Re: [Qemu-devel] [PATCH RFC] qmp, target-i386: device_list_properties for TYPE_CPU

[Andreas Färber]

Hi,

Am 12.02.2016 um 10:13 schrieb Valentin Rakush:
> This is RFC because there is another implementation option: it is
> possible to implement this functionality in the object_finalize for
> all available targets. All targets change will require more testing.
> Please let me know if all targets should be changed at once.

I thought I had already seen some Fujitsu/IBM patch to fix this...
(pointers appreciated) It should be fixed on the level where the problem
is introduced - i.e. if qom/cpu.c calls the cpu_exec_init() in
instance_init it needs to call the corresponding exit function in
instance_finalize; dito for target-i386/cpu.c or wherever. Or we try to
move it from instance_init to realize, avoiding it getting called in the
first place.

> 
> This patch changes qmp_device_list_properties and only target-i386
> to allow TYPE_CPU class properties to be quered with QMP interface and
> with -device core2duo-x86_64-cpu,help command line.
> 
> Signed-off-by: Valentin Rakush <address@hidden>
> Cc: Luiz Capitulino <address@hidden>
> Cc: Eric Blake <address@hidden>
> Cc: Markus Armbruster <address@hidden>
> Cc: Andreas Färber <address@hidden>
> Cc: Daniel P. Berrange <address@hidden>
> Cc: Eduardo Habkost <address@hidden>
> ---
>  qmp.c             | 19 +++++++++++++++++++
>  target-i386/cpu.c | 32 ++++++++++++++++++++++++++++++--
>  2 files changed, 49 insertions(+), 2 deletions(-)
> 
> diff --git a/qmp.c b/qmp.c
> index 6ae7230..2721f16 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -516,6 +516,7 @@ DevicePropertyInfoList *qmp_device_list_properties(const 
> char *typename,
>                                                     Error **errp)
>  {
>      ObjectClass *klass;
> +    ObjectClass *cpu_klass;

Please use cpu_class, only "class" is a reserved identifier.

>      Object *obj;
>      ObjectProperty *prop;
>      ObjectPropertyIterator iter;
> @@ -580,6 +581,24 @@ DevicePropertyInfoList *qmp_device_list_properties(const 
> char *typename,
>          prop_list = entry;
>      }
>  
> +    cpu_klass = object_class_dynamic_cast(klass, TYPE_CPU);
> +    if (cpu_klass) {
> +        CPUState *tmp_cpu = CPU(obj);
> +        CPUState *cs = first_cpu;
> +
> +        CPU_FOREACH(cs) {
> +            if (tmp_cpu->cpu_index == cs->cpu_index) {
> +#if defined(CONFIG_USER_ONLY)
> +                cpu_list_lock();
> +#endif
> +                QTAILQ_REMOVE(&cpus, cs, node);
> +#if defined(CONFIG_USER_ONLY)
> +                cpu_list_unlock();
> +#endif
> +            }
> +        }
> +    }
> +
>      object_unref(obj);
>  
>      return prop_list;
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 3fa14bf..8c32794 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -1479,7 +1479,7 @@ static void host_x86_cpu_class_init(ObjectClass *oc, 
> void *data)
>  
>      dc->props = host_x86_cpu_properties;
>      /* Reason: host_x86_cpu_initfn() dies when !kvm_enabled() */
> -    dc->cannot_destroy_with_object_finalize_yet = true;
> +    dc->cannot_destroy_with_object_finalize_yet = false;
>  }
>  
>  static void host_x86_cpu_initfn(Object *obj)
> @@ -3225,11 +3225,39 @@ static void x86_cpu_common_class_init(ObjectClass 
> *oc, void *data)
>      cc->cpu_exec_enter = x86_cpu_exec_enter;
>      cc->cpu_exec_exit = x86_cpu_exec_exit;
>  
> +    object_class_property_add(oc, "family", "int",
> +                        x86_cpuid_version_get_family,
> +                        x86_cpuid_version_set_family, NULL, NULL, NULL);

You add class properties here but I don't see you deleting the previous
instance properties anywhere?

> +    object_class_property_add(oc, "model", "int",
> +                        x86_cpuid_version_get_model,
> +                        x86_cpuid_version_set_model, NULL, NULL, NULL);
> +    object_class_property_add(oc, "stepping", "int",
> +                        x86_cpuid_version_get_stepping,
> +                        x86_cpuid_version_set_stepping, NULL, NULL, NULL);
> +    object_class_property_add_str(oc, "vendor",
> +                            x86_cpuid_get_vendor,
> +                            x86_cpuid_set_vendor, NULL);
> +    object_class_property_add_str(oc, "model-id",
> +                            x86_cpuid_get_model_id,
> +                            x86_cpuid_set_model_id, NULL);
> +    object_class_property_add(oc, "tsc-frequency", "int",
> +                        x86_cpuid_get_tsc_freq,
> +                        x86_cpuid_set_tsc_freq, NULL, NULL, NULL);
> +    object_class_property_add(oc, "apic-id", "int",
> +                        x86_cpuid_get_apic_id,
> +                        x86_cpuid_set_apic_id, NULL, NULL, NULL);
> +    object_class_property_add(oc, "feature-words", "X86CPUFeatureWordInfo",
> +                        x86_cpu_get_feature_words,
> +                        NULL, NULL, NULL, NULL);
> +    object_class_property_add(oc, "filtered-features", 
> "X86CPUFeatureWordInfo",
> +                        x86_cpu_get_feature_words,
> +                        NULL, NULL, NULL, NULL);
> +
>      /*
>       * Reason: x86_cpu_initfn() calls cpu_exec_init(), which saves the
>       * object in cpus -> dangling pointer after final object_unref().
>       */
> -    dc->cannot_destroy_with_object_finalize_yet = true;
> +    dc->cannot_destroy_with_object_finalize_yet = false;

This looks bogus, Markus will need to take a close look.

>  }
>  
>  static const TypeInfo x86_cpu_type_info = {
> 

Regards,
Andreas

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