virt/kvm/irq_comm.c - maze/linux - Git at Google

 /*
  * irq_comm.c: Common API for in kernel interrupt controller
  * Copyright (c) 2007, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  * Place - Suite 330, Boston, MA 02111-1307 USA.
  * Authors:
  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
  *
  */

 #include <linux/kvm_host.h>

 #include <asm/msidef.h>

 #include "irq.h"

 #include "ioapic.h"

 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
 			   struct kvm *kvm, int level)
 {
 #ifdef CONFIG_X86
 	return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
 #else
 	return -1;
 #endif
 }

 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
 			      struct kvm *kvm, int level)
 {
 	return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
 }

 void kvm_get_intr_delivery_bitmask(struct kvm_ioapic *ioapic,
 				   union kvm_ioapic_redirect_entry *entry,
 				   unsigned long *deliver_bitmask)
 {
 	struct kvm_vcpu *vcpu;

 	*deliver_bitmask = kvm_ioapic_get_delivery_bitmask(ioapic,
 				entry->fields.dest_id, entry->fields.dest_mode);
 	switch (entry->fields.delivery_mode) {
 	case IOAPIC_LOWEST_PRIORITY:
 		vcpu = kvm_get_lowest_prio_vcpu(ioapic->kvm,
 				entry->fields.vector, *deliver_bitmask);
 		*deliver_bitmask = 1 << vcpu->vcpu_id;
 		break;
 	case IOAPIC_FIXED:
 	case IOAPIC_NMI:
 		break;
 	default:
 		if (printk_ratelimit())
 			printk(KERN_INFO "kvm: unsupported delivery mode %d\n",
 				entry->fields.delivery_mode);
 		*deliver_bitmask = 0;
 	}
 }

 static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 		       struct kvm *kvm, int level)
 {
 	int vcpu_id, r = -1;
 	struct kvm_vcpu *vcpu;
 	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 	union kvm_ioapic_redirect_entry entry;
 	unsigned long deliver_bitmask;

 	BUG_ON(!ioapic);

 	entry.bits = 0;
 	entry.fields.dest_id = (e->msi.address_lo &
 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 	entry.fields.vector = (e->msi.data &
 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 	entry.fields.dest_mode = test_bit(MSI_ADDR_DEST_MODE_SHIFT,
 			(unsigned long *)&e->msi.address_lo);
 	entry.fields.trig_mode = test_bit(MSI_DATA_TRIGGER_SHIFT,
 			(unsigned long *)&e->msi.data);
 	entry.fields.delivery_mode = test_bit(
 			MSI_DATA_DELIVERY_MODE_SHIFT,
 			(unsigned long *)&e->msi.data);

 	/* TODO Deal with RH bit of MSI message address */

 	kvm_get_intr_delivery_bitmask(ioapic, &entry, &deliver_bitmask);

 	if (!deliver_bitmask) {
 		printk(KERN_WARNING "kvm: no destination for MSI delivery!");
 		return -1;
 	}
 	for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
 		if (!(deliver_bitmask & (1 << vcpu_id)))
 			continue;
 		deliver_bitmask &= ~(1 << vcpu_id);
 		vcpu = ioapic->kvm->vcpus[vcpu_id];
 		if (vcpu) {
 			if (r < 0)
 				r = 0;
 			r += kvm_apic_set_irq(vcpu, entry.fields.vector,
 					      entry.fields.trig_mode);
 		}
 	}
 	return r;
 }

 /* This should be called with the kvm->lock mutex held
  * Return value:
  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
  *  = 0   Interrupt was coalesced (previous irq is still pending)
  *  > 0   Number of CPUs interrupt was delivered to
  */
 int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
 {
 	struct kvm_kernel_irq_routing_entry *e;
 	unsigned long *irq_state, sig_level;
 	int ret = -1;

 	if (irq < KVM_IOAPIC_NUM_PINS) {
 		irq_state = (unsigned long *)&kvm->arch.irq_states[irq];

 		/* Logical OR for level trig interrupt */
 		if (level)
 			set_bit(irq_source_id, irq_state);
 		else
 			clear_bit(irq_source_id, irq_state);
 		sig_level = !!(*irq_state);
 	} else /* Deal with MSI/MSI-X */
 		sig_level = 1;

