Commit eba0226b authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
Browse files

KVM: Move IO APIC to its own lock 



The allows removal of irq_lock from the injection path.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 280aa177

arch/ia64/kvm/kvm-ia64.c

+2 −5
Original line number Diff line number Diff line
@@ -851,8 +851,7 @@ static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, 
	r = 0;

	switch (chip->chip_id) {

	case KVM_IRQCHIP_IOAPIC:

		memcpy(&chip->chip.ioapic, ioapic_irqchip(kvm),

				sizeof(struct kvm_ioapic_state));

		r = kvm_get_ioapic(kvm, &chip->chip.ioapic);

		break;

	default:

		r = -EINVAL;
@@ -868,9 +867,7 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip) 
	r = 0;

	switch (chip->chip_id) {

	case KVM_IRQCHIP_IOAPIC:

		memcpy(ioapic_irqchip(kvm),

				&chip->chip.ioapic,

				sizeof(struct kvm_ioapic_state));

		r = kvm_set_ioapic(kvm, &chip->chip.ioapic);

		break;

	default:

		r = -EINVAL;

arch/x86/kvm/i8259.c

+16 −6
Original line number Diff line number Diff line
@@ -38,7 +38,15 @@ static void pic_clear_isr(struct kvm_kpic_state *s, int irq) 
	s->isr_ack |= (1 << irq);

	if (s != &s->pics_state->pics[0])

		irq += 8;

	/*

	 * We are dropping lock while calling ack notifiers since ack

	 * notifier callbacks for assigned devices call into PIC recursively.

	 * Other interrupt may be delivered to PIC while lock is dropped but

	 * it should be safe since PIC state is already updated at this stage.

	 */

	spin_unlock(&s->pics_state->lock);

	kvm_notify_acked_irq(s->pics_state->kvm, SELECT_PIC(irq), irq);

	spin_lock(&s->pics_state->lock);

}



void kvm_pic_clear_isr_ack(struct kvm *kvm)
@@ -176,16 +184,18 @@ int kvm_pic_set_irq(void *opaque, int irq, int level) 
static inline void pic_intack(struct kvm_kpic_state *s, int irq)

{

	s->isr |= 1 << irq;

	if (s->auto_eoi) {

		if (s->rotate_on_auto_eoi)

			s->priority_add = (irq + 1) & 7;

		pic_clear_isr(s, irq);

	}

	/*

	 * We don't clear a level sensitive interrupt here

	 */

	if (!(s->elcr & (1 << irq)))

		s->irr &= ~(1 << irq);



	if (s->auto_eoi) {

		if (s->rotate_on_auto_eoi)

			s->priority_add = (irq + 1) & 7;

		pic_clear_isr(s, irq);

	}



}



int kvm_pic_read_irq(struct kvm *kvm)
@@ -294,9 +304,9 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val) 
				priority = get_priority(s, s->isr);

				if (priority != 8) {

					irq = (priority + s->priority_add) & 7;

					pic_clear_isr(s, irq);

					if (cmd == 5)

						s->priority_add = (irq + 1) & 7;

					pic_clear_isr(s, irq);

					pic_update_irq(s->pics_state);

				}

				break;

arch/x86/kvm/lapic.c

+1 −4
Original line number Diff line number Diff line
@@ -471,11 +471,8 @@ static void apic_set_eoi(struct kvm_lapic *apic) 
		trigger_mode = IOAPIC_LEVEL_TRIG;

	else

		trigger_mode = IOAPIC_EDGE_TRIG;

	if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)) {

		mutex_lock(&apic->vcpu->kvm->irq_lock);

	if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI))

		kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);

		mutex_unlock(&apic->vcpu->kvm->irq_lock);

	}

}



static void apic_send_ipi(struct kvm_lapic *apic)

arch/x86/kvm/x86.c

+2 −8
Original line number Diff line number Diff line
@@ -2038,9 +2038,7 @@ static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip) 
			sizeof(struct kvm_pic_state));

		break;

	case KVM_IRQCHIP_IOAPIC:

		memcpy(&chip->chip.ioapic,

			ioapic_irqchip(kvm),

			sizeof(struct kvm_ioapic_state));

		r = kvm_get_ioapic(kvm, &chip->chip.ioapic);

		break;

	default:

		r = -EINVAL;
@@ -2070,11 +2068,7 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip) 
		spin_unlock(&pic_irqchip(kvm)->lock);

		break;

	case KVM_IRQCHIP_IOAPIC:

		mutex_lock(&kvm->irq_lock);

		memcpy(ioapic_irqchip(kvm),

			&chip->chip.ioapic,

			sizeof(struct kvm_ioapic_state));

		mutex_unlock(&kvm->irq_lock);

		r = kvm_set_ioapic(kvm, &chip->chip.ioapic);

		break;

	default:

		r = -EINVAL;

virt/kvm/ioapic.c

+61 −19
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level) 
	union kvm_ioapic_redirect_entry entry;

	int ret = 1;



	mutex_lock(&ioapic->lock);

