Re: [Qemu-devel] [PATCH 3/4] savevm: fix savevm after migration

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Kevin Wolf (kwolf@redhat.com) wrote:
> Am 07.03.2017 um 10:59 hat Vladimir Sementsov-Ogievskiy geschrieben:
> > 07.03.2017 12:53, Kevin Wolf wrote:
> > >Am 25.02.2017 um 20:31 hat Vladimir Sementsov-Ogievskiy geschrieben:
> > >>After migration all drives are inactive and savevm will fail with
> > >>
> > >>qemu-kvm: block/io.c:1406: bdrv_co_do_pwritev:
> > >>    Assertion `!(bs->open_flags & 0x0800)' failed.
> > >>
> > >>Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> > >What's the exact state you're in? I tried to reproduce this, but just
> > >doing a live migration and then savevm on the destination works fine for
> > >me.
> > >
> > >Hm... Or do you mean on the source? In that case, I think the operation
> > >must fail, but of course more gracefully than now.
> > 
> > Yes, I mean on the source. It may not be migration for "mirgration",
> > but for dumping state to file. In that case it seems not wrong to
> > make a snapshot on source.
> 
> Yes, resuming on the source is definitely valid. I'm only questioning if
> 'savevm' (and by extension, any other command that modifies the VM or
> its images) should automagically regain control of the VM, or whether
> that should be more explicit.

How many things other than 'cont' and 'savevm' are there?

We should definitely fix it so  a savevm there doesn't assert,
but I'm also unsure if it's worth a separate explicit command.

Dave

> Kevin
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK