Re: [Qemu-devel] [PATCH v2 3/5] target/i386: Add support for CPUID_8000_001E for AMD

["Radim Krčmář" <rkrcmar@redhat.com>]

2018-02-23 21:30-0500, Babu Moger:
> From: Stanislav Lanci <pixo@polepetko.eu>
> 
> Populate threads/core_id/apic_ids/socket_id when CPUID_EXT3_TOPOEXT
> feature is supported. This is required to support hyperthreading
> feature on AMD CPUS. These are supported via CPUID_8000_001E extended
> functions.
> 
> Signed-off-by: Stanislav Lanci <pixo@polepetko.eu>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
>  target/i386/cpu.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index a5a480e..191e850 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -3666,6 +3666,14 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
>              *edx = 0;
>          }
>          break;
> +    case 0x8000001E:
> +        if (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) {
> +            *eax = cpu->apic_id;
> +            *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id;

Do we somewhere assert that AMD cannot have cpu->core_id > 255?
(qemu does allow weird configurations.)

Thanks.

> +            *ecx = cpu->socket_id;
> +            *edx = 0;
> +        }
> +        break;
>      case 0xC0000000:
>          *eax = env->cpuid_xlevel2;
>          *ebx = 0;
> -- 
> 1.8.3.1
>