Use gsi indexed array instead of scanning all entries on each interrupt
injection. Also maintain back mapping from irqchip/pin to gsi to speedup
interrupt acknowledgment notifications.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
include/linux/kvm_host.h | 11 +++++++-
virt/kvm/irq_comm.c | 57 +++++++++++++++++++++++++++++----------------
2 files changed, 46 insertions(+), 22 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6bcc79f..2715e59 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -128,7 +128,14 @@ struct kvm_kernel_irq_routing_entry {
} irqchip;
struct msi_msg msi;
};
- struct list_head link;
+ struct hlist_node link;
+};
+
+struct kvm_irq_routing_table {
+ int chip[3][KVM_IOAPIC_NUM_PINS];
+ struct kvm_kernel_irq_routing_entry *rt_entries;
+ u32 max_gsi;
+ struct hlist_head map[0];
};
struct kvm {
@@ -165,7 +172,7 @@ struct kvm {
#endif
#ifdef CONFIG_HAVE_KVM_IRQCHIP
- struct kvm_kernel_irq_routing_entry *irq_routing;
+ struct kvm_irq_routing_table *irq_routing;
spinlock_t irq_routing_lock;
struct hlist_head mask_notifier_list;
struct hlist_head irq_ack_notifier_list;
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index be30124..ae11114 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -128,6 +128,8 @@ static 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;
+ struct kvm_irq_routing_table *irq_rt;
+ struct hlist_node *n;
trace_kvm_set_irq(irq, level, irq_source_id);
@@ -150,15 +152,15 @@ static int __kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level,
* writes to the unused one.
*/
rcu_read_lock();
- for (e = rcu_dereference(kvm->irq_routing); e && e->set; e++) {
- if (e->gsi == irq) {
+ irq_rt = rcu_dereference(kvm->irq_routing);
+ if (irq < irq_rt->max_gsi)
+ hlist_for_each_entry(e, n, &irq_rt->map[irq], link) {
int r = e->set(e, kvm, sig_level, notifier);
if (r < 0)
continue;
ret = r + ((ret < 0) ? 0 : ret);
}
- }
rcu_read_unlock();
return ret;
}
@@ -175,21 +177,16 @@ int kvm_notifier_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;
+ unsigned gsi;
trace_kvm_ack_irq(irqchip, pin);
rcu_read_lock();
- for (e = rcu_dereference(kvm->irq_routing); e && e->set; e++) {
- if (e->irqchip.irqchip == irqchip &&
- e->irqchip.pin == pin) {
- gsi = e->gsi;
- break;
- }
- }
+ gsi = rcu_dereference(kvm->irq_routing)->chip[irqchip][pin];
+ if (gsi == -1)
+ gsi = pin;
hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list, link)
if (kian->gsi == gsi)
@@ -290,7 +287,8 @@ void kvm_free_irq_routing(struct kvm *kvm)
kfree(kvm->irq_routing);
}
-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;
@@ -316,6 +314,9 @@ static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
}
e->irqchip.irqchip = ue->u.irqchip.irqchip;
e->irqchip.pin = ue->u.irqchip.pin + delta;
+ if (e->irqchip.pin > KVM_IOAPIC_NUM_PINS)
+ goto out;
+ rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
break;
case KVM_IRQ_ROUTING_MSI:
e->set = kvm_set_msi;
@@ -326,6 +327,8 @@ 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;
@@ -337,23 +340,37 @@ int kvm_set_irq_routing(struct kvm *kvm,
unsigned nr,
unsigned flags)
{
- struct kvm_kernel_irq_routing_entry *new, *old;
- unsigned i;
+ struct kvm_irq_routing_table *new, *old;
+ u32 i, j, max_gsi = 0;
int r;
- /* last elemet is left zeored and indicates the end of the array */
- new = kzalloc(sizeof(*new) * (nr + 1), GFP_KERNEL);
+ for (i = 0; i < nr; ++i) {
+ if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
+ return -EINVAL;
+ max_gsi = max(max_gsi, ue[i].gsi);
+ }
+
+ max_gsi += 1;
+
+ new = kzalloc(sizeof(*new) + (max_gsi * sizeof(struct hlist_head)) +
+ (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
+ GFP_KERNEL);
if (!new)
return -ENOMEM;
+ new->rt_entries = (void *)&new->map[max_gsi];
+
+ new->max_gsi = max_gsi;
+ for (i = 0; i < 3; i++)
+ for (j = 0; j < KVM_IOAPIC_NUM_PINS; j++)
+ new->chip[i][j] = -1;
+
for (i = 0; i < nr; ++i) {
r = -EINVAL;
- if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
- goto out;
if (ue->flags)
goto out;
- r = setup_routing_entry(new + i, ue);
+ r = setup_routing_entry(new, &new->rt_entries[i], ue);
if (r)
goto out;
++ue;
--
1.6.2.1
--
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