4 files changed, 51 insertions, 18 deletions

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 82ada75f3ebf..85574b7c1bc1 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -225,6 +225,7 @@ struct __attribute__ ((__packed__)) vmcb {
 #define SVM_EVTINJ_VALID_ERR (1 << 11)
 
 #define SVM_EXITINTINFO_VEC_MASK SVM_EVTINJ_VEC_MASK
+#define SVM_EXITINTINFO_TYPE_MASK SVM_EVTINJ_TYPE_MASK
 
 #define SVM_EXITINTINFO_TYPE_INTR SVM_EVTINJ_TYPE_INTR
 #define SVM_EXITINTINFO_TYPE_NMI SVM_EVTINJ_TYPE_NMI
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index de741043c5b1..bba67b70c4b0 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1825,17 +1825,28 @@ static int task_switch_interception(struct vcpu_svm *svm,
                                     struct kvm_run *kvm_run)
 {
         u16 tss_selector;
+        int reason;
+        int int_type = svm->vmcb->control.exit_int_info &
+                SVM_EXITINTINFO_TYPE_MASK;
 
         tss_selector = (u16)svm->vmcb->control.exit_info_1;
+
         if (svm->vmcb->control.exit_info_2 &
             (1ULL << SVM_EXITINFOSHIFT_TS_REASON_IRET))
-                return kvm_task_switch(&svm->vcpu, tss_selector,
-                                       TASK_SWITCH_IRET);
-        if (svm->vmcb->control.exit_info_2 &
-            (1ULL << SVM_EXITINFOSHIFT_TS_REASON_JMP))
-                return kvm_task_switch(&svm->vcpu, tss_selector,
-                                       TASK_SWITCH_JMP);
-        return kvm_task_switch(&svm->vcpu, tss_selector, TASK_SWITCH_CALL);
+                reason = TASK_SWITCH_IRET;
+        else if (svm->vmcb->control.exit_info_2 &
+                 (1ULL << SVM_EXITINFOSHIFT_TS_REASON_JMP))
+                reason = TASK_SWITCH_JMP;
+        else if (svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_VALID)
+                reason = TASK_SWITCH_GATE;
+        else
+                reason = TASK_SWITCH_CALL;
+
+
+        if (reason != TASK_SWITCH_GATE || int_type == SVM_EXITINTINFO_TYPE_SOFT)
+                skip_emulated_instruction(&svm->vcpu);
+
+        return kvm_task_switch(&svm->vcpu, tss_selector, reason);
 }
 
 static int cpuid_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e4ad9d3c0636..c6997c0e8ca6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3038,22 +3038,40 @@ static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         struct vcpu_vmx *vmx = to_vmx(vcpu);
         unsigned long exit_qualification;
         u16 tss_selector;
-        int reason;
+        int reason, type, idt_v;
+
+        idt_v = (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK);
+        type = (vmx->idt_vectoring_info & VECTORING_INFO_TYPE_MASK);
 
         exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
 
         reason = (u32)exit_qualification >> 30;
-        if (reason == TASK_SWITCH_GATE && vmx->vcpu.arch.nmi_injected &&
-            (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
-            (vmx->idt_vectoring_info & VECTORING_INFO_TYPE_MASK)
-            == INTR_TYPE_NMI_INTR) {
-                vcpu->arch.nmi_injected = false;
-                if (cpu_has_virtual_nmis())
-                        vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
-                                      GUEST_INTR_STATE_NMI);
+        if (reason == TASK_SWITCH_GATE && idt_v) {
+                switch (type) {
+                case INTR_TYPE_NMI_INTR:
+                        vcpu->arch.nmi_injected = false;
+                        if (cpu_has_virtual_nmis())
+                                vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
+                                              GUEST_INTR_STATE_NMI);
+                        break;
+                case INTR_TYPE_EXT_INTR:
+                        kvm_clear_interrupt_queue(vcpu);
+                        break;
+                case INTR_TYPE_HARD_EXCEPTION:
+                case INTR_TYPE_SOFT_EXCEPTION:
+                        kvm_clear_exception_queue(vcpu);
+                        break;
+                default:
+                        break;
+                }
         }
         tss_selector = exit_qualification;
 
+        if (!idt_v || (type != INTR_TYPE_HARD_EXCEPTION &&
+                       type != INTR_TYPE_EXT_INTR &&
+                       type != INTR_TYPE_NMI_INTR))
+                skip_emulated_instruction(vcpu);
+
         if (!kvm_task_switch(vcpu, tss_selector, reason))
                 return 0;
 
@@ -3306,7 +3324,7 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
         vector = idt_vectoring_info & VECTORING_INFO_VECTOR_MASK;
         type = idt_vectoring_info & VECTORING_INFO_TYPE_MASK;
 
-        switch(type) {
+        switch (type) {
         case INTR_TYPE_NMI_INTR:
                 vmx->vcpu.arch.nmi_injected = true;
                 /*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index adcf73871a9d..bb04f11bf70f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3935,7 +3935,10 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
                 kvm_x86_ops->set_rflags(vcpu, eflags & ~X86_EFLAGS_NT);
         }
 
-        kvm_x86_ops->skip_emulated_instruction(vcpu);
+        /* set back link to prev task only if NT bit is set in eflags
+           note that old_tss_sel is not used afetr this point */
+        if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
+                old_tss_sel = 0xffff;
 
         /* set back link to prev task only if NT bit is set in eflags
            note that old_tss_sel is not used afetr this point */