On Fri, Jan 05, 2018 at 10:07:36AM -0600, Tom Lendacky wrote:
> To aid in speculation control, the LFENCE instruction will be turned into
> a serializing instruction. There is less performance impact using LFENCE
> in this way compared to MFENCE.
>
> With LFENCE now being a serializing instruction, it can be used in
> rdtsc_ordered() in place of MFENCE_RDTSC. The other two patches in this
> series make this change and remove the MFENCE_RDTSC feature.
>
> The following patches are included in this series:
> - Make LFENCE a serializing instruction on AMD
> - Change over to LFENCE_RDTSC from MFENCE_RDTSC on AMD
> - Remove the MFENCE_RDTSC feature
>
> This patch series is based on tip:x86/pti.
>
> ---
>
> Tom Lendacky (3):
> x86/cpu/AMD: Make LFENCE a serializing instruction
> x86/cpu/AMD: Use LFENCE_RDTSC instead of MFENCE_RDTSC
> x86/msr: Remove now unused definition of MFENCE_RDTSC feature
All three:
Reviewed-by: Borislav Petkov <b...@suse.de>
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
