From: Thomas Gleixner <tglx@linutronix.de>
To: speck@linutronix.de
Subject: Re: [patch V5 09/14] MDS basics 9
Date: Fri, 1 Mar 2019 20:15:36 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.21.1903012008500.1638@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20190301183914.y3kvjyneyncgwki7@treble>
On Fri, 1 Mar 2019, speck for Josh Poimboeuf wrote:
> On Fri, Mar 01, 2019 at 10:40:22AM -0600, Josh Poimboeuf wrote:
> > On Fri, Mar 01, 2019 at 05:03:39PM +0100, speck for Thomas Gleixner wrote:
> > > On Fri, 1 Mar 2019, speck for Josh Poimboeuf wrote:
> > > > Andrea brought up a good question privately -- this patch mitigates
> > > > MSBDS for HT, but HT will still be susceptible to the other two MDS
> > > > issues. So what's the point? It seems this patch only protects people
> > > > who don't care about MDS in the first place.
> > >
> > > Indeed for most CPU models it's pointless.
> > >
> > > The ones which are only affected by MSBDS are Atom Silvermont/Airmont which
> > > are all single threaded and the XEON PHIs.
> > >
> > > For XEON PHI it actually makes sense because XEON PHI does not have L1TF
> > > either.
> > >
> > > But yes, for everything else it's just window dressing.
> >
> > Makes sense. I didn't realize that some CPUs were affected by MSBDS and
> > not other MDSes.
> >
> > Can you add that justification to the documentation and/or patch
> > description?
>
> Or even better, can we only do the idle clearing on XEON PHI?
>
> Also it sounds like the mds vulnerabilities file shouldn't ever show
> "SMT vulnerable" for XEON PHI.
Yeah.
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?
Thanks,
tglx
next prev parent reply other threads:[~2019-03-01 19:15 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 [this message]
2019-03-01 22:38 ` Andrea Arcangeli
2019-03-01 22:58 ` Thomas Gleixner
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.21.1903012008500.1638@nanos.tec.linutronix.de \
--to=tglx@linutronix.de \
--cc=speck@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).