Re: [PATCH RFC 1/5] cpu/speculation: Add 'cpu_spec_mitigations=' cmdline options

Josh Poimboeuf
2019-04-11T13:15:40Z

On Wed, Apr 10, 2019 at 02:10:01PM +0200, Thomas Gleixner wrote:
> On Wed, 10 Apr 2019, Michael Ellerman wrote:
> > Josh Poimboeuf <jpoimboe@redhat.com> writes:
> >
> > > On Fri, Apr 05, 2019 at 06:01:36PM +0200, Borislav Petkov wrote:
> > >> Thinking about this more, we can shave off the first 4 chars and have it
> > >> be:
> > >>
> > >> spec_mitigations=
> > >>
> > >> I think it is painfully clear which speculation mitigations we mean. And
> > >> the other switches don't have "cpu_" prefixes too so...
> > >
> > > Sure, I'm ok with renaming it to that, if there are no objections.
> >
> > What about when we have a mitigation for a non-speculation related bug :)
>
> Those kind of silicon bugs are usually mitigated unconditionally.

Right.

But at least "mitigations=" is nice and short. We could clarify in the
documentation that it doesn't apply to *all* mitigations, only the ones
which are optional and which can affect performance.

And it would give us the freedom to include any future "optional"
mitigations, spec or not.

I kind of like it. But I could go either way.

--
Josh