Commit 46e624b9 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
Browse files

KVM: Change irq routing table to use gsi indexed array 



Use gsi indexed array instead of scanning all entries on each interrupt
injection.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 1a6e4a8c

include/linux/kvm_host.h

+18 −3
Original line number Diff line number Diff line
@@ -128,7 +128,17 @@ struct kvm_kernel_irq_routing_entry { 
		} irqchip;

		struct msi_msg msi;

	};

	struct list_head link;

	struct hlist_node link;

};



struct kvm_irq_routing_table {

	struct kvm_kernel_irq_routing_entry *rt_entries;

	u32 nr_rt_entries;

	/*

	 * Array indexed by gsi. Each entry contains list of irq chips

	 * the gsi is connected to.

	 */

	struct hlist_head map[0];

};



struct kvm {
@@ -166,7 +176,7 @@ struct kvm { 


	struct mutex irq_lock;

#ifdef CONFIG_HAVE_KVM_IRQCHIP

	struct list_head irq_routing; /* of kvm_kernel_irq_routing_entry */

	struct kvm_irq_routing_table *irq_routing;

	struct hlist_head mask_notifier_list;

#endif
@@ -390,7 +400,12 @@ void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq, 
				      struct kvm_irq_mask_notifier *kimn);

void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask);



int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);

#ifdef __KVM_HAVE_IOAPIC

void kvm_get_intr_delivery_bitmask(struct kvm_ioapic *ioapic,

				   union kvm_ioapic_redirect_entry *entry,

				   unsigned long *deliver_bitmask);

#endif

int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level);

void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);

void kvm_register_irq_ack_notifier(struct kvm *kvm,

				   struct kvm_irq_ack_notifier *kian);

virt/kvm/irq_comm.c

+53 −35
Original line number Diff line number Diff line
@@ -144,10 +144,12 @@ static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, 
 *  = 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)

int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)

{

	struct kvm_kernel_irq_routing_entry *e;

	int ret = -1;

	struct kvm_irq_routing_table *irq_rt;

	struct hlist_node *n;



	trace_kvm_set_irq(irq, level, irq_source_id);
@@ -157,8 +159,9 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level) 
	 * 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) {

	irq_rt = kvm->irq_routing;

	if (irq < irq_rt->nr_rt_entries)

		hlist_for_each_entry(e, n, &irq_rt->map[irq], link) {

			int r = e->set(e, kvm, irq_source_id, level);

			if (r < 0)

				continue;
@@ -170,20 +173,23 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level) 


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;

	int i;



	trace_kvm_ack_irq(irqchip, pin);



	list_for_each_entry(e, &kvm->irq_routing, link)

	for (i = 0; i < kvm->irq_routing->nr_rt_entries; i++) {

		struct kvm_kernel_irq_routing_entry *e;

		e = &kvm->irq_routing->rt_entries[i];

		if (e->type == KVM_IRQ_ROUTING_IRQCHIP &&

		    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)
@@ -280,26 +286,30 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask) 
			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)

{

	mutex_lock(&kvm->irq_lock);

	__kvm_free_irq_routing(&kvm->irq_routing);

	kfree(kvm->irq_routing);

	mutex_unlock(&kvm->irq_lock);

}



static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,

static int setup_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;

	struct kvm_kernel_irq_routing_entry *ei;

	struct hlist_node *n;



	/*

	 * Do not allow GSI to be mapped to the same irqchip more than once.

	 * Allow only one to one mapping between GSI and MSI.

	 */

	hlist_for_each_entry(ei, n, &rt->map[ue->gsi], link)

		if (ei->type == KVM_IRQ_ROUTING_MSI ||

		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)

			return r;



	e->gsi = ue->gsi;

	e->type = ue->type;
@@ -332,6 +342,8 @@ static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e, 
	default:

		goto out;

	}



	hlist_add_head(&e->link, &rt->map[e->gsi]);

	r = 0;

out:

	return r;
@@ -343,43 +355,49 @@ int kvm_set_irq_routing(struct kvm *kvm, 
			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;

	struct kvm_irq_routing_table *new, *old;

	u32 i, nr_rt_entries = 0;

	int r;



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

		if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)

			return -EINVAL;

		nr_rt_entries = max(nr_rt_entries, ue[i].gsi);

	}



	nr_rt_entries += 1;



	new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))

		      + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),

		      GFP_KERNEL);



	if (!new)

		return -ENOMEM;



	new->rt_entries = (void *)&new->map[nr_rt_entries];



	new->nr_rt_entries = nr_rt_entries;



	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);

		r = setup_routing_entry(new, &new->rt_entries[i], ue);

		if (r)

			goto out;

		++ue;

		list_add(&e->link, &irq_list);

		e = NULL;

	}



	mutex_lock(&kvm->irq_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);

	old = kvm->irq_routing;

	kvm->irq_routing = new;

	mutex_unlock(&kvm->irq_lock);



	new = old;

	r = 0;



out:

	kfree(e);

	__kvm_free_irq_routing(&irq_list);

	kfree(new);

	return r;

}

virt/kvm/kvm_main.c

+0 −1
Original line number Diff line number Diff line
@@ -957,7 +957,6 @@ static struct kvm *kvm_create_vm(void) 
	if (IS_ERR(kvm))

		goto out;

#ifdef CONFIG_HAVE_KVM_IRQCHIP

	INIT_LIST_HEAD(&kvm->irq_routing);

	INIT_HLIST_HEAD(&kvm->mask_notifier_list);

#endif