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 1SWgGf-0008S7-DJ for kexec@lists.infradead.org; Tue, 22 May 2012 04:00:18 +0000 Message-ID: <4FBB0DB7.3040909@cn.fujitsu.com> Date: Tue, 22 May 2012 11:53:27 +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> In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Eric Northup 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, Avi Kivity , Greg KH , ebiederm@xmission.com 5LqOIDIwMTLlubQwNeaciDIy5pelIDAyOjU4LCBFcmljIE5vcnRodXAg5YaZ6YGTOgo+IE9uIFdl ZCwgTWF5IDE2LCAyMDEyIGF0IDEyOjUwIEFNLCB6aGFuZ3lhbmZlaQo+IDx6aGFuZ3lhbmZlaUBj bi5mdWppdHN1LmNvbT4gd3JvdGU6Cj4+Cj4+IFRoaXMgcGF0Y2ggc2V0IGV4cG9ydHMgb2Zmc2V0 cyBvZiBWTUNTIGZpZWxkcyBhcyBub3RlIGluZm9ybWF0aW9uIGZvcgo+PiBrZHVtcC4gV2UgY2Fs bCBpdCBWTUNTSU5GTy4gVGhlIHB1cnBvc2Ugb2YgVk1DU0lORk8gaXMgdG8gcmV0cmlldmUKPj4g cnVudGltZSBzdGF0ZSBvZiBndWVzdCBtYWNoaW5lIGltYWdlLCBzdWNoIGFzIHJlZ2lzdGVycywg aW4gaG9zdAo+PiBtYWNoaW5lJ3MgY3Jhc2ggZHVtcCBhcyBWTUNTIGZvcm1hdC4gVGhlIHByb2Js ZW0gaXMgdGhhdCBWTUNTIGludGVybmFsCj4+IGlzIGhpZGRlbiBieSBJbnRlbCBpbiBpdHMgc3Bl Y2lmaWNhdGlvbi4gU28sIHdlIHNsb3ZlIHRoaXMgcHJvYmxlbQo+PiBieSByZXZlcnNlIGVuZ2lu ZWVyaW5nIGltcGxlbWVudGVkIGluIHRoaXMgcGF0Y2ggc2V0LiBUaGUgVk1DU0lORk8KPj4gaXMg ZXhwb3J0ZWQgdmlhIHN5c2ZzIHRvIGtleGVjLXRvb2xzIGp1c3QgbGlrZSBWTUNPUkVJTkZPLgo+ IAo+IFBlcmhhcHMgSSdtIHdyb25nLCBidXQgdGhpcyBzb2x1dGlvbiBzZWVtcyBtdWNoLCBtdWNo IG1vcmUgZHluYW1pYwo+IHRoYW4gaXQgbmVlZHMgdG8gYmUuCj4gCj4gVGhlIFZNQ1Mgb2Zmc2V0 cyBhcmVuJ3QgZ29pbmcgdG8gY2hhbmdlIGJldHdlZW4gZGlmZmVyZW50IGJvb3RzIG9uIHRoZQo+ IHNhbWUgQ1BVLCB1bmxlc3MgcGVyaGFwcyB0aGUgbWljcm9jb2RlIGhhcyBiZWVuIHVwZGF0ZWQu Cj4gCj4gU28geW91IGNhbiBoYXZlIHRoZSBWTUNTIG9mZnNldCBkdW1waW5nIGJlIGEgbWFudWFs bHktbG9hZGVkIG1vZHVsZS4KPiBCdWlsZCBhIGRhdGFiYXNlIG1hcHBpbmcgZnJvbSAoQ1BVSUQs IG1pY3JvY29kZSByZXZpc2lvbikgLT4gKFZNQ1NJTkZPKS4KPiBUaGVyZSdzIG5vIG5lZWQgZm9y IGFueXRoaW5nIGJleW9uZCB0aGUgKENQVUlELCBtaWNyb2NvZGUgcmV2aXNpb24pIHRvCj4gYmUg cHV0IGluIHRoZSBrZHVtcCwgc2luY2UgeW91ciBvZmZsaW5lIHByb2Nlc3Npbmcgb2YgYSBrZHVt cCBjYW4gdGhlbgo+IGxvb2sgdXAgdGhlIHJlc3QuCj4gCj4gSXQgbWVhbnMgeW91IGRvbid0IGhh dmUgdG8gaW50ZXJhY3Qgd2l0aCB0aGUgdm14IG1vZHVsZSBhdCBhbGwsIGFuZAo+IG5vIGV4dHJh IG1vZHVsZXMgb3IgY29kZSBoYXZlIHRvIGJlIGxvYWRlZCBvbiB0aGUgbWlsbGlvbnMgb2YgTGlu dXgKPiBtYWNoaW5lcyB0aGF0IHdvbid0IG5lZWQgdGhlIGZ1bmN0aW9uYWxpdHkuCj4gCgpXZSBo YXZlIGNvbnNpZGVyZWQgdGhpcyB3YXksIGJ1dCB0aGVyZSBhcmUgdHdvIGlzc3VlczoKMSkgdm14 