KVM: nSVM: Report NMIs as allowed when in L2 and Exit-on-NMI is set

Report NMIs as allowed when the vCPU is in L2 and L2 is being run with
Exit-on-NMI enabled, as NMIs are always unblocked from L1's perspective
in this case.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index a2bc33a..d8ae654 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -378,6 +378,11 @@ static inline bool svm_nested_virtualize_tpr(struct kvm_vcpu *vcpu)
 	return is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK);
 }
 
+static inline bool nested_exit_on_nmi(struct vcpu_svm *svm)
+{
+	return (svm->nested.intercept & (1ULL << INTERCEPT_NMI));
+}
+
 void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 			  struct vmcb *nested_vmcb, struct kvm_host_map *map);
 int nested_svm_vmrun(struct vcpu_svm *svm);