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Wysocki" , Greg KH , Thomas Gleixner , "H. Peter Anvin" , Alex Williamson , Jacob jun Pan , "Raj, Ashok" , Yi L Liu , baolu.lu@intel.com, "Tian, Kevin" , Sanjay K Kumar , "Luck, Tony" , Jing Lin , kwankhede@nvidia.com, eric.auger@redhat.com, parav@mellanox.com, dmaengine@vger.kernel.org, Linux Kernel Mailing List , X86 ML , linux-pci@vger.kernel.org, KVM list Subject: Re: [PATCH RFC 00/15] Add VFIO mediated device support and IMS support for the idxd driver. Message-ID: <20200503222229.GE19158@mellanox.com> References: <158751095889.36773.6009825070990637468.stgit@djiang5-desk3.ch.intel.com> <20200421235442.GO11945@mellanox.com> <20200423191846.GE13640@mellanox.com> <098aef60-35a4-dc44-be07-ea43c1a726c7@linux.intel.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <098aef60-35a4-dc44-be07-ea43c1a726c7@linux.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-ClientProxiedBy: MN2PR04CA0018.namprd04.prod.outlook.com (2603:10b6:208:d4::31) To VI1PR05MB4141.eurprd05.prod.outlook.com (2603:10a6:803:44::15) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from mlx.ziepe.ca (142.68.57.212) by MN2PR04CA0018.namprd04.prod.outlook.com (2603:10b6:208:d4::31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2958.20 via Frontend Transport; Sun, 3 May 2020 22:22:32 +0000 Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1jVN0H-0002RC-Dw; Sun, 03 May 2020 19:22:29 -0300 X-Originating-IP: [142.68.57.212] X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-HT: Tenant X-MS-Office365-Filtering-Correlation-Id: 4278179e-0f57-4139-b294-08d7efb07956 X-MS-TrafficTypeDiagnostic: VI1PR05MB4157:|VI1PR05MB4157: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:8882; X-Forefront-PRVS: 0392679D18 X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR05MB4141.eurprd05.prod.outlook.com;PTR:;CAT:NONE;SFTY:;SFS:(4636009)(136003)(376002)(346002)(396003)(39860400002)(366004)(33656002)(54906003)(2906002)(9746002)(9786002)(4744005)(1076003)(478600001)(52116002)(5660300002)(36756003)(186003)(6916009)(316002)(4326008)(26005)(2616005)(86362001)(8676002)(66946007)(7416002)(8936002)(66476007)(66556008)(24400500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: 9GysRJozWs3nhHCPOWWtnuLGnuIpZH7X7RP0e+/sMfY+TmNHH7cjUSTIRxmk+UHG8YSqfffpZdOupUuxIeGjAg2/c95/dSZXIvulAam/Pl5WNfWg2fMcPwNDc3NETmYtoVH5r1tshOjPigQHln1V6qqd6VohTXMvcxhLGMOvfLzEksiBC/5rMaQ/SJJkG8ORsrq+eT7U9ThUrw14qhZFNjSsGfVql2ise4VpKvx3UnK/NgRtJPAJJjwjTTbN0ExCXVE7sWI/E7iD6glU+SBbPiBD1QlUJCzCW7Pq6Jp+Ru77Ia5qdSo3yP/T1X02OsSUu3a9phqgaIbB7VkziFhpDqIg4nbjGPXg1ovY7Fn7VBMCmt5Pk8gaJCzTDOVhhVWAC23WwQAchaW9hCSDanqKWvPhBhZOfu9fx199NSFtVK1hdYxjAQd7haPR4Cq8gaqGB8gtKqoiicvrHTNfbDpWrxZCCgoX/05Maqtit0W/U0L5TGDLBHmQXa+2iCkoRKdfXreq0L3AN/bFyLWe0gudUT+xtUA3vOEDGEriH+w1OKnO56fT1sBy2XVAqATYs8l71v+3UDQ4bC2aAcx9U0H+te+aJOEsMRFq4fOQrvxJIp3S8dsiAMVHiy9ulsl5lG/TQlg8XvkTQeE0OXvjiLX1usK+yI25aRqZfHoLmsE+vdXn2WNenbN7eQ+j3LN8IRYohWdmAwqnb3lTyY7u77LMySwXzovqnu9rPmGpDbckUY/S3IhSpLUqQsK40Vt8nuiKIDz0J88F6MjEjTyqCu1I8a2LY1/bYScWHfq30UFfjhw= X-OriginatorOrg: Mellanox.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4278179e-0f57-4139-b294-08d7efb07956 X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 May 2020 22:22:32.8070 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: a652971c-7d2e-4d9b-a6a4-d149256f461b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: MMKu3pduSlpij2lIt6IfPRW1Ux7/NcjKZNefx/eSaxxDgm6zWMEb6fN7HljDlgjBgKtHW6gIVRvr3qo4TAFRNg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR05MB4157 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 01, 2020 at 03:31:51PM -0700, Dey, Megha wrote: > > > This has been my concern reviewing the implementation. IMS needs more > > > than one in-tree user to validate degrees of freedom in the api. I had > > > been missing a second "in-tree user" to validate the scope of the > > > flexibility that was needed. > > > > IMS is too narrowly specified. > > > > All platforms that support MSI today can support IMS. It is simply a > > way for the platform to give the driver an addr/data pair that triggers > > an interrupt when a posted write is performed to that pair. > > > > Well, yes and no. IMS requires interrupt remapping in addition to the > dynamic nature of IRQ allocation. You've mentioned remapping a few times, but I really can't understand why it has anything to do with platform_msi or IMS.. Jason