IHJlc291cmNlIGlzIHVuaXF1ZSBmb3IgYSBzaW5nbGUgY3B1LCBhbmQgaXQncyByaXNreSB0byBn cmFiIGl0IGZvcmNpYmx5Cm9uIHRoZSBlbnZpcm9ubWVudCB3aGVyZSBrdm0gbW9kdWxlIGlzIHVz ZWQsIGluIHBhcnRpY3VsYXIgb24gY3VzdG9tZXIncyBlbnZpcm9ubWVudC4KVG8gZG8gdGhpcyBz YWZlbHksIGt2bSBzdXBwb3J0IGlzIG5lZWRlZC4KCjIpIEl0IGhpZ2hseSBjb3N0cyB0byBwcmVw YXJlIGVhY2ggY3B1IHRvIGVhY2ggY3VzdG9tZXIgZW52aXJvbm1lbnQgdG8gY29sbGVjdAp2bWNz aW5mby4gQWZ0ZXIgYWxsLCB0aGVyZSBhcmUgdmFyaW91cyBlbnZpcm9ubWVudHMgb24gb3VyIGN1 c3RvbWVyJ3MuCgpPdXIgcGF0Y2ggcHJvdmlkZXMgYSBtb2R1bGUsIHNvIHRob3NlIHdobyBkb2Vz bid0IHdhbnQgdGhpcyBmZWF0dXJlIGNhbiBqdXN0CnN0b3AgaXQgYmVpbmcgYXV0by1sb2FkZWQg d2hlbiBzeXN0ZW0gc3RhcnRzIHVwLgoKVGhhbmtzClpoYW5nIFlhbmZlaQoKCl9fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmtleGVjIG1haWxpbmcgbGlzdApr ZXhlY0BsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxt YW4vbGlzdGluZm8va2V4ZWMK From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yanfei Zhang Subject: Re: [PATCH v2 0/5] Export offsets of VMCS fields as note information for kdump Date: Tue, 22 May 2012 11:53:27 +0800 Message-ID: <4FBB0DB7.3040909@cn.fujitsu.com> References: <4FB35C48.30708@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: dzickus-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, luto-3s7WtUTddSA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Joerg Roedel , 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, ludwig.nussel-l3A5Bk7waGM@public.gmane.org, Avi Kivity , Greg KH , ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org To: Eric Northup Return-path: In-Reply-To: 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 5LqOIDIwMTLlubQwNeaciDIy5pelIDAyOjU4LCBFcmljIE5vcnRodXAg5YaZ6YGTOgo+IE9uIFdl ZCwgTWF5IDE2LCAyMDEyIGF0IDEyOjUwIEFNLCB6aGFuZ3lhbmZlaQo+IDx6aGFuZ3lhbmZlaUBj bi5mdWppdHN1LmNvbT4gd3JvdGU6Cj4+Cj4+IFRoaXMgcGF0Y2ggc2V0IGV4cG9ydHMgb2Zmc2V0 cyBvZiBWTUNTIGZpZWxkcyBhcyBub3RlIGluZm9ybWF0aW9uIGZvcgo+PiBrZHVtcC4gV2UgY2Fs bCBpdCBWTUNTSU5GTy4gVGhlIHB1cnBvc2Ugb2YgVk1DU0lORk8gaXMgdG8gcmV0cmlldmUKPj4g cnVudGltZSBzdGF0ZSBvZiBndWVzdCBtYWNoaW5lIGltYWdlLCBzdWNoIGFzIHJlZ2lzdGVycywg aW4gaG9zdAo+PiBtYWNoaW5lJ3MgY3Jhc2ggZHVtcCBhcyBWTUNTIGZvcm1hdC4gVGhlIHByb2Js ZW0gaXMgdGhhdCBWTUNTIGludGVybmFsCj4+IGlzIGhpZGRlbiBieSBJbnRlbCBpbiBpdHMgc3Bl Y2lmaWNhdGlvbi4gU28sIHdlIHNsb3ZlIHRoaXMgcHJvYmxlbQo+PiBieSByZXZlcnNlIGVuZ2lu ZWVyaW5nIGltcGxlbWVudGVkIGluIHRoaXMgcGF0Y2ggc2V0LiBUaGUgVk1DU0lORk8KPj4gaXMg