KVM: VMX: Fix check for valid GVA on an EPT violation

[PATCH] KVM: VMX: Fix check for valid GVA on an EPT violation

Posted by Sukrit Bhatnagar 3 months ago

On an EPT violation, bit 7 of the exit qualification is set if the
guest linear-address is valid. The derived page fault error code
should not be checked for this bit.

Fixes: f3009482512e ("KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid")
Signed-off-by: Sukrit Bhatnagar <Sukrit.Bhatnagar@sony.com>
---
 arch/x86/kvm/vmx/common.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
index bc5ece76533a..412d0829d7a2 100644
--- a/arch/x86/kvm/vmx/common.h
+++ b/arch/x86/kvm/vmx/common.h
@@ -98,7 +98,7 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
 	error_code |= (exit_qualification & EPT_VIOLATION_PROT_MASK)
 		      ? PFERR_PRESENT_MASK : 0;
 
-	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
+	if (exit_qualification & EPT_VIOLATION_GVA_IS_VALID)
 		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
 			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
 
-- 
2.43.0

Re: [PATCH] KVM: VMX: Fix check for valid GVA on an EPT violation

Posted by Sean Christopherson 2 months, 4 weeks ago

On Thu, 06 Nov 2025 14:28:51 +0900, Sukrit Bhatnagar wrote:
> On an EPT violation, bit 7 of the exit qualification is set if the
> guest linear-address is valid. The derived page fault error code
> should not be checked for this bit.

Applied to kvm-x86 fixes (and it's in now in kvm/master as this "thank you" is
coming a bit late).  Thanks!

[1/1] KVM: VMX: Fix check for valid GVA on an EPT violation
      https://github.com/kvm-x86/linux/commit/d0164c161923

--
https://github.com/kvm-x86/linux/tree/next

Re: [PATCH] KVM: VMX: Fix check for valid GVA on an EPT violation

Posted by Xiaoyao Li 3 months ago

On 11/6/2025 1:28 PM, Sukrit Bhatnagar wrote:
> On an EPT violation, bit 7 of the exit qualification is set if the
> guest linear-address is valid. The derived page fault error code
> should not be checked for this bit.
> 
> Fixes: f3009482512e ("KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid")
> Signed-off-by: Sukrit Bhatnagar <Sukrit.Bhatnagar@sony.com>

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

> ---
>   arch/x86/kvm/vmx/common.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
> index bc5ece76533a..412d0829d7a2 100644
> --- a/arch/x86/kvm/vmx/common.h
> +++ b/arch/x86/kvm/vmx/common.h
> @@ -98,7 +98,7 @@ static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
>   	error_code |= (exit_qualification & EPT_VIOLATION_PROT_MASK)
>   		      ? PFERR_PRESENT_MASK : 0;
>   
> -	if (error_code & EPT_VIOLATION_GVA_IS_VALID)
> +	if (exit_qualification & EPT_VIOLATION_GVA_IS_VALID)
>   		error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) ?
>   			      PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
>