Re: [PATCH v2 1/8] KVM: SVM: Explicitly mark vmcb01 dirty after modifying VMCB intercepts

[Yosry Ahmed]

On Wed, Feb 18, 2026 at 03:09:51PM -0800, Sean Christopherson wrote:
> When reacting to an intercept update, explicitly mark vmcb01's intercepts
> dirty, as KVM always initially operates on vmcb01, and nested_svm_vmexit()
> isn't guaranteed to mark VMCB_INTERCEPTS as dirty.  I.e. if L2 is active,
> KVM will modify the intercepts for L1, but might not mark them as dirty
> before the next VMRUN of L1.
> 
> Fixes: 116a0a23676e ("KVM: SVM: Add clean-bit for intercetps, tsc-offset and pause filter count")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Reviewed-by: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>

> ---
>  arch/x86/kvm/svm/nested.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index de90b104a0dd..66701106a51b 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -128,11 +128,13 @@ void recalc_intercepts(struct vcpu_svm *svm)
>  	struct vmcb_ctrl_area_cached *g;
>  	unsigned int i;
>  
> -	vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
> +	vmcb_mark_dirty(svm->vmcb01.ptr, VMCB_INTERCEPTS);
>  
>  	if (!is_guest_mode(&svm->vcpu))
>  		return;
>  
> +	vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
> +
>  	c = &svm->vmcb->control;
>  	h = &svm->vmcb01.ptr->control;
>  	g = &svm->nested.ctl;
> -- 
> 2.53.0.345.g96ddfc5eaa-goog
>