Messages in this thread | | | Date | Thu, 3 Feb 2022 12:25:43 -0800 | From | Dave Hansen <> | Subject | Re: [PATCH 2/2] x86/cpufeatures: Add macros for Intel's new fast rep string features |
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On 2/3/22 11:43, Jim Mattson wrote: > Even if no one else cares, these features should be exposed to kvm > guests, and the code for the KVM_GET_SUPPORTED_CPUID ioctl is more > readable if the bits have corresponding X86_FEATURE macros.
I went digging around KVM_GET_SUPPORTED_CPUID and didn't see any obvious unreadable things resulting from not having these defines. Maybe I'm looking in the wrong spot. Do you have a slightly more specific pointer?
> +#define X86_FEATURE_FZRM (12*32+10) /* Fast zero-length REP MOVSB */ > +#define X86_FEATURE_FSRS (12*32+11) /* Fast short REP STOSB */ > +#define X86_FEATURE_FSRC (12*32+12) /* Fast short REP {CMPSB,SCASB} */
If the use really is for inside the kernel, maybe we should hide them from cpuinfo:
#define X86_FEATURE_FSRC (12*32+12) /* "" Fast short REP {CMPSB,SCASB} */
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