Re: [PATCH 1/2] migration: Add blocker information

[Peter Xu <peterx@redhat.com>]

On Tue, Feb 02, 2021 at 08:34:06AM -0600, Eric Blake wrote:
> On 2/2/21 7:55 AM, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > 
> > Modify query-migrate so that it has a flag indicating if outbound
> > migration is blocked, and if it is a list of reasons.
> > 
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> >  migration/migration.c | 25 +++++++++++++++++++++++--
> >  migration/savevm.c    | 13 +++++++++++++
> >  migration/savevm.h    |  1 +
> >  qapi/migration.json   |  6 ++++++
> >  4 files changed, 43 insertions(+), 2 deletions(-)
> > 
> 
> > +++ b/qapi/migration.json
> > @@ -224,6 +224,10 @@
> >  #        only returned if VFIO device is present, migration is supported by all
> >  #        VFIO devices and status is 'active' or 'completed' (since 5.2)
> >  #
> > +# @blocked: True if outgoing migration is blocked (since 6.0)
> > +#
> > +# @blocked-reasons: A list of reasons an outgoing migration is blocked (since 6.0)
> 
> A bit of redundancy here; the presence of blocked-reasons is sufficient
> to tell if migration is blocked, without needing a bool.  But having the
> bool is more type-friendly for machines, so I don't mind having both.

Agreed.

Also I'd also think we can directly export the device list to JSON then we can
have {"blockers": { "devices": {...}, "other": {...}}} so upper layer can do
more things like "would you want to unplug the device XXX to make it
migratable?" instead of parsing the error message first.

But non of the above is a big deal, I think:

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu