From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Explicitly check for an MMIO spte in the fast page fault flow. TDX will use a not-present entry for MMIO sptes, which can be mistaken for an access-tracked spte since both have SPTE_SPECIAL_MASK set. The fast page fault handles the case of changing access bits without obtaining mmu_lock. For example, clear write protect bit for dirty page tracking. MMIO emulation is handled in a slow path. So it doesn't affect the default VM case. Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> --- arch/x86/kvm/mmu/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index b68191aa39bf..9907cb759fd1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3167,7 +3167,7 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) break; sp = sptep_to_sp(sptep); - if (!is_last_spte(spte, sp->role.level)) + if (!is_last_spte(spte, sp->role.level) || is_mmio_spte(spte)) break; /* -- 2.25.1
