Re: [Qemu-devel] [PATCH RFC qom-cpu-next 1/6] cpu: Register VMStateDescription through CPUState

[Eduardo Habkost]

On Sat, Feb 02, 2013 at 04:04:11PM +0100, Andreas Färber wrote:
> In comparison to DeviceClass::vmsd, CPU VMState is split in two,
> "cpu_common" and "cpu", and uses cpu_index as instance_id instead of -1.
> Therefore add a CPU-specific CPUClass::vmsd field.
> 
> Unlike the legacy CPUArchState registration, rather register CPUState.
> 
> Signed-off-by: Juan Quintela <address@hidden>
> Signed-off-by: Andreas Färber <address@hidden>
> ---
>  exec.c            |   13 +++++++++++--
>  include/qom/cpu.h |    3 +++
>  2 Dateien geändert, 14 Zeilen hinzugefügt(+), 2 Zeilen entfernt(-)
> 
> diff --git a/exec.c b/exec.c
> index b85508b..5eee174 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -219,7 +219,7 @@ void cpu_exec_init_all(void)
>  #endif
>  }
>  
> -#if defined(CPU_SAVE_VERSION) && !defined(CONFIG_USER_ONLY)
> +#if !defined(CONFIG_USER_ONLY)
>  
>  static int cpu_common_post_load(void *opaque, int version_id)
>  {
> @@ -266,6 +266,9 @@ CPUState *qemu_get_cpu(int index)
>  void cpu_exec_init(CPUArchState *env)
>  {
>      CPUState *cpu = ENV_GET_CPU(env);
> +#if !defined(CONFIG_USER_ONLY) && !defined(CPU_SAVE_VERSION)
> +    CPUClass *cc = CPU_GET_CLASS(cpu);
> +#endif
>      CPUArchState **penv;
>      int cpu_index;
>  
> @@ -290,10 +293,16 @@ void cpu_exec_init(CPUArchState *env)
>  #if defined(CONFIG_USER_ONLY)
>      cpu_list_unlock();
>  #endif
> -#if defined(CPU_SAVE_VERSION) && !defined(CONFIG_USER_ONLY)
> +#if !defined(CONFIG_USER_ONLY)
>      vmstate_register(NULL, cpu_index, &vmstate_cpu_common, env);
> +#if defined(CPU_SAVE_VERSION)
>      register_savevm(NULL, "cpu", cpu_index, CPU_SAVE_VERSION,
>                      cpu_save, cpu_load, env);

What about introducing stub register_savevm() function in libqemustub.a,
so we can eliminate the CONFIG_USER_ONLY ifdefs?

(we already have vmstate_register()/vmstate_unregister() stubs).

> +#else

Do we have any architecture that sets CPU_SAVE_VERSION _and_ sets
cc->vmsd at the same time? If not, we could put the "if (cc->vmsd)
vmstate_register()" part outside any #ifdef/#else block.

> +    if (cc->vmsd != NULL) {
> +        vmstate_register(NULL, cpu_index, cc->vmsd, cpu);
> +    }
> +#endif
>  #endif
>  }
>  
> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> index 46f2247..b870752 100644
> --- a/include/qom/cpu.h
> +++ b/include/qom/cpu.h
> @@ -43,6 +43,7 @@ typedef struct CPUState CPUState;
>   * @class_by_name: Callback to map -cpu command line model name to an
>   * instantiatable CPU type.
>   * @reset: Callback to reset the #CPUState to its initial state.
> + * @vmsd: State description for migration.
>   *
>   * Represents a CPU family or model.
>   */
> @@ -54,6 +55,8 @@ typedef struct CPUClass {
>      ObjectClass *(*class_by_name)(const char *cpu_model);
>  
>      void (*reset)(CPUState *cpu);
> +
> +    const struct VMStateDescription *vmsd;
>  } CPUClass;
>  
>  struct KVMState;
> -- 
> 1.7.10.4
> 
> 

-- 
Eduardo