 	/* Not possible to detect if the guest uses the PIC or the
 	 * IOAPIC.  So set the bit in both. The guest will ignore
 	 * writes to the unused one.
 	 */
 	list_for_each_entry(e, &kvm->irq_routing, link)
 		if (e->gsi == irq) {
 			int r = e->set(e, kvm, sig_level);
 			if (r < 0)
 				continue;

 			ret = r + ((ret < 0) ? 0 : ret);
 		}
 	return ret;
 }

 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 {
 	struct kvm_kernel_irq_routing_entry *e;
 	struct kvm_irq_ack_notifier *kian;
 	struct hlist_node *n;
 	unsigned gsi = pin;

 	list_for_each_entry(e, &kvm->irq_routing, link)
 		if (e->irqchip.irqchip == irqchip &&
 		    e->irqchip.pin == pin) {
 			gsi = e->gsi;
 			break;
 		}

 	hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
 		if (kian->gsi == gsi)
 			kian->irq_acked(kian);
 }

 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 				   struct kvm_irq_ack_notifier *kian)
 {
 	hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
 }

 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
 {
 	hlist_del_init(&kian->link);
 }

 /* The caller must hold kvm->lock mutex */
 int kvm_request_irq_source_id(struct kvm *kvm)
 {
 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 	int irq_source_id = find_first_zero_bit(bitmap,
 				sizeof(kvm->arch.irq_sources_bitmap));

 	if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 		return -EFAULT;
 	}

 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 	set_bit(irq_source_id, bitmap);

 	return irq_source_id;
 }

 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 {
 	int i;

 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);

 	if (irq_source_id < 0 ||
 	    irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 		return;
 	}
 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 		clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 }

 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 				    struct kvm_irq_mask_notifier *kimn)
 {
 	kimn->irq = irq;
 	hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 }

 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 				      struct kvm_irq_mask_notifier *kimn)
 {
 	hlist_del(&kimn->link);
 }

 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 {
 	struct kvm_irq_mask_notifier *kimn;
 	struct hlist_node *n;

 	hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 		if (kimn->irq == irq)
 			kimn->func(kimn, mask);
 }

 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 {
 	struct kvm_kernel_irq_routing_entry *e, *n;

 	list_for_each_entry_safe(e, n, irq_routing, link)
 		kfree(e);
 }

 void kvm_free_irq_routing(struct kvm *kvm)
 {
 	__kvm_free_irq_routing(&kvm->irq_routing);
 }

 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 			       const struct kvm_irq_routing_entry *ue)
 {
 	int r = -EINVAL;
 	int delta;

 	e->gsi = ue->gsi;
 	switch (ue->type) {
 	case KVM_IRQ_ROUTING_IRQCHIP:
 		delta = 0;
 		switch (ue->u.irqchip.irqchip) {
 		case KVM_IRQCHIP_PIC_MASTER:
 			e->set = kvm_set_pic_irq;
 			break;
 		case KVM_IRQCHIP_PIC_SLAVE:
 			e->set = kvm_set_pic_irq;
 			delta = 8;
 			break;
 		case KVM_IRQCHIP_IOAPIC:
 				e->set = kvm_set_ioapic_irq;
 			break;
 		default:
 			goto out;
 		}
 		e->irqchip.irqchip = ue->u.irqchip.irqchip;
 		e->irqchip.pin = ue->u.irqchip.pin + delta;
 		break;
 	case KVM_IRQ_ROUTING_MSI:
 		e->set = kvm_set_msi;
 		e->msi.address_lo = ue->u.msi.address_lo;
 		e->msi.address_hi = ue->u.msi.address_hi;
 		e->msi.data = ue->u.msi.data;
 		break;
 	default:
 		goto out;
 	}
 	r = 0;
 out:
 	return r;
 }


