Re: [Qemu-devel] [PATCH 08/19] cpu: introduce get_arch_id() method and override it for target-i386

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 11 Apr 2013 16:04:26 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Thu, Apr 11, 2013 at 04:51:47PM +0200, Igor Mammedov wrote:
> > get_arch_id() adds possibility for generic code to get guest visible
> > CPI id without accessing CPUArchState. If target doesn't override it,
> > it will return cpu_index.
> > 
> > Override it on target-i386 to return APIC ID.
> 
> The code implementing the method looks OK, so:
> 
> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> 
> But I still need to understand better why exactly i386 needs to use it
> and make the externally-visible hotplug interface based on APIC IDs if
> all other architectures are going to be happy using CPU indexes to do
> the same thing.
get_arch_id() was prompted by 10/19 which is used not only by target-i386.
so it was introduced to make acpi_piix4 CPU hotplug more generic. And proved
to useful in a number of other places.

> 
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >  * it will be used later by new cpu_exists() generic function and
> >    acpi_piix.
> >  * s/cpu_firmware_id/cpu_arch_id/
> > ---
> >  include/qom/cpu.h |  2 ++
> >  qom/cpu.c         |  6 ++++++
> >  target-i386/cpu.c | 10 ++++++++++
> >  3 files changed, 18 insertions(+)
> > 
> > diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> > index 3664a1b..b376416 100644
> > --- a/include/qom/cpu.h
> > +++ b/include/qom/cpu.h
> > @@ -45,6 +45,7 @@ typedef struct CPUState CPUState;
> >   * instantiatable CPU type.
> >   * @reset: Callback to reset the #CPUState to its initial state.
> >   * @do_interrupt: Callback for interrupt handling.
> > + * @get_arch_id: Callback for getting architecture depended CPU ID
> >   * @vmsd: State description for migration.
> >   *
> >   * Represents a CPU family or model.
> > @@ -58,6 +59,7 @@ typedef struct CPUClass {
> >  
> >      void (*reset)(CPUState *cpu);
> >      void (*do_interrupt)(CPUState *cpu);
> > +    int64_t (*get_arch_id)(CPUState *cpu);
> >  
> >      const struct VMStateDescription *vmsd;
> >  } CPUClass;
> > diff --git a/qom/cpu.c b/qom/cpu.c
> > index fe85960..90cbd77 100644
> > --- a/qom/cpu.c
> > +++ b/qom/cpu.c
> > @@ -77,6 +77,11 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
> >      }
> >  }
> >  
> > +static int64_t cpu_common_get_arch_id(CPUState *cpu)
> > +{
> > +    return cpu->cpu_index;
> > +}
> > +
> >  static void cpu_class_init(ObjectClass *klass, void *data)
> >  {
> >      DeviceClass *dc = DEVICE_CLASS(klass);
> > @@ -84,6 +89,7 @@ static void cpu_class_init(ObjectClass *klass, void *data)
> >  
> >      k->class_by_name = cpu_common_class_by_name;
> >      k->reset = cpu_common_reset;
> > +    k->get_arch_id = cpu_common_get_arch_id;
> >      dc->realize = cpu_common_realizefn;
> >      dc->no_user = 1;
> >  }
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index c28436c..9cca031 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -2272,6 +2272,14 @@ static void x86_cpu_initfn(Object *obj)
> >      }
> >  }
> >  
> > +static int64_t x86_cpu_get_arch_id(CPUState *cpu)
> > +{
> > +    X86CPU *x86cpu = X86_CPU(cpu);
> > +    CPUX86State *env = &x86cpu->env;
> > +
> > +    return env->cpuid_apic_id;
> > +}
> > +
> >  static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
> >  {
> >      X86CPUClass *xcc = X86_CPU_CLASS(oc);
> > @@ -2286,6 +2294,8 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
> >  
> >      cc->do_interrupt = x86_cpu_do_interrupt;
> >      cpu_class_set_vmsd(cc, &vmstate_x86_cpu);
> > +
> > +    cc->get_arch_id = x86_cpu_get_arch_id;
> >  }
> >  
> >  static const TypeInfo x86_cpu_type_info = {
> > -- 
> > 1.8.2
> > 
> 
> -- 
> Eduardo


-- 
Regards,
  Igor