[MODERATED] Re: [PATCH 7/9] TAA 7
Borislav Petkov <[email protected]>
| Newsgroups | org.kernel.lore.historical-speck |
|---|---|
| Message-ID | <[email protected]> |
On Thu, Oct 24, 2019 at 10:35:17AM -0500, speck for Josh Poimboeuf wrote:
> On Wed, Oct 23, 2019 at 12:28:57PM +0200, speck for Pawan Gupta wrote:
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index ad6b69057bb0..e1aca10f2a7f 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -4856,6 +4856,11 @@
> >
> > on - Enable TSX on the system.
> > off - Disable TSX on the system.
> > + auto - Disable TSX if X86_BUG_TAA is present,
>
> Not quite true, since MDS-affected parts don't have the new microcode
> bits to disable TSX.
How's this:
"Disable TSX if the CPU is affected by the TSX Async Abort (TAA)
vulnerability and microcode provides a special MSR - TSX_CTRL_MSR -
which provides the required TSX control knobs. On MDS-affected parts
where VERW takes care of the TAA vulnerability, that controlling MSR is
not present and thus TSX cannot be disabled there."
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Regards/Gruss,
Boris.
SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg
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