When determining whether or not a SPTE needs to have SME/SEV's memory encryption flag set, do the moderately expension host MMIO pfn check if and only if the memory encryption mask is non-zero. Note, KVM could further optimize the host MMIO checks by making a single call to kvm_is_mmio_pfn(), but the tdp_enabled path (for EPT's memtype handling) will likely be split out to a separate flow[*]. At that point, a better approach would be to shove the call to kvm_is_mmio_pfn() into VMX code so that AMD+NPT without SME doesn't get hit with an unnecessary lookup. [*] https://lkml.kernel.org/r/20220321224358.1305530-3-bgardon@xxxxxxxxxx Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- arch/x86/kvm/mmu/spte.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 4739b53c9734..aab78574e03d 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -139,7 +139,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, else pte_access &= ~ACC_WRITE_MASK; - if (!kvm_is_mmio_pfn(pfn)) + if (shadow_me_mask && !kvm_is_mmio_pfn(pfn)) spte |= shadow_me_mask; spte |= (u64)pfn << PAGE_SHIFT; base-commit: 150866cd0ec871c765181d145aa0912628289c8a -- 2.36.0.rc0.470.gd361397f0d-goog