 int kvm_set_irq_routing(struct kvm *kvm,
 			const struct kvm_irq_routing_entry *ue,
 			unsigned nr,
 			unsigned flags)
 {
 	struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 	struct list_head tmp = LIST_HEAD_INIT(tmp);
 	struct kvm_kernel_irq_routing_entry *e = NULL;
 	unsigned i;
 	int r;

 	for (i = 0; i < nr; ++i) {
 		r = -EINVAL;
 		if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 			goto out;
 		if (ue->flags)
 			goto out;
 		r = -ENOMEM;
 		e = kzalloc(sizeof(*e), GFP_KERNEL);
 		if (!e)
 			goto out;
 		r = setup_routing_entry(e, ue);
 		if (r)
 			goto out;
 		++ue;
 		list_add(&e->link, &irq_list);
 		e = NULL;
 	}

 	mutex_lock(&kvm->lock);
 	list_splice(&kvm->irq_routing, &tmp);
 	INIT_LIST_HEAD(&kvm->irq_routing);
 	list_splice(&irq_list, &kvm->irq_routing);
 	INIT_LIST_HEAD(&irq_list);
 	list_splice(&tmp, &irq_list);
 	mutex_unlock(&kvm->lock);

 	r = 0;

 out:
 	kfree(e);
 	__kvm_free_irq_routing(&irq_list);
 	return r;
 }

 #define IOAPIC_ROUTING_ENTRY(irq) \
 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
 	  .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)

 #ifdef CONFIG_X86
 #  define PIC_ROUTING_ENTRY(irq) \
 	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,	\
 	  .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 #  define ROUTING_ENTRY2(irq) \
 	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 #else
 #  define ROUTING_ENTRY2(irq) \
 	IOAPIC_ROUTING_ENTRY(irq)
 #endif

 static const struct kvm_irq_routing_entry default_routing[] = {
 	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 #ifdef CONFIG_IA64
 	ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 	ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 	ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 	ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 	ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 	ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 	ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 	ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 	ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 	ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 	ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 	ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 #endif
 };

 int kvm_setup_default_irq_routing(struct kvm *kvm)
 {
 	return kvm_set_irq_routing(kvm, default_routing,
 				   ARRAY_SIZE(default_routing), 0);
 }
	/*
	* irq_comm.c: Common API for in kernel interrupt controller
	* Copyright (c) 2007, Intel Corporation.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	* Place - Suite 330, Boston, MA 02111-1307 USA.
	* Authors:
	* Yaozu (Eddie) Dong <Eddie.dong@intel.com>
	*
	*/

	#include <linux/kvm_host.h>

	#include <asm/msidef.h>

	#include "irq.h"

	#include "ioapic.h"

	static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
	struct kvm *kvm, int level)
	{
	#ifdef CONFIG_X86
	return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
	#else
	return -1;
	#endif
	}

	static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
	struct kvm *kvm, int level)
	{
	return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
	}

	void kvm_get_intr_delivery_bitmask(struct kvm_ioapic *ioapic,
	union kvm_ioapic_redirect_entry *entry,
	unsigned long *deliver_bitmask)
	{
	struct kvm_vcpu *vcpu;

	*deliver_bitmask = kvm_ioapic_get_delivery_bitmask(ioapic,
	entry->fields.dest_id, entry->fields.dest_mode);
	switch (entry->fields.delivery_mode) {
	case IOAPIC_LOWEST_PRIORITY:
	vcpu = kvm_get_lowest_prio_vcpu(ioapic->kvm,
	entry->fields.vector, *deliver_bitmask);
	*deliver_bitmask = 1 << vcpu->vcpu_id;
	break;
	case IOAPIC_FIXED:
	case IOAPIC_NMI:
	break;
	default:
	if (printk_ratelimit())
	printk(KERN_INFO "kvm: unsupported delivery mode %d\n",
	entry->fields.delivery_mode);
	*deliver_bitmask = 0;
	}
	}

	static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
	struct kvm *kvm, int level)
	{
	int vcpu_id, r = -1;
	struct kvm_vcpu *vcpu;
	struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
	union kvm_ioapic_redirect_entry entry;
	unsigned long deliver_bitmask;

