Re: [Qemu-devel] [PATCH] migration: introduce migrate_is_blocked()

[Amit Shah]

On (Wed) 11 May 2016 [14:10:34], Greg Kurz wrote:
> On Wed, 11 May 2016 13:59:19 +0200
> Paolo Bonzini <address@hidden> wrote:
> 
> > On 04/05/2016 21:44, Greg Kurz wrote:
> > > QEMU has currently two ways to prevent migration to occur:
> > > - migration blocker when it depends on runtime state
> > > - VMStateDescription.unmigratable when migration is not supported at all
> > > 
> > > This patch gathers all the logic into a single function to be called from
> > > both the savevm and the migrate paths.
> > > 
> > > This fixes a bug with 9p, at least, where savevm would succeed and the
> > > following would happen in the guest after loadvm:
> > > 
> > > $ ls /host
> > > ls: cannot access /host: Protocol error
> > > 
> > > With this patch:
> > > 
> > > (qemu) savevm foo
> > > Migration is disabled when VirtFS export path '/' is mounted in the guest
> > > using mount_tag 'host'
> > > 
> > > Signed-off-by: Greg Kurz <address@hidden>
> > > ---
> > > 
> > > Since there has been some activity on 9p again since a few weeks, maybe it
> > > is not too late for 2.6, if everybody agrees the fix is ok ?  
> > 
> > The patch is good, but I think the subject should be
> > 
> >     savevm: fail if migration blockers are present
> > 
> > The subject you used would be good for the include/migration and
> > migration/migration.c parts alone (where you introduce the function
> > without any semantic change).
> > 
> 
> Yeah, I agree the subject you are suggesting is far more informative :)

I'll apply this with the suggested subject.

Please CC the migration maintainers for faster processing next time
around.

Thanks,

                Amit