Re: [Qemu-devel] [PATCH 4/5] target-i386: set custom features/properties without intermediate x86_def_t

[Eduardo Habkost]

On Thu, Jan 17, 2013 at 04:16:33PM +0100, Igor Mammedov wrote:
> Move custom features parsing after built-in cpu_model defaults are set
> and set custom features directly on CPU instance. That allows to make
> clear distinction between built-in cpu model defaults that eventually
> should go into clas_init() and extra property setting which is done
> after defaults are set on CPU instance.
> 
> Impl. details:
>  - features that are already properties, are converted to normalized
>    (name, values) list. And after featurestr has been parsed,
>    properties from the list are applied directly to CPU instance.
>    * For now it provides uniform handling of properties with single
>      object_property_parse() property setter.
>    * And after current features/properties are converted into static
>      properties, it will take a trivial patch to switch to global properties.
>      Which will allow to:
>      * get CPU instance initialized with all parameters passed on -cpu ...
>        cmd. line from object_new() call.
>      * call cpu_model/featurestr parsing only once before CPUs are created
>      * open a road for removing CPUxxxState.cpu_model_str field, when other
>        CPUs are similarly converted to subclasses and static properties.
>  - re-factor error handling, to use Error instead of fprintf()s, since
>    it is anyway passed in for property setter.
> 
> Signed-off-by: Igor Mammedov <address@hidden>
> ---
>  target-i386/cpu.c |  144 
> ++++++++++++++++++++++++++++-------------------------
>  1 files changed, 77 insertions(+), 67 deletions(-)
> 
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 5cd7917..50e10b1 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -1302,9 +1302,24 @@ static int cpu_x86_find_by_name(x86_def_t 
> *x86_cpu_def, const char *name)
>      return 0;
>  }
>  
> +typedef struct NameValuePair {
> +    char *name;
> +    char *value;
> +    QTAILQ_ENTRY(NameValuePair) next;
> +} NameValuePair;
> +typedef QTAILQ_HEAD(NVList, NameValuePair) NVList;
> +
> +static void x86_cpu_add_nv_pair(NVList *list, const char *name,
> +                                const char *value) {
> +    NameValuePair *p = g_malloc0(sizeof(*p));
> +    p->name = g_strdup(name);
> +    p->value = g_strdup(value);
> +    QTAILQ_INSERT_TAIL(list, p, next);
> +}

I am not sure I like this extra complexity. We don't need it if we
simply set/register the properties directly.

I have a different proposal:

1) By now, use:
      object_property_parse(OBJECT(cpu), P, V, errp)
   in the places you are using:
      x86_cpu_add_nv_pair(&props, P, V)
   below.

2) The day we move to global properties, we just need to mechanically
   replace the occurrences of:
     object_property_parse(OBJECT(cpu), P, V, errp)
   with:
     qdev_prop_register_global("X86CPU", P, V)

What do you think?


