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

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 <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 target-i386/cpu-qom.h | 2 +-
 target-i386/cpu.c     | 7 ++++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

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 <pbonzini@redhat.com>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  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().

Regards,
Andreas

> +    }
> +
>      if (env->features[FEAT_7_0_EBX] && env->cpuid_level < 7) {
>          env->cpuid_level = 7;
>      }
> @@ -2929,7 +2934,7 @@ static void x86_cpu_initfn(Object *obj)
>                          NULL, NULL, (void *)cpu->filtered_features, NULL);
>  
>      cpu->hyperv_spinlock_attempts = HYPERV_SPINLOCK_NEVER_RETRY;
> -    cpu->apic_id = x86_cpu_apic_id_from_index(cs->cpu_index);
> +    cpu->apic_id = -1;
>  
>      x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
>

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 <pbonzini@redhat.com>
> > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> > ---
> >  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