Re: [PATCH v3 17/21] migration/savevm: don't worry if bitmap migration postcopy failed

[Dr. David Alan Gilbert]

* Eric Blake (eblake@redhat.com) wrote:
> On 7/24/20 3:43 AM, Vladimir Sementsov-Ogievskiy wrote:
> > First, if only bitmaps postcopy enabled (not ram postcopy)
> 
> is enabled (and not ram postcopy),
> 
> > postcopy_pause_incoming crashes on assertion assert(mis->to_src_file).
> 
> on an
> 
> > 
> > And anyway, bitmaps postcopy is not prepared to be somehow recovered.
> > The original idea instead is that if bitmaps postcopy failed, we just
> > loss some bitmaps, which is not critical. So, on failure we just need
> 
> lose
> 
> > to remove unfinished bitmaps and guest should continue execution on
> > destination.
> > 
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> > ---
> >   migration/savevm.c | 37 ++++++++++++++++++++++++++++++++-----
> >   1 file changed, 32 insertions(+), 5 deletions(-)
> > 
> 
> Definitely a bug fix, but I'd like David's opinion on whether this is still
> 5.1 material (because it is limited to just bitmaps migration, which is
> opt-in) or too risky (because we've already had several releases where it
> was broken, what's one more?).

I think it's OK for 5.1

Dave

> I'm less familiar with the code, so this is weak, but I did read through it
> and nothing jumped out at me, so:
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> -- 
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.           +1-919-301-3226
> Virtualization:  qemu.org | libvirt.org
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK