[RFC PATCH 35/67] KVM: x86/mmu: Explicitly check for MMIO spte in fast page fault

[isaku . yamahata]

From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

Explicity 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.

Signed-off-by: Sean Christopherson <sean.j.christopherson@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 76de8d48165d..c4d657b26066 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3090,7 +3090,7 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 				break;
 
 		sp = sptep_to_sp(iterator.sptep);
-		if (!is_last_spte(spte, sp->role.level))
+		if (!is_last_spte(spte, sp->role.level) || is_mmio_spte(spte))
 			break;
 
 		/*
-- 
2.17.1