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authorJan Kiszka <jan.kiszka@siemens.com>2011-09-11 10:16:20 +0200
committerAvi Kivity <avi@redhat.com>2011-09-25 19:52:39 +0300
commitc61fa9d63b40b06522c5f1d940b084323a090688 (patch)
treedbabc88d4096a9f155794a6bb48d8ac5274bc1fa /virt
parent9f9f6b78776be3de02e0c7533924e6954b918123 (diff)
downloadlinux-linaro-stable-c61fa9d63b40b06522c5f1d940b084323a090688.tar.gz
KVM: Avoid needless registrations of IRQ ack notifier for assigned devices
We only perform work in kvm_assigned_dev_ack_irq if the guest IRQ is of INTx type. This completely avoids the callback invocation in non-INTx cases by registering the IRQ ack notifier only for INTx. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/assigned-dev.c18
1 files changed, 8 insertions, 10 deletions
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index ea1bf5d424ea..84ead5489650 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -86,13 +86,9 @@ static irqreturn_t kvm_assigned_dev_thread(int irq, void *dev_id)
/* Ack the irq line for an assigned device */
static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
{
- struct kvm_assigned_dev_kernel *dev;
-
- if (kian->gsi == -1)
- return;
-
- dev = container_of(kian, struct kvm_assigned_dev_kernel,
- ack_notifier);
+ struct kvm_assigned_dev_kernel *dev =
+ container_of(kian, struct kvm_assigned_dev_kernel,
+ ack_notifier);
kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
@@ -110,8 +106,9 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
static void deassign_guest_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev)
{
- kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);
- assigned_dev->ack_notifier.gsi = -1;
+ if (assigned_dev->ack_notifier.gsi != -1)
+ kvm_unregister_irq_ack_notifier(kvm,
+ &assigned_dev->ack_notifier);
kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
assigned_dev->guest_irq, 0);
@@ -404,7 +401,8 @@ static int assign_guest_irq(struct kvm *kvm,
if (!r) {
dev->irq_requested_type |= guest_irq_type;
- kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
+ if (dev->ack_notifier.gsi != -1)
+ kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
} else
kvm_free_irq_source_id(kvm, dev->irq_source_id);