From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:55540) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RIcUW-0007xM-2o for qemu-devel@nongnu.org; Tue, 25 Oct 2011 04:36:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RIcUS-0007Zs-22 for qemu-devel@nongnu.org; Tue, 25 Oct 2011 04:36:12 -0400 Received: from mail-qy0-f180.google.com ([209.85.216.180]:55216) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RIcUR-0007ZX-Vk for qemu-devel@nongnu.org; Tue, 25 Oct 2011 04:36:08 -0400 Received: by qyk10 with SMTP id 10so348234qyk.4 for ; Tue, 25 Oct 2011 01:36:07 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <4EA674EF.9010308@redhat.com> Date: Tue, 25 Oct 2011 10:35:59 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <54c9dc1d-3104-4f42-9a20-d7f4da516bdc@zmail05.collab.prod.int.phx2.redhat.com> <4EA58488.50306@redhat.com> <4EA66E1E.90502@cn.fujitsu.com> <4EA67216.3050309@redhat.com> In-Reply-To: <4EA67216.3050309@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Question] dump memory when host pci device is used by guest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: qemu-devel , Jan Kiszka , "Richard W.M. Jones" , Luiz Capitulino , Dave Anderson , KAMEZAWA Hiroyuki On 10/25/2011 10:23 AM, Avi Kivity wrote: > On 10/25/2011 10:06 AM, Wen Congyang wrote: >> Hi, Avi Kivity, Dave Anderson >> >> I have two questions about it: >> >> 1. How to know the guest's physical base address in qemu? > > In fact, it's impossible. > > Perhaps crash can scan through the core looking for a signature. Need > to be careful since multiple signatures may be detected (a kdump kernel, > a kernel image in pagecache, or a nested guest). Crash uses a heuristic based on the IDT base to identify the base from migrate-to-file output. It also needs CR3 in order to read from virtual address. Paolo