Re: [Qemu-devel] [PATCH 4/5] Switch migrate_set_speed() to take an 'o' argument rather than a float.

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 28 Sep 2010 12:08:07 +0200
Markus Armbruster <armbru@redhat.com> wrote:

> Jes.Sorensen@redhat.com writes:
> 
> > From: Jes Sorensen <Jes.Sorensen@redhat.com>
> >
> > Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
> > ---
> >  migration.c     |    4 ++--
> >  qemu-monitor.hx |    2 +-
> >  2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/migration.c b/migration.c
> > index 468d517..9ee8b17 100644
> > --- a/migration.c
> > +++ b/migration.c
> > @@ -132,10 +132,10 @@ int do_migrate_cancel(Monitor *mon, const QDict *qdict, QObject **ret_data)
> >  
> >  int do_migrate_set_speed(Monitor *mon, const QDict *qdict, QObject **ret_data)
> >  {
> > -    double d;
> > +    int64_t d;
> >      FdMigrationState *s;
> >  
> > -    d = qdict_get_double(qdict, "value");
> > +    d = qdict_get_int(qdict, "value");
> >      d = MAX(0, MIN(UINT32_MAX, d));
> >      max_throttle = d;
> 
> This isn't backwards bug-compatible.
> 
> Before, a client could send any number.  Any fractional part was
> ignored.
> 
> Now, the number must be an integer.  Other numbers are rejected.
> 
> I don't care myself, but others have argued most forcefully for keeping
> QMP fully backward compatible from 0.13 on, so they might object.

Can't we have a small fix for 0.13? We still have time I guess.

> 
> > diff --git a/qemu-monitor.hx b/qemu-monitor.hx
> > index 49bcd8d..7f58fb2 100644
> > --- a/qemu-monitor.hx
> > +++ b/qemu-monitor.hx
> > @@ -1093,7 +1093,7 @@ EQMP
> >  
> >      {
> >          .name       = "migrate_set_speed",
> > -        .args_type  = "value:f",
> > +        .args_type  = "value:o",
> >          .params     = "value",
> >          .help       = "set maximum speed (in bytes) for migrations",
> >          .user_print = monitor_user_noop,
> 
> Doesn't this change the interpretation of "42" from 42 to (42 << 20)?
>