diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-04-15 03:49:09 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-04-29 19:49:16 +0300 |
| commit | 65936229d35883a1637730e628c3c84d3600025d (patch) | |
| tree | 012780c67025c690ff3ec8d56fcceb543afd8f8e | |
| parent | 296d5a17e793956f7b914336422043c939263409 (diff) | |
| download | linux-65936229d35883a1637730e628c3c84d3600025d.tar.xz | |
KVM: x86/mmu: Check for host MMIO exclusion from mem encrypt iff necessary
When determining whether or not a SPTE needs to have SME/SEV's memory
encryption flag set, do the moderately expensive 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@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220415004909.2216670-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/mmu/spte.c | 2 |
1 files changed, 1 insertions, 1 deletions
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; |