Re: [Qemu-devel] [PATCH v4 00/16] IOMMU: Enable interrupt remapping for Intel IOMMU

[Peter Xu]

On Mon, May 09, 2016 at 01:58:48PM +0200, Paolo Bonzini wrote:
> Is this enough too?
> 
> diff --git a/hw/intc/ioapic.c b/hw/intc/ioapic.c
> index 378e663..2443a35 100644
> --- a/hw/intc/ioapic.c
> +++ b/hw/intc/ioapic.c
> @@ -72,6 +72,7 @@ static void ioapic_service(IOAPICCommonState *s)
>                      (entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) & IOAPIC_DM_MASK;
>                  if (trig_mode == IOAPIC_TRIGGER_EDGE) {
>                      s->irr &= ~mask;
> +                    s->ioredtbl[i] &= ~IOAPIC_LVT_REMOTE_IRR;
>                  } else {
>                      coalesce = s->ioredtbl[i] & IOAPIC_LVT_REMOTE_IRR;
>                      s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;

I gave it a quick shot on this but still got the warning. :(

I _guess_ the problem is: the above change is in the "if" block of
(s->irr & mask), when the kernel plays the trick of EOI, the irq
should be pulled down already by the device (or say, irr bit is
cleared). So it does not go into this "if" block.

-- peterx