KVM: Do not re-execute INTn instruction.

Re-inject event instead. This is what Intel suggest. Also use correct
instruction length when re-injecting soft fault/interrupt.

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 977a785a9d75da6cdd4a8655289a8a791c7a5b27..1d6c3f757cb6e2a012538e1c379203ed6073182c 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -319,6 +319,8 @@ struct kvm_vcpu_arch {
        struct kvm_pio_request pio;
        void *pio_data;
 
+       u8 event_exit_inst_len;
+
        struct kvm_queued_exception {
                bool pending;
                bool has_error_code;
@@ -328,6 +330,7 @@ struct kvm_vcpu_arch {
 
        struct kvm_queued_interrupt {
                bool pending;
+               bool soft;
                u8 nr;
        } interrupt;
 
@@ -510,7 +513,7 @@ struct kvm_x86_ops {
        u32 (*get_interrupt_shadow)(struct kvm_vcpu *vcpu, int mask);
        void (*patch_hypercall)(struct kvm_vcpu *vcpu,
                                unsigned char *hypercall_addr);
-       void (*set_irq)(struct kvm_vcpu *vcpu, int vec);
+       void (*set_irq)(struct kvm_vcpu *vcpu);
        void (*set_nmi)(struct kvm_vcpu *vcpu);
        void (*queue_exception)(struct kvm_vcpu *vcpu, unsigned nr,
                                bool has_error_code, u32 error_code);

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1315ce025e5712db370f378705ede2ef22cd752f..377c4f17d1707358c18258222b4a760bc4c7b235 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2310,13 +2310,13 @@ static void svm_queue_irq(struct kvm_vcpu *vcpu, unsigned nr)
                SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR;
 }
 
-static void svm_set_irq(struct kvm_vcpu *vcpu, int irq)
+static void svm_set_irq(struct kvm_vcpu *vcpu)
 {
        struct vcpu_svm *svm = to_svm(vcpu);
 
        nested_svm_intr(svm);
 
-       svm_queue_irq(vcpu, irq);
+       svm_queue_irq(vcpu, vcpu->arch.interrupt.nr);
 }
 
 static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
@@ -2418,7 +2418,7 @@ static void svm_complete_interrupts(struct vcpu_svm *svm)
        case SVM_EXITINTINFO_TYPE_EXEPT:
                /* In case of software exception do not reinject an exception
                   vector, but re-execute and instruction instead */
-               if (vector == BP_VECTOR || vector == OF_VECTOR)
+               if (kvm_exception_is_soft(vector))
                        break;
                if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) {
                        u32 err = svm->vmcb->control.exit_int_info_err;
@@ -2428,7 +2428,7 @@ static void svm_complete_interrupts(struct vcpu_svm *svm)
                        kvm_queue_exception(&svm->vcpu, vector);
                break;
        case SVM_EXITINTINFO_TYPE_INTR:
-               kvm_queue_interrupt(&svm->vcpu, vector);
+               kvm_queue_interrupt(&svm->vcpu, vector, false);
                break;
        default:
                break;

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8981654ad061b16827c1a6236dfe7cd554f4ad35..29b49f09a019a82a369e1508c5fd860e9eeb37b1 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -801,8 +801,9 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
                return;
        }
 
-       if (nr == BP_VECTOR || nr == OF_VECTOR) {
-               vmcs_write32(VM_ENTRY_INSTRUCTION_LEN, 1);
+       if (kvm_exception_is_soft(nr)) {
+               vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
+                            vmx->vcpu.arch.event_exit_inst_len);
                intr_info |= INTR_TYPE_SOFT_EXCEPTION;
        } else
                intr_info |= INTR_TYPE_HARD_EXCEPTION;
@@ -2445,9 +2446,11 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu)
        vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
 }
 
-static void vmx_inject_irq(struct kvm_vcpu *vcpu, int irq)
+static void vmx_inject_irq(struct kvm_vcpu *vcpu)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
+       uint32_t intr;
+       int irq = vcpu->arch.interrupt.nr;
 
        KVMTRACE_1D(INJ_VIRQ, vcpu, (u32)irq, handler);
 