	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {

		entry = ioapic->redirtbl[irq];

		level ^= entry.fields.polarity;
@@ -198,34 +199,51 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level) 
		}

		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);

	}

	mutex_unlock(&ioapic->lock);



	return ret;

}



static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int pin,

static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,

				     int trigger_mode)

{

	union kvm_ioapic_redirect_entry *ent;

	int i;



	for (i = 0; i < IOAPIC_NUM_PINS; i++) {

		union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];



	ent = &ioapic->redirtbl[pin];

		if (ent->fields.vector != vector)

			continue;



		/*

		 * We are dropping lock while calling ack notifiers because ack

		 * notifier callbacks for assigned devices call into IOAPIC

		 * recursively. Since remote_irr is cleared only after call

		 * to notifiers if the same vector will be delivered while lock

		 * is dropped it will be put into irr and will be delivered

		 * after ack notifier returns.

		 */

		mutex_unlock(&ioapic->lock);

		kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);

		mutex_lock(&ioapic->lock);



	kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);

		if (trigger_mode != IOAPIC_LEVEL_TRIG)

			continue;



	if (trigger_mode == IOAPIC_LEVEL_TRIG) {

		ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);

		ent->fields.remote_irr = 0;

		if (!ent->fields.mask && (ioapic->irr & (1 << pin)))

			ioapic_service(ioapic, pin);

		if (!ent->fields.mask && (ioapic->irr & (1 << i)))

			ioapic_service(ioapic, i);

	}

}



void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)

{

	struct kvm_ioapic *ioapic = kvm->arch.vioapic;

	int i;



	for (i = 0; i < IOAPIC_NUM_PINS; i++)

		if (ioapic->redirtbl[i].fields.vector == vector)

			__kvm_ioapic_update_eoi(ioapic, i, trigger_mode);

	mutex_lock(&ioapic->lock);

	__kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);

	mutex_unlock(&ioapic->lock);

}



static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
@@ -250,8 +268,8 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len, 
	ioapic_debug("addr %lx\n", (unsigned long)addr);

	ASSERT(!(addr & 0xf));	/* check alignment */



	mutex_lock(&ioapic->kvm->irq_lock);

	addr &= 0xff;

	mutex_lock(&ioapic->lock);

	switch (addr) {

	case IOAPIC_REG_SELECT:

		result = ioapic->ioregsel;
@@ -265,6 +283,8 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len, 
		result = 0;

		break;

	}

	mutex_unlock(&ioapic->lock);



	switch (len) {

	case 8:

		*(u64 *) val = result;
@@ -277,7 +297,6 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len, 
	default:

		printk(KERN_WARNING "ioapic: wrong length %d\n", len);

	}

	mutex_unlock(&ioapic->kvm->irq_lock);

	return 0;

}
@@ -293,15 +312,15 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len, 
		     (void*)addr, len, val);

	ASSERT(!(addr & 0xf));	/* check alignment */



	mutex_lock(&ioapic->kvm->irq_lock);

	if (len == 4 || len == 8)

		data = *(u32 *) val;

	else {

		printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);

		goto unlock;

		return 0;

	}



	addr &= 0xff;

	mutex_lock(&ioapic->lock);

	switch (addr) {

	case IOAPIC_REG_SELECT:

		ioapic->ioregsel = data;
@@ -312,15 +331,14 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len, 
		break;

#ifdef	CONFIG_IA64

	case IOAPIC_REG_EOI:

		kvm_ioapic_update_eoi(ioapic->kvm, data, IOAPIC_LEVEL_TRIG);

		__kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);

		break;

#endif



	default:

		break;

	}

unlock:

	mutex_unlock(&ioapic->kvm->irq_lock);

	mutex_unlock(&ioapic->lock);

	return 0;

}
@@ -349,6 +367,7 @@ int kvm_ioapic_init(struct kvm *kvm) 
	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);

	if (!ioapic)

		return -ENOMEM;

	mutex_init(&ioapic->lock);

	kvm->arch.vioapic = ioapic;

	kvm_ioapic_reset(ioapic);

	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
@@ -360,3 +379,26 @@ int kvm_ioapic_init(struct kvm *kvm) 
	return ret;

}



int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)

{

	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);

	if (!ioapic)

		return -EINVAL;



	mutex_lock(&ioapic->lock);

	memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));

	mutex_unlock(&ioapic->lock);

	return 0;

}



int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)

{

	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);

	if (!ioapic)

		return -EINVAL;



	mutex_lock(&ioapic->lock);

	memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));

	mutex_unlock(&ioapic->lock);

	return 0;

}