Re: [PATCH v1 3/3] x86/bugs: Switch the selection of mitigation from CPU vendor to CPU features

From: Konrad Rzeszutek Wilk
Date: Fri Jun 15 2018 - 15:39:24 EST


On Fri, Jun 15, 2018 at 08:57:40PM +0200, Thomas Gleixner wrote:
> On Tue, 12 Jun 2018, Tom Lendacky wrote:
> > On 6/11/2018 9:01 AM, Konrad Rzeszutek Wilk wrote:
> > >> I think you will have to keep the case statements and explicitly check for
> > >> X86_FEATURE_AMD_SSBD before using SPEC_CTRL.
> > >
> > > .. we could or alternatively add an extra check for X86_FEATURE_AMD_SSBD ?
> >
> > Whichever you feel is best, so long as we only use SPEC_CTRL for SSBD on
> > AMD when X86_FEATURE_AMD_SSBD is present.
>
> Is there anyone working on a fix or has this been forgotten?

I have it on my TODO.

But a bit busy with the fpu lazy so will get to it done next week.

Maybe along with the X86_FEATURE_IA32_ARCH_CAPS Bit(1): IBRS_ALL to disable
retpoline on those machines.

CCing Alex

>
> Thanks,
>
> tglx