Re: [PATCH] hw/intc: Handle software disabling of APIC correctly

[Jay Khandkar <jaykhandkar2002@gmail.com>]

On Fri, Jul 29, 2022 at 06:09:01PM +0100, Peter Maydell wrote:
> On Tue, 12 Jul 2022 at 19:38, Jay Khandkar <jaykhandkar2002@gmail.com> wrote:
> >
> > When the local APIC is in a software disabled state, all local interrupt
> > sources must be masked and all attempts to unmask them should be
> > ignored. Currently, we don't do either. Fix this by handling it
> > correctly in apic_mem_write().
> >
> > Signed-off-by: Jay Khandkar <jaykhandkar2002@gmail.com>
> > ---
> >  hw/intc/apic.c | 16 +++++++++++++---
> >  1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/intc/apic.c b/hw/intc/apic.c
> > index 3df11c34d6..493c70af62 100644
> > --- a/hw/intc/apic.c
> > +++ b/hw/intc/apic.c
> > @@ -792,9 +792,16 @@ static void apic_mem_write(void *opaque, hwaddr addr, uint64_t val,
> >          s->dest_mode = val >> 28;
> >          break;
> >      case 0x0f:
> > -        s->spurious_vec = val & 0x1ff;
> > -        apic_update_irq(s);
> > -        break;
> > +        {
> > +            s->spurious_vec = val & 0x1ff;
> > +            if (!(val & APIC_SPURIO_ENABLED)) {
> > +                for (int i = 0; i < APIC_LVT_NB; i++) {
> > +                    s->lvt[i] |= APIC_LVT_MASKED;
> > +                }
> > +            }
> > +            apic_update_irq(s);
> > +            break;
> > +        }
> 
> What are the braces for here ? There's no local variable declaration...
> 
> thanks
> -- PMM
You are right, the braces are unnecessary for that part. I just put them in to
create a neat visually separate block. Can get rid of them.

Thanks,
Jay