Re: [PATCH] KVM: No disable_irq for MSI/MSI-X interrupt on device assignment

[Sheng Yang <sheng@linux.intel.com>]

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