Re: [Patch v5 11/16] x86/speculation: Add Spectre v2 app to app protection modes

From: Jiri Kosina
Date: Mon Nov 19 2018 - 18:49:52 EST


On Mon, 19 Nov 2018, Dave Hansen wrote:

> > What? IBPB makes tons of sense even without STIBP.
>
> I'm lost. :)
>
> I don't think anyone is talking about using STIBP *everywhere* that IBPB
> is in-use.
>
> We're just guessing that, if anybody is paranoid enough to ask for IBPB,
> *and* they have SMT, they almost certainly want STIBP too.

I think you are not lost :) and this is exactly what makes sense, and what
Tim's patchset implements.

--
Jiri Kosina
SUSE Labs