KVM: x86/mmu: Add helpers to return if KVM honors guest MTRRs

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Add helpers to check if KVM honors guest MTRRs instead of open coding the
logic in kvm_tdp_page_fault().  Future fixes and cleanups will also need
to determine if KVM should honor guest MTRRs, e.g. for CR0.CD toggling and
and non-coherent DMA transitions.

Provide an inner helper, __kvm_mmu_honors_guest_mtrrs(), so that KVM can
check if guest MTRRs were honored when stopping non-coherent DMA.

Note, there is no need to explicitly check that TDP is enabled, KVM clears
shadow_memtype_mask when TDP is disabled, i.e. it's non-zero if and only
if EPT is enabled.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/r/20230714065006.20201-1-yan.y.zhao@intel.com
Link: https://lore.kernel.org/r/20230714065043.20258-1-yan.y.zhao@intel.com
[sean: squash into a one patch, drop explicit TDP check massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

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This commit is contained in:

Yan Zhao 2023-07-14 14:50:06 +08:00 • committed by Sean Christopherson

parent 5804c19b80

commit 1affe455d6

2 changed files with 23 additions and 9 deletions

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7

arch/x86/kvm/mmu.h

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25

arch/x86/kvm/mmu/mmu.c

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