From mboxrd@z Thu Jan 1 00:00:00 1970 From: Samuel Thibault Subject: Re: doubt on domU segment mappings Date: Mon, 21 Jul 2008 18:36:29 +0100 Message-ID: <20080721173629.GI4501@implementation.uk.xensource.com> References: <1216659028.17572.15.camel@ec4t16cg-1518809> <20080721164244.GB4501@implementation.uk.xensource.com> <1216659873.17572.21.camel@ec4t16cg-1518809> <20080721165543.GD4501@implementation.uk.xensource.com> <1216660393.17572.30.camel@ec4t16cg-1518809> <20080721170830.GG4501@implementation.uk.xensource.com> <1216661791.17572.43.camel@ec4t16cg-1518809> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <1216661791.17572.43.camel@ec4t16cg-1518809> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Sandesh Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Sandesh, le Mon 21 Jul 2008 23:06:31 +0530, a =E9crit : > On Mon, 2008-07-21 at 18:08 +0100, Samuel Thibault wrote: > > > or at least the pt_base mapping. > >=20 > > Well the problem is that the domU most probably has destroyed it > > completely already. > can't i preserve them, at least the base pointers??? :) > can u just point to me where these segment mappings are recreated in > domU(linux 2.6.18.1). Linux domU starts in head-xen.S's startup_32, which calls start_kernel, which itself becomes the idle thread, so I guess it actually preserves it. As for the pt_base address, you can get it from linux itself from the xen_start_info structure. There is no way to get that from other domains. > > > > Again, dom0 doesn't map them any more, it doesn't need them any > > more. > > > then how will the domU kernel memory is accessed? are they mapped t= o > > the > > > domU pg_tables? > so even pt_base becomes invalid once domU has booted??=20 DomU is free to do so, yes. Samuel