From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754747Ab1GLSLe (ORCPT ); Tue, 12 Jul 2011 14:11:34 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:18120 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754626Ab1GLSLd (ORCPT ); Tue, 12 Jul 2011 14:11:33 -0400 Date: Tue, 12 Jul 2011 14:11:18 -0400 From: Konrad Rzeszutek Wilk To: Olaf Hering , linux-kernel@vger.kernel.org Cc: xen-devel@lists.xensource.com Subject: Re: [Xen-devel] [PATCH] xen: update machine_to_phys_order on resume Message-ID: <20110712181118.GA18662@dumpdata.com> References: <20110701104148.GA32729@aepfle.de> <20110712164342.GA12867@aepfle.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110712164342.GA12867@aepfle.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: rtcsinet22.oracle.com [66.248.204.30] X-CT-RefId: str=0001.0A090208.4E1C8E51.009F:SCFSTAT5015188,ss=1,re=-4.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 12, 2011 at 06:43:42PM +0200, Olaf Hering wrote: > > Migration of pv guests fails, the guest crashes on the target host once the > guest is unpaused after transit. It happens when the guest is started on a > small systen, then migrated from that small system to a large system. > If the guest is started on a large system, then migrated to a small system and > back to the large system, the migration will be successful. > > The issue is that mfn_to_pfn() makes use of machine_to_phys_order, which > is only configured once early in the boot process. After migration to a > large host the mfns will exceed the order from the small system and a > wrong code path is taken. > > Calling xen_setup_machphys_mapping() again in the resume path will avoid > the crash. Oh, duh! Let me queue that up for 3.0-rc7 unless there are objections? > > Signed-off-by: Olaf Hering > > --- > arch/x86/xen/mmu.c | 2 +- > arch/x86/xen/suspend.c | 2 ++ > 2 files changed, 3 insertions(+), 1 deletion(-) > > Index: linux-3.0-rc7/arch/x86/xen/mmu.c > =================================================================== > --- linux-3.0-rc7.orig/arch/x86/xen/mmu.c > +++ linux-3.0-rc7/arch/x86/xen/mmu.c > @@ -1623,7 +1623,7 @@ static void __init xen_map_identity_earl > set_page_prot(pmd, PAGE_KERNEL_RO); > } > > -void __init xen_setup_machphys_mapping(void) > +void xen_setup_machphys_mapping(void) > { > struct xen_machphys_mapping mapping; > unsigned long machine_to_phys_nr_ents; > Index: linux-3.0-rc7/arch/x86/xen/suspend.c > =================================================================== > --- linux-3.0-rc7.orig/arch/x86/xen/suspend.c > +++ linux-3.0-rc7/arch/x86/xen/suspend.c > @@ -43,6 +43,8 @@ void xen_arch_hvm_post_suspend(int suspe > > void xen_arch_post_suspend(int suspend_cancelled) > { > + xen_setup_machphys_mapping(); > + > xen_build_mfn_list_list(); > > xen_setup_shared_info(); > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel