Re: [Qemu-devel] [PATCH 1/1] x86: add CPU flags supported inside libvirt

[Eduardo Habkost]

On Fri, Jul 19, 2019 at 11:44:57PM +0200, Paolo Bonzini wrote:
> On 19/07/19 22:53, Eduardo Habkost wrote:
> > This is one is named "cqm" on Linux (X86_FEATURE_CQM).  I prefer
> > to keep consistency with the name already in use by Linux than
> > the one in libvirt that was never used.
> > 
> > You can still add a "cmt" alias property if you think it would be
> > useful.
> 
> Actually KVM does not mark it as supported:
> 
>         const u32 kvm_cpuid_7_0_ebx_x86_features =
>                 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
>                 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
>                 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
>                 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | 
> F(AVX512DQ) |
>                 F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt;

We can still add the feature name if we also set it on
.unmigratable_features, but I don't see why it would be useful.
Is anybody working to support exposing RDT-M to guests?

-- 
Eduardo