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authorSheng Yang <sheng@linux.intel.com>2009-04-30 10:58:42 +0800
committerAvi Kivity <avi@redhat.com>2009-09-10 08:32:43 +0300
commit968a6347936f9421b5bc5358b579e811c52726bc (patch)
tree0067fd4925db6763c701d9534e54b4b61be1712d /virt
parent017cb99e875f2d8ff375cbb576c794b081cd0bd5 (diff)
downloadlinux-linaro-stable-968a6347936f9421b5bc5358b579e811c52726bc.tar.gz
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')
-rw-r--r--virt/kvm/kvm_main.c22
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