From: Thomas Gleixner <tglx@linutronix.de>
To: speck@linutronix.de
Subject: Re: [patch V6 10/14] MDS basics 10
Date: Wed, 6 Mar 2019 19:35:26 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.21.1903061933140.1646@nanos.tec.linutronix.de> (raw)
In-Reply-To: <alpine.DEB.2.21.1903061629170.1646@nanos.tec.linutronix.de>
On Wed, 6 Mar 2019, speck for Thomas Gleixner wrote:
> On Wed, 6 Mar 2019, speck for Borislav Petkov wrote:
> > On Fri, Mar 01, 2019 at 10:47:48PM +0100, speck for Thomas Gleixner wrote:
> > > +/* Update the static key controlling the MDS CPU buffer clear in idle */
> > > +static void update_mds_branch_idle(void)
> > > +{
> > > + /*
> > > + * Enable the idle clearing on CPUs which are affected only by
> > > + * MDBDS and not any other MDS variant. The other variants cannot
> > > + * be mitigated when SMT is enabled,
> >
> > ... but we're not enabling the key when SMT on those is disabled,
> > AFAICT. Or is that coming later?
>
> Five lines down ....
Following up on our conversation on IRC, I've reworded the comment:
/*
* Enable the idle clearing if SMT is active on CPUs which are
* affected only by MSBDS and not any other MDS variant.
*
* The other variants cannot be mitigated when SMT is enabled, so
* clearing the buffers on idle just to prevent the Store Buffer
* repartitioning leak would be a window dressing exercise.
*/
if (!boot_cpu_has_bug(X86_BUG_MSBDS_ONLY))
return;
Thanks,
tglx
next prev parent reply other threads:[~2019-03-06 18:35 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-01 21:47 [patch V6 00/14] MDS basics 0 Thomas Gleixner
2019-03-01 21:47 ` [patch V6 01/14] MDS basics 1 Thomas Gleixner
2019-03-02 0:06 ` [MODERATED] " Frederic Weisbecker
2019-03-01 21:47 ` [patch V6 02/14] MDS basics 2 Thomas Gleixner
2019-03-02 0:34 ` [MODERATED] " Frederic Weisbecker
2019-03-02 8:34 ` Greg KH
2019-03-05 17:54 ` Borislav Petkov
2019-03-01 21:47 ` [patch V6 03/14] MDS basics 3 Thomas Gleixner
2019-03-02 1:12 ` [MODERATED] " Frederic Weisbecker
2019-03-01 21:47 ` [patch V6 04/14] MDS basics 4 Thomas Gleixner
2019-03-02 1:28 ` [MODERATED] " Frederic Weisbecker
2019-03-05 14:52 ` Thomas Gleixner
2019-03-06 20:00 ` [MODERATED] " Andrew Cooper
2019-03-06 20:32 ` Thomas Gleixner
2019-03-07 23:56 ` [MODERATED] " Andi Kleen
2019-03-08 0:36 ` Linus Torvalds
2019-03-01 21:47 ` [patch V6 05/14] MDS basics 5 Thomas Gleixner
2019-03-02 1:37 ` [MODERATED] " Frederic Weisbecker
2019-03-07 23:59 ` Andi Kleen
2019-03-08 6:37 ` Thomas Gleixner
2019-03-01 21:47 ` [patch V6 06/14] MDS basics 6 Thomas Gleixner
2019-03-04 6:28 ` [MODERATED] Encrypted Message Jon Masters
2019-03-05 14:55 ` Thomas Gleixner
2019-03-01 21:47 ` [patch V6 07/14] MDS basics 7 Thomas Gleixner
2019-03-02 2:22 ` [MODERATED] " Frederic Weisbecker
2019-03-05 15:30 ` Thomas Gleixner
2019-03-06 15:49 ` [MODERATED] " Frederic Weisbecker
2019-03-06 5:21 ` Borislav Petkov
2019-03-01 21:47 ` [patch V6 08/14] MDS basics 8 Thomas Gleixner
2019-03-03 2:54 ` [MODERATED] " Frederic Weisbecker
2019-03-04 6:57 ` [MODERATED] Encrypted Message Jon Masters
2019-03-04 7:06 ` Jon Masters
2019-03-04 8:12 ` Jon Masters
2019-03-05 15:34 ` Thomas Gleixner
2019-03-06 16:21 ` [MODERATED] " Jon Masters
2019-03-06 14:11 ` [MODERATED] Re: [patch V6 08/14] MDS basics 8 Borislav Petkov
2019-03-01 21:47 ` [patch V6 09/14] MDS basics 9 Thomas Gleixner
2019-03-06 16:14 ` [MODERATED] " Frederic Weisbecker
2019-03-01 21:47 ` [patch V6 10/14] MDS basics 10 Thomas Gleixner
2019-03-04 6:45 ` [MODERATED] Encrypted Message Jon Masters
2019-03-05 18:42 ` [MODERATED] Re: [patch V6 10/14] MDS basics 10 Andrea Arcangeli
2019-03-06 19:15 ` Thomas Gleixner
2019-03-06 14:31 ` [MODERATED] " Borislav Petkov
2019-03-06 15:30 ` Thomas Gleixner
2019-03-06 18:35 ` Thomas Gleixner [this message]
2019-03-06 19:34 ` [MODERATED] Re: " Borislav Petkov
2019-03-01 21:47 ` [patch V6 11/14] MDS basics 11 Thomas Gleixner
2019-03-01 21:47 ` [patch V6 12/14] MDS basics 12 Thomas Gleixner
2019-03-04 5:47 ` [MODERATED] Encrypted Message Jon Masters
2019-03-05 16:04 ` Thomas Gleixner
2019-03-05 16:40 ` [MODERATED] Re: [patch V6 12/14] MDS basics 12 mark gross
2019-03-06 14:42 ` Borislav Petkov
2019-03-01 21:47 ` [patch V6 13/14] MDS basics 13 Thomas Gleixner
2019-03-03 4:01 ` [MODERATED] " Josh Poimboeuf
2019-03-05 16:04 ` Thomas Gleixner
2019-03-05 16:43 ` [MODERATED] " mark gross
2019-03-01 21:47 ` [patch V6 14/14] MDS basics 14 Thomas Gleixner
2019-03-01 23:48 ` [patch V6 00/14] MDS basics 0 Thomas Gleixner
2019-03-04 5:30 ` [MODERATED] Encrypted Message Jon Masters
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