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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 178A7C433EF for ; Mon, 20 Jun 2022 04:03:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236212AbiFTEDl (ORCPT ); Mon, 20 Jun 2022 00:03:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232354AbiFTED2 (ORCPT ); Mon, 20 Jun 2022 00:03:28 -0400 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2068.outbound.protection.outlook.com [40.107.243.68]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7D7E63B4; Sun, 19 Jun 2022 21:03:22 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=hcUG2y8RZUYoSJtn7EFnVv6ogPh6f9dgHPlAJmJ3ue7k3x7DTUhnFTkchoy9uxhkj9y0xY0JSoi+rh/lk6kktU1eMJ5DjlPCh1FX05pXEAPg9Pfy/dWIP0M568uDxBEcZvL4aX/uDjszL9oJJfuxbGGzkM16nt5/d2BlSJlfPDjuernf2RRd2V0obLyBrJZMvz7WCao58y/EJKvfx4lJNjGrbiCHAsOG6pYY6EXA17cU13ZV+3xhpI+mdJpAv2lEXr8xaN5nXMjmrWhBQD+sATWNylTc77lz9J4bZiI/L30vsw+wZKc+f4+YMP8I7YS/mjhpnfNMzeo0pb7O2GKMVg== 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-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=ThP5EeQ+ZDBCUXmcDbpoKwZw2UMTcvHh72ohLmzMXLk=; b=C8rgNEcx8M751S1FKgmVLi9b9dBb3JXt+VBQpNDKEAwQVCJ2neehCfC8Cf45a0EPFbWFupzlNAw6zWjSKlLzRhMJoZP7BpmKU/Zdmi4lZvNQGu6eYgIiegwSdmiMhV2dGrdZaxrWRnevys6CDSAcvp+LEhpOaeTHngpUDUArvVm0gAPJSPD4x9zg4Rl4jfmk9u/0e1lbyyH9mPJy+66h3iy3OtS64zgLlNSyUNe79VpYOKxWBExx4C0JyQIlfEZLo0xaVctyzg3wSBC6xNZ5c6LIozMxnrgMAKp68SvwrobOileNZ2xux/Ev2xKd/cPA1+FeZpo5vuHvptjpVhE/EA== 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=ThP5EeQ+ZDBCUXmcDbpoKwZw2UMTcvHh72ohLmzMXLk=; b=Io2bu4a1GWJWiXgpz/3pFq0JSIAKkvKuXXWKO9guT7zf4pcD0zNccYFZjstkEka9rlTxhbPBJoUJ7if6TjqqL5ceXkP/ZDP+GfoBBuH9O8QGmH3jBU8kOOQ0no8zIJ4QdlKkWGHunzFOwWuigg492aCv3zjHmYM2bBsT99RXPta2CQlXP0LnBz0RcQW4d6l3V0c/0oBgeqeAGHU+lxj2VABiGPPUo2hp5Ss63EgLKDGO2inA9h7Bnj/HIfkjuBaceEtho26ML05mg+lexaNMpV48IXv9JUoE7/E4BxEtrZFIAIfK9gAXyHBr1Ud5ut5bKI8T+52j6niIPs4p+Fnhpw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from MN2PR12MB4192.namprd12.prod.outlook.com (2603:10b6:208:1d5::15) by DS7PR12MB5743.namprd12.prod.outlook.com (2603:10b6:8:72::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5353.18; Mon, 20 Jun 2022 04:03:20 +0000 Received: from MN2PR12MB4192.namprd12.prod.outlook.com ([fe80::ac35:7c4b:3282:abfb]) by MN2PR12MB4192.namprd12.prod.outlook.com ([fe80::ac35:7c4b:3282:abfb%3]) with mapi id 15.20.5353.022; Mon, 20 Jun 2022 04:03:20 +0000 Date: Mon, 20 Jun 2022 01:03:17 -0300 From: Jason Gunthorpe To: Nicolin Chen Cc: "robin.murphy@arm.com" , "Tian, Kevin" , "joro@8bytes.org" , "will@kernel.org" , "marcan@marcan.st" , "sven@svenpeter.dev" , "robdclark@gmail.com" , "baolu.lu@linux.intel.com" , "matthias.bgg@gmail.com" , "orsonzhai@gmail.com" , "baolin.wang7@gmail.com" , "zhang.lyra@gmail.com" , "jean-philippe@linaro.org" , "alex.williamson@redhat.com" , "jordan@cosmicpenguin.net" , "thierry.reding@gmail.com" , "alyssa@rosenzweig.io" , "linux-s390@vger.kernel.org" , "saiprakash.ranjan@codeaurora.org" , "kvm@vger.kernel.org" , "jonathanh@nvidia.com" , "linux-arm-kernel@lists.infradead.org" , "yangyingliang@huawei.com" , "gerald.schaefer@linux.ibm.com" , "linux-arm-msm@vger.kernel.org" , "christophe.jaillet@wanadoo.fr" , "linux-tegra@vger.kernel.org" , "tglx@linutronix.de" , "virtualization@lists.linux-foundation.org" , "isaacm@codeaurora.org" , "cohuck@redhat.com" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "linux-mediatek@lists.infradead.org" , "dwmw2@infradead.org" Subject: Re: [PATCH v2 5/5] vfio/iommu_type1: Simplify group attachment Message-ID: <20220620040317.GD5219@nvidia.com> References: <20220616000304.23890-1-nicolinc@nvidia.com> <20220616000304.23890-6-nicolinc@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MW2PR2101CA0018.namprd21.prod.outlook.com (2603:10b6:302:1::31) To MN2PR12MB4192.namprd12.prod.outlook.com (2603:10b6:208:1d5::15) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 2ffc12fa-3882-4ffd-dd09-08da5271cfd2 X-MS-TrafficTypeDiagnostic: DS7PR12MB5743:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 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:MN2PR12MB4192.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230016)(4636009)(366004)(39860400002)(136003)(376002)(346002)(396003)(6862004)(6506007)(2906002)(66476007)(66556008)(4326008)(8676002)(478600001)(8936002)(7406005)(36756003)(26005)(4744005)(316002)(6666004)(6486002)(83380400001)(37006003)(66946007)(54906003)(6636002)(38100700002)(86362001)(7416002)(5660300002)(6512007)(2616005)(1076003)(186003)(33656002)(41300700001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?TLROKD5CyEvZwCEnYD+GwakM1HU80UbqCmUp6VciYy3HN6tADoFspt2LtA8b?= =?us-ascii?Q?LGjtqYvQOzlY/Xxsyl2hfIqPkVMhKBe1bTCoNNg1UZnMoMZO4edeaeFJ8/do?= =?us-ascii?Q?2IJLxdl04coMCUqRr7rxELADb0qzaaqgKQjR+X6B9pSu4VVDlar1mUaluOyh?= =?us-ascii?Q?TsUvXx2L87KVKihrV2JOHbM+b6xuw9rrO3hoSAf0qui0OVDBNrWAq4KMyVUl?= =?us-ascii?Q?BgCtbtAuTCLrco8g8ObiaPaEsgcyFxoFjW+FLE3jFaDgUXoPdHjz5yduNsdf?= =?us-ascii?Q?8MrA/NIwvJQffK6tUZ7+4CpAW5Ruf8sMgpCqj0YpRqT/1sTpUkVTNMAuFzBU?= =?us-ascii?Q?Nr56fInXKRXFykXH740ac1prA1N9IpOi45Hq2qycrENH0eqwiB4ndibeO8Zc?= =?us-ascii?Q?9Ylhy71E0Uq/fJLUhec6/QK3FeJJFguDnC06wQWvXJIZEQHHi5YssE3lGr88?= =?us-ascii?Q?Bs12EhkeU9KTqKnX/owBPd1vhrD4Pd7egL/8FLcJg80kHoksx6tVq6bORjYO?= =?us-ascii?Q?u+p63AHJrG9HFoDy1fT5x29ax7R+2+gvpseRrqBofSKStlG5JtLe9pwHcUfk?