On Wed, Jan 30, 2019 at 10:54:04AM +0000, Dr. David Alan Gilbert wrote:
> * Daniel P. Berrangé (berra...@redhat.com) wrote:
> > On Wed, Jan 30, 2019 at 10:32:29AM +0000, Dr. David Alan Gilbert (git)
> > wrote:
> > > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
> > >
> > > Add migration parameters that control RARP/GARP announcement timeouts.
> > >
> > > Based on earlier patches by myself and
> > > Vladislav Yasevich <vyase...@redhat.com>
> > >
> > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> > > ---
> > > hmp.c | 28 +++++++++++
> > > include/migration/misc.h | 2 +
> > > include/qemu/typedefs.h | 1 +
> > > migration/migration.c | 100 +++++++++++++++++++++++++++++++++++++++
> > > qapi/migration.json | 54 +++++++++++++++++++--
> > > 5 files changed, 182 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/qapi/migration.json b/qapi/migration.json
> > > index 7a795ecc16..113bb5d925 100644
> > > --- a/qapi/migration.json
> > > +++ b/qapi/migration.json
> > > @@ -6,6 +6,7 @@
> > > ##
> > >
> > > { 'include': 'common.json' }
> > > +{ 'include': 'net.json' }
> >
> >
> > > @@ -572,6 +588,18 @@
> > > ##
> > > # @MigrateSetParameters:
> > > #
> > > +# @announce-initial: Initial delay (in ms) before sending the first
> > > announce
> > > +# (Since 4.0)
> > > +#
> > > +# @announce-max: Maximum delay (in ms) between packets in the announcment
> > > +# (Since 4.0)
> > > +#
> > > +# @announce-rounds: Number of self-announce packets sent after migration
> > > +# (Since 4.0)
> > > +#
> > > +# @announce-step: Increase in delay (in ms) between subsequent packets in
> > > +# the announcement (Since 4.0)
> > > +#
> > > # @compress-level: compression level
> > > #
> > > # @compress-threads: compression thread count
> > > @@ -653,7 +681,11 @@
> > > # TODO either fuse back into MigrationParameters, or make
> > > # MigrationParameters members mandatory
> > > { 'struct': 'MigrateSetParameters',
> > > - 'data': { '*compress-level': 'int',
> > > + 'data': { '*announce-initial': 'size',
> > > + '*announce-max': 'size',
> > > + '*announce-rounds': 'size',
> > > + '*announce-step': 'size',
> > > + '*compress-level': 'int',
> > > '*compress-threads': 'int',
> > > '*compress-wait-thread': 'bool',
> > > '*decompress-threads': 'int',
> >
> > Historically we've just had a flat list of migration parameters, but
> > QAPI doesn't require this. So I wonder about just referencing the
> > type you defined in the previous patch:
> >
> > '*announce': 'AnnounceParameters
> >
> > from a QMP pov this is trivial & feels more natural. The only downside
> > I see is that for HMP it would need to be flattened to what it is here.
> > We generally tend to prefer QMP's natural style, even if it doesn't
> > match what's nicest for HMP.
>
> I don't trust that's true from QMP; the logic to keep the parameters
> optional so that you can set a parameter individually is already pretty
> hairy.
Yes, this different design would mean that the overall 'announce' parmaeter
was optional. If you did provide one of the parameters though, you would
need to provide all 4 of them. I don't think that's a bad thing though, as
the values really only make sense when considered as a whole. So setting
one announce parameter without knowing what the other values are is somewhat
unreliable.
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
