From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22DB3C04AB1 for ; Thu, 9 May 2019 07:02:19 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E7D14208C3 for ; Thu, 9 May 2019 07:02:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7D14208C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:49324 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hOd4J-0006MU-0T for qemu-devel@archiver.kernel.org; Thu, 09 May 2019 03:02:15 -0400 Received: from eggs.gnu.org ([209.51.188.92]:57023) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hOd3P-0005dc-Gq for qemu-devel@nongnu.org; Thu, 09 May 2019 03:01:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hOd3K-0003Bs-Jp for qemu-devel@nongnu.org; Thu, 09 May 2019 03:01:19 -0400 Received: from mga09.intel.com ([134.134.136.24]:3100) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hOd3K-0003A6-CN for qemu-devel@nongnu.org; Thu, 09 May 2019 03:01:14 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 May 2019 00:01:10 -0700 X-ExtLoop1: 1 Received: from joy-optiplex-7040.sh.intel.com (HELO joy-OptiPlex-7040) ([10.239.13.9]) by fmsmga001.fm.intel.com with ESMTP; 09 May 2019 00:01:05 -0700 Date: Thu, 9 May 2019 02:55:27 -0400 From: Yan Zhao To: Boris Fiuczynski Message-ID: <20190509065527.GG24397@joy-OptiPlex-7040> References: <20190506014514.3555-1-yan.y.zhao@intel.com> <20190506014904.3621-1-yan.y.zhao@intel.com> <20190507151826.502be009@x1.home> <20190508112740.GA24397@joy-OptiPlex-7040> <20190508152242.4b54a5e7@x1.home> <5eac912c-e753-b5f6-83a4-b646f991d858@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5eac912c-e753-b5f6-83a4-b646f991d858@linux.ibm.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.24 Subject: Re: [Qemu-devel] [libvirt] [PATCH v2 1/2] vfio/mdev: add version attribute for mdev device X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Yan Zhao Cc: "cjia@nvidia.com" , "kvm@vger.kernel.org" , "aik@ozlabs.ru" , "Zhengxiao.zx@alibaba-inc.com" , "shuangtai.tst@alibaba-inc.com" , "qemu-devel@nongnu.org" , "kwankhede@nvidia.com" , "eauger@redhat.com" , "Liu, Yi L" , "eskultet@redhat.com" , "Yang, Ziye" , "mlevitsk@redhat.com" , Halil Pasic , "libvir-list@redhat.com" , "arei.gonglei@huawei.com" , "felipe@nutanix.com" , "Ken.Xue@amd.com" , "Tian, Kevin" , "dgilbert@redhat.com" , "zhenyuw@linux.intel.com" , "jonathan.davies@nutanix.com" , Alex Williamson , "intel-gvt-dev@lists.freedesktop.org" , "Liu, Changpeng" , Tony Krowiak , Pierre Morel , "cohuck@redhat.com" , "linux-kernel@vger.kernel.org" , "Wang, Zhi A" , "dinechin@redhat.com" , "He, Shaopeng" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, May 08, 2019 at 11:27:47PM +0800, Boris Fiuczynski wrote: > On 5/8/19 11:22 PM, Alex Williamson wrote: > >>> I thought there was a request to make this more specific to migration > >>> by renaming it to something like migration_version. Also, as an > >>> > >> so this attribute may not only include a mdev device's parent device info and > >> mdev type, but also include numeric software version of vendor specific > >> migration code, right? > > It's a vendor defined string, it should be considered opaque to the > > user, the vendor can include whatever they feel is relevant. > > > Would a vendor also be allowed to provide a string expressing required > features as well as containing backend resource requirements which need > to be compatible for a successful migration? Somehow a bit like a cpu > model... maybe even as json or xml... > I am asking this with vfio-ap in mind. In that context checking > compatibility of two vfio-ap mdev devices is not as simple as checking > if version A is smaller or equal to version B. > I think so. vendor driver is allowed to put whatever content into the migration_version string as long as it thinks it's necessary. vendor driver only needs ensure in the target mdev device, the write(2) operation on its migration_version attribute would correctly fail or succeeed based on the input string. Thanks Yan > -- > Mit freundlichen Grüßen/Kind regards > Boris Fiuczynski > > IBM Deutschland Research & Development GmbH > Vorsitzender des Aufsichtsrats: Matthias Hartmann > Geschäftsführung: Dirk Wittkopp > Sitz der Gesellschaft: Böblingen > Registergericht: Amtsgericht Stuttgart, HRB 243294 >