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Commit 8fdb2351 authored by Jan Kiszka's avatar Jan Kiszka Committed by Avi Kivity
Browse files

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: default avatarJan Kiszka <jan.kiszka@siemens.com>
Acked-by: default avatarSheng Yang <sheng@linux.intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 291fd39b

arch/x86/kvm/i8254.c

+9 −6
Original line number Diff line number Diff line
@@ -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);

	}

}

arch/x86/kvm/irq.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/lapic.c

+10 −10
Original line number Diff line number Diff line
@@ -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);

	}

}