Re: [PATCH v2] x86/speculation: Add support for STIBP always-on preferred mode

From: Lendacky, Thomas
Date: Wed Dec 12 2018 - 10:01:56 EST

On 12/12/2018 08:32 AM, Boris Petkov wrote:
> On December 12, 2018 3:04:35 PM GMT+01:00, "Lendacky, Thomas" <Thomas.Lendacky@xxxxxxx> wrote:
>> Not sure I completely follow. Are you saying to do what I did in my
>> first patch or something different from that yet?
> I'm saying that STIBP_ALWAYS_ON should be implemented the same way like IBRS_ENHANCED is and there's no need for a static bool. AFAICT.
> Or am I missing something?

Ok, I think you're saying to do what my first patch did or something very
close to that. Which is to just set always-on mode if STIBP protection is
requested and the STIBP_ALWAYS_ON CPUID bit is set (even if the equivalent
"=on" is supplied on the command line?). That would mean having the new
mode and new string(s).

If that's not what you're saying, then maybe I just need more coffee this
morning :)