Messages in this thread | | | Date | Fri, 26 Jan 2018 19:49:15 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/cpufeatures: Cleanup AMD speculation feature bits |
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On Fri, Jan 26, 2018 at 06:45:18PM +0000, David Woodhouse wrote: > On Fri, 2018-01-26 at 19:41 +0100, Borislav Petkov wrote: > > +#define X86_FEATURE_AMD_IBPB (13*32+12) /* "" Indirect Branch Prediction Barrier MSR */ > > Stray quotes.
No no, those quotes are magical. :)
They don't show the string in /proc/cpuinfo, see arch/x86/kernel/cpu/mkcapflags.sh
> > +#define X86_FEATURE_IBRS (13*32+14) /* Indirect Branch Restricted Speculation */ > > Please don't call it that. Call it X86_FEATURE_AMD_IBRS and leave > X86_FEATURE_IBRS to parallel X86_FEATURE_IBPB as the *software* bit > which is vendor-independent.
Do we have a X86_FEATURE_IBRS bit?
If so, then this bit should become
#define X86_FEATURE_AMD_IBRS (13*32+14) /* "" Speculation Control MSR only (AMD) */
*with* the magic quotes.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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