Re: [Qemu-devel] [PATCH v3 1/8] apic: add global apic_get_class()

[Igor Mammedov]

On Mon, 3 Oct 2016 13:03:33 -0300
Eduardo Habkost <address@hidden> wrote:

> On Fri, Sep 30, 2016 at 06:10:06PM +0200, Radim Krčmář wrote:
> > Every configuration has only up to one APIC class and we'll be extending
> > the class with a function that can be called without an instanced
> > object, so a direct access to the class is convenient.
> > 
> > This patch will break compilation if some code uses apic_get_class()
> > with CONFIG_USER_ONLY.
> > 
> > Suggested-by: Eduardo Habkost <address@hidden>
> > Signed-off-by: Radim Krčmář <address@hidden>
> > ---
> > v2: assert() instead of error_report() and exit() [Peter]
> > v3: completely rewrite the mechanism [Eduardo]
> > 
> > It still looks horrible, so I'll be glad for any advice.
> > And what is CONFIG_USER_ONLY?
> > ---
> >  hw/intc/apic_common.c           |  1 +
> >  include/hw/i386/apic_internal.h |  2 ++
> >  target-i386/cpu.c               | 14 +++++++++++---
> >  3 files changed, 14 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
> > index 14ac43c18666..8d01c9c8750e 100644
> > --- a/hw/intc/apic_common.c
> > +++ b/hw/intc/apic_common.c
> > @@ -18,6 +18,7 @@
> >   * License along with this library; if not, see 
> > <http://www.gnu.org/licenses/>
> >   */
> >  #include "qemu/osdep.h"
> > +#include "qemu/error-report.h"
> >  #include "qapi/error.h"
> >  #include "qemu-common.h"
> >  #include "cpu.h"
> > diff --git a/include/hw/i386/apic_internal.h 
> > b/include/hw/i386/apic_internal.h
> > index 06c4e9f6f95b..286684857e9f 100644
> > --- a/include/hw/i386/apic_internal.h
> > +++ b/include/hw/i386/apic_internal.h
> > @@ -222,4 +222,6 @@ static inline int apic_get_bit(uint32_t *tab, int index)
> >      return !!(tab[i] & mask);
> >  }
> >  
> > +APICCommonClass *apic_get_class(void);
> > +
> >  #endif /* QEMU_APIC_INTERNAL_H */
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 333309b9a70e..6acf9c3c2372 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -2845,9 +2845,8 @@ static void mce_init(X86CPU *cpu)
> >  }
> >  
> >  #ifndef CONFIG_USER_ONLY
> > -static void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
> > +APICCommonClass *apic_get_class(void)
> >  {
> > -    APICCommonState *apic;
> >      const char *apic_type = "apic";
> >  
> >      if (kvm_apic_in_kernel()) {
> > @@ -2856,7 +2855,16 @@ static void x86_cpu_apic_create(X86CPU *cpu, Error 
> > **errp)
> >          apic_type = "xen-apic";
> >      }
> >  
> > -    cpu->apic_state = DEVICE(object_new(apic_type));
> > +    return APIC_COMMON_CLASS(object_class_by_name(apic_type));
> > +}
> > +
> > +static void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
> > +{
> > +    APICCommonState *apic;
> > +    ObjectClass *apic_object_class = OBJECT_CLASS(apic_get_class());
> > +
> > +    assert(apic_object_class);
> > +    cpu->apic_state = 
> > DEVICE(object_new_with_type(apic_object_class->type));  
[...]

> (e.g. I wonder if we could have a container object for all APICs
> (icc-bus?), and move the send_msi() method and the
> apic_get_class() logic to it).
That's probably not worth all the boilerplate code it would bring.

> 
> >  
> >      object_property_add_child(OBJECT(cpu), "lapic",
> >                                OBJECT(cpu->apic_state), &error_abort);
> > -- 
> > 2.10.0
> >   
>