Re: [Qemu-devel] [RFC PATCH v2 11/23] ppc: Create sockets and cores for CPUs

[Bharata B Rao]

On Wed, Mar 25, 2015 at 01:39:02PM +1100, David Gibson wrote:
> On Mon, Mar 23, 2015 at 07:05:52PM +0530, Bharata B Rao wrote:
> > ppc machine init functions create individual CPU threads. Change this
> > for sPAPR by switching to socket creation. CPUs are created recursively
> > by socket and core instance init routines.
> > 
> > TODO: Switching to socket level CPU creation is done only for sPAPR
> > target now.
> > 
> > Signed-off-by: Bharata B Rao <address@hidden>
> > ---
> >  hw/ppc/cpu-core.c           | 17 +++++++++++++++++
> >  hw/ppc/cpu-socket.c         | 15 +++++++++++++++
> >  hw/ppc/spapr.c              | 15 ++++++++-------
> >  target-ppc/cpu.h            |  1 +
> >  target-ppc/translate_init.c | 46 
> > +++++++++++++++++++++++++++++++++++++++++++++
> >  5 files changed, 87 insertions(+), 7 deletions(-)
> > 
> > diff --git a/hw/ppc/cpu-core.c b/hw/ppc/cpu-core.c
> > index ed0481f..f60646d 100644
> > --- a/hw/ppc/cpu-core.c
> > +++ b/hw/ppc/cpu-core.c
> > @@ -7,6 +7,8 @@
> >  
> >  #include "hw/qdev.h"
> >  #include "hw/ppc/cpu-core.h"
> > +#include "hw/boards.h"
> > +#include <sysemu/cpus.h>
> >  
> >  static int ppc_cpu_core_realize_child(Object *child, void *opaque)
> >  {
> > @@ -32,10 +34,25 @@ static void ppc_cpu_core_class_init(ObjectClass *oc, 
> > void *data)
> >      dc->realize = ppc_cpu_core_realize;
> >  }
> >  
> > +static void ppc_cpu_core_instance_init(Object *obj)
> > +{
> > +    int i;
> > +    PowerPCCPU *cpu = NULL;
> > +    MachineState *machine = MACHINE(qdev_get_machine());
> > +
> > +    for (i = 0; i < smp_threads; i++) {
> > +        cpu = POWERPC_CPU(cpu_ppc_create(TYPE_POWERPC_CPU, 
> > machine->cpu_model));
> > +        object_property_add_child(obj, "thread[*]", OBJECT(cpu), 
> > &error_abort);
> > +        object_unref(OBJECT(cpu));
> > +    }
> > +}
> > +
> >  static const TypeInfo ppc_cpu_core_type_info = {
> >      .name = TYPE_POWERPC_CPU_CORE,
> >      .parent = TYPE_DEVICE,
> >      .class_init = ppc_cpu_core_class_init,
> > +    .instance_init = ppc_cpu_core_instance_init,
> > +    .instance_size = sizeof(PowerPCCPUCore),
> 
> The PowerPCCPUCore structure isn't defined in this patch (I assume it
> already existed), which suggests that setting the instance_size should
> have already been in an earlier patch.

PowerPCCPUCore is already defined, but I put the instance_size here
since I needed instance_init only here. I thought it is better to
have instance_init and instance_size populated together.

> 
> >  };
> >  
> >  static void ppc_cpu_core_register_types(void)
> > diff --git a/hw/ppc/cpu-socket.c b/hw/ppc/cpu-socket.c
> > index 602a060..f901336 100644
> > --- a/hw/ppc/cpu-socket.c
> > +++ b/hw/ppc/cpu-socket.c
> > @@ -8,6 +8,7 @@
> >  #include "hw/qdev.h"
> >  #include "hw/ppc/cpu-socket.h"
> >  #include "sysemu/cpus.h"
> > +#include "cpu.h"
> >  
> >  static int ppc_cpu_socket_realize_child(Object *child, void *opaque)
> >  {
> > @@ -33,10 +34,24 @@ static void ppc_cpu_socket_class_init(ObjectClass *oc, 
> > void *data)
> >      dc->realize = ppc_cpu_socket_realize;
> >  }
> >  
> > +static void ppc_cpu_socket_instance_init(Object *obj)
> > +{
> > +    int i;
> > +    Object *core;
> > +
> > +    for (i = 0; i < smp_cores; i++) {
> > +        core = object_new(TYPE_POWERPC_CPU_CORE);
> > +        object_property_add_child(obj, "core[*]", core, &error_abort);
> > +        object_unref(core);
> > +    }
> > +}
> > +
> >  static const TypeInfo ppc_cpu_socket_type_info = {
> >      .name = TYPE_POWERPC_CPU_SOCKET,
> >      .parent = TYPE_CPU_SOCKET,
> >      .class_init = ppc_cpu_socket_class_init,
> > +    .instance_init = ppc_cpu_socket_instance_init,
> > +    .instance_size = sizeof(PowerPCCPUSocket),
> 
> Likewise for PowerPCCPUSocket.
> >  
> > +/*
> > + * This is essentially same as cpu_generic_init() but without a set
> > + * realize call.
> > + */
> 
> In which case it would probably make more sense to have this be a
> generic function, and implement cpu_generic_init() in terms of it.

Actually multiple people are touching that part of the code, I so I
figured it will be a bit easier for now to contain the changes within ppc.
But yes, eventually we should do what you are suggesting.