KVM: SVM: Explicitly mark vmcb01 dirty after modifying VMCB intercepts

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@vger.kernel.org
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Link: https://patch.msgid.link/20260218230958.2877682-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 1c5f0f08bb8c9dce3e87864660669bda00806564..5b639d98bf09d83d2374801c7a7541c147e1e001 100644 (file)
--- 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;