a common static function in arm.c, shared between both architectures. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
fe71557a |
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24-Sep-2014 |
Tang Chen <tangchen@cn.fujitsu.com> |
kvm: Add arch specific mmu notifier for page invalidation This will be used to let the guest run while the APIC access page is not pinned. Because subsequent patches will fill in the function for x86, place the (still empty) x86 implementation in the x86.c file instead of adding an inline function in kvm_host.h. Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
57128468 |
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22-Sep-2014 |
Andres Lagar-Cavilla <andreslc@google.com> |
kvm: Fix page ageing bugs 1. We were calling clear_flush_young_notify in unmap_one, but we are within an mmu notifier invalidate range scope. The spte exists no more (due to range_start) and the accessed bit info has already been propagated (due to kvm_pfn_set_accessed). Simply call clear_flush_young. 2. We clear_flush_young on a primary MMU PMD, but this may be mapped as a collection of PTEs by the secondary MMU (e.g. during log-dirty). This required expanding the interface of the clear_flush_young mmu notifier, so a lot of code has been trivially touched. 3. In the absence of shadow_accessed_mask (e.g. EPT A bit), we emulate the access bit by blowing the spte. This requires proper synchronizing with MMU notifier consumers, like every other removal of spte's does. Signed-off-by: Andres Lagar-Cavilla <andreslc@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
13a34e06 |
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28-Aug-2014 |
Radim Krčmář <rkrcmar@redhat.com> |
KVM: remove garbage arg to *hardware_{en,dis}able In the beggining was on_each_cpu(), which required an unused argument to kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten. Remove unnecessary arguments that stem from this. Signed-off-by: Radim KrÄmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
0865e636 |
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28-Aug-2014 |
Radim Krčmář <rkrcmar@redhat.com> |
KVM: static inline empty kvm_arch functions Using static inline is going to save few bytes and cycles. For example on powerpc, the difference is 700 B after stripping. (5 kB before) This patch also deals with two overlooked empty functions: kvm_arch_flush_shadow was not removed from arch/mips/kvm/mips.c 2df72e9bc KVM: split kvm_arch_flush_shadow and kvm_arch_sched_in never made it into arch/ia64/kvm/kvm-ia64.c. e790d9ef6 KVM: add kvm_arch_sched_in Signed-off-by: Radim KrÄmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
65647300 |
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29-Aug-2014 |
Paolo Bonzini <pbonzini@redhat.com> |
KVM: forward declare structs in kvm_types.h Opaque KVM structs are useful for prototypes in asm/kvm_host.h, to avoid "'struct foo' declared inside parameter list" warnings (and consequent breakage due to conflicting types). Move them from individual files to a generic place in linux/kvm_types.h. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
4000be42 |
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26-Aug-2014 |
Will Deacon <will@kernel.org> |
KVM: ARM/arm64: fix broken __percpu annotation Running sparse results in a bunch of noisy address space mismatches thanks to the broken __percpu annotation on kvm_get_running_vcpus. This function returns a pcpu pointer to a pointer, not a pointer to a pcpu pointer. This patch fixes the annotation, which kills the warnings from sparse. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
6951e48b |
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26-Aug-2014 |
Will Deacon <will@kernel.org> |
KVM: ARM/arm64: fix non-const declaration of function returning const Sparse kicks up about a type mismatch for kvm_target_cpu: arch/arm64/kvm/guest.c:271:25: error: symbol 'kvm_target_cpu' redeclared with different type (originally declared at ./arch/arm64/include/asm/kvm_host.h:45) - different modifiers so fix this by adding the missing const attribute to the function declaration. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
dedf97e8 |
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31-Jul-2014 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: fix 64bit CP15 VM access for 32bit guests Commit f0a3eaff71b8 (ARM64: KVM: fix big endian issue in access_vm_reg for 32bit guest) changed the way we handle CP15 VM accesses, so that all 64bit accesses are done via vcpu_sys_reg. This looks like a good idea as it solves indianness issues in an elegant way, except for one small detail: the register index is doesn't refer to the same array! We end up corrupting some random data structure instead. Fix this by reverting to the original code, except for the introduction of a vcpu_cp15_64_high macro that deals with the endianness thing. Tested on Juno with 32bit SMP guests. Cc: Victor Kamensky <victor.kamensky@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
72564016 |
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24-Apr-2014 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: common infrastructure for handling AArch32 CP14/CP15 As we're about to trap a bunch of CP14 registers, let's rework the CP15 handling so it can be generalized and work with multiple tables. Reviewed-by: Anup Patel <anup.patel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
0c557ed4 |
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24-Apr-2014 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: add trap handlers for AArch64 debug registers Add handlers for all the AArch64 debug registers that are accessible from EL0 or EL1. The trapping code keeps track of the state of the debug registers, allowing for the switch code to implement a lazy switching strategy. Reviewed-by: Anup Patel <anup.patel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
f0a3eaff |
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02-Jul-2014 |
Victor Kamensky <victor.kamensky@linaro.org> |
