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-rw-r--r--virt/kvm/ioapic.c46
-rw-r--r--virt/kvm/ioapic.h2
2 files changed, 46 insertions, 2 deletions
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index e8ce34c9db32..0ba4057d271b 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -405,6 +405,26 @@ void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
spin_unlock(&ioapic->lock);
}
+static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
+{
+ int i;
+ struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic,
+ eoi_inject.work);
+ spin_lock(&ioapic->lock);
+ for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+ union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
+
+ if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG)
+ continue;
+
+ if (ioapic->irr & (1 << i) && !ent->fields.remote_irr)
+ ioapic_service(ioapic, i, false);
+ }
+ spin_unlock(&ioapic->lock);
+}
+
+#define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
+
static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
struct kvm_ioapic *ioapic, int vector, int trigger_mode)
{
@@ -435,8 +455,26 @@ static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
ent->fields.remote_irr = 0;
- if (ioapic->irr & (1 << i))
- ioapic_service(ioapic, i, false);
+ if (!ent->fields.mask && (ioapic->irr & (1 << i))) {
+ ++ioapic->irq_eoi[i];
+ if (ioapic->irq_eoi[i] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
+ /*
+ * Real hardware does not deliver the interrupt
+ * immediately during eoi broadcast, and this
+ * lets a buggy guest make slow progress
+ * even if it does not correctly handle a
+ * level-triggered interrupt. Emulate this
+ * behavior if we detect an interrupt storm.
+ */
+ schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
+ ioapic->irq_eoi[i] = 0;
+ trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
+ } else {
+ ioapic_service(ioapic, i, false);
+ }
+ } else {
+ ioapic->irq_eoi[i] = 0;
+ }
}
}
@@ -565,12 +603,14 @@ static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
{
int i;
+ cancel_delayed_work_sync(&ioapic->eoi_inject);
for (i = 0; i < IOAPIC_NUM_PINS; i++)
ioapic->redirtbl[i].fields.mask = 1;
ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
ioapic->ioregsel = 0;
ioapic->irr = 0;
ioapic->id = 0;
+ memset(ioapic->irq_eoi, 0x00, IOAPIC_NUM_PINS);
rtc_irq_eoi_tracking_reset(ioapic);
update_handled_vectors(ioapic);
}
@@ -589,6 +629,7 @@ int kvm_ioapic_init(struct kvm *kvm)
if (!ioapic)
return -ENOMEM;
spin_lock_init(&ioapic->lock);
+ INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work);
kvm->arch.vioapic = ioapic;
kvm_ioapic_reset(ioapic);
kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
@@ -609,6 +650,7 @@ void kvm_ioapic_destroy(struct kvm *kvm)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
+ cancel_delayed_work_sync(&ioapic->eoi_inject);
if (ioapic) {
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
kvm->arch.vioapic = NULL;
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 90d43e95dcf8..e23b70634f1e 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -59,6 +59,8 @@ struct kvm_ioapic {
spinlock_t lock;
DECLARE_BITMAP(handled_vectors, 256);
struct rtc_status rtc_status;
+ struct delayed_work eoi_inject;
+ u32 irq_eoi[IOAPIC_NUM_PINS];
};
#ifdef DEBUG