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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE,SPF_PASS autolearn=no 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 AEA07C433ED for ; Mon, 3 May 2021 16:05:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78936611AB for ; Mon, 3 May 2021 16:05:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231182AbhECQG3 (ORCPT ); Mon, 3 May 2021 12:06:29 -0400 Received: from mail-bn8nam12on2059.outbound.protection.outlook.com ([40.107.237.59]:15712 "EHLO NAM12-BN8-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231133AbhECQG2 (ORCPT ); Mon, 3 May 2021 12:06:28 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=K4ZVQJYuFxTNKhYHeKYi6G7d3PPAQLd9cK756ACgjNbq819PDVvzdVMqEAfd/tfzunyB73bJSTwrD/ehxdcRY7NHVUiz+hAmZMFzp2mDmihPH7DE1rtFq1P5I3xVEn5h5YPFZ7WlswPMHdeYCELrZIJP6IFb1dcv4juKzYgFJygk4DSej3TH8xJOP5e7Bp6ZWTkW4bX1YeQA2uejxx/0Ew/bfQF0KPObn3+qB0KHOoEybTGGRTRvrAzV4CJ5YY09Fop5wi4OxQfnSbkhDZIPzCTzCH2EAw5w7jGa+kwNcs/kuzOdKtBrjjvUIbSXV/Xhq+2+2aAP14ywRbeSkl6dsg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=5L2XLVuc7VtR24tCqFEn2YxELbEwg75eNiDbvo22F0M=; b=GhQHgH82TdZ2PFDTCR1flkJ+6QZVrcKlFKP48AL52K9zCF10trOCIEL8j6sGfe3KjkkFkwRFHoEkzYuVx5+9/aHL2MBBLak+Cje4pksax4r4TcEkrpajp2TD2AndjCbmV/UQKpvt//PJbpJLJgiCSrxXOwoZ/EuH6frFjFgI0vRMMAgoDi0Ck2wOd9X7+KppVXknOb0co+TV20mil1mlbF7266V7sS9m7TbiAKYWjj6NssErLRrBo4l2yidCapW3wJOnFlvVY3pZNz12KiFst//VNYiOERWHIM1LHex894VHh96zqrWkvcFXq1O/F55+5zszlXu6Fc0O2AXeqwo3MA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=5L2XLVuc7VtR24tCqFEn2YxELbEwg75eNiDbvo22F0M=; b=Wi7jP3Ea0sNIfYfuQeaSDrlS34K4gqZS5x4Pg+QEIud3Z02mZAWx5HZgjpuYWrkT7eJ3LdvBnAV5QuU0IQKDneOoiC4TYCpPHb2JT1YNbZBvHbeYBnbe0OxpWwEb8gNmFNrwenOz7vNtSiGqx6J4/mSyD21SINIpiTSKb3r3/sQmE/0BxURvtgEpHb/NEVmfRDJTdL+rP12eB+buOokStKYziHuBQ5Oi9fERdUTBZ76LbucCDPLn2wb/1dBL0K76QR5l5+ERx0INnJddj5Rj9oKPceVv3udORU0mQ2/zHvdxU35y1uFGS/bRXtvZoLWyMDzNYDLcGP0S4BlvpJH+Uw== Authentication-Results: gibson.dropbear.id.au; dkim=none (message not signed) header.d=none;gibson.dropbear.id.au; dmarc=none action=none header.from=nvidia.com; Received: from DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) by DM6PR12MB3212.namprd12.prod.outlook.com (2603:10b6:5:186::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4087.43; Mon, 3 May 2021 16:05:33 +0000 Received: from DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::ddb4:2cbb:4589:f039]) by DM6PR12MB3834.namprd12.prod.outlook.com ([fe80::ddb4:2cbb:4589:f039%4]) with mapi id 15.20.4087.043; Mon, 3 May 2021 16:05:33 +0000 Date: Mon, 3 May 2021 13:05:30 -0300 From: Jason Gunthorpe To: David Gibson Cc: Alex Williamson , "Liu, Yi L" , Jacob Pan , Auger Eric , Jean-Philippe Brucker , "Tian, Kevin" , LKML , Joerg Roedel , Lu Baolu , David Woodhouse , "iommu@lists.linux-foundation.org" , "cgroups@vger.kernel.org" , Tejun Heo , Li Zefan , Johannes Weiner , Jean-Philippe Brucker , Jonathan Corbet , "Raj, Ashok" , "Wu, Hao" , "Jiang, Dave" , Alexey Kardashevskiy Subject: Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs Message-ID: <20210503160530.GL1370958@nvidia.com> References: <20210421105451.56d3670a@redhat.com> <20210421175203.GN1370958@nvidia.com> <20210421133312.15307c44@redhat.com> <20210421230301.GP1370958@nvidia.com> <20210422111337.6ac3624d@redhat.com> <20210427172432.GE1370958@nvidia.com> <20210429002149.GZ1370958@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Originating-IP: [206.223.160.26] X-ClientProxiedBy: YT2PR01CA0002.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:38::7) To DM6PR12MB3834.namprd12.prod.outlook.com (2603:10b6:5:14a::12) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from mlx.ziepe.ca (206.223.160.26) by YT2PR01CA0002.