Re: [Xen-devel] [PATCH v2 3/6] x86/AMD: distinguish compute units from hyper-threads

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Wed, Jul 18, 2018 at 02:20:29AM -0600, Jan Beulich wrote:
> Fam17 replaces CUs by HTs, which we should reflect accordingly, even if
> the difference is not very big. The most relevant change (requiring some
> code restructuring) is that the topoext feature no longer means there is
> a valid CU ID.
> 
> Take the opportunity and convert wrongly plain int variables in
> set_cpu_sibling_map() to unsigned int.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> Reviewed-by: Brian Woods <brian.woods@xxxxxxx>

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

> ---
> v2: Don't break (bogus) indentation style in amd_get_topology().
> 
> --- a/xen/arch/x86/cpu/amd.c
> +++ b/xen/arch/x86/cpu/amd.c
> @@ -504,17 +504,23 @@ static void amd_get_topology(struct cpui
>                  u32 eax, ebx, ecx, edx;
>  
>                  cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
> -                c->compute_unit_id = ebx & 0xFF;
>                  c->x86_num_siblings = ((ebx >> 8) & 0x3) + 1;
> +
> +                if (c->x86 < 0x17)
> +                        c->compute_unit_id = ebx & 0xFF;
> +                else {
> +                        c->cpu_core_id = ebx & 0xFF;
> +                        c->x86_max_cores /= c->x86_num_siblings;
> +                }

Should compute_unit_id and cpu_core_id be inside of an union in
cpuinfo_x86?

Roger.

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