Re: [PATCH 4/8] target/i386: add AVX10 feature and AVX10 version property

[Tao Su <tao1.su@linux.intel.com>]

On Tue, Oct 29, 2024 at 04:18:54PM +0100, Paolo Bonzini wrote:
> From: Tao Su <tao1.su@linux.intel.com>

[ ... ]

>  static void max_x86_cpu_realize(DeviceState *dev, Error **errp)
>  {
>      Object *obj = OBJECT(dev);
> +    X86CPU *cpu = X86_CPU(dev);
> +    CPUX86State *env = &cpu->env;
>  
>      if (!object_property_get_int(obj, "family", &error_abort)) {
>          if (X86_CPU(obj)->env.features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
> @@ -5351,6 +5357,14 @@ static void max_x86_cpu_realize(DeviceState *dev, Error **errp)
>          }
>      }
>  
> +    if ((env->features[FEAT_7_1_EDX] & CPUID_7_1_EDX_AVX10) && !env->avx10_version) {

CPUID_7_1_EDX_AVX10 is not set now and will be set in x86_cpu_realizefn().
How about just checking !env->avx10_version? Because cpu_x86_cpuid will
also check (env->features[FEAT_7_1_EDX] & CPUID_7_1_EDX_AVX10).

> +        uint32_t eax, ebx, ecx, edx;
> +        x86_cpu_get_supported_cpuid(0x24, 0,
> +                                    &eax, &ebx, &ecx, &edx);
> +
> +        env->avx10_version = ebx & 0xff;
> +    }
> +
>      x86_cpu_realizefn(dev, errp);
>  }
>  
> @@ -6331,6 +6345,9 @@ static void x86_cpu_load_model(X86CPU *cpu, X86CPUModel *model)
>       */
>      object_property_set_str(OBJECT(cpu), "vendor", def->vendor, &error_abort);
>  
> +    object_property_set_int(OBJECT(cpu), "avx10-version", def->avx10_version,
> +                            &error_abort);

NIT: avx10-version is defined as UINT8, is it better to use object_property_set_uint?

> +
>      x86_cpu_apply_version_props(cpu, model);
>  
>      /*
> @@ -6859,6 +6876,16 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
>          }
>          break;
>      }
> +    case 0x24: {
> +        *eax = 0;
> +        *ebx = 0;
> +        *ecx = 0;
> +        *edx = 0;
> +        if (env->features[FEAT_7_1_EDX] & CPUID_7_1_EDX_AVX10) {
> +            *ebx = env->avx10_version;
> +        }

The CPUIDs of vector lengths are missing here, according to your previous
comment, it should be:

+        if ((env->features[FEAT_7_1_EDX] & CPUID_7_1_EDX_AVX10) && count == 0) {
+            *ebx = env->features[FEAT_24_0_EBX] | env->avx10_version;
+        }

[ ... ]