Re: [PATCH][v2] Hybrid extension support in Xen

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

On Tuesday 02 February 2010 21:52:55 Ian Campbell wrote:
> On Tue, 2010-02-02 at 08:16 +0000, Sheng Yang wrote:
> > diff --git a/xen/arch/x86/hvm/irq.c b/xen/arch/x86/hvm/irq.c
> > --- a/xen/arch/x86/hvm/irq.c
> > +++ b/xen/arch/x86/hvm/irq.c
> > @@ -46,8 +46,18 @@ static void __hvm_pci_intx_assert(
> >      if ( (hvm_irq->pci_link_assert_count[link]++ == 0) && isa_irq &&
> >           (hvm_irq->gsi_assert_count[isa_irq]++ == 0) )
> >      {
> > -        vioapic_irq_positive_edge(d, isa_irq);
> > -        vpic_irq_positive_edge(d, isa_irq);
> > +        if ( !is_hybrid_evtchn_enabled_domain(d) )
> > +        {
> > +            vioapic_irq_positive_edge(d, isa_irq);
> > +            vpic_irq_positive_edge(d, isa_irq);
> > +        }
> > +        else
> > +        {
> > +            /* TODO fix the critical region here */
> > +            spin_unlock(&d->arch.hvm_domain.irq_lock);
> > +            send_guest_global_virq(d, VIRQ_EMUL_PIN(isa_irq));
> > +            spin_lock(&d->arch.hvm_domain.irq_lock);
> > +       }
> >      }
> >  }
> 
> This can't be right, at least not without a big comment explaining why
> it is safe to drop the lock here...

... Would address this in the next version.

-- 
regards
Yang, Sheng