KVM: arm64: vgic-v3: Use u32 to manage the line level from userspace

Despite the userspace ABI clearly defining the bits dealt with by
KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO as a __u32, the kernel uses a u64.

Use a u32 to match the userspace ABI, which will subsequently lead
to some simplifications.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

KVM: arm64: Don't read a HW interrupt pending state in user context

Since 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state
from the HW"), we're able to source the pending bit for an interrupt
that is stored either on the physical distributor or on a device.

However, this state is only available when the vcpu is loaded,
and is not intended to be accessed from userspace. Unfortunately,
the GICv2 emulation doesn't provide specific userspace accessors,
and we fallback with the ones that are intended for the guest,
with fatal consequences.

Add a new vgic_uaccess_read_pending() accessor for userspace
to use, build on top of the existing vgic_mmio_read_pending().

Reported-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Fixes: 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW")
Link: https://lore.kernel.org/r/20220607131427.1164881-2-maz@kernel.org
Cc: stable@vger.kernel.org

KVM: arm64: Constify kvm_io_gic_ops

The only usage of kvm_io_gic_ops is to make a comparison with its
address and to pass its address to kvm_iodevice_init() which takes a
pointer to const kvm_io_device_ops as input. Make it const to allow the
compiler to put it in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211204213518.83642-1-rikard.falkeborn@gmail.com

KVM: arm64: Move virt/kvm/arm to arch/arm64

Now that the 32bit KVM/arm host is a distant memory, let's move the
whole of the KVM/arm64 code into the arm64 tree.

As they said in the song: Welcome Home (Sanitarium).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org