Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755871AbdIGSuH (ORCPT ); Thu, 7 Sep 2017 14:50:07 -0400 Received: from mail-it0-f46.google.com ([209.85.214.46]:38435 "EHLO mail-it0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753640AbdIGSuF (ORCPT ); Thu, 7 Sep 2017 14:50:05 -0400 X-Google-Smtp-Source: AOwi7QBgNVejSSIGRZqX95g8kivoWm5cezyTOf3KkeOLgfXUc+F21L99V2hz97+3P0aTmBhAU20/LA== Date: Thu, 7 Sep 2017 12:50:02 -0600 From: Tycho Andersen To: Ralph Campbell Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "kernel-hardening@lists.openwall.com" , Marco Benatto , Juerg Haefliger , "x86@kernel.org" Subject: Re: [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) Message-ID: <20170907185002.g5r5oaeyghtx2fgl@docker> References: <20170907173609.22696-1-tycho@docker.com> <20170907173609.22696-4-tycho@docker.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1041 Lines: 28 On Thu, Sep 07, 2017 at 06:33:09PM +0000, Ralph Campbell wrote: > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2736,6 +2736,8 @@ > > > > nox2apic [X86-64,APIC] Do not enable x2APIC mode. > > > > + noxpfo [X86-64] Disable XPFO when CONFIG_XPFO is on. > > + > > cpu0_hotplug [X86] Turn on CPU0 hotplug feature when > > CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off. > > Some features depend on CPU0. Known dependencies > <... snip> > > A bit more description for system administrators would be very useful. > Perhaps something like: > > noxpfo [XPFO,X86-64] Disable eXclusive Page Frame Ownership (XPFO) > Physical pages mapped into user applications will also be mapped > in the kernel's address space as if CONFIG_XPFO was not enabled. > > Patch 05 should also update kernel-parameters.txt and add "ARM64" to the config option list for noxpfo. Nice catch, thanks. I'll fix both. Cheers, Tycho