KVM: SVM: WARN if an invalid posted interrupt IRTE entry is added

Now that the AMD IOMMU doesn't signal success incorrectly, WARN if KVM
attempts to track an AMD IRTE entry without metadata.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20250404193923.1413163-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 8e09f6ae98fd997cda6c5ae15325073f5efa91da..7338879d1c0c48098e37b6344b16d96eaba5b2c1 100644 (file)
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -796,12 +796,15 @@ static int svm_ir_list_add(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi)
        struct amd_svm_iommu_ir *ir;
        u64 entry;
 
+       if (WARN_ON_ONCE(!pi->ir_data))
+               return -EINVAL;
+
        /**
         * In some cases, the existing irte is updated and re-set,
         * so we need to check here if it's already been * added
         * to the ir_list.
         */
-       if (pi->ir_data && (pi->prev_ga_tag != 0)) {
+       if (pi->prev_ga_tag) {
                struct kvm *kvm = svm->vcpu.kvm;
                u32 vcpu_id = AVIC_GATAG_TO_VCPUID(pi->prev_ga_tag);
                struct kvm_vcpu *prev_vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);