diff mbox series

[09/17] KVM: x86/mmu: WARN and skip MMIO cache on private, reserved page faults

Message ID 20240507155817.3951344-10-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86/mmu: Page fault and MMIO cleanups | expand

Commit Message

Paolo Bonzini May 7, 2024, 3:58 p.m. UTC
From: Sean Christopherson <seanjc@google.com>

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@google.com>
Message-ID: <20240228024147.41573-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Xiaoyao Li May 13, 2024, 6:15 a.m. UTC | #1
On 5/7/2024 11:58 PM, Paolo Bonzini wrote:
> From: Sean Christopherson <seanjc@google.com>
> 
> 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@google.com>
> Message-ID: <20240228024147.41573-9-seanjc@google.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>

> ---
>   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;
diff mbox series

Patch

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;