KVM: SVM: Add NMI injection support

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 53533ea17555c05c410ffcf813416f017c7e46db..eb140aae2f32e9c357b6bdb056fe4bda67d5c95c 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -763,6 +763,7 @@ enum {
 #define HF_GIF_MASK            (1 << 0)
 #define HF_HIF_MASK            (1 << 1)
 #define HF_VINTR_MASK          (1 << 2)
+#define HF_NMI_MASK            (1 << 3)
 
 /*
  * Hardware virtualization extension instructions may fault if a

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1b09ef5388560bfe72ccf71b9ba20c3c30df7ac4..50c1db93a17dc1496edd97a07d834cc4be745874 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1841,6 +1841,14 @@ static int cpuid_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
        return 1;
 }
 
+static int iret_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+       ++svm->vcpu.stat.nmi_window_exits;
+       svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET);
+       svm->vcpu.arch.hflags &= ~HF_NMI_MASK;
+       return 1;
+}
+
 static int invlpg_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
 {
        if (emulate_instruction(&svm->vcpu, kvm_run, 0, 0, 0) != EMULATE_DONE)
@@ -2118,6 +2126,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
        [SVM_EXIT_VINTR]                        = interrupt_window_interception,
        /* [SVM_EXIT_CR0_SEL_WRITE]             = emulate_on_interception, */
        [SVM_EXIT_CPUID]                        = cpuid_interception,
+       [SVM_EXIT_IRET]                         = iret_interception,
        [SVM_EXIT_INVD]                         = emulate_on_interception,
        [SVM_EXIT_HLT]                          = halt_interception,
        [SVM_EXIT_INVLPG]                       = invlpg_interception,
@@ -2225,6 +2234,13 @@ static void pre_svm_run(struct vcpu_svm *svm)
                new_asid(svm, svm_data);
 }
 
+static void svm_inject_nmi(struct vcpu_svm *svm)
+{
+       svm->vmcb->control.event_inj = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_NMI;
+       vcpu->arch.hflags |= HF_NMI_MASK;
+       svm->vmcb->control.intercept |= (1UL << INTERCEPT_IRET);
+       ++vcpu->stat.nmi_injections;
+}
 
 static inline void svm_inject_irq(struct vcpu_svm *svm, int irq)
 {
@@ -2276,6 +2292,14 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
                vmcb->control.intercept_cr_write |= INTERCEPT_CR8_MASK;
 }
 
+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);
+}
+
 static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
 {
        struct vcpu_svm *svm = to_svm(vcpu);
@@ -2291,16 +2315,35 @@ static void enable_irq_window(struct kvm_vcpu *vcpu)
        svm_inject_irq(to_svm(vcpu), 0x0);
 }
 
+static void enable_nmi_window(struct kvm_vcpu *vcpu)
+{
+       struct vcpu_svm *svm = to_svm(vcpu);
+
+       if (svm->vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK)
+               enable_irq_window(vcpu);
+}
+
 static void svm_intr_inject(struct kvm_vcpu *vcpu)
 {
        /* try to reinject previous events if any */
+       if (vcpu->arch.nmi_injected) {
+               svm_inject_nmi(to_svm(vcpu));
+               return;
+       }
+
        if (vcpu->arch.interrupt.pending) {
                svm_queue_irq(to_svm(vcpu), vcpu->arch.interrupt.nr);
                return;
        }
 
        /* try to inject new event if pending */
-       if (kvm_cpu_has_interrupt(vcpu)) {
+       if (vcpu->arch.nmi_pending) {
+               if (svm_nmi_allowed(vcpu)) {
+                       vcpu->arch.nmi_pending = false;
+                       vcpu->arch.nmi_injected = true;
+                       svm_inject_nmi(vcpu);
+               }
+       } else if (kvm_cpu_has_interrupt(vcpu)) {
                if (svm_interrupt_allowed(vcpu)) {
                        kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
                        svm_queue_irq(to_svm(vcpu), vcpu->arch.interrupt.nr);
@@ -2319,7 +2362,10 @@ static void svm_intr_assist(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
        svm_intr_inject(vcpu);
 
-       if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
+       /* enable NMI/IRQ window open exits if needed */
+       if (vcpu->arch.nmi_pending)
+               enable_nmi_window(vcpu);
+       else if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
                enable_irq_window(vcpu);
 
 out: