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 1SKopD-0003oW-Vj for kexec@lists.infradead.org; Thu, 19 Apr 2012 10:42:57 +0000 Message-ID: <4F8FEC22.400@redhat.com> Date: Thu, 19 Apr 2012 13:42:42 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [PATCH 0/4] Export offsets of VMCS fields as note information for kdump References: <4F8E7A5B.5030904@redhat.com> <4F8E8E3D.8040707@cn.fujitsu.com> <4F8EABF7.805@redhat.com> <20120419.193640.59653378.d.hatayama@jp.fujitsu.com> In-Reply-To: <20120419.193640.59653378.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 01:36 PM, HATAYAMA Daisuke wrote: > From: Avi Kivity > Subject: Re: [PATCH 0/4] Export offsets of VMCS fields as note information for kdump > Date: Wed, 18 Apr 2012 14:56:39 +0300 > > > On 04/18/2012 12:49 PM, zhangyanfei wrote: > >> >> > >> > > >> > What type of resource? Can you give an example? > >> > > >> Sorry. No concrete example for now. > >> > >> We are developing this on a conservative policy and I have put the vmcs processing > >> in a new module in patch set v2 as you required. The new module is auto-loaded when > >> the vmx cpufeature is detected and it depends on module kvm-intel. Loading and unloading > >> this module will have no side effect on the running guests. > >> > >> And one thing I have to stress is that, we can see guest image as crash dump from > >> guest machine's view if we have the vmcsinfo, this itself is useful. > > > > Why is it useful? Without a concrete example, it's hard to justify the > > code bloat. > > > > 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? -- error compiling committee.c: too many arguments to function _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec