Re: [Qemu-devel] [PATCH 15/20] target-i386: set custom 'xlevel' without intermediate x86_def_t

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 19 Dec 2012 15:58:40 -0200
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Mon, Dec 17, 2012 at 05:01:27PM +0100, Igor Mammedov wrote:
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >  target-i386/cpu.c |    4 +++-
> >  1 files changed, 3 insertions(+), 1 deletions(-)
> > 
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 0cb0931..714ae79 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -1326,7 +1326,9 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features,
> >                  if (numvalue < 0x80000000) {
> >                      numvalue += 0x80000000;
> >                  }
> > -                x86_cpu_def->xlevel = numvalue;
> > +                val = g_strdup_printf("%u", numvalue);
> 
> Why not just eliminate the string->integer conversion entirely, and move
> it inside x86_cpuid_set_xlevel()?
Silent fixup of an incorrect input value doesn't look like a candidate for
making into property setter, more correct way is bailing out. But for
compatibility sake we can't just remove it without giving userbase a warning.
Perhaps candidate for next release notes.
And when it's removed, this branch could be collapsed in catch-all(feat=val)
branch + adding input value check to xlevel property setter.
 
> 
> > +                qdict_put(*props, featurestr, qstring_from_str(val));
> 
> If you made cpu_x86_parse_featurestr() set the properties directly on
> the object instead of creating an intermediate directionary, it could
> simply call object_property_set_int() (if for some reason it's
> impossible to eliminate the string->int conversion above).
I've explained in answer to [10/20] why.
Besides normalizing input first to uniform set and then applying it
to object using only one approach whether it via cpu_x86_set_props() or
global properties seems to me more straightforward and reduces chance of error.
and might allow completely get rid of cpu_x86_parse_featurestr() call in
cpu_init() call chain. cpu_x86_parse_featurestr() should/might be called only
once to create a set of properties that are applied later to each created CPU.

> 
> > +                g_free(val);
> >              } else if (!strcmp(featurestr, "vendor")) {
> >                  qdict_put(*props, featurestr, qstring_from_str(val));
> >                  x86_cpu_def->vendor_override = true;
> > -- 
> > 1.7.1
> > 
> > 
> 
> -- 
> Eduardo


-- 
Regards,
  Igor