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.