Re: [PATCH 0/2] Introduce panic hypercall

Avi Kivity
2011-06-20T17:23:29Z

On 06/20/2011 08:13 PM, Jan Kiszka wrote:
> > A watchdog has the advantage that is also detects lockups.
> >
> > In fact you could implement the panic device via the existing
> > watchdogs. Simply program the timer for the minimum interval and
> > *don't* service the interrupt. This would work for non-virt setups as
> > well as another way to issue a reset.
>
> If you manage to bring down the other guest CPUs fast enough. Otherwise,
> they may corrupt your crashdump before the host had a chance to collect
> all pieces. Synchronous signaling to the hypervisor is a bit safer.

You could NMI-IPI them. But I agree a synchronous signal is better
(note it's not race-free itself).

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