Re: [PATCH RFC 2/5] x86/speculation: Add support for 'cpu_spec_mitigations=' cmdline options

From: Josh Poimboeuf
Date: Fri Apr 05 2019 - 12:05:46 EST


On Fri, Apr 05, 2019 at 05:26:50PM +0200, Borislav Petkov wrote:
> On Fri, Apr 05, 2019 at 09:31:01AM -0500, Josh Poimboeuf wrote:
> > My thinking was that the individual options could be used to override
> > the global option. But maybe that's overkill? I dunno.
>
> You mean if the user deliberately types:
>
> "cpu_spec_mitigations=off spectre_v2=auto"
>
> on the cmdline to turn off all and then enable only one?
>
> Hmm, yap, sounds like an overkill to me. Then I'd probably do:
>
> pr_err("Make up your mind already!\n");
> return;
>
> :-))
>
> I'd say let's do the simpler and cleaner thing now and think about
> supporting this overkill when it really turns out that it is needed.

Fair enough.

> > I assume you mean just the part where L1TF_MITIGATION_DEFAULT is added?
>
> Yap.

Ok.

--
Josh