virt/kvm/irq_comm.c - 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>
  *
  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  */

 #include <linux/kvm_host.h>
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <trace/events/kvm.h>

 #include <asm/msidef.h>
 #ifdef CONFIG_IA64
 #include <asm/iosapic.h>
 #endif

 #include "irq.h"

 #include "ioapic.h"

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

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

 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
 {
 #ifdef CONFIG_IA64
 	return irq->delivery_mode ==
 		(IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
 #else
 	return irq->delivery_mode == APIC_DM_LOWEST;
 #endif
 }

 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
 		struct kvm_lapic_irq *irq, unsigned long *dest_map)
 {
 	int i, r = -1;
 	struct kvm_vcpu *vcpu, *lowest = NULL;

 	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
 			kvm_is_dm_lowest_prio(irq)) {
 		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
 		irq->delivery_mode = APIC_DM_FIXED;
 	}

 	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
 		return r;

 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		if (!kvm_apic_present(vcpu))
 			continue;

 		if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
 					irq->dest_id, irq->dest_mode))
 			continue;

 		if (!kvm_is_dm_lowest_prio(irq)) {
 			if (r < 0)
 				r = 0;
 			kvm_apic_set_irq(vcpu, irq, dest_map);
 			r++;
 		} else if (kvm_lapic_enabled(vcpu)) {
 			if (!lowest)
 				lowest = vcpu;
 			else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
 				lowest = vcpu;
 		}
 	}

 	if (lowest) {
 		kvm_apic_set_irq(lowest, irq, dest_map);
 		r = 1;
 	}

 	return r;
 }

 static inline void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
 				   struct kvm_lapic_irq *irq)
 {
 	trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);

 	irq->dest_id = (e->msi.address_lo &
 			MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 	irq->vector = (e->msi.data &
 			MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 	irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 	irq->delivery_mode = e->msi.data & 0x700;
 	irq->level = 1;
 	irq->shorthand = 0;
 	/* TODO Deal with RH bit of MSI message address */
 }

 int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
 {
 	struct kvm_lapic_irq irq;

 	if (!level)
 		return -1;

 	kvm_set_msi_irq(e, &irq);

 	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
 }


 static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
 			 struct kvm *kvm)
 {
 	struct kvm_lapic_irq irq;
 	int r;

 	kvm_set_msi_irq(e, &irq);

 	if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
 		return r;
 	else
 		return -EWOULDBLOCK;
 }

 /*
  * Deliver an IRQ in an atomic context if we can, or return a failure,
  * user can retry in a process context.
  * Return value:
  *  -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
  *  Other values - No need to retry.
  */
 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 {
 	struct kvm_kernel_irq_routing_entry *e;
 	int ret = -EINVAL;
 	struct kvm_irq_routing_table *irq_rt;

 	trace_kvm_set_irq(irq, level, irq_source_id);

 	/*
 	 * Injection into either PIC or IOAPIC might need to scan all CPUs,
 	 * which would need to be retried from thread context;  when same GSI
 	 * is connected to both PIC and IOAPIC, we'd have to report a
 	 * partial failure here.
 	 * Since there's no easy way to do this, we only support injecting MSI
 	 * which is limited to 1:1 GSI mapping.
 	 */
 	rcu_read_lock();
 	irq_rt = rcu_dereference(kvm->irq_routing);
 	if (irq < irq_rt->nr_rt_entries)
 		hlist_for_each_entry(e, &irq_rt->map[irq], link) {
 			if (likely(e->type == KVM_IRQ_ROUTING_MSI))
 				ret = kvm_set_msi_inatomic(e, kvm);
 			else
 				ret = -EWOULDBLOCK;
 			break;
 		}
 	rcu_read_unlock();
 	return ret;
 }

 int kvm_request_irq_source_id(struct kvm *kvm)
 {
 	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 	int irq_source_id;

 	mutex_lock(&kvm->irq_lock);
 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);

 	if (irq_source_id >= BITS_PER_LONG) {
 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 		irq_source_id = -EFAULT;
 		goto unlock;
 	}

