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| author | Sheng Yang <sheng@linux.intel.com> | 2009-04-30 10:58:42 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-09-10 08:32:43 +0300 |
| commit | 968a6347936f9421b5bc5358b579e811c52726bc (patch) | |
| tree | 0067fd4925db6763c701d9534e54b4b61be1712d /virt/kvm/kvm_main.c | |
| parent | 017cb99e875f2d8ff375cbb576c794b081cd0bd5 (diff) | |
| download | lwn-968a6347936f9421b5bc5358b579e811c52726bc.tar.gz lwn-968a6347936f9421b5bc5358b579e811c52726bc.zip | |
KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
Disable interrupt at interrupt handler and enable it when guest ack is for
the level triggered interrupt, to prevent reinjected interrupt. MSI/MSI-X don't
need it.
One possible problem is multiply same vector interrupt injected between irq
handler and scheduled work handler would be merged as one for MSI/MSI-X.
But AFAIK, the drivers handle it well.
The patch fixed the oplin card performance issue(MSI-X performance is half of
MSI/INTx).
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index dee321e58894..2d9bc439d9a9 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -120,7 +120,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) { struct kvm_assigned_dev_kernel *assigned_dev; struct kvm *kvm; - int irq, i; + int i; assigned_dev = container_of(work, struct kvm_assigned_dev_kernel, interrupt_work); @@ -143,20 +143,10 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, guest_entries[i].vector, 1); - irq = assigned_dev->host_msix_entries[i].vector; - if (irq != 0) - enable_irq(irq); - assigned_dev->host_irq_disabled = false; } - } else { + } else kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, assigned_dev->guest_irq, 1); - if (assigned_dev->irq_requested_type & - KVM_DEV_IRQ_GUEST_MSI) { - enable_irq(assigned_dev->host_irq); - assigned_dev->host_irq_disabled = false; - } - } spin_unlock_irq(&assigned_dev->assigned_dev_lock); mutex_unlock(&assigned_dev->kvm->lock); @@ -179,8 +169,10 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id) schedule_work(&assigned_dev->interrupt_work); - disable_irq_nosync(irq); - assigned_dev->host_irq_disabled = true; + if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) { + disable_irq_nosync(irq); + assigned_dev->host_irq_disabled = true; + } out: spin_unlock_irqrestore(&assigned_dev->assigned_dev_lock, flags); @@ -417,6 +409,7 @@ static int assigned_device_enable_guest_msi(struct kvm *kvm, { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = -1; + dev->host_irq_disabled = false; return 0; } #endif @@ -427,6 +420,7 @@ static int assigned_device_enable_guest_msix(struct kvm *kvm, { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = -1; + dev->host_irq_disabled = false; return 0; } #endif |