Re: [Qemu-devel] pvpanic plans?

[Michael S. Tsirkin]

On Thu, Oct 31, 2013 at 05:17:24PM +0100, Paolo Bonzini wrote:
> Il 31/10/2013 17:14, Michael S. Tsirkin ha scritto:
> >> PANICKED->DEBUG was added by commit bc7d0e667.  That commit can be
> >> reverted if the panicked state is removed from runstate_needs_reset.
> > 
> > Okay so let's drop the code duplication and explicitly make
> > them the same?
> > 
> > Signed-off-by: Michael S. Tsirkin <address@hidden>
> > 
> > 
> > diff --git a/vl.c b/vl.c
> > index 46c29c4..e12d317 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -638,10 +638,6 @@ static const RunStateTransition 
> > runstate_transitions_def[] = {
> >      { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
> >      { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
> >  
> > -    { RUN_STATE_GUEST_PANICKED, RUN_STATE_PAUSED },
> > -    { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
> > -    { RUN_STATE_GUEST_PANICKED, RUN_STATE_DEBUG },
> > -
> >      { RUN_STATE_MAX, RUN_STATE_MAX },
> >  };
> >  
> > @@ -660,6 +656,12 @@ static void runstate_init(void)
> >  
> >      for (p = &runstate_transitions_def[0]; p->from != RUN_STATE_MAX; p++) {
> >          runstate_valid_transitions[p->from][p->to] = true;
> > +        /* Panicked state is same as paused, we only made it different so
> > +         * management can detect a panic.
> > +         */
> > +        if (p->from == RUN_STATE_PAUSED) {
> > +            runstate_valid_transitions[RUN_STATE_GUEST_PANICKED][p->to] = 
> > true;
> 
> It makes only sense to me if you do that for IO_ERROR and WATCHDOG as
> well, and perhaps there are others I'm missing.  Just add a comment
> before runstate_transitions_def's entries for PANICKED, IO_ERROR and
> WATCHDOG.
> 
> But again, it is somewhat separate from the issue at hand, which is to
> finally make pvpanic usable and hopefully before 1.7.
> 
> Paolo

The issue is that you can't continue from panicked state.
You should be able to do that without going through paused.

> > +        }
> >      }
> >  }
> >  
> > @@ -686,8 +688,7 @@ int runstate_is_running(void)
> >  bool runstate_needs_reset(void)
> >  {
> >      return runstate_check(RUN_STATE_INTERNAL_ERROR) ||
> > -        runstate_check(RUN_STATE_SHUTDOWN) ||
> > -        runstate_check(RUN_STATE_GUEST_PANICKED);
> > +        runstate_check(RUN_STATE_SHUTDOWN);
> >  }
> >  
> >  StatusInfo *qmp_query_status(Error **errp)
> >