Re: [Qemu-devel] [PATCH v3 27/35] postcopy/outgoing: implement forward/backword prefault

[Isaku Yamahata <yamahata@valinux.co.jp>]

On Thu, Nov 01, 2012 at 02:10:45PM -0600, Eric Blake wrote:
> On 10/30/2012 02:33 AM, Isaku Yamahata wrote:
> > When page is requested, send surrounding pages are also sent.
> > 
> > Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
> > ---
> >  hmp-commands.hx      |   15 ++++++++-----
> >  hmp.c                |    3 +++
> >  migration-postcopy.c |   57 +++++++++++++++++++++++++++++++++++++++++++++-----
> >  migration.c          |   20 ++++++++++++++++++
> >  migration.h          |    2 ++
> >  qapi-schema.json     |    3 ++-
> >  6 files changed, 89 insertions(+), 11 deletions(-)
> > 
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index b054760..5e2c77c 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -826,26 +826,31 @@ ETEXI
> >  
> >      {
> >          .name       = "migrate",
> > -        .args_type  = "detach:-d,blk:-b,inc:-i,postcopy:-p,nobg:-n,uri:s",
> > -        .params     = "[-d] [-b] [-i] [-p [-n]] uri",
> > +        .args_type  = "detach:-d,blk:-b,inc:-i,postcopy:-p,nobg:-n,uri:s,"
> > +	              "forward:i?,backward:i?",
> > +        .params     = "[-d] [-b] [-i] [-p [-n] uri [forward] [backword]",
> 
> I don't care what we do to the 'migrate' HMP command, but for QMP...
> 
> > +++ b/qapi-schema.json
> > @@ -2095,7 +2095,8 @@
> >  ##
> >  { 'command': 'migrate',
> >    'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool', '*detach': 'bool' ,
> > -           '*postcopy': 'bool', '*nobg': 'bool'} }
> > +           '*postcopy': 'bool', '*nobg': 'bool',
> > +           '*forward': 'int', '*backward': 'int'} }
> 
> Do we really want to be adding new options to migrate (and if so,
> where's the documentation), or do we need a new monitor command similar
> to migrate-set-capabilities or migrate-set-cache-size?

Okay, migrate-set-capabilities seems usable for boolean and scalable
for future extension.
On the other hand, migrate-set-cache-size takes only single integer
as arguments. So it doesn't seem usable without modification.
How about this?

{ 'type': 'MigrationParameters',
  'data': {'parameter': 'name': 'str', 'value': 'int' } }

{ 'command': 'migrate-set-parameters',
   'data': { 'parameters' ['MigrationParameters']}}


{ 'command': 'query-migrate-parameters',
  'returns': [['MigrationParameters']]}
-- 
yamahata