KVM: Move IO APIC to its own lock
The allows removal of irq_lock from the injection path.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 9fe140b..38a2d20 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -182,6 +182,7 @@
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 @@
}
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,
- int trigger_mode)
+static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
+ int trigger_mode)
{
- union kvm_ioapic_redirect_entry *ent;
+ int i;
- ent = &ioapic->redirtbl[pin];
+ for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+ union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
- kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
+ if (ent->fields.vector != vector)
+ continue;
- if (trigger_mode == IOAPIC_LEVEL_TRIG) {
+ /*
+ * 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);
+
+ if (trigger_mode != IOAPIC_LEVEL_TRIG)
+ continue;
+
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 @@
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 @@
result = 0;
break;
}
+ mutex_unlock(&ioapic->lock);
+
switch (len) {
case 8:
*(u64 *) val = result;
@@ -277,7 +297,6 @@
default:
printk(KERN_WARNING "ioapic: wrong length %d\n", len);
}
- mutex_unlock(&ioapic->kvm->irq_lock);
return 0;
}
@@ -293,15 +312,15 @@
(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 @@
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 @@
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 @@
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;
+}
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 6e461ad..419c43b 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -45,6 +45,7 @@
struct kvm_io_device dev;
struct kvm *kvm;
void (*ack_notifier)(void *opaque, int irq);
+ struct mutex lock;
};
#ifdef DEBUG
@@ -74,4 +75,7 @@
void kvm_ioapic_reset(struct kvm_ioapic *ioapic);
int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq);
+int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
+int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state);
+
#endif
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 6c94614..fadf440 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -146,8 +146,8 @@
*/
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_kernel_irq_routing_entry *e, irq_set[KVM_NR_IRQCHIPS];
+ int ret = -1, i = 0;
struct kvm_irq_routing_table *irq_rt;
struct hlist_node *n;
@@ -162,14 +162,19 @@
rcu_read_lock();
irq_rt = rcu_dereference(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;
-
- ret = r + ((ret < 0) ? 0 : ret);
- }
+ hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
+ irq_set[i++] = *e;
rcu_read_unlock();
+
+ while(i--) {
+ int r;
+ r = irq_set[i].set(&irq_set[i], kvm, irq_source_id, level);
+ if (r < 0)
+ continue;
+
+ ret = r + ((ret < 0) ? 0 : ret);
+ }
+
return ret;
}