	BUG_ON(!ioapic);

	entry.bits = 0;
	entry.fields.dest_id = (e->msi.address_lo &
	MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
	entry.fields.vector = (e->msi.data &
	MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
	entry.fields.dest_mode = test_bit(MSI_ADDR_DEST_MODE_SHIFT,
	(unsigned long *)&e->msi.address_lo);
	entry.fields.trig_mode = test_bit(MSI_DATA_TRIGGER_SHIFT,
	(unsigned long *)&e->msi.data);
	entry.fields.delivery_mode = test_bit(
	MSI_DATA_DELIVERY_MODE_SHIFT,
	(unsigned long *)&e->msi.data);

	/* TODO Deal with RH bit of MSI message address */

	kvm_get_intr_delivery_bitmask(ioapic, &entry, &deliver_bitmask);

	if (!deliver_bitmask) {
	printk(KERN_WARNING "kvm: no destination for MSI delivery!");
	return -1;
	}
	for (vcpu_id = 0; deliver_bitmask != 0; vcpu_id++) {
	if (!(deliver_bitmask & (1 << vcpu_id)))
	continue;
	deliver_bitmask &= ~(1 << vcpu_id);
	vcpu = ioapic->kvm->vcpus[vcpu_id];
	if (vcpu) {
	if (r < 0)
	r = 0;
	r += kvm_apic_set_irq(vcpu, entry.fields.vector,
	entry.fields.trig_mode);
	}
	}
	return r;
	}

	/* This should be called with the kvm->lock mutex held
	* Return value:
	* < 0 Interrupt was ignored (masked or not delivered for other reasons)
	* = 0 Interrupt was coalesced (previous irq is still pending)
	* > 0 Number of CPUs interrupt was delivered to
	*/
	int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
	{
	struct kvm_kernel_irq_routing_entry *e;
	unsigned long *irq_state, sig_level;
	int ret = -1;

	if (irq < KVM_IOAPIC_NUM_PINS) {
	irq_state = (unsigned long *)&kvm->arch.irq_states[irq];

	/* Logical OR for level trig interrupt */
	if (level)
	set_bit(irq_source_id, irq_state);
	else
	clear_bit(irq_source_id, irq_state);
	sig_level = !!(*irq_state);
	} else /* Deal with MSI/MSI-X */
	sig_level = 1;

	/* Not possible to detect if the guest uses the PIC or the
	* IOAPIC. So set the bit in both. The guest will ignore
	* writes to the unused one.
	*/
	list_for_each_entry(e, &kvm->irq_routing, link)
	if (e->gsi == irq) {
	int r = e->set(e, kvm, sig_level);
	if (r < 0)
	continue;

	ret = r + ((ret < 0) ? 0 : ret);
	}
	return ret;
	}

	void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
	{
	struct kvm_kernel_irq_routing_entry *e;
	struct kvm_irq_ack_notifier *kian;
	struct hlist_node *n;
	unsigned gsi = pin;

	list_for_each_entry(e, &kvm->irq_routing, link)
	if (e->irqchip.irqchip == irqchip &&
	e->irqchip.pin == pin) {
	gsi = e->gsi;
	break;
	}

	hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
	if (kian->gsi == gsi)
	kian->irq_acked(kian);
	}

	void kvm_register_irq_ack_notifier(struct kvm *kvm,
	struct kvm_irq_ack_notifier *kian)
	{
	hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
	}

	void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
	{
	hlist_del_init(&kian->link);
	}

	/* The caller must hold kvm->lock mutex */
	int kvm_request_irq_source_id(struct kvm *kvm)
	{
	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
	int irq_source_id = find_first_zero_bit(bitmap,
	sizeof(kvm->arch.irq_sources_bitmap));

	if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
	printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
	return -EFAULT;
	}

	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
	set_bit(irq_source_id, bitmap);

	return irq_source_id;
	}

	void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
	{
	int i;