@@ -2462,8 +2465,14 @@ static void vmx_inject_irq(struct kvm_vcpu *vcpu, int irq)
                kvm_rip_write(vcpu, vmx->rmode.irq.rip - 1);
                return;
        }
-       vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
-                       irq | INTR_TYPE_EXT_INTR | INTR_INFO_VALID_MASK);
+       intr = irq | INTR_INFO_VALID_MASK;
+       if (vcpu->arch.interrupt.soft) {
+               intr |= INTR_TYPE_SOFT_INTR;
+               vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
+                            vmx->vcpu.arch.event_exit_inst_len);
+       } else
+               intr |= INTR_TYPE_EXT_INTR;
+       vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr);
 }
 
 static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
@@ -3024,6 +3033,7 @@ static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                                              GUEST_INTR_STATE_NMI);
                        break;
                case INTR_TYPE_EXT_INTR:
+               case INTR_TYPE_SOFT_INTR:
                        kvm_clear_interrupt_queue(vcpu);
                        break;
                case INTR_TYPE_HARD_EXCEPTION:
@@ -3295,16 +3305,24 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
                vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
                                GUEST_INTR_STATE_NMI);
                break;
-       case INTR_TYPE_HARD_EXCEPTION:
        case INTR_TYPE_SOFT_EXCEPTION:
+               vmx->vcpu.arch.event_exit_inst_len =
+                       vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+               /* fall through */
+       case INTR_TYPE_HARD_EXCEPTION:
                if (idt_vectoring_info & VECTORING_INFO_DELIVER_CODE_MASK) {
                        u32 err = vmcs_read32(IDT_VECTORING_ERROR_CODE);
                        kvm_queue_exception_e(&vmx->vcpu, vector, err);
                } else
                        kvm_queue_exception(&vmx->vcpu, vector);
                break;
+       case INTR_TYPE_SOFT_INTR:
+               vmx->vcpu.arch.event_exit_inst_len =
+                       vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+               /* fall through */
        case INTR_TYPE_EXT_INTR:
-               kvm_queue_interrupt(&vmx->vcpu, vector);
+               kvm_queue_interrupt(&vmx->vcpu, vector,
+                       type == INTR_TYPE_SOFT_INTR);
                break;
        default:
                break;

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 54eec3565485b61f84aadc3fc21450d73de439ed..73cfe87fba105ee2dc2fca758782f27908611b90 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1441,7 +1441,7 @@ static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
                return -ENXIO;
        vcpu_load(vcpu);
 
-       kvm_queue_interrupt(vcpu, irq->irq);
+       kvm_queue_interrupt(vcpu, irq->irq, false);
 
        vcpu_put(vcpu);
 
@@ -3161,7 +3161,7 @@ static void inject_irq(struct kvm_vcpu *vcpu)
        }
 
        if (vcpu->arch.interrupt.pending) {
-               kvm_x86_ops->set_irq(vcpu, vcpu->arch.interrupt.nr);
+               kvm_x86_ops->set_irq(vcpu);
                return;
        }
 
@@ -3174,8 +3174,9 @@ static void inject_irq(struct kvm_vcpu *vcpu)
                }
        } else if (kvm_cpu_has_interrupt(vcpu)) {
                if (kvm_x86_ops->interrupt_allowed(vcpu)) {
-                       kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
-                       kvm_x86_ops->set_irq(vcpu, vcpu->arch.interrupt.nr);
+                       kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
+                                           false);
+                       kvm_x86_ops->set_irq(vcpu);
                }
        }
 }
@@ -4098,7 +4099,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
        pending_vec = find_first_bit(
                (const unsigned long *)sregs->interrupt_bitmap, max_bits);
        if (pending_vec < max_bits) {
-               kvm_queue_interrupt(vcpu, pending_vec);
+               kvm_queue_interrupt(vcpu, pending_vec, false);
                pr_debug("Set back pending irq %d\n", pending_vec);
                if (irqchip_in_kernel(vcpu->kvm))
                        kvm_pic_clear_isr_ack(vcpu->kvm);

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index c1f1a8ceba64036b44c7df3ee5fce91cc5142d86..4c8e10af78e88004acc1dd9df3c2fd2fa36cd85c 100644 (file)
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -8,9 +8,11 @@ static inline void kvm_clear_exception_queue(struct kvm_vcpu *vcpu)
        vcpu->arch.exception.pending = false;
 }
 
-static inline void kvm_queue_interrupt(struct kvm_vcpu *vcpu, u8 vector)
+static inline void kvm_queue_interrupt(struct kvm_vcpu *vcpu, u8 vector,
+       bool soft)
 {
        vcpu->arch.interrupt.pending = true;
+       vcpu->arch.interrupt.soft = soft;
        vcpu->arch.interrupt.nr = vector;
 }
 
@@ -24,4 +26,9 @@ static inline bool kvm_event_needs_reinjection(struct kvm_vcpu *vcpu)
        return vcpu->arch.exception.pending || vcpu->arch.interrupt.pending ||
                vcpu->arch.nmi_injected;
 }
+
+static inline bool kvm_exception_is_soft(unsigned int nr)
+{
+       return (nr == BP_VECTOR) || (nr == OF_VECTOR);
+}
 #endif