Re: [Qemu-devel] [PATCH v3 4/5] target-i386: Require APIC ID to be explicitly set before CPU realize

[Eduardo Habkost]

On Mon, Mar 02, 2015 at 06:50:44PM +0100, Andreas Färber wrote:
> Am 26.02.2015 um 22:42 schrieb Eduardo Habkost:
> > Instead of setting APIC ID automatically when creating a X86CPU, require
> > the property to be set before realizing the object (which all callers of
> > cpu_x86_create() already do).
> > 
> > Reviewed-by: Paolo Bonzini <address@hidden>
> > Signed-off-by: Eduardo Habkost <address@hidden>
> > ---
> >  target-i386/cpu-qom.h | 2 +-
> >  target-i386/cpu.c     | 7 ++++++-
> >  2 files changed, 7 insertions(+), 2 deletions(-)
> > 
> > diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
> > index 4a6f48a..31a0c1e 100644
> > --- a/target-i386/cpu-qom.h
> > +++ b/target-i386/cpu-qom.h
> > @@ -93,7 +93,7 @@ typedef struct X86CPU {
> >      bool expose_kvm;
> >      bool migratable;
> >      bool host_features;
> > -    uint32_t apic_id;
> > +    int64_t apic_id;
> >  
> >      /* if true the CPUID code directly forward host cache leaves to the 
> > guest */
> >      bool cache_info_passthrough;
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index c4a96b6..9819c47 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -2786,6 +2786,11 @@ static void x86_cpu_realizefn(DeviceState *dev, 
> > Error **errp)
> >      Error *local_err = NULL;
> >      static bool ht_warned;
> >  
> > +    if (cpu->apic_id < 0) {
> 
> Since you were setting it immediately before setting realized=true,
> 
> #ifdef CONFIG_USER_ONLY
>     cpu->apic_id = cs->cpu_index;
> #else
> 
> > +        error_setg(errp, "apic-id property was not initialized properly");
> > +        return;
> 
> #endif
> 
> would keep any x86-specific logic out of cpu_init().

My initial intention was to make a x86-specific cpu_init() to avoid
#ifdefs in the code, but considering that it would be interesting to
finally start using cpu_generic_init(), it would make sense to have the
#ifdef on realize.

Anyway, the good news is that we probably don't even need to set apic_id
= cpu_index on *-user, making the #ifdef unnecessary. See my replies
to Peter at:
  [PULL 08/11] linux-user: Check for cpu_init() errors

-- 
Eduardo