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 C098AC678DC for ; Fri, 18 Aug 2023 00:55:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356760AbjHRAym (ORCPT ); Thu, 17 Aug 2023 20:54:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237092AbjHRAyZ (ORCPT ); Thu, 17 Aug 2023 20:54:25 -0400 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2047.outbound.protection.outlook.com [40.107.237.47]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 070E73583; Thu, 17 Aug 2023 17:54:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=aSUJPQK2Lfata11kvQIoimWF3yedDJDJfudBmlCAsHY7MWKpr6IzzWxid27g5xF9iIUDpUikzQeD5dXuDJcVkV39ZTcwzowmNEAw8UTuj1GDp/i8QhQiOxa0KBk6SISAz8VkGT9pyFtKgBxpOEmlGgBk1VnDKm9n2/j0pFOL8Od0E29wzys318OXTiI3F/47mM6+4WSQHGmf4h3zPRmzHa9K5ai0drDf7tV7aauwvyWWDnX3mQpVkcMRIMXHD5BXMNhIx4qjfmWR8BHh7BrzhiXTpVFLzVZeaKApAk+a52soW3FEwa9HnkADT2B/Ol7SnzLBnWzxshTMVlHQu9/Vhw== 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=yHzsmlTsAVpzhs1ImNeAGuzxhkYruxKkkD2ZMlSblc4=; b=AtJJWtzjFvjm7kJK43MesS8NfotKQ2zQ8P/NBkNi8mJoFOJy1VUNbacbsfAty4VXxVoSjkJS8se+tGGEG3W3kmEXbXIiRPIQprh7JRyFrXCxKi9Qr3QsKvVYYFITKma1+rGuQVmsbpHpSfZarz/1wQoQdIFmRRGCWbvFqHhnszXVIyEySkYeS4LrFpTIznWvpgVALL6gtMgmcrLBvAX6yG39MgtTBUxJmgEI/mDhL/Umku+r5yOUjVfTiy4E5+2a4aDZnmgc1OWEytGwkNyG3PFgCidAkyLX6HxJ1iwYnBISkWm5somztLB/ZZR1xK5WKxbKBoSl0rwQ5beKymA4WA== 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=yHzsmlTsAVpzhs1ImNeAGuzxhkYruxKkkD2ZMlSblc4=; b=OJbytGOQV34LJ2BzaqZr7oR6ZsZ343xSEqJ6FGWFMTrZK0lC0qHjDutfCsTt/rHsYkm2QCzNsg1uPU8cnk4YnOxZEOGf7tIZO70bb9w2Ts3FKeGv3S3riLoEmtrihmMCEerTeeQC1Wcja3DjFdLB2DvOJH/X+6qnlGOfapkSL1mRjPw+IYvrR0H4xtUKzeTXOQK19ZzhfWduiVZxE0zS/7Dfud3rh5+Av6dmnRzanT+zZgdGkAUW4Q0g1nha7XOVDLUtI3YM/X/xt/mI8wTYSs9MxrLPqqxc0dprMmB73A7CV1nlC4Fs85rbj4qtRVNi8BxA1uWtW00ZHC8DZV46Rg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) by CH3PR12MB8910.namprd12.prod.outlook.com (2603:10b6:610:179::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6678.29; Fri, 18 Aug 2023 00:54:21 +0000 Received: from LV2PR12MB5869.namprd12.prod.outlook.com ([fe80::5111:16e8:5afe:1da1]) by LV2PR12MB5869.namprd12.prod.outlook.com ([fe80::5111:16e8:5afe:1da1%6]) with mapi id 15.20.6678.031; Fri, 18 Aug 2023 00:54:21 +0000 Date: Thu, 17 Aug 2023 21:54:20 -0300 From: Jason Gunthorpe To: "Liu, Yi L" Cc: Nicolin Chen , "Tian, Kevin" , "joro@8bytes.org" , "alex.williamson@redhat.com" , "robin.murphy@arm.com" , "baolu.lu@linux.intel.com" , "cohuck@redhat.com" , "eric.auger@redhat.com" , "kvm@vger.kernel.org" , "mjrosato@linux.ibm.com" , "chao.p.peng@linux.intel.com" , "yi.y.sun@linux.intel.com" , "peterx@redhat.com" , "jasowang@redhat.com" , "shameerali.kolothum.thodi@huawei.com" , "lulu@redhat.com" , "suravee.suthikulpanit@amd.com" , "iommu@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "linux-kselftest@vger.kernel.org" , "Duan, Zhenzhong" Subject: Re: [PATCH v8 3/5] iommufd: Add IOMMU_GET_HW_INFO Message-ID: References: <20230816121349.104436-1-yi.l.liu@intel.com> <20230816121349.104436-4-yi.l.liu@intel.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BL1PR13CA0240.namprd13.prod.outlook.com (2603:10b6:208:2bf::35) To LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV2PR12MB5869:EE_|CH3PR12MB8910:EE_ X-MS-Office365-Filtering-Correlation-Id: 1cf69673-2c40-43e1-7d61-08db9f85a8cd 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:LV2PR12MB5869.