From 8fdb2351d51b040146f10a624387bbd102d851c0 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Mon, 20 Oct 2008 10:20:02 +0200 Subject: [PATCH] KVM: x86: Fix and refactor NMI watchdog emulation This patch refactors the NMI watchdog delivery patch, consolidating tests and providing a proper API for delivering watchdog events. An included micro-optimization is to check only for apic_hw_enabled in kvm_apic_local_deliver (the test for LVT mask is covering the soft-disabled case already). Signed-off-by: Jan Kiszka Acked-by: Sheng Yang Signed-off-by: Avi Kivity --- arch/x86/kvm/i8254.c | 15 +++++++++------ arch/x86/kvm/irq.h | 2 +- arch/x86/kvm/lapic.c | 20 ++++++++++---------- 3 files changed, 20 insertions(+), 17 deletions(-) diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 580cc1d..b6fcf5a 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -612,15 +612,18 @@ static void __inject_pit_timer_intr(struct kvm *kvm) mutex_unlock(&kvm->lock); /* - * Provides NMI watchdog support in IOAPIC mode. - * The route is: PIT -> PIC -> LVT0 in NMI mode, - * timer IRQs will continue to flow through the IOAPIC. + * Provides NMI watchdog support via Virtual Wire mode. + * The route is: PIT -> PIC -> LVT0 in NMI mode. + * + * Note: Our Virtual Wire implementation is simplified, only + * propagating PIT interrupts to all VCPUs when they have set + * LVT0 to NMI delivery. Other PIC interrupts are just sent to + * VCPU0, and only if its LVT0 is in EXTINT mode. */ for (i = 0; i < KVM_MAX_VCPUS; ++i) { vcpu = kvm->vcpus[i]; - if (!vcpu) - continue; - kvm_apic_local_deliver(vcpu, APIC_LVT0); + if (vcpu) + kvm_apic_nmi_wd_deliver(vcpu); } } diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index 71e37a5..b9e9051 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -87,7 +87,7 @@ void kvm_pic_reset(struct kvm_kpic_state *s); void kvm_timer_intr_post(struct kvm_vcpu *vcpu, int vec); void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu); void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu); -int kvm_apic_local_deliver(struct kvm_vcpu *vcpu, int lvt_type); +void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu); void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu); void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu); void __kvm_migrate_timers(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 304f9dd..0b0d413 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -973,14 +973,12 @@ int apic_has_pending_timer(struct kvm_vcpu *vcpu) return 0; } -int kvm_apic_local_deliver(struct kvm_vcpu *vcpu, int lvt_type) +static int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type) { - struct kvm_lapic *apic = vcpu->arch.apic; + u32 reg = apic_get_reg(apic, lvt_type); int vector, mode, trig_mode; - u32 reg; - if (apic && apic_enabled(apic)) { - reg = apic_get_reg(apic, lvt_type); + if (apic_hw_enabled(apic) && !(reg & APIC_LVT_MASKED)) { vector = reg & APIC_VECTOR_MASK; mode = reg & APIC_MODE_MASK; trig_mode = reg & APIC_LVT_LEVEL_TRIGGER; @@ -989,9 +987,12 @@ int kvm_apic_local_deliver(struct kvm_vcpu *vcpu, int lvt_type) return 0; } -static inline int __inject_apic_timer_irq(struct kvm_lapic *apic) +void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu) { - return kvm_apic_local_deliver(apic->vcpu, APIC_LVTT); + struct kvm_lapic *apic = vcpu->arch.apic; + + if (apic) + kvm_apic_local_deliver(apic, APIC_LVT0); } static enum hrtimer_restart apic_timer_fn(struct hrtimer *data) @@ -1086,9 +1087,8 @@ void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; - if (apic && apic_lvt_enabled(apic, APIC_LVTT) && - atomic_read(&apic->timer.pending) > 0) { - if (__inject_apic_timer_irq(apic)) + if (apic && atomic_read(&apic->timer.pending) > 0) { + if (kvm_apic_local_deliver(apic, APIC_LVTT)) atomic_dec(&apic->timer.pending); } } -- 1.8.2.3