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

[Ani Sinha]

> On Dec 22, 2019, at 1:45 PM, Paolo Bonzini <address@hidden> wrote:
> 
> 
> 
> Il dom 22 dic 2019, 08:49 Ani Sinha <address@hidden> ha scritto:
> 
> Ping …
> 
> Why ping? You got questions from Eduardo, so you need to answer them and/or 
> send a fixed version of the patch.
> 


Maybe he responded privately but I did not get any questions from Eduardo.

Ani


> Thanks,
> 
> Paolo
> 
> 
> > On Dec 18, 2019, at 5:23 PM, Paolo Bonzini <address@hidden> wrote:
> > 
> > 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
>