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(39860400002)(136003)(366004)(396003)(346002)(376002)(451199024)(186009)(1800799009)(54906003)(316002)(66946007)(66556008)(66476007)(6916009)(5660300002)(41300700001)(38100700002)(8936002)(8676002)(4326008)(26005)(2906002)(4744005)(478600001)(86362001)(7416002)(6512007)(36756003)(6506007)(6486002)(2616005);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?vsRjHuZIHYOGdNvpC80GZMPKt5s4JMwDUAqEzyjVgeMRhWqp89WZAml2v6SI?= =?us-ascii?Q?EDFAKvcsz2Sf0AE+QmBL/CdvURInFiq62d6LRuRZ2uXkazSQ5KC9xRcE0dA3?= =?us-ascii?Q?nbRWhla+t9DDqzvjPQQKzg6dfM7mtNm35SmNa/hxje0527L9l2RMpBHx5+WC?= =?us-ascii?Q?NTEQd7BsxGul9zluEzXLmTbt6tYJ0SgoupGyuCjsWYNhEDwZTJzZZmVLpuVZ?= =?us-ascii?Q?33+jX68UJmMouHC2PLmBytuKgTnjFWm86SzX0AJHJwzzHJsJtkOiyynvdoSa?= =?us-ascii?Q?0BdODUypFZ0iCXxd5b7rbXfuB7BBj/v7YLyfgtQaOe5Z3bKt2Fh/68bgRe9N?= =?us-ascii?Q?f0rsdf9yNlMBV3hAQFKg7wLbuLRDzx68z4O0FUeXU0VVPgPmJtMo9dtwaICI?= =?us-ascii?Q?fhUBmibAUWkgKk/Q7Oht3JenyDOtlybSnfTOkdtyGzDOV7cAcsyntiqNIjxj?= =?us-ascii?Q?xdU5ipADO6pPCDAeHBhqxplXlgUhWbnWYJUSryMPOUdJ2Xm2QK8bN9wLs4rY?= =?us-ascii?Q?kfPTNwf2aGTmzYqrAiv5Xt37fwNe5DGvPqDyMbGxUjfK55kQEogfWkuYrewf?= =?us-ascii?Q?qj85jMqIDvcHXxsTA7Tj3ghIJrTj63CsITBYaePyRXhSoTl5u8AQsM7cKk1H?= =?us-ascii?Q?Gleaf0pafmL5/pZ8TXgFYK8WbyJ5K4tKk+hWbxoXftIgNllKcpDSUynALF4G?= =?us-ascii?Q?hjeS/nHGa7POdq0ePS8qC2znUUCgYVKaJm2RDKrDuICwHQbSmJ6wUXijSkTt?= =?us-ascii?Q?bG4ELVYo9SUn6+kZkbkA4uWcP8wxAkYmlcBVmEVyfcVrNBlMhvuC70tX4aK4?= =?us-ascii?Q?HRY1kFrVUqnH9ykP9cgzV3Dv6MUOSMP/lXgGsk0Qv2Qrv6HNX2YibGYusl5C?= =?us-ascii?Q?EJOoMyv2v2NwVtV/mKJayCW2nP3SCxS5zLt7vk5e+oJCnmxQFtphl/BlPAbh?= =?us-ascii?Q?kakY/ZSauh77B+QlM2mvfTyBvoHmDpl7C4R/Pp4s6X4OveO/EshYllftK25V?= =?us-ascii?Q?e9JVPGHmTTqPwqx3amrLpngHJdNWcQwkYyCIjha+LcrG1olYYweD+/pcM2EX?= =?us-ascii?Q?EKJcyF/fOaq0tRlvnSR4YKkNbxMUXm7lb6jl5dmyOJnqU7itmttNdfVMayD+?= =?us-ascii?Q?J4wPXSy3ezF1NAkyL7rqliZuoJtWcc962LbBD6IRQ+eMXcUQ4OA7We6MIpPN?= =?us-ascii?Q?Xq9KwkRdRXRB4qe7w5036EvTsmzo4Lt+GSlWS/EeqcvyPvgGufEt5GuAJgDi?= =?us-ascii?Q?l4njSIcVp1KTy4y8Rzk8yD7CFo3EQG1LY0f7mY6rLUnxYMR9LYy/eW84x7/1?= =?us-ascii?Q?Mx2iPTA1/CZbwhd9JsBPDyny5Owml5rS3LDzoJoBwxLViOFJTGJ3cfkLfs/S?= =?us-ascii?Q?MJH8ZDoZ7qrOEyCk0AYEI4XT3+VucGIcZZQ0ZlPwWibU8VVZARjPyl3TX3HI?= =?us-ascii?Q?ggzvPqwbE5iqpfaqnvIZUuZqsVXX1p5DnuQBkfhx2d8yPMgYC02qek+GaYem?= =?us-ascii?Q?MjmqN6yBQPhvKLWzK4XvadvxSmOPv6PAK3Ap747SFP4g90/ssuLPNHFybJH2?= =?us-ascii?Q?OI3hOrGheDM7ty2dHFxEjRr16AX9mq/88x07oYTa?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1cf69673-2c40-43e1-7d61-08db9f85a8cd X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Aug 2023 00:54:21.5915 (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: 5Sha9wAPlBVr0CAJv9SsX1sEhCPzmeQu6tEeooYCXa2G28P/YffH4p260E/OYubf X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB8910 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Aug 18, 2023 at 12:04:29AM +0000, Liu, Yi L wrote: > > > > +int iommufd_get_hw_info(struct iommufd_ucmd *ucmd) > > > > +{ > > > > + struct iommu_hw_info *cmd = ucmd->cmd; > > > > + void __user *user_ptr = u64_to_user_ptr(cmd->data_uptr); > > > > + const struct iommu_ops *ops; > > > > + struct iommufd_device *idev; > > > > + unsigned int data_len; > > > > + unsigned int copy_len; > > > > + void *data = NULL; > > [..] > > > > + } else { > > > > + cmd->out_data_type = IOMMU_HW_INFO_TYPE_NONE; > > > > + data_len = 0; > > > > + data = NULL; > > > > > > data is already initialized as NULL. > > Probably we can set data_len = 0 and the out_data_type to _NONE is > the top as well. Any preference? I think it is clear to remove the variable initialization so this branch is more explicit Jason