From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757862AbYAJCHg (ORCPT ); Wed, 9 Jan 2008 21:07:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754738AbYAJCH3 (ORCPT ); Wed, 9 Jan 2008 21:07:29 -0500 Received: from mga11.intel.com ([192.55.52.93]:27079 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753877AbYAJCH2 (ORCPT ); Wed, 9 Jan 2008 21:07:28 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.24,264,1196668800"; d="scan'208";a="492204140" Subject: Re: [PATCH -mm 2/2] kexec/i386: kexec page table code clean up - page table setup in C From: "Huang, Ying" To: Vivek Goyal Cc: "Eric W. Biederman" , Andrew Morton , linux-kernel@vger.kernel.org, Horms , magnus.damn@gmail.com In-Reply-To: <20080110010531.GA23143@redhat.com> References: <1199847470.8126.16.camel@caritas-dev.intel.com> <20080110010531.GA23143@redhat.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Thu, 10 Jan 2008 10:08:09 +0800 Message-Id: <1199930889.8752.7.camel@caritas-dev.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 X-OriginalArrivalTime: 10 Jan 2008 02:07:17.0619 (UTC) FILETIME=[868EAC30:01C8532D] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2008-01-09 at 20:05 -0500, Vivek Goyal wrote: > On Wed, Jan 09, 2008 at 10:57:50AM +0800, Huang, Ying wrote: > > This patch transforms the kexec page tables setup code from asseumbler > > code to iC code in machine_kexec_prepare. This improves readability and > > reduces code line number. > > > > I think this will create issues for Xen. Initially page table setup > was in C but Xen Guests could not modify the page tables. I think Xen > folks implemented a hypercall where they passed all the page table pages > and the control pages and then hypervisor executed the control page(which > in turn setup the page tables). I think that's why page table setup > code is on the control page in assembly. > > You might want to go through Xen kexec implementation and dig through > kexec mailing list archive. OK, I will check the Xen kexec implementation. > CCing Magnus and Horms. They had done the page tables related changes > for Xen. Best Regards, Huang Ying