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.

> +#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.