 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 #ifdef CONFIG_X86
 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 #endif
 	set_bit(irq_source_id, bitmap);
 unlock:
 	mutex_unlock(&kvm->irq_lock);

 	return irq_source_id;
 }

 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 {
 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 #ifdef CONFIG_X86
 	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
 #endif

 	mutex_lock(&kvm->irq_lock);
 	if (irq_source_id < 0 ||
 	    irq_source_id >= BITS_PER_LONG) {
 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 		goto unlock;
 	}
 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 	if (!irqchip_in_kernel(kvm))
 		goto unlock;

 	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
 #ifdef CONFIG_X86
 	kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
 #endif
 unlock:
 	mutex_unlock(&kvm->irq_lock);
 }

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

 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 				      struct kvm_irq_mask_notifier *kimn)
 {
 	mutex_lock(&kvm->irq_lock);
 	hlist_del_rcu(&kimn->link);
 	mutex_unlock(&kvm->irq_lock);
 	synchronize_rcu();
 }

 void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
 			     bool mask)
 {
 	struct kvm_irq_mask_notifier *kimn;
 	int gsi;

 	rcu_read_lock();
 	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
 	if (gsi != -1)
 		hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)
 			if (kimn->irq == gsi)
 				kimn->func(kimn, mask);
 	rcu_read_unlock();
 }

 int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
 			  struct kvm_kernel_irq_routing_entry *e,
 			  const struct kvm_irq_routing_entry *ue)
 {
 	int r = -EINVAL;
 	int delta;
 	unsigned max_pin;

 	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;
 			max_pin = PIC_NUM_PINS;
 			break;
 		case KVM_IRQCHIP_PIC_SLAVE:
 			e->set = kvm_set_pic_irq;
 			max_pin = PIC_NUM_PINS;
 			delta = 8;
 			break;
 		case KVM_IRQCHIP_IOAPIC:
 			max_pin = KVM_IOAPIC_NUM_PINS;
 			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;
 		if (e->irqchip.pin >= max_pin)
 			goto out;
 		rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
 		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;
 }

 #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>
	*
	* Copyright 2010 Red Hat, Inc. and/or its affiliates.
	*/

	#include <linux/kvm_host.h>
	#include <linux/slab.h>
	#include <linux/export.h>
	#include <trace/events/kvm.h>

	#include <asm/msidef.h>
	#ifdef CONFIG_IA64
	#include <asm/iosapic.h>
	#endif

	#include "irq.h"

	#include "ioapic.h"

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

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

	inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
	{
	#ifdef CONFIG_IA64
	return irq->delivery_mode ==
	(IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
	#else
	return irq->delivery_mode == APIC_DM_LOWEST;
	#endif
	}

	int kvm_irq_delivery_to_apic(struct kvm kvm, struct kvm_lapic src,
	struct kvm_lapic_irq irq, unsigned long dest_map)
	{
	int i, r = -1;
	struct kvm_vcpu vcpu, lowest = NULL;

	if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
	kvm_is_dm_lowest_prio(irq)) {
	printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
	irq->delivery_mode = APIC_DM_FIXED;
	}

	if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map))
	return r;

	kvm_for_each_vcpu(i, vcpu, kvm) {
	if (!kvm_apic_present(vcpu))
	continue;

	if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
	irq->dest_id, irq->dest_mode))
	continue;

	if (!kvm_is_dm_lowest_prio(irq)) {
	if (r < 0)
	r = 0;
	kvm_apic_set_irq(vcpu, irq, dest_map);
	r++;
	} else if (kvm_lapic_enabled(vcpu)) {
	if (!lowest)
	lowest = vcpu;
	else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
	lowest = vcpu;
	}
	}

	if (lowest) {
	kvm_apic_set_irq(lowest, irq, dest_map);
	r = 1;
	}

	return r;
	}

	static inline void kvm_set_msi_irq(struct kvm_kernel_irq_routing_entry *e,
	struct kvm_lapic_irq *irq)
	{
	trace_kvm_msi_set_irq(e->msi.address_lo, e->msi.data);

	irq->dest_id = (e->msi.address_lo &
	MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
	irq->vector = (e->msi.data &
	MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
	irq->dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
	irq->trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
	irq->delivery_mode = e->msi.data & 0x700;
	irq->level = 1;
	irq->shorthand = 0;
	/* TODO Deal with RH bit of MSI message address */
	}

	int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
	struct kvm *kvm, int irq_source_id, int level, bool line_status)
	{
	struct kvm_lapic_irq irq;

	if (!level)
	return -1;

	kvm_set_msi_irq(e, &irq);

	return kvm_irq_delivery_to_apic(kvm, NULL, &irq, NULL);
	}


	static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
	struct kvm *kvm)
	{
	struct kvm_lapic_irq irq;
	int r;

	kvm_set_msi_irq(e, &irq);

	if (kvm_irq_delivery_to_apic_fast(kvm, NULL, &irq, &r, NULL))
	return r;
	else
	return -EWOULDBLOCK;
	}

