* [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
@ 2009-04-30 2:58 Sheng Yang
2009-05-04 8:25 ` Avi Kivity
2009-05-31 9:48 ` Avi Kivity
0 siblings, 2 replies; 6+ messages in thread
From: Sheng Yang @ 2009-04-30 2:58 UTC (permalink / raw)
To: Avi Kivity, Marcelo Tosatti; +Cc: kvm, Sheng Yang
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>
---
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 eebc5ed..de8f205 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
--
1.5.4.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
2009-04-30 2:58 [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment Sheng Yang
@ 2009-05-04 8:25 ` Avi Kivity
2009-05-04 8:30 ` Sheng Yang
2009-05-31 9:48 ` Avi Kivity
1 sibling, 1 reply; 6+ messages in thread
From: Avi Kivity @ 2009-05-04 8:25 UTC (permalink / raw)
To: Sheng Yang; +Cc: Marcelo Tosatti, kvm
Sheng Yang wrote:
> 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).
>
>
> 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);
>
I don't have the spin_lock_irqrestore() here. The patch applies, but
with fuzz. Am I missing a patch?
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
2009-05-04 8:25 ` Avi Kivity
@ 2009-05-04 8:30 ` Sheng Yang
2009-05-04 8:34 ` Avi Kivity
0 siblings, 1 reply; 6+ messages in thread
From: Sheng Yang @ 2009-05-04 8:30 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, kvm
On Monday 04 May 2009 16:25:55 Avi Kivity wrote:
> Sheng Yang wrote:
> > 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).
> >
> >
> > 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);
>
> I don't have the spin_lock_irqrestore() here. The patch applies, but
> with fuzz. Am I missing a patch?
Oh, it's Marcelo's patchset...
[patch 0/4] use smp_send_reschedule in vcpu_kick / assigned dev host intx race
fix
--
regards
Yang, Sheng
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
2009-05-04 8:30 ` Sheng Yang
@ 2009-05-04 8:34 ` Avi Kivity
2009-05-04 8:37 ` Sheng Yang
0 siblings, 1 reply; 6+ messages in thread
From: Avi Kivity @ 2009-05-04 8:34 UTC (permalink / raw)
To: Sheng Yang; +Cc: Marcelo Tosatti, kvm
Sheng Yang wrote:
> On Monday 04 May 2009 16:25:55 Avi Kivity wrote:
>
>> Sheng Yang wrote:
>>
>>> 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).
>>>
>>>
>>> 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);
>>>
>> I don't have the spin_lock_irqrestore() here. The patch applies, but
>> with fuzz. Am I missing a patch?
>>
>
> Oh, it's Marcelo's patchset...
>
> [patch 0/4] use smp_send_reschedule in vcpu_kick / assigned dev host intx race
> fix
>
Okay, I am working my queue in reverse order :)
But please note dependencies on other patches for me.
--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
2009-05-04 8:34 ` Avi Kivity
@ 2009-05-04 8:37 ` Sheng Yang
0 siblings, 0 replies; 6+ messages in thread
From: Sheng Yang @ 2009-05-04 8:37 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, kvm
On Monday 04 May 2009 16:34:00 Avi Kivity wrote:
> Sheng Yang wrote:
> > On Monday 04 May 2009 16:25:55 Avi Kivity wrote:
> >> Sheng Yang wrote:
> >>> 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).
> >>>
> >>>
> >>> 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);
> >>
> >> I don't have the spin_lock_irqrestore() here. The patch applies, but
> >> with fuzz. Am I missing a patch?
> >
> > Oh, it's Marcelo's patchset...
> >
> > [patch 0/4] use smp_send_reschedule in vcpu_kick / assigned dev host intx
> > race fix
>
> Okay, I am working my queue in reverse order :)
>
> But please note dependencies on other patches for me.
Yes, sorry for totally forgot (mine based on his patchset)... :(
--
regards
Yang, Sheng
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment
2009-04-30 2:58 [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment Sheng Yang
2009-05-04 8:25 ` Avi Kivity
@ 2009-05-31 9:48 ` Avi Kivity
1 sibling, 0 replies; 6+ messages in thread
From: Avi Kivity @ 2009-05-31 9:48 UTC (permalink / raw)
To: Sheng Yang; +Cc: Marcelo Tosatti, kvm
Sheng Yang wrote:
> 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).
>
Applied, thanks.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 6+ messages in thread
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2009-04-30 2:58 [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment Sheng Yang
2009-05-04 8:25 ` Avi Kivity
2009-05-04 8:30 ` Sheng Yang
2009-05-04 8:34 ` Avi Kivity
2009-05-04 8:37 ` Sheng Yang
2009-05-31 9:48 ` Avi Kivity
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