From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SKpar-0006Um-Uw for kexec@lists.infradead.org; Thu, 19 Apr 2012 11:32:11 +0000 Message-ID: <4F8FF7AC.1060309@redhat.com> Date: Thu, 19 Apr 2012 14:31:56 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [PATCH 0/4] Export offsets of VMCS fields as note information for kdump References: <4F8EABF7.805@redhat.com> <20120419.193640.59653378.d.hatayama@jp.fujitsu.com> <4F8FEC22.400@redhat.com> <20120419.202707.276752866.d.hatayama@jp.fujitsu.com> In-Reply-To: <20120419.202707.276752866.d.hatayama@jp.fujitsu.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: HATAYAMA Daisuke Cc: dzickus@redhat.com, luto@mit.edu, gregkh@suse.de, kvm@vger.kernel.org, joerg.roedel@amd.com, mtosatti@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, paul.gortmaker@windriver.com, zhangyanfei@cn.fujitsu.com, ebiederm@xmission.com, ludwig.nussel@suse.de On 04/19/2012 02:27 PM, HATAYAMA Daisuke wrote: > >> The reason why we want to retrieve guest machine's memory image as > >> crash dump is that then we can debug guest machine's status using > >> symbolic debugger such as gdb and crash utility. > >> > >> This is very useful. Please consider the situation where engineers are > >> forced to look into guest machine's memory image through qemu-kvm's > >> process core dump using gdb without any symbolic information. It's > >> very inefficient. > > > > I still don't follow. If qemu crashed, the values in guest registers > > are irrelevant. In what way can the help debug the qemu crash? > > > > It would be not helpful for the qemu crash case you are concerned > about. We want to use the guest state data to look into guest > machine's image in the crasshed qemu. Why? -- error compiling committee.c: too many arguments to function _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0/4] Export offsets of VMCS fields as note information for kdump Date: Thu, 19 Apr 2012 14:31:56 +0300 Message-ID: <4F8FF7AC.1060309@redhat.com> References: <4F8EABF7.805@redhat.com> <20120419.193640.59653378.d.hatayama@jp.fujitsu.com> <4F8FEC22.400@redhat.com> <20120419.202707.276752866.d.hatayama@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: dzickus-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, luto-3s7WtUTddSA@public.gmane.org, gregkh-l3A5Bk7waGM@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, joerg.roedel-5C7GfCeVMHo@public.gmane.org, mtosatti-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, zhangyanfei-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, ludwig.nussel-l3A5Bk7waGM@public.gmane.org To: HATAYAMA Daisuke Return-path: In-Reply-To: <20120419.202707.276752866.d.hatayama-+CUm20s59erQFUHtdCDX3A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kexec-bounces-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Errors-To: kexec-bounces+glkk-kexec=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: kvm.vger.kernel.org On 04/19/2012 02:27 PM, HATAYAMA Daisuke wrote: > >> The reason why we want to retrieve guest machine's memory image as > >> crash dump is that then we can debug guest machine's status using > >> symbolic debugger such as gdb and crash utility. > >> > >> This is very useful. Please consider the situation where engineers are > >> forced to look into guest machine's memory image through qemu-kvm's > >> process core dump using gdb without any symbolic information. It's > >> very inefficient. > > > > I still don't follow. If qemu crashed, the values in guest registers > > are irrelevant. In what way can the help debug the qemu crash? > > > > It would be not helpful for the qemu crash case you are concerned > about. We want to use the guest state data to look into guest > machine's image in the crasshed qemu. Why? -- error compiling committee.c: too many arguments to function From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754908Ab2DSLcR (ORCPT ); Thu, 19 Apr 2012 07:32:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33470 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753040Ab2DSLcP (ORCPT ); Thu, 19 Apr 2012 07:32:15 -0400 Message-ID: <4F8FF7AC.1060309@redhat.com> Date: Thu, 19 Apr 2012 14:31:56 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-Version: 1.0 To: HATAYAMA Daisuke CC: zhangyanfei@cn.fujitsu.com, mtosatti@redhat.com, ebiederm@xmission.com, luto@mit.edu, joerg.roedel@amd.com, dzickus@redhat.com, paul.gortmaker@windriver.com, gregkh@suse.de, ludwig.nussel@suse.de, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH 0/4] Export offsets of VMCS fields as note information for kdump References: <4F8EABF7.805@redhat.com> <20120419.193640.59653378.d.hatayama@jp.fujitsu.com> <4F8FEC22.400@redhat.com> <20120419.202707.276752866.d.hatayama@jp.fujitsu.com> In-Reply-To: <20120419.202707.276752866.d.hatayama@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/19/2012 02:27 PM, HATAYAMA Daisuke wrote: > >> The reason why we want to retrieve guest machine's memory image as > >> crash dump is that then we can debug guest machine's status using > >> symbolic debugger such as gdb and crash utility. > >> > >> This is very useful. Please consider the situation where engineers are > >> forced to look into guest machine's memory image through qemu-kvm's > >> process core dump using gdb without any symbolic information. It's > >> very inefficient. > > > > I still don't follow. If qemu crashed, the values in guest registers > > are irrelevant. In what way can the help debug the qemu crash? > > > > It would be not helpful for the qemu crash case you are concerned > about. We want to use the guest state data to look into guest > machine's image in the crasshed qemu. Why? -- error compiling committee.c: too many arguments to function