Re: [PATCH v2] x86/bugs: Break down mitigations configurations

Pawan Gupta
2023-06-21T17:31:47Z

On Wed, Jun 21, 2023 at 08:54:17AM -0700, Breno Leitao wrote:
> On Tue, Jun 20, 2023 at 05:13:27PM -0700, Pawan Gupta wrote:
> > On Fri, Jun 16, 2023 at 09:48:50AM -0700, Breno Leitao wrote:
> > > There is no way to disable MDS, TAA, MMIO Stale data mitigation today at
> > > compilation time. These mitigations are enabled even if
> > > CONFIG_SPECULATION_MITIGATIONS is unset.
> > >
> > > Create a new KCONFIG option for each mitigation under
> > > CONFIG_SPECULATION_MITIGATIONS that allows these
> > > mitigations to be disabled by default at compilation time.
> >
> > I don't think all mitigations are still controllable at build-time e.g.
> > spectre_v2 eIBRS mitigation will still be deployed irrespective of the
> > config.
>
> Right. This patchset only cares about MDS, TAA and MMIO. I am more than
> happy to send a new patch to also disable spectre_v2 eIBRS.

What about Retbleed, L1TF, SRBDS etc? I thought the goal is to control
all speculation mitigations?

To be consistent CONFIG_SPECULATION_MITIGATIONS should control all
speculation mitigations.