s390: fix various typos

Fix various typos found with codespell.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

KVM: s390: pci: fix virtual-physical confusion on module unload/load

When the kvm module is unloaded, zpci_setup_aipb() perists some data in the
zpci_aipb structure in s390 pci code. Note that this struct is also passed
to firmware in the zpci_set_irq_ctrl() call and thus the GAIT must be a
physical address.

On module re-insertion, the GAIT is restored from this structure in
zpci_reset_aipb(). But it is a physical address, hence this may cause
issues when the kvm module is unloaded and loaded again.

Fix virtual vs physical address confusion (which currently are the same) by
adding the necessary physical-to-virtual-conversion in zpci_reset_aipb().

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20230222155503.43399-1-nrb@linux.ibm.com
Message-Id: <20230222155503.43399-1-nrb@linux.ibm.com>

KVM: s390: Mark __kvm_s390_init() and its descendants as __init

Tag __kvm_s390_init() and its unique helpers as __init. These functions
are only ever called during module_init(), but could not be tagged
accordingly while they were invoked from the common kvm_arch_init(),
which is not __init because of x86.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20221130230934.1014142-29-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

iommu/s390: Make attach succeed even if the device is in error state

If a zPCI device is in the error state while switching IOMMU domains
zpci_register_ioat() will fail and we would end up with the device not
attached to any domain. In this state since zdev->dma_table == NULL
a reset via zpci_hot_reset_device() would wrongfully re-initialize the
device for DMA API usage using zpci_dma_init_device(). As automatic
recovery is currently disabled while attached to an IOMMU domain this
only affects slot resets triggered through other means but will affect
automatic recovery once we switch to using dma-iommu.

Additionally with that switch common code expects attaching to the
default domain to always work so zpci_register_ioat() should only fail
if there is no chance to recover anyway, e.g. if the device has been
unplugged.

Improve the robustness of attach by specifically looking at the status
returned by zpci_mod_fc() to determine if the device is unavailable and
in this case simply ignore the error. Once the device is reset
zpci_hot_reset_device() will then correctly set the domain's DMA
translation tables.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221109142903.4080275-2-schnelle@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

KVM: s390: pci: Fix allocation size of aift kzdev elements

The 'kzdev' field of struct 'zpci_aift' is an array of pointers to
'kvm_zdev' structs. Allocate the proper size accordingly.

Reported by Coccinelle:
WARNING: Use correct pointer type argument for sizeof

Fixes: 98b1d33dac5f ("KVM: s390: pci: do initial setup for AEN interpretation")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221026013234.960859-1-rafaelmendsr@gmail.com
Message-Id: <20221026013234.960859-1-rafaelmendsr@gmail.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

KVM: s390: pci: register pci hooks without interpretation

The kvm registration hooks must be registered even if the facilities
necessary for zPCI interpretation are unavailable, as vfio-pci-zdev will
expect to use the hooks regardless.
This fixes an issue where vfio-pci-zdev will fail its open function
because of a missing kvm_register when running on hardware that does not
support zPCI interpretation.

Fixes: ca922fecda6c ("KVM: s390: pci: Hook to access KVM lowlevel from VFIO")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20220920193025.135655-1-mjrosato@linux.ibm.com
Message-Id: <20220920193025.135655-1-mjrosato@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

KVM: s390: pci: fix GAIT physical vs virtual pointers usage

The GAIT and all of its entries must be represented by physical
addresses as this structure is shared with underlying firmware.
We can keep a virtual address of the GAIT origin in order to
handle processing in the kernel, but when traversing the entries
we must again convert the physical AISB stored in that GAIT entry
into a virtual address in order to process it.

Note: this currently doesn't fix a real bug, since virtual addresses
are indentical to physical ones.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Acked-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220907155952.87356-1-mjrosato@linux.ibm.com
Message-Id: <20220907155952.87356-1-mjrosato@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

KVM: s390: pci: fix plain integer as NULL pointer warnings

Fix some sparse warnings that a plain integer 0 is being used instead of
NULL.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220915175514.167899-1-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

KVM: s390: pci: Hook to access KVM lowlevel from VFIO

We have a cross dependency between KVM and VFIO when using
s390 vfio_pci_zdev extensions for PCI passthrough
To be able to keep both subsystem modular we add a registering
hook inside the S390 core code.

This fixes a build problem when VFIO is built-in and KVM is built
as a module.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Fixes: 09340b2fca007 ("KVM: s390: pci: add routines to start/stop interpretive execution")
Cc: <stable@vger.kernel.org>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20220819122945.9309-1-pmorel@linux.ibm.com
Message-Id: <20220819122945.9309-1-pmorel@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

KVM: s390: add KVM_S390_ZPCI_OP to manage guest zPCI devices

The KVM_S390_ZPCI_OP ioctl provides a mechanism for managing
hardware-assisted virtualization features for s390x zPCI passthrough.
Add the first 2 operations, which can be used to enable/disable
the specified device for Adapter Event Notification interpretation.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20220606203325.110625-21-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

KVM: s390: pci: add routines to start/stop interpretive execution

These routines will be invoked at the time an s390x vfio-pci device is
associated with a KVM (or when the association is removed), allowing
the zPCI device to enable or disable load/store intepretation mode;
this requires the host zPCI device to inform firmware of the unique
token (GISA designation) that is associated with the owning KVM.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-17-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding

These routines will be wired into a kvm ioctl in order to respond to
requests to enable / disable a device for Adapter Event Notifications /
Adapter Interuption Forwarding.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-16-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

KVM: s390: pci: do initial setup for AEN interpretation

Initial setup for Adapter Event Notification Interpretation for zPCI
passthrough devices. Specifically, allocate a structure for forwarding of
adapter events and pass the address of this structure to firmware.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-13-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

KVM: s390: pci: add basic kvm_zdev structure

This structure will be used to carry kvm passthrough information related to
zPCI devices.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-12-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>