Re: [PATCH v5 1/1] x86/cpufeatures: Implement Predictive Store Forwarding control.

[Thomas Gleixner <tglx@linutronix.de>]

On Mon, May 10 2021 at 06:10, RK Saripalli wrote:
> On 5/7/2021 10:13 AM, Thomas Gleixner wrote:
>> What's wrong with just treating this in the same way in which we treat
>> all other speculative vulnerabilities and provide a consistent picture
>> to the user?
>> 
>> Something like the below. You get the idea.
>
> Thomas, thank you very much for the comments.
>
> I provided the links to the original patches which treat PSF similar to other
> speculative vulnerabilities.
>
> Could you review them please?. The first patch is the cover letter.
>
> https://lore.kernel.org/lkml/20210406155004.230790-1-rsaripal@amd.com/
> https://lore.kernel.org/lkml/20210406155004.230790-2-rsaripal@amd.com/
> https://lore.kernel.org/lkml/20210406155004.230790-3-rsaripal@amd.com/
> https://lore.kernel.org/lkml/20210406155004.230790-4-rsaripal@amd.com/
> https://lore.kernel.org/lkml/20210406155004.230790-5-rsaripal@amd.com/
> https://lore.kernel.org/lkml/20210406155004.230790-6-rsaripal@amd.com/

They are going into the right direction, i.e. detection and reporting.

Vs. mitigation control the question is whether we need the full
machinery of prctl/seccomp and so forth especially under the aspect that
the SSBD mitigation already covers the PSF issue.

So for the start a simple on/off might be good enough.

Kees, any opinions?

Thanks,

        tglx