From b463a6f744a263fccd7da14db1afdc880371a280 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 20 Jul 2010 15:06:17 +0300 Subject: [PATCH] KVM: Non-atomic interrupt injection Change the interrupt injection code to work from preemptible, interrupts enabled context. This works by adding a ->cancel_injection() operation that undoes an injection in case we were not able to actually enter the guest (this condition could never happen with atomic injection). Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm.c | 12 +++++++++++ arch/x86/kvm/vmx.c | 11 ++++++++++ arch/x86/kvm/x86.c | 36 +++++++++++++++------------------ 4 files changed, 40 insertions(+), 20 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b43686a44877..80224bf5d4f8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -552,6 +552,7 @@ struct kvm_x86_ops { void (*queue_exception)(struct kvm_vcpu *vcpu, unsigned nr, bool has_error_code, u32 error_code, bool reinject); + void (*cancel_injection)(struct kvm_vcpu *vcpu); int (*interrupt_allowed)(struct kvm_vcpu *vcpu); int (*nmi_allowed)(struct kvm_vcpu *vcpu); bool (*get_nmi_mask)(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 1d2ea65d3537..1a85fc507cf7 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3261,6 +3261,17 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) } } +static void svm_cancel_injection(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + struct vmcb_control_area *control = &svm->vmcb->control; + + control->exit_int_info = control->event_inj; + control->exit_int_info_err = control->event_inj_err; + control->event_inj = 0; + svm_complete_interrupts(svm); +} + #ifdef CONFIG_X86_64 #define R "r" #else @@ -3631,6 +3642,7 @@ static struct kvm_x86_ops svm_x86_ops = { .set_irq = svm_set_irq, .set_nmi = svm_inject_nmi, .queue_exception = svm_queue_exception, + .cancel_injection = svm_cancel_injection, .interrupt_allowed = svm_interrupt_allowed, .nmi_allowed = svm_nmi_allowed, .get_nmi_mask = svm_get_nmi_mask, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3237f6cc930d..70af3db372d7 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3895,6 +3895,16 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx) IDT_VECTORING_ERROR_CODE); } +static void vmx_cancel_injection(struct kvm_vcpu *vcpu) +{ + __vmx_complete_interrupts(to_vmx(vcpu), + vmcs_read32(VM_ENTRY_INTR_INFO_FIELD), + VM_ENTRY_INSTRUCTION_LEN, + VM_ENTRY_EXCEPTION_ERROR_CODE); + + vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0); +} + /* * Failure to inject an interrupt should give us the information * in IDT_VECTORING_INFO_FIELD. However, if the failure occurs @@ -4348,6 +4358,7 @@ static struct kvm_x86_ops vmx_x86_ops = { .set_irq = vmx_inject_irq, .set_nmi = vmx_inject_nmi, .queue_exception = vmx_queue_exception, + .cancel_injection = vmx_cancel_injection, .interrupt_allowed = vmx_interrupt_allowed, .nmi_allowed = vmx_nmi_allowed, .get_nmi_mask = vmx_get_nmi_mask, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e7198036db61..a465bd29f381 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5005,7 +5005,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) int r; bool req_int_win = !irqchip_in_kernel(vcpu->kvm) && vcpu->run->request_interrupt_window; - bool req_event; if (vcpu->requests) { if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) @@ -5041,6 +5040,21 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (unlikely(r)) goto out; + if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) { + inject_pending_event(vcpu); + + /* enable NMI/IRQ window open exits if needed */ + if (vcpu->arch.nmi_pending) + kvm_x86_ops->enable_nmi_window(vcpu); + else if (kvm_cpu_has_interrupt(vcpu) || req_int_win) + kvm_x86_ops->enable_irq_window(vcpu); + + if (kvm_lapic_enabled(vcpu)) { + update_cr8_intercept(vcpu); + kvm_lapic_sync_to_vapic(vcpu); + } + } + preempt_disable(); kvm_x86_ops->prepare_guest_switch(vcpu); @@ -5053,35 +5067,17 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) local_irq_disable(); - req_event = kvm_check_request(KVM_REQ_EVENT, vcpu); - if (!atomic_read(&vcpu->guest_mode) || vcpu->requests || need_resched() || signal_pending(current)) { - if (req_event) - kvm_make_request(KVM_REQ_EVENT, vcpu); atomic_set(&vcpu->guest_mode, 0); smp_wmb(); local_irq_enable(); preempt_enable(); + kvm_x86_ops->cancel_injection(vcpu); r = 1; goto out; } - if (req_event || req_int_win) { - inject_pending_event(vcpu); - - /* enable NMI/IRQ window open exits if needed */ - if (vcpu->arch.nmi_pending) - kvm_x86_ops->enable_nmi_window(vcpu); - else if (kvm_cpu_has_interrupt(vcpu) || req_int_win) - kvm_x86_ops->enable_irq_window(vcpu); - - if (kvm_lapic_enabled(vcpu)) { - update_cr8_intercept(vcpu); - kvm_lapic_sync_to_vapic(vcpu); - } - } - srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); kvm_guest_enter(); -- 2.20.1