Re: [PATCH 3.16 045/305] x86/speculation: Apply IBPB more strictly to avoid cross-process data leak

[Andi Kleen]

On Sun, Feb 03, 2019 at 08:05:53PM +0100, Jiri Kosina wrote:
> On Sun, 3 Feb 2019, Ben Hutchings wrote:
> 
> > 3.16.63-rc1 review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Jiri Kosina <jkosina@xxxxxxx>
> > 
> > commit dbfe2953f63c640463c630746cd5d9de8b2f63ae upstream.
> 
> You really want the whole IBPB+STIBP revamp from upstream, otherwise 
> you're going to get noticeable performance penalties on some workloads 
> with some microcodes.

Yes, we would need the opt-in/opt-out support too.

Please don't merge it just as is.

-Andi