Re: NetBSD dom0 PVH: hardware interrupts stalls

[Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>]

On Fri, Nov 27, 2020 at 12:29:35PM +0100, Jan Beulich wrote:
> On 27.11.2020 11:59, Roger Pau Monné wrote:
> > --- a/xen/arch/x86/hvm/irq.c
> > +++ b/xen/arch/x86/hvm/irq.c
> > @@ -187,6 +187,10 @@ void hvm_gsi_assert(struct domain *d, unsigned int gsi)
> >       * to know if the GSI is pending or not.
> >       */
> >      spin_lock(&d->arch.hvm.irq_lock);
> > +    if ( gsi == TRACK_IRQ )
> > +        debugtrace_printk("hvm_gsi_assert irq %u trig %u assert count 
> > %u\n",
> > +                          gsi, trig, hvm_irq->gsi_assert_count[gsi]);
> 
> This produces
> 
> 81961 hvm_gsi_assert irq 34 trig 1 assert count 1
> 
> Since the logging occurs ahead of the call to assert_gsi(), it
> means we don't signal anything to Dom0, because according to our
> records there's still an IRQ in flight. Unfortunately we only
> see the tail of the trace, so it's not possible to tell how / when
> we got into this state.
> 
> Manuel - is this the only patch you have in place? Or did you keep
> any prior ones? Iirc there once was one where Roger also suppressed
> some de-assert call.

Yes, I have some of the previous patches (otherwise Xen panics).
Attached is the diffs I currently have 

-- 
Manuel Bouyer <bouyer@xxxxxxxxxxxxxxx>
     NetBSD: 26 ans d'experience feront toujours la difference
--

Attachment: xen.diff
Description: Text document