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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2011-09-11 10:16:20 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-09-25 19:52:39 +0300 |
| commit | c61fa9d63b40b06522c5f1d940b084323a090688 (patch) | |
| tree | dbabc88d4096a9f155794a6bb48d8ac5274bc1fa /virt/kvm | |
| parent | 9f9f6b78776be3de02e0c7533924e6954b918123 (diff) | |
| download | lwn-c61fa9d63b40b06522c5f1d940b084323a090688.tar.gz lwn-c61fa9d63b40b06522c5f1d940b084323a090688.zip | |
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/kvm')
| -rw-r--r-- | virt/kvm/assigned-dev.c | 18 |
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); |