Re: [Qemu-devel] KVM: Windows 64-bit troubles with user space irqchip

[Gleb Natapov]

On Sun, Feb 06, 2011 at 12:26:40PM +0200, Avi Kivity wrote:
> On 02/03/2011 04:15 PM, Gleb Natapov wrote:
> >>
> >>  Maybe this is true for the in-kernel model, but I don't see the issue
> >>  (anymore) for the way user space works.
> >>
> >With patch below I can boot Windows7.
> >
> >diff --git a/hw/apic.c b/hw/apic.c
> >index 146deca..fdcac88 100644
> >--- a/hw/apic.c
> >+++ b/hw/apic.c
> >@@ -600,7 +600,7 @@ int apic_get_interrupt(DeviceState *d)
> >      intno = get_highest_priority_int(s->irr);
> >      if (intno<  0)
> >          return -1;
> >-    if (s->tpr&&  intno<= s->tpr)
> >+    if ((s->tpr>>  4)&&  (intno>>  4)<= (s->tpr>>  4))
> >          return s->spurious_vec&  0xff;
> >      reset_bit(s->irr, intno);
> >      set_bit(s->isr, intno);
> 
> That still allows interrupts that have higher priority than the TPR,
> but lower priority than interrupts in the ISR to be injected.  I
> think we need to use the PPR here (same as apic_update_irq()).
> 
We shouldn't get here if isr is non-empty, but see the patch I posted
today to qemu-devel. It does what you say anyway.

--
                        Gleb.