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From: Jiri Kosina <jkosina@suse.com>
To: speck@linutronix.de
Subject: [MODERATED] Re: [PATCH v4 06/28] MDSv4 11
Date: Tue, 15 Jan 2019 13:01:49 +0100 (CET)	[thread overview]
Message-ID: <nycvar.YFH.7.76.1901151300170.6626@cbobk.fhfr.pm> (raw)
In-Reply-To: <892e7dbe-a531-539d-61f4-a723a40f0109@intel.com>

On Mon, 14 Jan 2019, speck for Dave Hansen wrote:

> > +	case X86_BUG_MDS:
> > +		/* Assumes Hypervisor exposed HT state to us if in guest */
> > +		if (boot_cpu_has(X86_FEATURE_MD_CLEAR)) {
> > +			if (cpu_smt_control !=3D CPU_SMT_ENABLED)
> > +				return sprintf(buf, "Mitigation:
> > microcode\n");
> > +			return sprintf(buf, "Mitigation: microcode, HT
> > vulnerable\n");
> > +		}
> > +		return sprintf(buf, "Vulnerable\n");
> 
> What are we trying to convey by saying "HT vulnerable"?  There are a ton
> of patches in this set that do HT mitigations, so just saying
> "vulnerable" seems a bit cynical.

If I read the code correctly, the only case where SMT is taken care of 
wrt. MDS is when one of the siblings is in idle (mwait/hlt). Other than 
that, SMT is pretty much uncovered if both threads are actually executing 
code AFAICS.

-- 
Jiri Kosina
SUSE Labs

  reply	other threads:[~2019-01-15 12:02 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-12  1:29 [MODERATED] [PATCH v4 00/28] MDSv4 2 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 01/28] MDSv4 3 Andi Kleen
2019-01-15 14:11   ` [MODERATED] " Andrew Cooper
2019-01-12  1:29 ` [MODERATED] [PATCH v4 02/28] MDSv4 22 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 03/28] MDSv4 20 Andi Kleen
2019-01-14 18:50   ` [MODERATED] " Dave Hansen
2019-01-14 19:29     ` Andi Kleen
2019-01-14 19:38       ` Linus Torvalds
2019-01-12  1:29 ` [MODERATED] [PATCH v4 04/28] MDSv4 8 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 05/28] MDSv4 10 Andi Kleen
2019-01-14 19:20   ` [MODERATED] " Dave Hansen
2019-01-14 19:31     ` Andi Kleen
2019-01-18  7:33     ` [MODERATED] Encrypted Message Jon Masters
2019-01-14 23:39   ` Tim Chen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 06/28] MDSv4 11 Andi Kleen
2019-01-14 19:23   ` [MODERATED] " Dave Hansen
2019-01-15 12:01     ` Jiri Kosina [this message]
2019-01-12  1:29 ` [MODERATED] [PATCH v4 07/28] MDSv4 0 Andi Kleen
2019-01-14  4:03   ` [MODERATED] " Josh Poimboeuf
2019-01-14  4:38     ` Andi Kleen
2019-01-14  4:55       ` Josh Poimboeuf
2019-01-12  1:29 ` [MODERATED] [PATCH v4 08/28] MDSv4 19 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 09/28] MDSv4 16 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 10/28] MDSv4 24 Andi Kleen
2019-01-15  1:05   ` [MODERATED] Encrypted Message Tim Chen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 11/28] MDSv4 21 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 12/28] MDSv4 25 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 13/28] MDSv4 4 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 14/28] MDSv4 17 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 15/28] MDSv4 9 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 16/28] MDSv4 6 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 17/28] MDSv4 18 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 18/28] MDSv4 26 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 19/28] MDSv4 14 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 20/28] MDSv4 23 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 21/28] MDSv4 15 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 22/28] MDSv4 5 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 23/28] MDSv4 13 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 24/28] MDSv4 28 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 25/28] MDSv4 1 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 26/28] MDSv4 27 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 27/28] MDSv4 7 Andi Kleen
2019-01-12  1:29 ` [MODERATED] [PATCH v4 28/28] MDSv4 12 Andi Kleen
2019-01-12  3:04 ` [MODERATED] Re: [PATCH v4 00/28] MDSv4 2 Andi Kleen

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