	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);

	if (irq_source_id < 0 \|\|
	irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
	printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
	return;
	}
	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
	clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
	}

	void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
	struct kvm_irq_mask_notifier *kimn)
	{
	kimn->irq = irq;
	hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
	}

	void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
	struct kvm_irq_mask_notifier *kimn)
	{
	hlist_del(&kimn->link);
	}

	void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
	{
	struct kvm_irq_mask_notifier *kimn;
	struct hlist_node *n;

	hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
	if (kimn->irq == irq)
	kimn->func(kimn, mask);
	}

	static void __kvm_free_irq_routing(struct list_head *irq_routing)
	{
	struct kvm_kernel_irq_routing_entry e, n;

	list_for_each_entry_safe(e, n, irq_routing, link)
	kfree(e);
	}

	void kvm_free_irq_routing(struct kvm *kvm)
	{
	__kvm_free_irq_routing(&kvm->irq_routing);
	}

	static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
	const struct kvm_irq_routing_entry *ue)
	{
	int r = -EINVAL;
	int delta;

	e->gsi = ue->gsi;
	switch (ue->type) {
	case KVM_IRQ_ROUTING_IRQCHIP:
	delta = 0;
	switch (ue->u.irqchip.irqchip) {
	case KVM_IRQCHIP_PIC_MASTER:
	e->set = kvm_set_pic_irq;
	break;
	case KVM_IRQCHIP_PIC_SLAVE:
	e->set = kvm_set_pic_irq;
	delta = 8;
	break;
	case KVM_IRQCHIP_IOAPIC:
	e->set = kvm_set_ioapic_irq;
	break;
	default:
	goto out;
	}
	e->irqchip.irqchip = ue->u.irqchip.irqchip;
	e->irqchip.pin = ue->u.irqchip.pin + delta;
	break;
	case KVM_IRQ_ROUTING_MSI:
	e->set = kvm_set_msi;
	e->msi.address_lo = ue->u.msi.address_lo;
	e->msi.address_hi = ue->u.msi.address_hi;
	e->msi.data = ue->u.msi.data;
	break;
	default:
	goto out;
	}
	r = 0;
	out:
	return r;
	}


	int kvm_set_irq_routing(struct kvm *kvm,
	const struct kvm_irq_routing_entry *ue,
	unsigned nr,
	unsigned flags)
	{
	struct list_head irq_list = LIST_HEAD_INIT(irq_list);
	struct list_head tmp = LIST_HEAD_INIT(tmp);
	struct kvm_kernel_irq_routing_entry *e = NULL;
	unsigned i;
	int r;

	for (i = 0; i < nr; ++i) {
	r = -EINVAL;
	if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
	goto out;
	if (ue->flags)
	goto out;
	r = -ENOMEM;
	e = kzalloc(sizeof(*e), GFP_KERNEL);
	if (!e)
	goto out;
	r = setup_routing_entry(e, ue);
	if (r)
	goto out;
	++ue;
	list_add(&e->link, &irq_list);
	e = NULL;
	}

	mutex_lock(&kvm->lock);
	list_splice(&kvm->irq_routing, &tmp);
	INIT_LIST_HEAD(&kvm->irq_routing);
	list_splice(&irq_list, &kvm->irq_routing);
	INIT_LIST_HEAD(&irq_list);
	list_splice(&tmp, &irq_list);
	mutex_unlock(&kvm->lock);

	r = 0;

	out:
	kfree(e);
	__kvm_free_irq_routing(&irq_list);
	return r;
	}

	#define IOAPIC_ROUTING_ENTRY(irq) \
	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
	.u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
	#define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)

	#ifdef CONFIG_X86
	# define PIC_ROUTING_ENTRY(irq) \
	{ .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP, \
	.u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
	# define ROUTING_ENTRY2(irq) \
	IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
	#else
	# define ROUTING_ENTRY2(irq) \
	IOAPIC_ROUTING_ENTRY(irq)
	#endif

	static const struct kvm_irq_routing_entry default_routing[] = {
	ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
	ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
	ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
	ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
	ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
	ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
	ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
	ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
	ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
	ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
	ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
	ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
	#ifdef CONFIG_IA64
	ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
	ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
	ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
	ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
	ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
	ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
	ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
	ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
	ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
	ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
	ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
	ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
	#endif
	};

	int kvm_setup_default_irq_routing(struct kvm *kvm)
	{
	return kvm_set_irq_routing(kvm, default_routing,
	ARRAY_SIZE(default_routing), 0);
	}