Re: [Qemu-ppc] [PATCH] spapr: move registration of "host" CPU core type to machine code

[Greg Kurz]

On Tue, 26 Sep 2017 12:57:39 +1000
David Gibson <address@hidden> wrote:

> On Mon, Sep 25, 2017 at 11:47:33AM +0200, Greg Kurz wrote:
> > The CPU core abstraction belongs to the machine code. This also gets
> > rid of some code duplication.
> > 
> > Signed-off-by: Greg Kurz <address@hidden>
> > ---
> > 
> > hw/ppc/spapr_cpu_core.h is also included elsewhere in target/ppc/kvm.c
> > but this is already handled by the following cleanup patch:  
> 
> I don't really see what the advantage of this is.  As others have
> pointed out it leads to the host type being registered very late,
> which could cause problems.
> 

Well, the goal was to consolidate the code to register sPAPRCPUCore types in
the spapr code, instead of open-coding it in spapr_cpu_core.c and kvm.c... 

But now I realize that delaying the registration even more is a bad idea. And,
the other way round, registering a static type earlier as asked by Igor would
require all parent types to be already registered, which seems to be impossible
to guarantee with the current code.

Maybe we could at least have kvm_ppc_register_host_cpu_type() to call a
function in spapr_cpu_core.c instead of duplicating the registration code ?

> > 
> > https://patchwork.ozlabs.org/patch/817598/
> > ---
> >  hw/ppc/spapr.c                  |    4 ++++
> >  hw/ppc/spapr_cpu_core.c         |   34 ++++++++++++++++++++++------------
> >  include/hw/ppc/spapr_cpu_core.h |    2 +-
> >  target/ppc/kvm.c                |   12 ------------
> >  4 files changed, 27 insertions(+), 25 deletions(-)
> > 
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 0ce3ec87ac59..e82c8532ffb0 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -2349,6 +2349,10 @@ static void ppc_spapr_init(MachineState *machine)
> >      }
> >  
> >      /* init CPUs */
> > +    if (kvm_enabled()) {
> > +        spapr_cpu_core_register_host_type();
> > +    }
> > +
> >      if (machine->cpu_model == NULL) {
> >          machine->cpu_model = kvm_enabled() ? "host" : smc->tcg_default_cpu;
> >      }
> > diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
> > index c08ee7571a50..6e224ba029ec 100644
> > --- a/hw/ppc/spapr_cpu_core.c
> > +++ b/hw/ppc/spapr_cpu_core.c
> > @@ -317,7 +317,7 @@ static Property spapr_cpu_core_properties[] = {
> >      DEFINE_PROP_END_OF_LIST()
> >  };
> >  
> > -void spapr_cpu_core_class_init(ObjectClass *oc, void *data)
> > +static void spapr_cpu_core_class_init(ObjectClass *oc, void *data)
> >  {
> >      DeviceClass *dc = DEVICE_CLASS(oc);
> >      sPAPRCPUCoreClass *scc = SPAPR_CPU_CORE_CLASS(oc);
> > @@ -337,6 +337,20 @@ static const TypeInfo spapr_cpu_core_type_info = {
> >      .class_size = sizeof(sPAPRCPUCoreClass),
> >  };
> >  
> > +static void spapr_cpu_core_register_type(const char *model_name)
> > +{
> > +    TypeInfo type_info = {
> > +        .parent = TYPE_SPAPR_CPU_CORE,
> > +        .instance_size = sizeof(sPAPRCPUCore),
> > +        .class_init = spapr_cpu_core_class_init,
> > +        .class_data = (void *) model_name,
> > +    };
> > +
> > +    type_info.name = g_strdup_printf("%s-"TYPE_SPAPR_CPU_CORE, model_name);
> > +    type_register(&type_info);
> > +    g_free((void *)type_info.name);
> > +}
> > +
> >  static void spapr_cpu_core_register_types(void)
> >  {
> >      int i;
> > @@ -344,18 +358,14 @@ static void spapr_cpu_core_register_types(void)
> >      type_register_static(&spapr_cpu_core_type_info);
> >  
> >      for (i = 0; i < ARRAY_SIZE(spapr_core_models); i++) {
> > -        TypeInfo type_info = {
> > -            .parent = TYPE_SPAPR_CPU_CORE,
> > -            .instance_size = sizeof(sPAPRCPUCore),
> > -            .class_init = spapr_cpu_core_class_init,
> > -            .class_data = (void *) spapr_core_models[i],
> > -        };
> > -
> > -        type_info.name = g_strdup_printf("%s-" TYPE_SPAPR_CPU_CORE,
> > -                                         spapr_core_models[i]);
> > -        type_register(&type_info);
> > -        g_free((void *)type_info.name);
> > +        spapr_cpu_core_register_type(spapr_core_models[i]);
> >      }
> > +
> > +}
> > +
> > +void spapr_cpu_core_register_host_type(void)
> > +{
> > +    spapr_cpu_core_register_type("host");
> >  }
> >  
> >  type_init(spapr_cpu_core_register_types)
> > diff --git a/include/hw/ppc/spapr_cpu_core.h 
> > b/include/hw/ppc/spapr_cpu_core.h
> > index 93051e9ecf56..e3e906343048 100644
> > --- a/include/hw/ppc/spapr_cpu_core.h
> > +++ b/include/hw/ppc/spapr_cpu_core.h
> > @@ -36,5 +36,5 @@ typedef struct sPAPRCPUCoreClass {
> >  } sPAPRCPUCoreClass;
> >  
> >  char *spapr_get_cpu_core_type(const char *model);
> > -void spapr_cpu_core_class_init(ObjectClass *oc, void *data);
> > +void spapr_cpu_core_register_host_type(void);
> >  #endif
> > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> > index 5b281b2f1b6d..8dd80993ec9e 100644
> > --- a/target/ppc/kvm.c
> > +++ b/target/ppc/kvm.c
> > @@ -37,7 +37,6 @@
> >  #include "hw/sysbus.h"
> >  #include "hw/ppc/spapr.h"
> >  #include "hw/ppc/spapr_vio.h"
> > -#include "hw/ppc/spapr_cpu_core.h"
> >  #include "hw/ppc/ppc.h"
> >  #include "sysemu/watchdog.h"
> >  #include "trace.h"
> > @@ -2502,17 +2501,6 @@ static int kvm_ppc_register_host_cpu_type(void)
> >      oc = object_class_by_name(type_info.name);
> >      g_assert(oc);
> >  
> > -#if defined(TARGET_PPC64)
> > -    type_info.name = g_strdup_printf("%s-"TYPE_SPAPR_CPU_CORE, "host");
> > -    type_info.parent = TYPE_SPAPR_CPU_CORE,
> > -    type_info.instance_size = sizeof(sPAPRCPUCore);
> > -    type_info.instance_init = NULL;
> > -    type_info.class_init = spapr_cpu_core_class_init;
> > -    type_info.class_data = (void *) "host";
> > -    type_register(&type_info);
> > -    g_free((void *)type_info.name);
> > -#endif
> > -
> >      /*
> >       * Update generic CPU family class alias (e.g. on a POWER8NVL host,
> >       * we want "POWER8" to be a "family" alias that points to the current
> >   
> 



-- 
Gregory Kurz                                     address@hidden
                                                 address@hidden
Software Engineer @ IBM/LTC                      http://www.ibm.com
Tel 33-5-6218-1607

"Anarchy is about taking complete responsibility for yourself."
        Alan Moore.

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