Xen-Devel Archive on lore.kernel.org
 help / color / Atom feed
From: Paul Durrant <xadimgnik@gmail.com>
To: "'Jan Beulich'" <jbeulich@suse.com>,
	"'Andrew Cooper'" <andrew.cooper3@citrix.com>
Cc: 'Xen-devel' <xen-devel@lists.xenproject.org>,
	"\'Wei Liu\'" <wl@xen.org>,
	"\'Roger Pau Monné\'" <roger.pau@citrix.com>
Subject: RE: [PATCH for-4.14] x86/spec-ctrl: Protect against CALL/JMP straight-line speculation
Date: Wed, 1 Jul 2020 14:23:18 +0100
Message-ID: <001201d64faa$ca8a6370$5f9f2a50$@xen.org> (raw)
In-Reply-To: <41b49d79-e0fa-161a-bb27-a9a2ccf361f5@suse.com>

> -----Original Message-----
> From: Jan Beulich <jbeulich@suse.com>
> Sent: 01 July 2020 13:27
> To: Andrew Cooper <andrew.cooper3@citrix.com>
> Cc: Xen-devel <xen-devel@lists.xenproject.org>; Wei Liu <wl@xen.org>; Roger Pau Monné
> <roger.pau@citrix.com>; Paul Durrant <paul@xen.org>
> Subject: Re: [PATCH for-4.14] x86/spec-ctrl: Protect against CALL/JMP straight-line speculation
> 
> On 01.07.2020 13:58, Andrew Cooper wrote:
> > Some x86 CPUs speculatively execute beyond indirect CALL/JMP instructions.
> >
> > With CONFIG_INDIRECT_THUNK / Retpolines, indirect CALL/JMP instructions are
> > converted to direct CALL/JMP's to __x86_indirect_thunk_REG(), leaving just a
> > handful of indirect JMPs implementing those stubs.
> >
> > There is no architectrual execution beyond an indirect JMP, so use INT3 as
> > recommended by vendors to halt speculative execution.  This is shorter than
> > LFENCE (which would also work fine), but also shows up in logs if we do
> > unexpected execute them.
> >
> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> 
> Reviewed-by: Jan Beulich <jbeulich@suse.com>

Release-acked-by: Paul Durrant <paul@xen.org>



      reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-01 11:58 Andrew Cooper
2020-07-01 12:26 ` Jan Beulich
2020-07-01 13:23   ` Paul Durrant [this message]

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='001201d64faa$ca8a6370$5f9f2a50$@xen.org' \
    --to=xadimgnik@gmail.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=jbeulich@suse.com \
    --cc=paul@xen.org \
    --cc=roger.pau@citrix.com \
    --cc=wl@xen.org \
    --cc=xen-devel@lists.xenproject.org \
    /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

Xen-Devel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/xen-devel/0 xen-devel/git/0.git
	git clone --mirror https://lore.kernel.org/xen-devel/1 xen-devel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 xen-devel xen-devel/ https://lore.kernel.org/xen-devel \
		xen-devel@lists.xenproject.org xen-devel@lists.xen.org
	public-inbox-index xen-devel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.xenproject.lists.xen-devel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git