	/*
	* Deliver an IRQ in an atomic context if we can, or return a failure,
	* user can retry in a process context.
	* Return value:
	* -EWOULDBLOCK - Can't deliver in atomic context: retry in a process context.
	* Other values - No need to retry.
	*/
	int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
	{
	struct kvm_kernel_irq_routing_entry *e;
	int ret = -EINVAL;
	struct kvm_irq_routing_table *irq_rt;

	trace_kvm_set_irq(irq, level, irq_source_id);

	/*
	* Injection into either PIC or IOAPIC might need to scan all CPUs,
	* which would need to be retried from thread context; when same GSI
	* is connected to both PIC and IOAPIC, we'd have to report a
	* partial failure here.
	* Since there's no easy way to do this, we only support injecting MSI
	* which is limited to 1:1 GSI mapping.
	*/
	rcu_read_lock();
	irq_rt = rcu_dereference(kvm->irq_routing);
	if (irq < irq_rt->nr_rt_entries)
	hlist_for_each_entry(e, &irq_rt->map[irq], link) {
	if (likely(e->type == KVM_IRQ_ROUTING_MSI))
	ret = kvm_set_msi_inatomic(e, kvm);
	else
	ret = -EWOULDBLOCK;
	break;
	}
	rcu_read_unlock();
	return ret;
	}

	int kvm_request_irq_source_id(struct kvm *kvm)
	{
	unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
	int irq_source_id;

	mutex_lock(&kvm->irq_lock);
	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);

	if (irq_source_id >= BITS_PER_LONG) {
	printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
	irq_source_id = -EFAULT;
	goto unlock;
	}

	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
	#ifdef CONFIG_X86
	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
	#endif
	set_bit(irq_source_id, bitmap);
	unlock:
	mutex_unlock(&kvm->irq_lock);

	return irq_source_id;
	}

	void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
	{
	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
	#ifdef CONFIG_X86
	ASSERT(irq_source_id != KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID);
	#endif

	mutex_lock(&kvm->irq_lock);
	if (irq_source_id < 0 \|\|
	irq_source_id >= BITS_PER_LONG) {
	printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
	goto unlock;
	}
	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
	if (!irqchip_in_kernel(kvm))
	goto unlock;

	kvm_ioapic_clear_all(kvm->arch.vioapic, irq_source_id);
	#ifdef CONFIG_X86
	kvm_pic_clear_all(pic_irqchip(kvm), irq_source_id);
	#endif
	unlock:
	mutex_unlock(&kvm->irq_lock);
	}

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

	void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
	struct kvm_irq_mask_notifier *kimn)
	{
	mutex_lock(&kvm->irq_lock);
	hlist_del_rcu(&kimn->link);
	mutex_unlock(&kvm->irq_lock);
	synchronize_rcu();
	}

	void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
	bool mask)
	{
	struct kvm_irq_mask_notifier *kimn;
	int gsi;

	rcu_read_lock();
	gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
	if (gsi != -1)
	hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)
	if (kimn->irq == gsi)
	kimn->func(kimn, mask);
	rcu_read_unlock();
	}

	int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
	struct kvm_kernel_irq_routing_entry *e,
	const struct kvm_irq_routing_entry *ue)
	{
	int r = -EINVAL;
	int delta;
	unsigned max_pin;

	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;
	max_pin = PIC_NUM_PINS;
	break;
	case KVM_IRQCHIP_PIC_SLAVE:
	e->set = kvm_set_pic_irq;
	max_pin = PIC_NUM_PINS;
	delta = 8;
	break;
	case KVM_IRQCHIP_IOAPIC:
	max_pin = KVM_IOAPIC_NUM_PINS;
	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;
	if (e->irqchip.pin >= max_pin)
	goto out;
	rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
	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;
	}

	#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);
	}