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:38::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4087.39 via Frontend Transport; Mon, 3 May 2021 16:05:32 +0000 Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1ldb4c-00GNw4-A5; Mon, 03 May 2021 13:05:30 -0300 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: a8afecc6-dd9b-470e-2422-08d90e4d47a3 X-MS-TrafficTypeDiagnostic: DM6PR12MB3212: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; 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:DM6PR12MB3834.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(396003)(346002)(376002)(366004)(136003)(39860400002)(8676002)(186003)(33656002)(478600001)(8936002)(38100700002)(66556008)(1076003)(426003)(2616005)(6916009)(36756003)(26005)(2906002)(66476007)(86362001)(66946007)(316002)(7416002)(9786002)(9746002)(5660300002)(4744005)(4326008)(54906003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?cJkb6uk4OhwcMBnNmeJblzK7mFZZd/ezDOw60xiwGPKX2b3CjCmrpu4gqFJi?= =?us-ascii?Q?DZIZ0Mz8WEornubgoca77jG4Gz4UEJj4Fa4hvpHhmZA8hyCd8ogrKXX9DdvE?= =?us-ascii?Q?yCWqYhDO+8MVZymhKY3Wltm8wObXYABZaIQ2wxzU7NpqFiy293rkUPPyFWGp?= =?us-ascii?Q?hJ9iU/IAmJMkunE6LDtdPDnx7bdLGzkEsCEKRx1sZr1XPSPX4PFoVI9gimrl?= =?us-ascii?Q?EVZwNajDqKxTopCkKS17myjZ1t8LwamqRf2bJnUlXZcXQCE75Ij8NIKmMCRj?= =?us-ascii?Q?NNi8b7+YnakEnCBV2Lf11LCrE5FfR2qeX3cVcMtfLXhqYk7ZRXdetjfhIrxi?= =?us-ascii?Q?wJ67T0CV6unJlNwSpYTMe4ZdFzFQX+3PZcaHFjKeXhG4NWAmoHLd+n9vZeus?= =?us-ascii?Q?gnWoE04hIdF3z3BbC9QbsH5N422rTBYKcPgcyy0L8jExfO4LSXS5w4pXWdjr?= =?us-ascii?Q?O6z0JQvdosq4s80ETthmpvY/8JInLGM4fLZjOaTjfkuXfmtqmkh4IRRK2t+Y?= =?us-ascii?Q?VFiqET2g06PQo0XDRrA8WANRpNYa2cIAzHjYA2NHWN7CFKMTGjsnjb3rs98Z?= =?us-ascii?Q?Um6Ygx4ZkLswO4B+gIFPdoBas3JExiW4IwAlyUV+Tn53Br2SVNxzjKA4OWDm?= =?us-ascii?Q?cAMjGmA9ahSI8Ds564JhjdQMCJhCyoQYfevshMLVJQwA5quFqcJBRNWORsae?= =?us-ascii?Q?G5fCHGkE/hndIneuZ1qFFchKPvp87Ft+qNhsRPadnmpYMdbKJEJ++lBKf7fi?= =?us-ascii?Q?7d2agQ2M9bCVUEAnNEbteIzTrJc3c5YSszZTUBJXWbDjipjNWSOT5BoATJiI?= =?us-ascii?Q?DqFKA/HF2w1I3xUNYd/vzuUPfUd6t+7LmSV4fwXdFGZnjOUF5Ah7RUZZSiTz?= =?us-ascii?Q?tTRLBzDxj+AB6Ouucg82otfDyBd+gsu3I3vZV6f0A0vk3yoHXb0uEyzMsyVO?= =?us-ascii?Q?+8iluTKgf+FWgQXaDNYLoPibNH0z4iV4VGBvD/B+hR/SCbjolGaEsJWtkcRt?= =?us-ascii?Q?RRGThdjI4sg4OeX8Ky/8/qTQCgUFLrudtLl3U6u7aSF8p8mkgIpP8a+cVyl7?= =?us-ascii?Q?BHTxVwl5Vaz3CNnZhxzZsle/SqrbFHhq0wsoXpfrYCuhyJ7bFIAJ2MwrPqE5?= =?us-ascii?Q?qzbkHO2JQyZjIyuET79eaHwmkx2hTBZtofjmodqDC6MqFnyGZDNVyBwCRCyc?= =?us-ascii?Q?Jje8m9XSeQW4m7w7aXXQRFnbYyXl8Y0BRfOr7Sh6KYIk/QrX95BsVsLPp3Wb?= =?us-ascii?Q?ttJ0saqPZQ2wKwCNsGtYZBRLSCVPCLdPIEmBdK+3VBlHcAME7oAa+tZiCdQH?= =?us-ascii?Q?pOhTBW9lXDeH+nOPM6QYGPuH?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: a8afecc6-dd9b-470e-2422-08d90e4d47a3 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB3834.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 May 2021 16:05:33.0448 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 7xsuIVxNjE+atuaSiQeBCCLNGPIzvmGcc5DjK+5h8qsA3c37lolYFMMd2ZqyWyHS X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB3212 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 29, 2021 at 01:20:22PM +1000, David Gibson wrote: > > There is a certain appeal to having some > > 'PPC_TCE_CREATE_SPECIAL_IOASID' entry point that has a wack of extra > > information like windows that can be optionally called by the viommu > > driver and it remains well defined and described. > > Windows really aren't ppc specific. They're absolutely there on x86 > and everything else as well - it's just that people are used to having > a window at 0.. that you can often get away with > treating it sloppily. My point is this detailed control seems to go on to more than just windows. As you say the vIOMMU is emulating specific HW that needs to have kernel interfaces to match it exactly. I'm remarking that trying to unify every HW IOMMU implementation that ever has/will exist into a generic API complete enough to allow the vIOMMU to be created is likely to result in an API too complicated to understand.. Jason