ZXhwb3J0ZWQgdmlhIHN5c2ZzIHRvIGtleGVjLXRvb2xzIGp1c3QgbGlrZSBWTUNPUkVJTkZPLgo+ IAo+IFBlcmhhcHMgSSdtIHdyb25nLCBidXQgdGhpcyBzb2x1dGlvbiBzZWVtcyBtdWNoLCBtdWNo IG1vcmUgZHluYW1pYwo+IHRoYW4gaXQgbmVlZHMgdG8gYmUuCj4gCj4gVGhlIFZNQ1Mgb2Zmc2V0 cyBhcmVuJ3QgZ29pbmcgdG8gY2hhbmdlIGJldHdlZW4gZGlmZmVyZW50IGJvb3RzIG9uIHRoZQo+ IHNhbWUgQ1BVLCB1bmxlc3MgcGVyaGFwcyB0aGUgbWljcm9jb2RlIGhhcyBiZWVuIHVwZGF0ZWQu Cj4gCj4gU28geW91IGNhbiBoYXZlIHRoZSBWTUNTIG9mZnNldCBkdW1waW5nIGJlIGEgbWFudWFs bHktbG9hZGVkIG1vZHVsZS4KPiBCdWlsZCBhIGRhdGFiYXNlIG1hcHBpbmcgZnJvbSAoQ1BVSUQs IG1pY3JvY29kZSByZXZpc2lvbikgLT4gKFZNQ1NJTkZPKS4KPiBUaGVyZSdzIG5vIG5lZWQgZm9y IGFueXRoaW5nIGJleW9uZCB0aGUgKENQVUlELCBtaWNyb2NvZGUgcmV2aXNpb24pIHRvCj4gYmUg cHV0IGluIHRoZSBrZHVtcCwgc2luY2UgeW91ciBvZmZsaW5lIHByb2Nlc3Npbmcgb2YgYSBrZHVt cCBjYW4gdGhlbgo+IGxvb2sgdXAgdGhlIHJlc3QuCj4gCj4gSXQgbWVhbnMgeW91IGRvbid0IGhh dmUgdG8gaW50ZXJhY3Qgd2l0aCB0aGUgdm14IG1vZHVsZSBhdCBhbGwsIGFuZAo+IG5vIGV4dHJh IG1vZHVsZXMgb3IgY29kZSBoYXZlIHRvIGJlIGxvYWRlZCBvbiB0aGUgbWlsbGlvbnMgb2YgTGlu dXgKPiBtYWNoaW5lcyB0aGF0IHdvbid0IG5lZWQgdGhlIGZ1bmN0aW9uYWxpdHkuCj4gCgpXZSBo YXZlIGNvbnNpZGVyZWQgdGhpcyB3YXksIGJ1dCB0aGVyZSBhcmUgdHdvIGlzc3VlczoKMSkgdm14 IHJlc291cmNlIGlzIHVuaXF1ZSBmb3IgYSBzaW5nbGUgY3B1LCBhbmQgaXQncyByaXNreSB0byBn cmFiIGl0IGZvcmNpYmx5Cm9uIHRoZSBlbnZpcm9ubWVudCB3aGVyZSBrdm0gbW9kdWxlIGlzIHVz ZWQsIGluIHBhcnRpY3VsYXIgb24gY3VzdG9tZXIncyBlbnZpcm9ubWVudC4KVG8gZG8gdGhpcyBz YWZlbHksIGt2bSBzdXBwb3J0IGlzIG5lZWRlZC4KCjIpIEl0IGhpZ2hseSBjb3N0cyB0byBwcmVw YXJlIGVhY2ggY3B1IHRvIGVhY2ggY3VzdG9tZXIgZW52aXJvbm1lbnQgdG8gY29sbGVjdAp2bWNz aW5mby4gQWZ0ZXIgYWxsLCB0aGVyZSBhcmUgdmFyaW91cyBlbnZpcm9ubWVudHMgb24gb3VyIGN1 c3RvbWVyJ3MuCgpPdXIgcGF0Y2ggcHJvdmlkZXMgYSBtb2R1bGUsIHNvIHRob3NlIHdobyBkb2Vz bid0IHdhbnQgdGhpcyBmZWF0dXJlIGNhbiBqdXN0CnN0b3AgaXQgYmVpbmcgYXV0by1sb2FkZWQg d2hlbiBzeXN0ZW0gc3RhcnRzIHVwLgoKVGhhbmtzClpoYW5nIFlhbmZlaQoKCl9fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmtleGVjIG1haWxpbmcgbGlzdApr ZXhlY0BsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxt YW4vbGlzdGluZm8va2V4ZWMK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750866Ab2EVEAR (ORCPT ); Tue, 22 May 2012 00:00:17 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:40826 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750710Ab2EVEAO convert rfc822-to-8bit (ORCPT ); Tue, 22 May 2012 00:00:14 -0400 X-IronPort-AV: