Re: [Qemu-ppc] [RFC PATCH v0] spapr: Introduce sPAPRCPUCoreClass

[Bharata B Rao]

On Thu, Sep 08, 2016 at 11:51:32AM +1000, David Gibson wrote:
> On Fri, Sep 02, 2016 at 03:06:38PM +0530, Bharata B Rao wrote:
> > Each spapr cpu core type defines an instance_init routine which just
> > populates the CPU class name. This can be done in the class_init
> > commonly for all core types which simplifies the registration.
> > This is inspired by how PowerNV core types are registered.
> > 
> > Certain types of spapr cpu cores ('host' and generic type based on host
> > CPU) are initialized in target-ppc/kvm.c. To convert these type
> > registrations to use class_init, we need to expose
> > spapr_cpu_core_class_init() outside of spapr_cpu_core.c.
> > 
> > Commit d11b268e1765 added a generic sPAPR CPU core family
> > type to support cases like POWER8 CPU type on POWER8E host CPU.
> > Switching to class_init would fix such scenarios to use the right
> > CPU thread type instead of defaulting to host-powerpc64-cpu.
> > 
> > In an unrelated cleanup, fix a typo in .get_hotplug_handler routine.
> > 
> > Signed-off-by: Bharata B Rao <address@hidden>
> 
> I like the concept, but...
> 
> [snip]
> >  static const TypeInfo spapr_cpu_core_type_info = {
> > @@ -415,17 +377,26 @@ static const TypeInfo spapr_cpu_core_type_info = {
> >      .parent = TYPE_CPU_CORE,
> >      .abstract = true,
> >      .instance_size = sizeof(sPAPRCPUCore),
> > -    .class_init = spapr_cpu_core_class_init,
> 
> .. I'm pretty sure you need .class_size = sizeof(sPAPRCPUCoreClass)
> here, or initializing the cpu_class field will corrupt memory.

Ok.

The other thing I am not comfortable with is exposing
.class_init routine outside of spapr_cpu_core.c so that cpu cores
can be initialized from target-ppc/kvm.c. Any opinion on that ?

Regards,
Bharata.