historical-speck.lore.kernel.org archive mirror
 help / color / mirror / Atom feed
From: mark gross <mgross@linux.intel.com>
To: speck@linutronix.de
Subject: [MODERATED] Re: [PATCH 3/4] V7 more sampling fun 3
Date: Wed, 15 Apr 2020 15:21:44 -0700	[thread overview]
Message-ID: <20200415222144.GB100223@mtg-dev.jf.intel.com> (raw)
In-Reply-To: <873694oqgv.fsf@nanos.tec.linutronix.de>

On Wed, Apr 15, 2020 at 02:58:40PM +0200, speck for Thomas Gleixner wrote:
> Mark,
> 
> speck for mark gross <speck@linutronix.de> writes:
> > On Tue, Apr 14, 2020 at 03:05:44PM -0500, speck for Josh Poimboeuf wrote:
> >> On Thu, Jan 16, 2020 at 02:16:07PM -0800, speck for mark gross wrote:
> >> > +static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
> >> > +	VULNBL_INTEL_STEPPING(KABYLAKE_L,	X86_STEPPINGS(0, 0xA),		SRBDS),
> >> > +	VULNBL_INTEL_STEPPING(KABYLAKE_L,	X86_STEPPINGS(0xB, 0xC),	SRBDS_IF_TSX),
> >> > +	VULNBL_INTEL_STEPPING(KABYLAKE,		X86_STEPPINGS(0, 0xB),		SRBDS),
> >> > +	VULNBL_INTEL_STEPPING(KABYLAKE,		X86_STEPPINGS(0xC, 0xD),	SRBDS_IF_TSX),
> >> 
> >> Another readability tweak: "0x0" helps with vertical alignment:
> >> 
> >> 	VULNBL_INTEL_STEPPING(KABYLAKE_L,	X86_STEPPINGS(0x0, 0xA),	SRBDS),
> >> 	VULNBL_INTEL_STEPPING(KABYLAKE_L,	X86_STEPPINGS(0xB, 0xC),	SRBDS_IF_TSX),
> >> 	VULNBL_INTEL_STEPPING(KABYLAKE,		X86_STEPPINGS(0x0, 0xB),	SRBDS),
> >> 	VULNBL_INTEL_STEPPING(KABYLAKE,		X86_STEPPINGS(0xC, 0xD),	SRBDS_IF_TSX),
> >
> > FWIW the white paper no longer calls out individual steppings as vulnerable
> > only if TSX so I'm losing the SRBDS_IF_TSX stuff.
> 
> So we lose the complete TSX conditionals or do they now apply to all
> NO_MDS CPUs?
we apply the TSX test to all  MDS_NO CPU's.

FWIW I greatly appreciate your efforts in cleaning up the x86 macros that we
needed in earlier versions of the white paper.  The white paper splits out
different steppings to differentiate older parts that were affected by MDS from
the newer versions that had MDS_NO (and so had the option of mitigating SRBDS
by turning off TSX).  But, recently it changed such that stepping isn't needed
to determine vulnerability.

Depending on how people want to list things we can split out the MDS_NO CPU's
or collapse them and not depend on the stepping.  i.e. use X86_STEPPINGS_ALL or
just use the legacy interfaces that don't know about stepping.  Which is what
I'm planning to do as it will make back porting easier.

sorry,
--mark

  reply	other threads:[~2020-04-15 22:21 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-13 18:10 [MODERATED] [PATCH 0/4] V7 more sampling fun 0 mark gross
2020-01-16 22:16 ` [MODERATED] [PATCH 3/4] V7 more sampling fun 3 mark gross
2020-01-30 19:12 ` [MODERATED] [PATCH 4/4] V7 more sampling fun 4 mark gross
2020-03-17  0:56 ` [MODERATED] [PATCH 2/4] V7 more sampling fun 2 mark gross
2020-03-17  0:56 ` [MODERATED] [PATCH 1/4] V7 more sampling fun 1 mark gross
2020-04-14  3:48 ` [MODERATED] Re: [PATCH 3/4] V7 more sampling fun 3 mark gross
2020-04-14 16:23   ` Thomas Gleixner
2020-04-14 20:03     ` [MODERATED] " mark gross
2020-04-14 10:58 ` Thomas Gleixner
2020-04-14 16:43   ` [MODERATED] " mark gross
2020-04-14 20:02 ` Josh Poimboeuf
2020-04-14 21:03   ` mark gross
2020-04-14 21:23     ` Josh Poimboeuf
2020-04-14 21:53       ` mark gross
2020-04-14 20:05 ` Josh Poimboeuf
2020-04-14 21:59   ` mark gross
2020-04-14 22:46     ` Josh Poimboeuf
2020-04-15 20:59       ` mark gross
2020-04-15 12:58     ` Thomas Gleixner
2020-04-15 22:21       ` mark gross [this message]
2020-04-15 17:51 ` [MODERATED] Re: [PATCH 1/4] V7 more sampling fun 1 Borislav Petkov
2020-04-15 23:58   ` mark gross

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=20200415222144.GB100223@mtg-dev.jf.intel.com \
    --to=mgross@linux.intel.com \
    --cc=speck@linutronix.de \
    --subject='[MODERATED] Re: [PATCH 3/4] V7 more sampling fun 3' \
    /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

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).