= =?us-ascii?Q?jByM7I+UMr1KH+8b9BExQqdrmZ1kpnTClTqIBbDpQJ9Yu3Risimd2uOyqOtX?= =?us-ascii?Q?/kAdvEPsIO7GFf47AQv1jOrrxx7Df2MER2wvJx0uaOrsWUX9TjPHBBVBnucb?= =?us-ascii?Q?T2z7CYXfpKpGb7VnUga/7H0arAx/AB/1ys+F8spl8m9kk9S1tK3rIoKb0dC7?= =?us-ascii?Q?X6rmrRfvmCZmoEgfOe/ktuxfP5ATQbBqYljfSffD2qhFJruNaf17zsh7jMle?= =?us-ascii?Q?8Q2+ekV6YOngLVk88pvKB4AwnVYSWT/1sMUZepXrzzHrIAS6KZnquUTVbL99?= =?us-ascii?Q?Oo1JYJ2xTeYIzIUc+1Kluje/r14M4x5Ic16jyPmUsxqBMLWhYVXwcSIb17vX?= =?us-ascii?Q?zRt33TPmhGcmDEiTFihjA4wMYHu5Ncw72gq7IYp8wFSoIOoVo3myGbFwDo8F?= =?us-ascii?Q?cH3UjKtHIF/XRpzcqG8xctytB8xa7UIb+AmMBr+Mtv8HYide59+RNYkNTDP4?= =?us-ascii?Q?dNtxUbub+1//9HjFmZXuzJDj1DTllWPBPIrBeJLqOAkJZQRBc6HEuozqvD0H?= =?us-ascii?Q?qw9PHAoaW6oVKSvup3Um3hvPGSswEE/y0FZdqagwDx88kVyhOeUg6fKTb4Hb?= =?us-ascii?Q?rZkSHy0glyHPESeseDHUDI2VBdhCTg0oC5PhtEbvjXWEeXhkC+tw6g9YeyBd?= =?us-ascii?Q?CpkkE7Q16rLxBmuE+NGQQaF8de9ZBYN+pRtgjsyQ7E28Y1QT4zEkLF5BexGU?= =?us-ascii?Q?icTvlfgytvVLBjcCYrQn0j2GMK3BXcrPmNQio1+xKUFa7Mok0e8+a4Rxei6d?= =?us-ascii?Q?gSiSI6kzcsnVtXEZ3bHUjIWnAh/AJreRJxy4PU/UmBaf74Kxxs9M/OC1FJV9?= =?us-ascii?Q?ox5W9vVA/c0aCey4/DeD6cgX+xLfgizZI5sHQIprmKeTIVxekt7vcZlUU5jh?= =?us-ascii?Q?3j1u8zOM8lSu5KmNBLEYcZMi/delh2fW6WbVT5XzyOK//RrEfdEkdNfGLEkJ?= =?us-ascii?Q?MojxSFQ3Bw2xSbCVRf4NYyzFnvxI+Fa7QKzPONfXgpsYZCqPZBCRHq5+h/BE?= =?us-ascii?Q?W22YqjCnzNQaMhMksaXArA1l7elvpzL+XcS5whxq9jnP/Gy67yH6ZydsZiXV?= =?us-ascii?Q?eGQFGLzFCa9o0hSbtdSssMg/nQSKWuk30D3E1Kz4CXbikUbDtDeix3BEqMkd?= =?us-ascii?Q?FVtfifxlFQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2ffc12fa-3882-4ffd-dd09-08da5271cfd2 X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jun 2022 04:03:20.0967 (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: oRZunGZtKJI1pF4+CC1DhZ8W9+HBQAB2476EZ0NtLO8aMbrpDgLnqm3qQb2EGifz X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB5743 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 17, 2022 at 04:07:20PM -0700, Nicolin Chen wrote: > > > > > + vfio_iommu_aper_expand(iommu, &iova_copy); > > > > > > > > but now it's done for every group detach. The aperture is decided > > > > by domain geometry which is not affected by attached groups. > > > > > > Yea, I've noticed this part. Actually Jason did this change for > > > simplicity, and I think it'd be safe to do so? > > > > Perhaps detach_destroy() can return a Boolean to indicate whether > > a domain is destroyed. > > It could be a solution but doesn't feel that common for a clean > function to have a return value indicating a special case. Maybe > passing in "&domain" so that we can check if it's NULL after? It is harmless to do every time, it just burns a few CPU cycles on a slow path. We don't need complexity to optmize it. Jason