KVM: SVM: Fix nested nmi handling

The patch introducing nested nmi handling had a bug. The
check does not belong to enable_nmi_window but must be in
nmi_allowed. This patch fixes this.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ab78eb8ba899..ec205847be6a 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2771,8 +2771,12 @@ static int svm_nmi_allowed(struct kvm_vcpu *vcpu)
 {
         struct vcpu_svm *svm = to_svm(vcpu);
         struct vmcb *vmcb = svm->vmcb;
-        return !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
-                !(svm->vcpu.arch.hflags & HF_NMI_MASK);
+        int ret;
+        ret = !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
+              !(svm->vcpu.arch.hflags & HF_NMI_MASK);
+        ret = ret && gif_set(svm) && nested_svm_nmi(svm);
+
+        return ret;
 }
 
 static bool svm_get_nmi_mask(struct kvm_vcpu *vcpu)
@@ -2841,11 +2845,9 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu)
          * Something prevents NMI from been injected. Single step over possible
          * problem (IRET or exception injection or interrupt shadow)
          */
-        if (gif_set(svm) && nested_svm_nmi(svm)) {
-                svm->nmi_singlestep = true;
-                svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
-                update_db_intercept(vcpu);
-        }
+        svm->nmi_singlestep = true;
+        svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
+        update_db_intercept(vcpu);
 }
 
 static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)