diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c index acc4d19ae62a..b448197728be 100644 --- a/arch/ia64/kernel/irq_ia64.c +++ b/arch/ia64/kernel/irq_ia64.c @@ -610,6 +610,9 @@ static struct irqaction ipi_irqaction = { .name = "IPI" }; +/* + * KVM uses this interrupt to force a cpu out of guest mode + */ static struct irqaction resched_irqaction = { .handler = dummy_handler, .flags = IRQF_DISABLED, diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index be4413e1f43f..80c57b0a21c4 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -668,7 +668,7 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) host_ctx = kvm_get_host_context(vcpu); guest_ctx = kvm_get_guest_context(vcpu); - vcpu->guest_mode = 1; + clear_bit(KVM_REQ_KICK, &vcpu->requests); r = kvm_vcpu_pre_transition(vcpu); if (r < 0) @@ -685,7 +685,7 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) kvm_vcpu_post_transition(vcpu); vcpu->arch.launched = 1; - vcpu->guest_mode = 0; + set_bit(KVM_REQ_KICK, &vcpu->requests); local_irq_enable(); /* @@ -1879,24 +1879,18 @@ void kvm_arch_hardware_unsetup(void) { } -static void vcpu_kick_intr(void *info) -{ -#ifdef DEBUG - struct kvm_vcpu *vcpu = (struct kvm_vcpu *)info; - printk(KERN_DEBUG"vcpu_kick_intr %p \n", vcpu); -#endif -} - void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { - int ipi_pcpu = vcpu->cpu; - int cpu = get_cpu(); + int me; + int cpu = vcpu->cpu; if (waitqueue_active(&vcpu->wq)) wake_up_interruptible(&vcpu->wq); - if (vcpu->guest_mode && cpu != ipi_pcpu) - smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu, 0); + me = get_cpu(); + if (cpu != me && (unsigned) cpu < nr_cpu_ids && cpu_online(cpu)) + if (!test_and_set_bit(KVM_REQ_KICK, &vcpu->requests)) + smp_send_reschedule(cpu); put_cpu(); } diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index 13f33ea8ccaa..3b2e55e8ad2b 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -172,6 +172,9 @@ void smp_reschedule_interrupt(struct pt_regs *regs) { ack_APIC_irq(); inc_irq_stat(irq_resched_count); + /* + * KVM uses this interrupt to force a cpu out of guest mode + */ } void smp_call_function_interrupt(struct pt_regs *regs) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 75927700a26d..3c4c327490af 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3230,6 +3230,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) local_irq_disable(); + clear_bit(KVM_REQ_KICK, &vcpu->requests); + smp_mb__after_clear_bit(); + if (vcpu->requests || need_resched() || signal_pending(current)) { local_irq_enable(); preempt_enable(); @@ -3237,13 +3240,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) goto out; } - vcpu->guest_mode = 1; - /* - * Make sure that guest_mode assignment won't happen after - * testing the pending IRQ vector bitmap. - */ - smp_wmb(); - if (vcpu->arch.exception.pending) __queue_exception(vcpu); else @@ -3288,7 +3284,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) set_debugreg(vcpu->arch.host_dr6, 6); set_debugreg(vcpu->arch.host_dr7, 7); - vcpu->guest_mode = 0; + set_bit(KVM_REQ_KICK, &vcpu->requests); local_irq_enable(); ++vcpu->stat.exits; @@ -4571,30 +4567,20 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) || vcpu->arch.nmi_pending; } -static void vcpu_kick_intr(void *info) -{ -#ifdef DEBUG - struct kvm_vcpu *vcpu = (struct kvm_vcpu *)info; - printk(KERN_DEBUG "vcpu_kick_intr %p \n", vcpu); -#endif -} - void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { - int ipi_pcpu = vcpu->cpu; - int cpu; + int me; + int cpu = vcpu->cpu; if (waitqueue_active(&vcpu->wq)) { wake_up_interruptible(&vcpu->wq); ++vcpu->stat.halt_wakeup; } - /* - * We may be called synchronously with irqs disabled in guest mode, - * So need not to call smp_call_function_single() in that case. - */ - cpu = get_cpu(); - if (vcpu->guest_mode && vcpu->cpu != cpu) - smp_call_function_single(ipi_pcpu, vcpu_kick_intr, vcpu, 0); + + me = get_cpu(); + if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) + if (!test_and_set_bit(KVM_REQ_KICK, &vcpu->requests)) + smp_send_reschedule(cpu); put_cpu(); } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index bdce8e1303c9..161816284192 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -38,6 +38,7 @@ #define KVM_REQ_UNHALT 6 #define KVM_REQ_MMU_SYNC 7 #define KVM_REQ_KVMCLOCK_UPDATE 8 +#define KVM_REQ_KICK 9 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 @@ -72,7 +73,6 @@ struct kvm_vcpu { struct mutex mutex; int cpu; struct kvm_run *run; - int guest_mode; unsigned long requests; unsigned long guest_debug; int fpu_active;