KVM: SVM: Check for nested intercepts on NMI injection

This patch implements the NMI intercept checking for nested
svm.

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

1 files changed, 20 insertions, 3 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ef40b90219f..9f1143105e0 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1486,6 +1486,21 @@ static inline bool nested_svm_intr(struct vcpu_svm *svm)
         return true;
 }
 
+/* This function returns true if it is save to enable the nmi window */
+static inline bool nested_svm_nmi(struct vcpu_svm *svm)
+{
+        if (!is_nested(svm))
+                return true;
+
+        if (!(svm->nested.intercept & (1ULL << INTERCEPT_NMI)))
+                return true;
+
+        svm->vmcb->control.exit_code = SVM_EXIT_NMI;
+        svm->nested.exit_required = true;
+
+        return false;
+}
+
 static void *nested_svm_map(struct vcpu_svm *svm, u64 gpa, struct page **_page)
 {
         struct page *page;
@@ -2687,9 +2702,11 @@ 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)
          */
-        svm->nmi_singlestep = true;
-        svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
-        update_db_intercept(vcpu);
+        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);
+        }
 }
 
 static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)