> +        object_property_parse(OBJECT(cpu), p->value, p->name, errp);
> +
>  /* Parse "+feature,-feature,feature=foo" CPU feature string
>   */
> -static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features)
> +static void cpu_x86_parse_featurestr(X86CPU *cpu, char *features, Error 
> **errp)
>  {
>      char *featurestr; /* Single 'key=value" string being parsed */
>      /* Features to be added */
> @@ -1312,6 +1327,9 @@ static int cpu_x86_parse_featurestr(x86_def_t 
> *x86_cpu_def, char *features)
>      /* Features to be removed */
>      FeatureWordArray minus_features = { 0 };
>      uint32_t numvalue;
> +    CPUX86State *env = &cpu->env;
> +    NVList props = QTAILQ_HEAD_INITIALIZER(props);
> +    NameValuePair *p, *tmp;
>  
>      featurestr = features ? strtok(features, ",") : NULL;
>  
> @@ -1324,77 +1342,57 @@ static int cpu_x86_parse_featurestr(x86_def_t 
> *x86_cpu_def, char *features)
>          } else if ((val = strchr(featurestr, '='))) {
>              *val = 0; val++;
>              if (!strcmp(featurestr, "family")) {
> -                char *err;
> -                numvalue = strtoul(val, &err, 0);
> -                if (!*val || *err || numvalue > 0xff + 0xf) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> -                }
> -                x86_cpu_def->family = numvalue;
> +                x86_cpu_add_nv_pair(&props, featurestr, val);
>              } else if (!strcmp(featurestr, "model")) {
> -                char *err;
> -                numvalue = strtoul(val, &err, 0);
> -                if (!*val || *err || numvalue > 0xff) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> -                }
> -                x86_cpu_def->model = numvalue;
> +                x86_cpu_add_nv_pair(&props, featurestr, val);
>              } else if (!strcmp(featurestr, "stepping")) {
> -                char *err;
> -                numvalue = strtoul(val, &err, 0);
> -                if (!*val || *err || numvalue > 0xf) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> -                }
> -                x86_cpu_def->stepping = numvalue ;
> +                x86_cpu_add_nv_pair(&props, featurestr, val);
>              } else if (!strcmp(featurestr, "level")) {
> -                char *err;
> -                numvalue = strtoul(val, &err, 0);
> -                if (!*val || *err) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> -                }
> -                x86_cpu_def->level = numvalue;
> +                x86_cpu_add_nv_pair(&props, featurestr, val);
>              } else if (!strcmp(featurestr, "xlevel")) {
>                  char *err;
> +                char num[32];
> +
>                  numvalue = strtoul(val, &err, 0);
>                  if (!*val || *err) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> +                    error_setg(errp, "bad numerical value %s\n", val);
> +                    goto out;
>                  }
>                  if (numvalue < 0x80000000) {
>                      fprintf(stderr, "xlevel value shall always be >= 
> 0x80000000"
>                              ", fixup will be deprecated in future 
> versions\n");
>                      numvalue += 0x80000000;
>                  }
> -                x86_cpu_def->xlevel = numvalue;
> +                snprintf(num, sizeof(num), "%" PRIu32, numvalue);
> +                x86_cpu_add_nv_pair(&props, featurestr, num);
>              } else if (!strcmp(featurestr, "vendor")) {
> -                pstrcpy(x86_cpu_def->vendor, sizeof(x86_cpu_def->vendor), 
> val);
> +                x86_cpu_add_nv_pair(&props, featurestr, val);
>              } else if (!strcmp(featurestr, "model_id")) {
> -                pstrcpy(x86_cpu_def->model_id, sizeof(x86_cpu_def->model_id),
> -                        val);
> +                x86_cpu_add_nv_pair(&props, "model-id", val);
>              } else if (!strcmp(featurestr, "tsc_freq")) {
>                  int64_t tsc_freq;
>                  char *err;
> +                char num[32];
>  
>                  tsc_freq = strtosz_suffix_unit(val, &err,
>                                                 STRTOSZ_DEFSUFFIX_B, 1000);
>                  if (tsc_freq < 0 || *err) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> +                    error_setg(errp, "bad numerical value %s\n", val);
> +                    goto out;
>                  }
> -                x86_cpu_def->tsc_khz = tsc_freq / 1000;
> +                snprintf(num, sizeof(num), "%" PRId64, tsc_freq);
> +                x86_cpu_add_nv_pair(&props, "tsc-frequency", num);
>              } else if (!strcmp(featurestr, "hv_spinlocks")) {
>                  char *err;
>                  numvalue = strtoul(val, &err, 0);
>                  if (!*val || *err) {
> -                    fprintf(stderr, "bad numerical value %s\n", val);
> -                    goto error;
