From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753086Ab2E2HJ0 (ORCPT ); Tue, 29 May 2012 03:09:26 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:57549 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752706Ab2E2HJY convert rfc822-to-8bit (ORCPT ); Tue, 29 May 2012 03:09:24 -0400 X-IronPort-AV: E=Sophos;i="4.75,675,1330876800"; d="scan'208";a="5066651" Message-ID: <4FC47579.2040504@cn.fujitsu.com> Date: Tue, 29 May 2012 15:06:33 +0800 From: Yanfei Zhang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Avi Kivity CC: mtosatti@redhat.com, ebiederm@xmission.com, luto@mit.edu, Joerg Roedel , dzickus@redhat.com, paul.gortmaker@windriver.com, ludwig.nussel@suse.de, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kexec@lists.infradead.org, Greg KH Subject: Re: [PATCH v2 0/5] Export offsets of VMCS fields as note information for kdump References: <4FB35C48.30708@cn.fujitsu.com> <4FB92D5A.3060507@redhat.com> <4FB9A92D.7050108@cn.fujitsu.com> <4FB9FE08.4050905@redhat.com> <4FBA05F6.8070804@cn.fujitsu.com> <4FBA0C8A.2050003@redhat.com> <4FBB0ACA.2040907@cn.fujitsu.com> <4FC30C40.80500@cn.fujitsu.com> <4FC37D94.3080404@redhat.com> In-Reply-To: <4FC37D94.3080404@redhat.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/05/29 15:07:30, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/05/29 15:07:36 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 于 2012年05月28日 21:28, Avi Kivity 写道: > On 05/28/2012 08:25 AM, Yanfei Zhang wrote: >> >> Dou you have any comments about this patch set? > > I still have a hard time understanding why it is needed. If the host > crashes, there is no reason to look at guest state; the host should > survive no matter what the guest does. > > OK. Let me summarize it. 1. Why is this patch needed? (Our requirement) We once came to a buggy situation: a host scheduler bug caused guest machine's vcpu stopped for a long time and then led to heartbeat stop (host is still running). we want to have an efficient way to make the bug analysis when we come to the similar situation where guest machine doesn't work well due to something of host machine's, Because we should debug both host machine's and guest machine's sides to look for the reasons, so we want to get both host machine's crash dump and guest machine's crash dump at the same time when the buggy situation remains. 2. What will we do? If this bug was found on customer's environment, we have two ways to avoid affecting other guest machines running on the same host. First, we could do bug analysis on another environment to reproduce the buggy situation; Second, we could migrate other guest machines to other hosts. After the buggy situation is reproduced, we panic the host *manually*. Then we could use userland tools to get guest machine's crash dump from host machine's with the feature provided by this patch set. Finally we could analyse them separately to find which side causes the problem. Thanks Zhang Yanfei From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from [222.73.24.84] (helo=song.cn.fujitsu.com) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SZGYh-0005LZ-Ez for kexec@lists.infradead.org; Tue, 29 May 2012 07:09:38 +0000 Message-ID: <4FC47579.2040504@cn.fujitsu.com> Date: Tue, 29 May 2012 15:06:33 +0800 From: Yanfei Zhang MIME-Version: 1.0 Subject: Re: [PATCH v2 0/5] Export offsets of VMCS fields as note information for kdump References: <4FB35C48.30708@cn.fujitsu.com> <4FB92D5A.3060507@redhat.com> <4FB9A92D.7050108@cn.fujitsu.com> <4FB9FE08.4050905@redhat.com> <4FBA05F6.8070804@cn.fujitsu.com> <4FBA0C8A.2050003@redhat.com> <4FBB0ACA.2040907@cn.fujitsu.com> <4FC30C40.80500@cn.fujitsu.com> <4FC37D94.3080404@redhat.com> In-Reply-To: <4FC37D94.3080404@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="gb2312" Content-Transfer-Encoding: base64 Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Avi Kivity Cc: dzickus@redhat.com, luto@mit.edu, kvm@vger.kernel.org, Joerg Roedel , mtosatti@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, paul.gortmaker@windriver.com, ludwig.nussel@suse.de, ebiederm@xmission.com, Greg KH 09ogMjAxMsTqMDXUwjI4yNUgMjE6MjgsIEF2aSBLaXZpdHkg0LS1wDoKPiBPbiAwNS8yOC8yMDEy IDA4OjI1IEFNLCBZYW5mZWkgWmhhbmcgd3JvdGU6Cj4+Cj4+IERvdSB5b3UgaGF2ZSBhbnkgY29t bWVudHMgYWJvdXQgdGhpcyBwYXRjaCBzZXQ/Cj4gCj4gSSBzdGlsbCBoYXZlIGEgaGFyZCB0aW1l IHVuZGVyc3RhbmRpbmcgd2h5IGl0IGlzIG5lZWRlZC4gIElmIHRoZSBob3N0Cj4gY3Jhc2hlcywg dGhlcmUgaXMgbm8gcmVhc29uIHRvIGxvb2sgYXQgZ3Vlc3Qgc3RhdGU7IHRoZSBob3N0IHNob3Vs ZAo+IHN1cnZpdmUgbm8gbWF0dGVyIHdoYXQgdGhlIGd1ZXN0IGRvZXMuCj4gCj4gCgpPSy4gTGV0 IG1lIHN1bW1hcml6ZSBpdC4KCjEuIFdoeSBpcyB0aGlzIHBhdGNoIG5lZWRlZD8gKE91ciByZXF1 aXJlbWVudCkKICAgCldlIG9uY2UgY2FtZSB0byBhIGJ1Z2d5IHNpdHVhdGlvbjogYSBob3N0IHNj aGVkdWxlciBidWcgY2F1c2VkIGd1ZXN0IG1hY2hpbmUncwp2Y3B1IHN0b3BwZWQgZm9yIGEgbG9u ZyB0aW1lIGFuZCB0aGVuIGxlZCB0byBoZWFydGJlYXQgc3RvcCAoaG9zdCBpcyBzdGlsbCBydW5u aW5nKS4KICAgCndlIHdhbnQgdG8gaGF2ZSBhbiBlZmZpY2llbnQgd2F5IHRvIG1ha2UgdGhlIGJ1 ZyBhbmFseXNpcyB3aGVuIHdlIGNvbWUgdG8gdGhlIHNpbWlsYXIKc2l0dWF0aW9uIHdoZXJlIGd1 ZXN0IG1hY2hpbmUgZG9lc24ndCB3b3JrIHdlbGwgZHVlIHRvIHNvbWV0aGluZyBvZiBob3N0IG1h Y2hpbmUncywgCgpCZWNhdXNlIHdlIHNob3VsZCBkZWJ1ZyBib3RoIGhvc3QgbWFjaGluZSdzIGFu ZCBndWVzdCBtYWNoaW5lJ3Mgc2lkZXMgdG8gbG9vayBmb3IKdGhlIHJlYXNvbnMsIHNvIHdlIHdh bnQgdG8gZ2V0IGJvdGggaG9zdCBtYWNoaW5lJ3MgY3Jhc2ggZHVtcCBhbmQgZ3Vlc3QgbWFjaGlu ZSdzCmNyYXNoIGR1bXAgYXQgdGhlIHNhbWUgdGltZSB3aGVuIHRoZSBidWdneSBzaXR1YXRpb24g cmVtYWlucy4gCgoyLiBXaGF0IHdpbGwgd2UgZG8/CiAgIApJZiB0aGlzIGJ1ZyB3YXMgZm91bmQg b24gY3VzdG9tZXIncyBlbnZpcm9ubWVudCwgd2UgaGF2ZSB0d28gd2F5cyB0byBhdm9pZAphZmZl Y3Rpbmcgb3RoZXIgZ3Vlc3QgbWFjaGluZXMgcnVubmluZyBvbiB0aGUgc2FtZSBob3N0LiBGaXJz dCwgd2UgY291bGQgZG8gYnVnCmFuYWx5c2lzIG9uIGFub3RoZXIgZW52aXJvbm1lbnQgdG8gcmVw cm9kdWNlIHRoZSBidWdneSBzaXR1YXRpb247IFNlY29uZCwgd2UKY291bGQgbWlncmF0ZSBvdGhl ciBndWVzdCBtYWNoaW5lcyB0byBvdGhlciBob3N0cy4gCgpBZnRlciB0aGUgYnVnZ3kgc2l0dWF0 aW9uIGlzIHJlcHJvZHVjZWQsIHdlIHBhbmljIHRoZSBob3N0ICptYW51YWxseSouClRoZW4gd2Ug Y291bGQgdXNlIHVzZXJsYW5kIHRvb2xzIHRvIGdldCBndWVzdCBtYWNoaW5lJ3MgY3Jhc2ggZHVt cCBmcm9tIGhvc3QgbWFjaGluZSdzCndpdGggdGhlIGZlYXR1cmUgcHJvdmlkZWQgYnkgdGhpcyBw YXRjaCBzZXQuIEZpbmFsbHkgd2UgY291bGQgYW5hbHlzZSB0aGVtIHNlcGFyYXRlbHkKdG8gZmlu ZCB3aGljaCBzaWRlIGNhdXNlcyB0aGUgcHJvYmxlbS4KClRoYW5rcwpaaGFuZyBZYW5mZWkKCiAg IAoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18Ka2V4ZWMg bWFpbGluZyBsaXN0CmtleGVjQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJh ZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9rZXhlYwo=