On 5/7/2024 11:58 PM, Paolo Bonzini wrote:
From: Sean Christopherson <seanjc@xxxxxxxxxx>
WARN and skip the emulated MMIO fastpath if a private, reserved page fault
is encountered, as private+reserved should be an impossible combination
(KVM should never create an MMIO SPTE for a private access).
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-ID: <20240228024147.41573-9-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d52794663290..0d884d0b0f35 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5819,6 +5819,9 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err
r = RET_PF_INVALID;
if (unlikely(error_code & PFERR_RSVD_MASK)) {
+ if (WARN_ON_ONCE(error_code & PFERR_PRIVATE_ACCESS))
+ return -EFAULT;
+
r = handle_mmio_page_fault(vcpu, cr2_or_gpa, direct);
if (r == RET_PF_EMULATE)
goto emulate;