E=Sophos;i="4.75,636,1330876800"; d="scan'208";a="5008519" Message-ID: <4FBB0DB7.3040909@cn.fujitsu.com> Date: Tue, 22 May 2012 11:53:27 +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: Eric Northup CC: Avi Kivity , 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> In-Reply-To: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/05/22 11:53:23, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/05/22 11:53:34 Content-Type: text/plain; charset=UTF-8 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22日 02:58, Eric Northup 写道: > On Wed, May 16, 2012 at 12:50 AM, zhangyanfei > wrote: >> >> This patch set exports offsets of VMCS fields as note information for >> kdump. We call it VMCSINFO. The purpose of VMCSINFO is to retrieve >> runtime state of guest machine image, such as registers, in host >> machine's crash dump as VMCS format. The problem is that VMCS internal >> is hidden by Intel in its specification. So, we slove this problem >> by reverse engineering implemented in this patch set. The VMCSINFO >> is exported via sysfs to kexec-tools just like VMCOREINFO. > > Perhaps I'm wrong, but this solution seems much, much more dynamic > than it needs to be. > > The VMCS offsets aren't going to change between different boots on the > same CPU, unless perhaps the microcode has been updated. > > So you can have the VMCS offset dumping be a manually-loaded module. > Build a database mapping from (CPUID, microcode revision) -> (VMCSINFO). > There's no need for anything beyond the (CPUID, microcode revision) to > be put in the kdump, since your offline processing of a kdump can then > look up the rest. > > It means you don't have to interact with the vmx module at all, and > no extra modules or code have to be loaded on the millions of Linux > machines that won't need the functionality. > We have considered this way, but there are two issues: 1) vmx resource is unique for a single cpu, and it's risky to grab it forcibly on the environment where kvm module is used, in particular on customer's environment. To do this safely, kvm support is needed. 2) It highly costs to prepare each cpu to each customer environment to collect vmcsinfo. After all, there are various environments on our customer's. Our patch provides a module, so those who doesn't want this feature can just stop it being auto-loaded when system starts up. Thanks Zhang Yanfei