linux-kernel - Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20181119135149.GN22247@dhcp22.suse.cz>
Date:   Mon, 19 Nov 2018 14:51:49 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     Jiri Kosina <jikos@...nel.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Dave Hansen <dave.hansen@...el.com>,
        Andi Kleen <ak@...ux.intel.com>, Borislav Petkov <bp@...e.de>,
        LKML <linux-kernel@...r.kernel.org>, linux-mm@...ck.org
Subject: Re: [PATCH] l1tf: drop the swap storage limit restriction when
 l1tf=off

On Mon 19-11-18 14:36:32, Jiri Kosina wrote:
> On Wed, 14 Nov 2018, Michal Hocko wrote:
> 
> > > > +				It also drops the swap size and available
> > > > +				RAM limit restriction.
> > > 
> > > Minor nit: I think this should explicitly mention that those two things 
> > > are related to bare metal mitigation, to avoid any confusion (as otherwise 
> > > the l1tf cmdline parameter is purely about hypervisor mitigations).
> > 
> > Do you have any specific wording in mind?
> > 
> > It also drops the swap size and available RAM limit restrictions on both
> > hypervisor and bare metal.
> > 
> > Sounds better?
> > 
> > > With that
> > > 
> > > 	Acked-by: Jiri Kosina <jkosina@...e.cz>
> > 
> > Thanks!
> 
> Yes, I think that makes it absolutely clear. Thanks,

OK. Here is the incremental diff on top of the patch. I will fold and
repost later this week. I assume people are still catching up after LPC
and I do not want to spam them even more.

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a54f2bd39e77..c5aa4b4a797d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2096,7 +2096,8 @@
 				Disables hypervisor mitigations and doesn't
 				emit any warnings.
 				It also drops the swap size and available
-				RAM limit restriction.
+				RAM limit restriction on both hypervisor and
+				bare metal.
 
 			Default is 'flush'.
 
diff --git a/Documentation/admin-guide/l1tf.rst b/Documentation/admin-guide/l1tf.rst
index b00464a9c09c..2e65e6cb033e 100644
--- a/Documentation/admin-guide/l1tf.rst
+++ b/Documentation/admin-guide/l1tf.rst
@@ -405,7 +405,8 @@ The kernel command line allows to control the L1TF mitigations at boot
 
   off		Disables hypervisor mitigations and doesn't emit any
 		warnings.
-		It also drops the swap size and available RAM limit restrictions.
+		It also drops the swap size and available RAM limit restrictions
+                on both hypervisor and bare metal.
 
   ============  =============================================================
 
-- 
Michal Hocko
SUSE Labs