Re: [PATCH 06/20] tools/xenstore: remove all watches when a domain has stopped

[Juergen Gross <jgross@xxxxxxxx>]

On 07.11.22 19:33, Julien Grall wrote:
> On 07/11/2022 07:54, Juergen Gross wrote:
> > On 06.11.22 22:18, Julien Grall wrote:
> > > Hi Juergen,
> > >
> > > On 01/11/2022 15:28, Juergen Gross wrote:
> > > > When a domain has been recognized to have stopped, remove all its
> > > > registered watches. This avoids sending watch events to the dead domain
> > > > when all the nodes related to it are being removed by the Xen tools.
> > >  From my understanding, shutdown doesn't mean dead. It may be used during 
> > > migration (or snapshotting), where we don't want to touch the state in case 
> > > of a cancellation (or resume).
> > > For instance, see the command XS_RESUME which will clear domain->shutdown.
> > Oh, good catch!
> >
> > I need to additionally check the "shutdown reason". I can remove the
> > watches only in case of the reason not having been "suspend".
> This is quite fragile because we may add new shutdown code in the future that 
> could resume.
> I think it would be better to only delete the watches if the domain is 
> effectively dying (I don't think it can come back from that state)
This is how it is done today.

The domain's Xenstore entries are removed before the domain is being
destroyed.


Juergen

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