Re: [Qemu-devel] [PATCH 2/3] target-i386: Introduce x86_cpu_load_host_data() function

[Eduardo Habkost]

On Thu, Jun 23, 2016 at 04:59:28PM +0200, Igor Mammedov wrote:
> On Mon, 20 Jun 2016 17:12:43 -0300
> Eduardo Habkost <address@hidden> wrote:
> 
> > The code that loads host-specific information inside
> > x86_cpu_realizefn() will be reused by the implementation of
> > query-host-cpu, so move it to a separate function.
> > 
> > Signed-off-by: Eduardo Habkost <address@hidden>
> > ---
> >  target-i386/cpu.c | 23 ++++++++++++++++-------
> >  1 file changed, 16 insertions(+), 7 deletions(-)
> > 
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index aadd0b9..3d3635d 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -1491,6 +1491,20 @@ void x86_cpu_change_kvm_default(const char
> > *prop, const char *value) static uint32_t
> > x86_cpu_get_supported_feature_word(FeatureWord w, bool
> > migratable_only); 
> > +/* Load host-dependent CPU information, when applicable */
> > +static void x86_cpu_load_host_data(X86CPU *cpu)
> > +{
> > +    CPUX86State *env = &cpu->env;
> > +    FeatureWord w;
> > +
> > +    if (cpu->host_features) {
> > +        for (w = 0; w < FEATURE_WORDS; w++) {
> > +            env->features[w] =
> > +                x86_cpu_get_supported_feature_word(w,
> > cpu->migratable);
> > +        }
> > +    }
> > +}
> > +
> >  #ifdef CONFIG_KVM
> >  
> >  static int cpu_x86_fill_model_id(char *str)
> > @@ -3012,18 +3026,13 @@ static void x86_cpu_realizefn(DeviceState
> > *dev, Error **errp) return;
> >      }
> >  
> > +    x86_cpu_load_host_data(cpu);
> this function should be below TODO comment as it applies to moved
> code.

It was on purpose. The comment is actually about the
plus_features/minus_features code, that is the hack we want to
remove after cpu->host_features is fixed.

Placing the comment before the x86_cpu_load_host_data() call
wouldn't make sense, as the host_features code is now hidden
inside the function.

> 
> with this fixed
> Reviewed-by: Igor Mammedov <address@hidden>

Considering the above explanation, do you prefer that I keep the
patch as-is, or move the comment inside x86_cpu_load_host_data()?

(I will not move it before the x86_cpu_load_host_data() call)


> 
> > +
> >      /*TODO: cpu->host_features incorrectly overwrites features
> >       * set using "feat=on|off". Once we fix this, we can convert
> >       * plus_features & minus_features to global properties
> >       * inside x86_cpu_parse_featurestr() too.
> >       */
> > -    if (cpu->host_features) {
> > -        for (w = 0; w < FEATURE_WORDS; w++) {
> > -            env->features[w] =
> > -                x86_cpu_get_supported_feature_word(w,
> > cpu->migratable);
> > -        }
> > -    }
> > -
> >      for (w = 0; w < FEATURE_WORDS; w++) {
> >          cpu->env.features[w] |= plus_features[w];
> >          cpu->env.features[w] &= ~minus_features[w];
> 

-- 
Eduardo