> +                    error_setg(errp, "bad numerical value %s\n", val);
> +                    goto out;
>                  }
>                  hyperv_set_spinlock_retries(numvalue);
>              } else {
> -                fprintf(stderr, "unrecognized feature %s\n", featurestr);
> -                goto error;
> +                error_setg(errp, "unrecognized feature %s\n", featurestr);
> +                goto out;
>              }
>          } else if (!strcmp(featurestr, "check")) {
>              check_cpuid = 1;
> @@ -1405,31 +1403,46 @@ static int cpu_x86_parse_featurestr(x86_def_t 
> *x86_cpu_def, char *features)
>          } else if (!strcmp(featurestr, "hv_vapic")) {
>              hyperv_enable_vapic_recommended(true);
>          } else {
> -            fprintf(stderr, "feature string `%s' not in format 
> (+feature|-feature|feature=xyz)\n", featurestr);
> -            goto error;
> +            error_setg(errp, "feature string `%s' not in format (+feature|"
> +                       "-feature|feature=xyz)\n", featurestr);
> +            goto out;
>          }
>          featurestr = strtok(NULL, ",");
>      }
> -    x86_cpu_def->features |= plus_features[FEAT_1_EDX];
> -    x86_cpu_def->ext_features |= plus_features[FEAT_1_ECX];
> -    x86_cpu_def->ext2_features |= plus_features[FEAT_8000_0001_EDX];
> -    x86_cpu_def->ext3_features |= plus_features[FEAT_8000_0001_ECX];
> -    x86_cpu_def->ext4_features |= plus_features[FEAT_C000_0001_EDX];
> -    x86_cpu_def->kvm_features |= plus_features[FEAT_KVM];
> -    x86_cpu_def->svm_features |= plus_features[FEAT_SVM];
> -    x86_cpu_def->cpuid_7_0_ebx_features |= plus_features[FEAT_7_0_EBX];
> -    x86_cpu_def->features &= ~minus_features[FEAT_1_EDX];
> -    x86_cpu_def->ext_features &= ~minus_features[FEAT_1_ECX];
> -    x86_cpu_def->ext2_features &= ~minus_features[FEAT_8000_0001_EDX];
> -    x86_cpu_def->ext3_features &= ~minus_features[FEAT_8000_0001_ECX];
> -    x86_cpu_def->ext4_features &= ~minus_features[FEAT_C000_0001_EDX];
> -    x86_cpu_def->kvm_features &= ~minus_features[FEAT_KVM];
> -    x86_cpu_def->svm_features &= ~minus_features[FEAT_SVM];
> -    x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_features[FEAT_7_0_EBX];
> -    return 0;
> +    env->cpuid_features |= plus_features[FEAT_1_EDX];
> +    env->cpuid_ext_features |= plus_features[FEAT_1_ECX];
> +    env->cpuid_ext2_features |= plus_features[FEAT_8000_0001_EDX];
> +    env->cpuid_ext3_features |= plus_features[FEAT_8000_0001_ECX];
> +    env->cpuid_ext4_features |= plus_features[FEAT_C000_0001_EDX];
> +    env->cpuid_kvm_features |= plus_features[FEAT_KVM];
> +    env->cpuid_svm_features |= plus_features[FEAT_SVM];
> +    env->cpuid_7_0_ebx_features |= plus_features[FEAT_7_0_EBX];
> +    env->cpuid_features &= ~minus_features[FEAT_1_EDX];
> +    env->cpuid_ext_features &= ~minus_features[FEAT_1_ECX];
> +    env->cpuid_ext2_features &= ~minus_features[FEAT_8000_0001_EDX];
> +    env->cpuid_ext3_features &= ~minus_features[FEAT_8000_0001_ECX];
> +    env->cpuid_ext4_features &= ~minus_features[FEAT_C000_0001_EDX];
> +    env->cpuid_kvm_features &= ~minus_features[FEAT_KVM];
> +    env->cpuid_svm_features &= ~minus_features[FEAT_SVM];
> +    env->cpuid_7_0_ebx_features &= ~minus_features[FEAT_7_0_EBX];
> +
> +    /* Set features on X86CPU object based on a provided key,value list */
> +    QTAILQ_FOREACH_SAFE(p, &props, next, tmp) {
> +        /* TODO: switch to using global properties after subclasses and
> +         * static properties are done */
> +        object_property_parse(OBJECT(cpu), p->value, p->name, errp);
> +        if (error_is_set(errp)) {
> +            goto out;
> +        }
> +    }
>  
> -error:
> -    return -1;
> +out:
> +    QTAILQ_FOREACH_SAFE(p, &props, next, tmp) {
> +        QTAILQ_REMOVE(&props, p, next);
> +        g_free(p->value);
> +        g_free(p->name);
> +        g_free(p);
> +    }
>  }
>  
>  /* generate a composite string into buf of all cpuid names in featureset
> @@ -1559,10 +1572,6 @@ int cpu_x86_register(X86CPU *cpu, const char 
> *cpu_model)
>      def->kvm_features |= kvm_default_features;
>      def->ext_features |= CPUID_EXT_HYPERVISOR;
>  
> -    if (cpu_x86_parse_featurestr(def, features) < 0) {
> -        error_setg(&error, "Invalid cpu_model string format: %s", cpu_model);
> -        goto out;
> -    }
>      assert(def->vendor[0]);
>      object_property_set_str(OBJECT(cpu), def->vendor, "vendor", &error);
>      object_property_set_int(OBJECT(cpu), def->level, "level", &error);
> @@ -1584,6 +1593,7 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu_model)
>  
>      object_property_set_str(OBJECT(cpu), def->model_id, "model-id", &error);
>  
> +    cpu_x86_parse_featurestr(cpu, features, &error);
>  out:
>      g_strfreev(model_pieces);
>      if (error) {
> -- 
> 1.7.1
> 

-- 
Eduardo