Re: [Qemu-devel] [PATCH 13/19] target-i386: cpu: attach ICC bus to CPU on its creation

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 15 Apr 2013 17:38:51 +0200
Andreas Färber <afaerber@suse.de> wrote:

> Am 11.04.2013 16:51, schrieb Igor Mammedov:
> > ... during startup,  so it would be possible to uplug it later
> 
> unplug?
CPU won't be unplug-able if it's not on ICC bus.

> 
> > and set bus_type to TYPE_ICC_BUS for X86CPU type to make device_add
> > attach hotplugged CPU to ICC bus.
> > 
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> > ---
> >  target-i386/cpu.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 4ddc18a..2bb38d6 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -41,6 +41,7 @@
> >  #endif
> >  
> >  #include "sysemu/sysemu.h"
> > +#include "hw/i386/icc_bus.h"
> >  #ifndef CONFIG_USER_ONLY
> >  #include "hw/xen/xen.h"
> >  #include "hw/sysbus.h"
> > @@ -1610,6 +1611,7 @@ X86CPU *cpu_x86_create(const char *cpu_model, Error
> > **errp) gchar **model_pieces;
> >      char *name, *features;
> >      Error *error = NULL;
> > +    Object *icc_bus = object_resolve_path_type("icc-bus", TYPE_ICC_BUS,
> > NULL); 
> >      model_pieces = g_strsplit(cpu_model, ",", 2);
> >      if (!model_pieces[0]) {
> > @@ -1620,6 +1622,10 @@ X86CPU *cpu_x86_create(const char *cpu_model,
> > Error **errp) features = model_pieces[1];
> >  
> >      cpu = X86_CPU(object_new(TYPE_X86_CPU));
> > +    if (icc_bus) {
> > +        qdev_set_parent_bus(DEVICE(cpu), BUS(icc_bus));
> > +        object_unref(OBJECT(cpu));
> 
> Why are you unref'ing here? (Paolo?)

To leave only one reference to it since qdev_set_parent_bus() just
incremented it. Like it's done in qdev_try_create().

> 
> > +    }
> >      env = &cpu->env;
> >      env->cpu_model_str = cpu_model;
> >  
> 
> > @@ -2330,6 +2336,7 @@ static void x86_cpu_common_class_init(ObjectClass
> > *oc, void *data) 
> >      xcc->parent_realize = dc->realize;
> >      dc->realize = x86_cpu_realizefn;
> > +    dc->bus_type = TYPE_ICC_BUS;
> >  
> >      xcc->parent_reset = cc->reset;
> >      cc->reset = x86_cpu_reset;
> 
> I was relieved when I recently saw this was all the magic required to
> put it onto the new ICC bus. I thought we'd need to mess with ICCDevice
> base classes, but that seems to be used for APIC and IOAPIC only.
> 
> Andreas
>