From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id EFDFF6B1A3E for ; Mon, 19 Nov 2018 08:51:52 -0500 (EST) Received: by mail-ed1-f70.google.com with SMTP id n32-v6so15502118edc.17 for ; Mon, 19 Nov 2018 05:51:52 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id 6si8725616edx.32.2018.11.19.05.51.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Nov 2018 05:51:51 -0800 (PST) Date: Mon, 19 Nov 2018 14:51:49 +0100 From: Michal Hocko Subject: Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off Message-ID: <20181119135149.GN22247@dhcp22.suse.cz> References: <20181113184910.26697-1-mhocko@kernel.org> <20181114073229.GC23419@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Jiri Kosina Cc: Thomas Gleixner , Linus Torvalds , Dave Hansen , Andi Kleen , Borislav Petkov , LKML , linux-mm@kvack.org 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 > > > > 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