From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753423AbcLGQKu (ORCPT ); Wed, 7 Dec 2016 11:10:50 -0500 Received: from mail-bn3nam01on0120.outbound.protection.outlook.com ([104.47.33.120]:43200 "EHLO NAM01-BN3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752987AbcLGQKt (ORCPT ); Wed, 7 Dec 2016 11:10:49 -0500 From: KY Srinivasan To: Olaf Hering , "vkuznets@redhat.com" CC: "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "devel@linuxdriverproject.org" Subject: RE: move hyperv CHANNELMSG_UNLOAD from crashed kernel to kdump kernel Thread-Topic: move hyperv CHANNELMSG_UNLOAD from crashed kernel to kdump kernel Thread-Index: AQHSUGcX2rMR2fVQK0y/0wJ0y+Ek/aD8lNrQgAAMiQCAAAVI4A== Date: Wed, 7 Dec 2016 16:10:46 +0000 Message-ID: References: <20161207085110.GC1618@aepfle.de> <7CEFFEF3-911A-4D37-AC37-DF8C6A3395BF@aepfle.de> In-Reply-To: <7CEFFEF3-911A-4D37-AC37-DF8C6A3395BF@aepfle.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=kys@microsoft.com; x-originating-ip: [2601:600:8c00:1040:610d:6d5b:cbd7:998c] x-ms-office365-filtering-correlation-id: f2a37d21-7bef-43b0-833d-08d41ebb9a88 x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001);SRVR:DM5PR03MB2492; x-microsoft-exchange-diagnostics: 1;DM5PR03MB2492;7:1BcCe65/rcGm2yRSj+KnwV90D4FQst4bHcGagazas3Vp9/joCgeVxNitxhwSGSfXFd9TWuVme7M/mQiu0dhelqmTwmd7ond3ZM2gRwRm0MsV4asoOis125NeyZmxwweH3N1lV5/n48ROBmx6RIG3JV+8zzfmSCIuzDL4HcH0jf/mBqR1MFoY0n2nhcjH3Y6gqFRoysZqikC0ErVWMHJADHWDNhL+p0Mfcz7+ppijPjMxJ8q2wk7xmZMbMRYKxbZnNbQXuNjLW/8N2iKCAT9dTnHVn0+M+rtfbkJOjm5D6kFvUzPHoWEpQTOEXlu52/2Cm0sXrFbbmuQ8qkQt93cxAciFyqrarttXvnhu7kaC5REK8ptcQmCny/P+fqpFwQNQ1zOcf3jhfibvizropu04epjDWqugOhQy9TUF5IJBjY3y+oV4Tuewk+ZniI1JMze8XbaFraYUcriA2vhpMQmGzwxDmUVFP2DE53AtXgd/usQ= x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(9452136761055); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(61425038)(6040375)(601004)(2401047)(5005006)(8121501046)(3002001)(10201501046)(6055026)(61426038)(61427038)(6041248)(20161123560025)(20161123564025)(20161123562025)(20161123555025)(20161123558021)(6047074)(6072148);SRVR:DM5PR03MB2492;BCL:0;PCL:0;RULEID:;SRVR:DM5PR03MB2492; x-forefront-prvs: 01494FA7F7 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(7916002)(377454003)(199003)(189002)(13464003)(77096006)(39410400001)(6506006)(6116002)(229853002)(8936002)(8676002)(81166006)(33656002)(81156014)(39450400002)(102836003)(9686002)(39850400001)(97736004)(39860400001)(5001770100001)(122556002)(39840400001)(8990500004)(10090500001)(92566002)(86362001)(4326007)(2950100002)(86612001)(38730400001)(5005710100001)(189998001)(5660300001)(7696004)(2900100001)(10290500002)(2906002)(106356001)(106116001)(3280700002)(99286002)(3660700001)(105586002)(76176999)(76576001)(305945005)(74316002)(54356999)(50986999)(68736007)(2501003)(7846002)(7736002)(101416001);DIR:OUT;SFP:1102;SCL:1;SRVR:DM5PR03MB2492;H:DM5PR03MB2490.namprd03.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Dec 2016 16:10:46.5176 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR03MB2492 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id uB7GAtHI024624 > -----Original Message----- > From: Olaf Hering [mailto:olaf@aepfle.de] > Sent: Wednesday, December 7, 2016 7:47 AM > To: KY Srinivasan ; vkuznets@redhat.com > Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; > devel@linuxdriverproject.org > Subject: RE: move hyperv CHANNELMSG_UNLOAD from crashed kernel to > kdump kernel > > Am 7. Dezember 2016 16:04:29 MEZ, schrieb KY Srinivasan > : > > >Yes; I had played with this approach a while ago. The issue is that the > >host knows about a > >bunch of in memory state that will be different in the kexec kernel. > >For instance if we did all > >the cleanup as part of the boot sequence, we will need access to all > >the interrupt/messaging > >infrastructure that was set up in the previous kernel. > > > Where is that stored? Perhaps it should be put into one place, so that the > new kernel can find and use it. All the state required to handle interrupts is needed as well as the state needed to issue unload. Look at vmbus_isr() for the needed interrupt handling state. The entire code path from the isr routine will have to be executed. Is there a mechanism for stashing away state that can be retrieved in the context of the execed kernel. K. Y > > Olaf