Re: [Qemu-devel] [PATCH 2/2] target-i386: make cpu_x86_create() get Error argument

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 12 Dec 2012 16:16:23 -0200
Eduardo Habkost <ehabkost@redhat.com> wrote:

> Instead of forcing the caller to guess what went wrong while creating
> the CPU object, return error information in a Error argument.
> 
> Also, as cpu_x86_create() won't print error messages itself anymore,
> change cpu_x86_init() to print any error returned by cpu_x86_create()
> or cpu_x86_realize().
> 
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
> ---
>  target-i386/cpu.c    |  8 ++++++--
>  target-i386/cpu.h    |  2 +-
>  target-i386/helper.c | 21 ++++++++++++++-------
>  3 files changed, 21 insertions(+), 10 deletions(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index b242bf1..fba872d 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -1542,7 +1542,7 @@ static void filter_features_for_kvm(X86CPU *cpu)
>  /* Create and initialize a X86CPU object, based on the full CPU model string
>   * (that may include "+feature,-feature,feature=xxx" feature strings)
>   */
> -X86CPU *cpu_x86_create(const char *cpu_model)
> +X86CPU *cpu_x86_create(const char *cpu_model, Error **errp)
>  {
>      X86CPU *cpu;
>      CPUX86State *env;
> @@ -1559,12 +1559,14 @@ X86CPU *cpu_x86_create(const char *cpu_model)
>  
>      model_pieces = g_strsplit(cpu_model, ",", 2);
>      if (!model_pieces[0]) {
> +        error_setg(errp, "invalid CPU model string: %s", cpu_model);
>          goto error;
>      }
>      name = model_pieces[0];
>      features = model_pieces[1];
>  
>      if (cpu_x86_find_by_name(def, name) < 0) {
> +        error_setg(errp, "CPU model not found: %s", name);
>          goto error;
>      }
>  
> @@ -1575,13 +1577,15 @@ X86CPU *cpu_x86_create(const char *cpu_model)
>                              &def->svm_features, &def->cpuid_7_0_ebx_features);
>  
>      if (cpu_x86_parse_featurestr(def, features) < 0) {
> +        error_setg(errp, "Error parsing feature string: %s",
> +                   features ? features : "(none)");
It could be simplified, it shouldn't get here if features == NULL

>          goto error;
>      }
>  
>      cpudef_2_x86_cpu(cpu, def, &error);
>  
>      if (error) {
> -        fprintf(stderr, "%s\n", error_get_pretty(error));
> +        error_propagate(errp, error);
Why do it here but not above?

>          error_free(error);
>          goto error;
>      }
> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
[...]
>  
>  X86CPU *cpu_x86_init(const char *cpu_model)
>  {
> -    X86CPU *cpu;
> +    X86CPU *cpu = NULL;
>      Error *error = NULL;
>  
> -    cpu = cpu_x86_create(cpu_model);
> -    if (!cpu) {
> -        return NULL;
> +    cpu = cpu_x86_create(cpu_model, &error);
> +    if (error) {
> +        goto error;
>      }
>  
>      x86_cpu_realize(OBJECT(cpu), &error);
if x86_cpu_realize() behave as visit* functions, i.e. return early if
error has been already set, error check & goto could be removed here
and above and consolidated at function exit.

>      if (error) {
> -        error_free(error);
> -        object_delete(OBJECT(cpu));
> -        return NULL;
> +        goto error;
>      }
>      return cpu;
> +
> +error:
> +    if (cpu) {
> +        object_delete(OBJECT(cpu));
> +    }
> +    error_report("%s", error_get_pretty(error));
> +    error_free(error);
> +    return NULL;
>  }
>  
>  #if !defined(CONFIG_USER_ONLY)
> -- 
> 1.7.11.7
> 


-- 
Regards,
  Igor