From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754661AbaIDNC6 (ORCPT ); Thu, 4 Sep 2014 09:02:58 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:30207 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754489AbaIDNC5 (ORCPT ); Thu, 4 Sep 2014 09:02:57 -0400 X-IronPort-AV: E=Sophos;i="5.04,465,1406592000"; d="scan'208";a="169069444" Message-ID: <540862FE.7070108@citrix.com> Date: Thu, 4 Sep 2014 14:02:54 +0100 From: Andrew Cooper User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.6.0 MIME-Version: 1.0 To: David Vrabel , Juergen Gross , , , , , Subject: Re: [Xen-devel] [PATCH 3/3] xen: eliminate scalability issues from initial mapping setup References: <1409834326-29287-1-git-send-email-jgross@suse.com> <1409834326-29287-4-git-send-email-jgross@suse.com> <54086244.7020601@citrix.com> In-Reply-To: <54086244.7020601@citrix.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/14 13:59, David Vrabel wrote: > On 04/09/14 13:38, Juergen Gross wrote: >> Direct Xen to place the initial P->M table outside of the initial >> mapping, as otherwise the 1G (implementation) / 2G (theoretical) >> restriction on the size of the initial mapping limits the amount >> of memory a domain can be handed initially. > The three level p2m limits memory to 512 GiB on x86-64 but this patch > doesn't seem to address this limit and thus seems a bit useless to me. > > David Any increase of the p2m beyond 3 levels will need to come with substantial libxc changes first. 3 level p2ms are hard coded throughout all the PV build and migrate code. ~Andrew