From: Thomas Gleixner <tglx@linutronix.de>
To: speck@linutronix.de
Subject: Re: [patch V5 09/14] MDS basics 9
Date: Fri, 1 Mar 2019 23:58:27 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.21.1903012350420.1638@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20190301223859.GT14294@redhat.com>
On Fri, 1 Mar 2019, speck for Andrea Arcangeli wrote:
> On Fri, Mar 01, 2019 at 08:15:36PM +0100, speck for Thomas Gleixner wrote:
> > > Also it sounds like the mds vulnerabilities file shouldn't ever show
> > > "SMT vulnerable" for XEON PHI.
> >
> > Yeah.
>
> So maybe this patch should be moved to the end of the series flagged
> as an incremental XEON PHI optimization by also adding the other XEON
> PHI specific change for the l1tf default mitigation and the respective
> alteration of the vulnerabilities mds/l1tf sysfs file outputs.
>
> Is the verw measurable before mwait/hlt? I was just afraid this could
> hurt who needs to keep HT on for performance reasons and that won't be
> safe anyway if HT is kept on.
>
> Unless we also alter the vulnerabilites file like Josh suggested, XEON
> PHI owners not reading the fineprint (assuming it's reachable for
> them) may decide then to disable HT for security reasons anyway and
> they won't even benefit from the XEON PHI mwait/hlt specific static
> key to keep HT enabled safely.
I already did those changes to the sysfs file and updated documentation
accordingly. Will send an updated series soon.
> > So I was looking at that table again and found the following stepping
> > related info:
> >
> > 06_8EH,06_9EH <=B Kaby/Coffe Lake Yes Yes Yes Yes
> > 06_9E 0xC Coffee Lake No Yes Yes Yes
> > 06_8E 0xB Whiskey Lake(ULT) No Yes Yes Yes
> >
> > 06_8E 0xC Whiskey L (ULT refresh) No No No No
> > 06_9E 0xD Whiskey Lake (Deskto) No No No No
> >
> >
> > 06_55H 5 Cascade Lake No Yes Yes Yes
> >
> > 06_55H 6 Cascade Lake No No No No
> >
> > Will these 'fixed' steppings have MDS_NO set?
>
> I couldn't understand the table, so I'm can't answer this one.
Sorry I dropped the first line:
Family_model, Stepping, Codename, MFBDS, MSBDS, MLPDS Vector, MLPDS Split line.
So the thing is that newer steppings are fixed vs. all of the issues. I
surely hope that these have MDS_NO set in MSR_IA32_ARCH_CAPABILITIES.
If that's not the case, then we'll end up with stepping specific quirks
which would be an utter mess.
Can anyone @Intel please answer this question?
Thanks,
tglx
next prev parent reply other threads:[~2019-03-01 22:58 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-27 15:09 [patch V5 00/14] MDS basics 0 Thomas Gleixner
2019-02-27 15:09 ` [patch V5 01/14] MDS basics 1 Thomas Gleixner
2019-02-28 13:08 ` Thomas Gleixner
2019-02-27 15:09 ` [patch V5 02/14] MDS basics 2 Thomas Gleixner
2019-02-28 13:55 ` [MODERATED] " Josh Poimboeuf
2019-02-28 14:09 ` Thomas Gleixner
2019-02-28 20:23 ` [MODERATED] " Josh Poimboeuf
2019-03-01 16:04 ` Thomas Gleixner
2019-02-27 15:09 ` [patch V5 03/14] MDS basics 3 Thomas Gleixner
2019-02-27 16:34 ` [MODERATED] " Greg KH
2019-02-27 15:09 ` [patch V5 04/14] MDS basics 4 Thomas Gleixner
2019-02-27 15:09 ` [patch V5 05/14] MDS basics 5 Thomas Gleixner
2019-02-27 15:09 ` [patch V5 06/14] MDS basics 6 Thomas Gleixner
2019-02-27 15:09 ` [patch V5 07/14] MDS basics 7 Thomas Gleixner
2019-02-27 17:07 ` [MODERATED] " Greg KH
2019-02-27 15:09 ` [patch V5 08/14] MDS basics 8 Thomas Gleixner
2019-02-28 8:11 ` [MODERATED] " Greg KH
2019-02-27 15:09 ` [patch V5 09/14] MDS basics 9 Thomas Gleixner
2019-03-01 14:04 ` [MODERATED] " Josh Poimboeuf
2019-03-01 16:03 ` Thomas Gleixner
2019-03-01 16:40 ` [MODERATED] " Josh Poimboeuf
2019-03-01 18:39 ` Josh Poimboeuf
2019-03-01 19:15 ` Thomas Gleixner
2019-03-01 22:38 ` [MODERATED] " Andrea Arcangeli
2019-03-01 22:58 ` Thomas Gleixner [this message]
2019-03-02 19:22 ` [MODERATED] Re: [SPAM] " Dave Hansen
2019-03-02 20:39 ` Thomas Gleixner
2019-02-27 15:09 ` [patch V5 10/14] MDS basics 10 Thomas Gleixner
2019-02-27 15:09 ` [patch V5 11/14] MDS basics 11 Thomas Gleixner
2019-02-27 15:09 ` [patch V5 12/14] MDS basics 12 Thomas Gleixner
2019-03-01 22:00 ` [MODERATED] " mark gross
2019-02-27 15:09 ` [patch V5 13/14] MDS basics 13 Thomas Gleixner
2019-03-01 22:04 ` [MODERATED] " mark gross
2019-02-27 15:09 ` [patch V5 14/14] MDS basics 14 Thomas Gleixner
2019-02-27 17:49 ` Thomas Gleixner
2019-02-27 16:26 ` [MODERATED] Re: [patch V5 00/14] MDS basics 0 Linus Torvalds
2019-02-27 17:51 ` Thomas Gleixner
2019-02-27 18:13 ` Thomas Gleixner
2019-02-27 19:50 ` [MODERATED] " Linus Torvalds
2019-02-27 20:05 ` Thomas Gleixner
2019-02-27 21:04 ` Thomas Gleixner
2019-02-28 1:04 ` [MODERATED] " Josh Poimboeuf
2019-02-27 23:06 ` mark gross
2019-02-28 6:58 ` Thomas Gleixner
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