Re: [Qemu-devel] [RFC 2 PATCH 15/16] i386: Fix pkg_id offset for epyc mode

[Eduardo Habkost]

On Fri, Sep 06, 2019 at 07:13:22PM +0000, Moger, Babu wrote:
> Signed-off-by: Babu Moger <address@hidden>
> ---
>  target/i386/cpu.c |   24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index f25491a029..f8b1fc5c07 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -4094,9 +4094,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
> uint32_t count,
>                     uint32_t *eax, uint32_t *ebx,
>                     uint32_t *ecx, uint32_t *edx)
>  {
> +    MachineState *ms = MACHINE(qdev_get_machine());
>      X86CPU *cpu = env_archcpu(env);
>      CPUState *cs = env_cpu(env);
> -    uint32_t die_offset;
> +    uint32_t die_offset, pkg_offset;
>      uint32_t limit;
>      uint32_t signature[3];
>  
> @@ -4119,6 +4120,21 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
> uint32_t count,
>          index = env->cpuid_level;
>      }
>  
> +    if (ms->epyc) {
> +        X86CPUTopoInfo topo_info = {
> +            .numa_nodes = nb_numa_nodes,
> +            .nr_sockets = ms->smp.sockets,
> +            .nr_cores = ms->smp.cores,
> +            .nr_threads = ms->smp.threads,
> +        };

Why aren't you using initialize_topo_info() here?

> +        unsigned nodes = nodes_in_pkg(&topo_info);
> +        pkg_offset = apicid_pkg_offset_epyc(nodes, MAX_CCX, MAX_CORES_IN_CCX,
> +                                            cs->nr_threads);
> +    } else {
> +        pkg_offset = apicid_pkg_offset(env->nr_dies, cs->nr_cores,
> +                                       cs->nr_threads);
> +    }

I think we won't need this at all if we simply:

1) Add nodes_per_pkg to X86CPUTopoInfo;
2) make nodes_per_pkg configurable;
3) just use topo->nr_dies and topo->nr_cores instead of those
   constants.

-- 
Eduardo