[MODERATED] Re: [PATCH v5 08/11] TAAv5 8

On Wed, Oct 16, 2019 at 06:52:15AM +0200, speck for Jiri Kosina wrote:
> yOn Tue, 15 Oct 2019, speck for Josh Poimboeuf wrote:
> 
> > So if I understand correctly, you're postulating that distros want:
> > 
> > a) TAA_BUG && MDS_NO=0 => TSX on
> > b) TAA_BUG && MDS_NO=1 => TSX off
> > c) !TAA_BUG            => TSX on
> > 
> > How are you reaching that conclusion?  It seems horribly confusing for
> > TSX users, but again maybe I'm missing something.
> > 
> > It seems to me that "heavy users of TSX" would want tsx=on, no matter
> > what.  And so we would need to leave that as the default in order to not
> > break those users.
> 
> But then we're not defaulting to safe behavior, which is confusing too, 
> because we almost (SMT being the exception) always did in the past for all 
> the other previous issues.

Why wouldn't it be safe behavior?  For both TAA_BUG cases, we can
mitigate TSX with verw buffer clearing.

-- 
Josh