[PATCH 0/2] KVM: arm64: Drop support for VPIPT i-cache policy

[Marc Zyngier]

ARMv8.2 introduced support for VPIPT i-caches, the V standing for
VMID-tagged. Although this looks like a reasonable idea, no
implementation has ever made it into the wild.

Linux has supported this for almost 6 years (amusingly, just as the
architecture was dropping support for AVIVT i-caches), but we have no
way to even test it, and it is likely that this code is just
bit-rotting. This isn't great.

Since this only impacts KVM, let's drop the support from the
hypervisor. The kernel itself can still work as a guest on such a
system, assuming that there is HW and a hypervisor that supports this
architecture variation.

On the other hand, if you are aware of such an implementation and can
actively test KVM on this setup, please shout!

	M.

Marc Zyngier (2):
  KVM: arm64: Disable KVM on systems with a VPIPT i-cache
  KVM: arm64: Remove VPIPT I-cache handling

 arch/arm64/include/asm/kvm_mmu.h |  3 +--
 arch/arm64/kvm/arm.c             |  5 +++++
 arch/arm64/kvm/hyp/nvhe/tlb.c    | 35 --------------------------------
 arch/arm64/kvm/hyp/vhe/tlb.c     | 13 ------------
 4 files changed, 6 insertions(+), 50 deletions(-)

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2.34.1