ARM64: KVM: fix big endian issue in access_vm_reg for 32bit guest Fix issue with 32bit guests running on top of BE KVM host. Indexes of high and low words of 64bit cp15 register are swapped in case of big endian code, since 64bit cp15 state is restored or saved with double word write or read instruction. Define helper macro to access low words of 64bit cp15 register. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
67b2abfe |
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09-Jul-2013 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: vgic: enable GICv2 emulation on top on GICv3 hardware Add the last missing bits that enable GICv2 emulation on top of GICv3 hardware. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
1a9b1305 |
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21-Jun-2013 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: split GICv2 world switch from hyp code Move the GICv2 world switch code into its own file, and add the necessary indirection to the arm64 switch code. Also introduce a new type field to the vgic_params structure. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
7d0f84aa |
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28-Apr-2014 |
Anup Patel <anup.patel@linaro.org> |
ARM/ARM64: KVM: Add base for PSCI v0.2 emulation Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to VCPUs. This patch extends current in-kernel PSCI emulation to provide PSCI v0.2 interface to VCPUs. By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for keeping the ABI backward-compatible. To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU init using KVM_ARM_VCPU_INIT ioctl. Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
da781470 |
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12-Dec-2013 |
Anup Patel <anup.patel@linaro.org> |
arm64: KVM: Add Kconfig option for max VCPUs per-Guest Current max VCPUs per-Guest is set to 4 which is preventing us from creating a Guest (or VM) with 8 VCPUs on Host (e.g. X-Gene Storm SOC) with 8 Host CPUs. The correct value of max VCPUs per-Guest should be same as the max CPUs supported by GICv2 which is 8 but, increasing value of max VCPUs per-Guest can make things slower hence we add Kconfig option to let KVM users select appropriate max VCPUs per-Guest. Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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#
ef0cfe71 |
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02-Oct-2013 |
Christoffer Dall <christoffer.dall@linaro.org> |
KVM: arm64: Get rid of KVM_HPAGE defines Now when the main kvm code relying on these defines has been moved to the x86 specific part of the world, we can get rid of these. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Gleb Natapov <gleb@redhat.com>
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#
473bdc0e |
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30-Sep-2013 |
Anup Patel <anup.patel@linaro.org> |
ARM64: KVM: Implement kvm_vcpu_preferred_target() function This patch implements kvm_vcpu_preferred_target() function for KVM ARM64 which will help us implement KVM_ARM_PREFERRED_TARGET ioctl for user space. Signed-off-by: Anup Patel <anup.patel@linaro.org> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
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#
6c8c0c4d |
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21-Jul-2013 |
Chen Gang <gang.chen@asianux.com> |
arm64: KVM: use 'int' instead of 'u32' for variable 'target' in kvm_host.h. 'target' will be set to '-1' in kvm_arch_vcpu_init(), and it need check 'target' whether less than zero or not in kvm_vcpu_initialized(). So need define target as 'int' instead of 'u32', just like ARM has done. The related warning: arch/arm64/kvm/../../../arch/arm/kvm/arm.c:497:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits] Signed-off-by: Chen Gang <gang.chen@asianux.com> [Marc: reformated the Subject line to fit the series] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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0d854a60 |
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07-Feb-2013 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: enable initialization of a 32bit vcpu Wire the init of a 32bit vcpu by allowing 32bit modes in pstate, and providing sensible defaults out of reset state. This feature is of course conditioned by the presence of 32bit capability on the physical CPU, and is checked by the KVM_CAP_ARM_EL1_32BIT capability. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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40033a61 |
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06-Feb-2013 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: define 32bit specific registers Define the 32bit specific registers (SPSRs, cp15...). Most CPU registers are directly mapped to a 64bit register (r0->x0...). Only the SPSRs have separate registers. cp15 registers are also mapped into their 64bit counterpart in most cases. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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dcd2e40c |
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12-Dec-2012 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: PSCI implementation Wire the PSCI backend into the exit handling code. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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092bd143 |
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17-Dec-2012 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: hypervisor initialization code Provide EL2 with page tables and stack, and set the vectors to point to the full blown world-switch code. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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4f8d6632 |
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10-Dec-2012 |
Marc Zyngier <maz@kernel.org> |
arm64: KVM: kvm_arch and kvm_vcpu_arch definitions Provide the architecture dependent structures for VM and vcpu abstractions. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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