Re: [PATCH 2/3] x86/speculation: Support Automatic IBRS

[Kim Phillips]

On 11/5/22 6:39 AM, David Laight wrote:
> From: Borislav Petkov
> > Sent: 04 November 2022 21:52
> >
> > On Fri, Nov 04, 2022 at 04:36:50PM -0500, Kim Phillips wrote:
> > >   - Allow for spectre_v2=autoibrs in the kernel command line,
> > >     reverting to auto-selection if the feature isn't available.
> >
> > Why?
> >
> > What the whole logic here should do is enable autoibrs when detected
> > automatically, without the need for the user to even select it as it is
> > the superior mitigation.
>
> The only useful option is to allow a different option be
> selected for code testing.
> So maybe you want an option for completeness - for when
> an 'even better' option is available.

This is true.

Kim