Re: [PATCH] hw/intc/arm_gicv3_cpuif: Tolerate spurious EOIR writes - Jean-Philippe Brucker

From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: peter.maydell@linaro.org, qemu-arm@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [PATCH] hw/intc/arm_gicv3_cpuif: Tolerate spurious EOIR writes
Date: Thu, 3 Jun 2021 15:14:05 +0200	[thread overview]
Message-ID: <YLjVnWV7ZgEj/cpw@myrica> (raw)
In-Reply-To: <31c4e422-5451-3c0a-f5e6-df75559c9a9b@redhat.com>

On Thu, Jun 03, 2021 at 02:39:30PM +0200, Philippe Mathieu-Daudé wrote:
> > diff --git a/hw/intc/arm_gicv3_cpuif.c b/hw/intc/arm_gicv3_cpuif.c
> > index 81f94c7f4a..1d0964c9bf 100644
> > --- a/hw/intc/arm_gicv3_cpuif.c
> > +++ b/hw/intc/arm_gicv3_cpuif.c
> > @@ -1357,7 +1357,8 @@ static void icc_eoir_write(CPUARMState *env, const ARMCPRegInfo *ri,
> >          }
> >          break;
> >      default:
> > -        g_assert_not_reached();
> > +        /* No interrupt was active, this is UNPREDICTABLE. Ignore it. */
> 
> A qemu_log_mask(LOG_GUEST_ERROR, ...) call here could be useful,
> do you mind adding it?

No problem. I had it at first, but then wondered if that meant I should
update similar cases in the GIC device that silently ignore guest errors
at the moment (e.g. the guest writes a number > 1023 to EOIR) and decided
against it. I'll resend with only this error report if there is no
objection.

Thanks,
Jean

> > +        return;
> >      }
> >  
> >      icc_drop_prio(cs, grp);
> > 
> 