Hi Paolo, On 08/17/2017 11:45 AM, Paolo Bonzini wrote:
On 15/08/2017 19:00, Brijesh Singh wrote:The following features bits have been added/removed compare to Opteron_G5 Added: monitor, movbe, rdrand, mmxext, ffxsr, rdtscp, cr8legacy, osvw, fsgsbase, bmi1, avx2, smep, bmi2, rdseed, adx, smap, clfshopt, sha xsaveopt, xsavec, xgetbv1, arat Removed: xop, fma4, tbmInteresting, why were these removed?
I don't know exact reason why these were removed - I am going with whatever is listed as supported feature bit in PPR [1], but I will ask around and let you know. I believe some of these instruction are superseded with newer instructions (e.g fma4->fma) [1] http://support.amd.com/TechDocs/54945_PPR_Family_17h_Models_00h-0Fh.pdf
Do we want to add "topoext" support too? What about mwaitx?
Looking at PPR I think we can safely enable "topoext" - it is listed as fixed to 1 but "mwaitx" support depends on the MSR condition. If host BIOS does not set the MSR then we may not able to use "mwaitx" feature. Actually, I was trying to ensure that in this patch I do not use a feature which is not supported by KVM. Looking at kvm_cpuid_8000_0001_ecx_x86_features [2] hinted me that both "topoext" and "mwaitx" was not supported hence I skipped it. I can add comment to remind us. http://elixir.free-electrons.com/linux/latest/source/arch/x86/kvm/cpuid.c#L360 -Brijesh
