[libvirt] [PATCH] qemu: Allow graceful domain destroy

[Daniel P. Berrange]

On Wed, Aug 24, 2011 at 09:53:49AM +0200, Jiri Denemark wrote:
> On Tue, Aug 23, 2011 at 14:31:29 +0100, Daniel P. Berrange wrote:
> > On Tue, Aug 23, 2011 at 02:36:02PM +0200, Michal Privoznik wrote:
> > > On 22.08.2011 20:31, Daniel P. Berrange wrote:
> > > > We need to make this more controllable by apps, by making it possible
> > > > to send just the SIGTERM and not the SIGKILL. Then we can add a new
> > > > flag to virDomainDestroy to request this SIGTERM only behaviour. If
> > > > the guest does not actually die, the mgmt app can then just reinvoke
> > > > virDomainDestroy without the flag, to get the full SIGTERM+SIGKILL
> > > > behaviour we have today.
> > > 
> > > Sending signal to qemu process is just a part of domain destroying. What
> > > about cleanup code (emitting event, audit log, removing transient
> > > domain, ...)? Can I rely on monitor EOF handling code?  What should be
> > > the return value for this case when only SIGTERM is sent?
> > 
> > QEMU will send an event on the monitor when it shuts down cleanly
> > via 'SIGQUIT' - we already handle that.
> 
> Yes, but that will confuse libvirt and apps because we won't be able to
> distinguish between normal shutdown and destroy with flushed caches. But
> that should probably be solved in qemu by sending different events in this two
> cases.

Well if that is the case, then we already have that problem, because
libvirt is already sending SIGQUIT to destroy QEMU.

Regards,
Daniel
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