Re: [PATCH] i386: pass CLZERO to guests with EPYC CPU model on AMD ZEN platform

[Paolo Bonzini]

On 18/12/19 10:05, Ani Sinha wrote:
> CLZERO CPUID should be passed on to the guests that use EPYC or EPYC-IBPB CPU
> model when the AMD ZEN based host supports it. This change makes it recognize
> this CPUID for guests which use EPYC or EPYC-IBPB CPU model.
> 
> Signed-off-by: Ani Sinha <address@hidden>
> ---
>  target/i386/cpu.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 69f518a..55f0691 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -3813,6 +3813,8 @@ static X86CPUDefinition builtin_x86_defs[] = {
>              CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A | CPUID_EXT3_ABM |
>              CPUID_EXT3_CR8LEG | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM |
>              CPUID_EXT3_TOPOEXT,
> +        .features[FEAT_8000_0008_EBX] =
> +            CPUID_8000_0008_EBX_CLZERO,
>          .features[FEAT_7_0_EBX] =
>              CPUID_7_0_EBX_FSGSBASE | CPUID_7_0_EBX_BMI1 | CPUID_7_0_EBX_AVX2 
> |
>              CPUID_7_0_EBX_SMEP | CPUID_7_0_EBX_BMI2 | CPUID_7_0_EBX_RDSEED |
> 

This needs to be done only for newer machine type (or is it CPU model
versions now? need Eduardo to respond).

Paolo