From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB1F42CCD0; Fri, 12 Jul 2024 05:20:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.11 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720761637; cv=fail; b=gJDIdLgeAOeDpSlQl013HctMQC8p/mH4fieDk3N/67fvCZ9nSoem21jXXWygJ6t7sC2aKdGxtupIBejQ9/0FvqyUDkcqufcjb9BVCuvdKd0/zv0bxVov1gLKcP+SR4SbFZDqR5OgCjGrt5QflrTpU60esLWyxZCT0XMYV9Hy9rg= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720761637; c=relaxed/simple; bh=MpyHWwI6KeZTA9ItCAsb8Iny0TpyFoSMDxk7rIhhiN4=; h=Date:From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=S9xANslvXjZ4dBge2a6gLiTg0gJ3QQZeB0HqmiAzs4a3yoUJQDZhNBXj3RvGog8x6yC0qmfU8x8oD9pMMD//G0sFGt+2doJK5xHjKvVepr1nh+hVLVaNDAU8B7fPMyNglcTmCO8sKrNAc1YAiwRWBr/rqvSOgIH/wNQ4gjoCRD4= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=DkM5qLRR; arc=fail smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="DkM5qLRR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1720761636; x=1752297636; h=date:from:to:cc:subject:message-id:reply-to:references: in-reply-to:mime-version; bh=MpyHWwI6KeZTA9ItCAsb8Iny0TpyFoSMDxk7rIhhiN4=; b=DkM5qLRRr7LTGonayqEz7Eg/zSJk9HnGKRnyDQIGEzawS/D5wnvfROHT 58x3vyxOkwlZ9zEIzvDh2E39Du3+2P9b7bFOHisIE0vtFycDDkC2Oytcz UDxhNxHZ9iO3HUA5M1vnnyzto6139ZMrAjAj1XDVVniaQVcO0ePcJSnsS sp2jLwMnZIM6ef6CU9kBMBABO7u9zrHBzRKiRkct2+qJWuR6qZoT1O0oq XTClk14DTLkxRx2bgNQMLa8DZ/rtSylCtkehb4SlrafnZ4HkOs+qMDTiu mtC05KRsCVDS956sPkBCk5qRHHROkfZjANbPsTet86qhpJZ6wVnRLZLL2 Q==; X-CSE-ConnectionGUID: XQjvSyt9TleAuMrt2lkMsw== X-CSE-MsgGUID: aYBNvmD7RiqmaTYkEIMFyw== X-IronPort-AV: E=McAfee;i="6700,10204,11130"; a="28789609" X-IronPort-AV: E=Sophos;i="6.09,202,1716274800"; d="scan'208";a="28789609" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2024 22:20:35 -0700 X-CSE-ConnectionGUID: pDa0J2spTtukc9nlrsjSyA== X-CSE-MsgGUID: wocbz1V6TqyNtEQ12MOx8A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,202,1716274800"; d="scan'208";a="53098421" Received: from fmsmsx602.amr.corp.intel.com ([10.18.126.82]) by fmviesa003.fm.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 11 Jul 2024 22:20:34 -0700 Received: from fmsmsx612.amr.corp.intel.com (10.18.126.92) by fmsmsx602.amr.corp.intel.com (10.18.126.82) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Thu, 11 Jul 2024 22:20:34 -0700 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx612.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Thu, 11 Jul 2024 22:20:34 -0700 Received: from fmsedg602.ED.cps.intel.com (10.1.192.136) by fmsmsx610.amr.corp.intel.com (10.18.126.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39 via Frontend Transport; Thu, 11 Jul 2024 22:20:34 -0700 Received: from NAM04-MW2-obe.outbound.protection.outlook.com (104.47.73.168) by edgegateway.intel.com (192.55.55.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Thu, 11 Jul 2024 22:20:34 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=l9v4HeLOuuOCYbeGMPfmfWHySRItxPYo4M69l0OrJ3h9IsgLq1Gj55JQnWy8qcJyBGO/yqZqA/KhH+rk0L/H0rc+TkaIZY3mIenPSS5uEPlRNMAibkr3YhJ6Go9vWij86AkcrRpLnoQ1sGd6uRuUdlBztUqrwrMgscBEjbQJ66Gb49yi6MzSNed0/lpvPjlfTQ10TefuiPPWQc/2IXSWubg6gjhu2YG9RQiqyMpp6bPqEOvEkyvYhvIQzfc51SSCVtoL2ip1DFCYHkTg7Cs3EMxqiEmTYF1y58OkKasLaN+XHMnCS5OQzAVjPcYYv/74lqo6sJNcUXMkMik9F7d9Cg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=PTSrdwOiLW9LM0HBupR9ophyG8P84MuZ8rEvI/yL90E=; b=UtkipLqWcGi8hBaZcbqk3jVRW4lQoYjIh2hIhsB1IVPbDtNIgXlmbqJnpodzZ2zcoYKiqY+Hi5OfA311JbX1AUMgv2ZuxZKHmm57MAlhyUjPk1R6atRXPqiEyMCK4rNBa6lUt+SV1Lu/vfQ/Ue/lQ0vlsuv+nbRxmOdTfvsglXxERh7GBmirsTSPk38ba5LfNkthg/1liyB1ZEamfeBoY/4lxe+dQk+Aah3pk6W0DmhHXR1aeAg03kvr5tNx1Gpe35Em/9TYyNBvADrHLl+gZOplcySX24G1E3FFRlXAtgZRS6aoIBw21KuCtMpcO0/oo84K5UHhOvuzI2OxPkq2OQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from DS7PR11MB5966.namprd11.prod.outlook.com (2603:10b6:8:71::6) by MW3PR11MB4538.namprd11.prod.outlook.com (2603:10b6:303:57::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7762.20; Fri, 12 Jul 2024 05:20:32 +0000 Received: from DS7PR11MB5966.namprd11.prod.outlook.com ([fe80::e971:d8f4:66c4:12ca]) by DS7PR11MB5966.namprd11.prod.outlook.com ([fe80::e971:d8f4:66c4:12ca%2]) with mapi id 15.20.7741.033; Fri, 12 Jul 2024 05:20:32 +0000 Date: Fri, 12 Jul 2024 13:19:09 +0800 From: Yan Zhao To: Jason Gunthorpe CC: Yi Liu , "Tian, Kevin" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "alex.williamson@redhat.com" , "peterx@redhat.com" , "ajones@ventanamicro.com" Subject: Re: [PATCH] vfio: Reuse file f_inode as vfio device inode Message-ID: Reply-To: Yan Zhao References: <20240627124209.GK2494510@nvidia.com> <20240710144044.GA1482543@nvidia.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20240710144044.GA1482543@nvidia.com> X-ClientProxiedBy: SG2PR02CA0052.apcprd02.prod.outlook.com (2603:1096:4:54::16) To DS7PR11MB5966.namprd11.prod.outlook.com (2603:10b6:8:71::6) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR11MB5966:EE_|MW3PR11MB4538:EE_ X-MS-Office365-Filtering-Correlation-Id: 432f27c8-f184-45d4-8bcd-08dca23259dc X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?l3jqxTb9wV3o17qrCO6Be0LlgtmE4+eCswd1qO+y/DDazwMswXd644404QNM?= =?us-ascii?Q?BiUyi0QIl5dqRb9DemWeRWLglrMjTvPnT1wMutDoPgkn/+tuUOhp7XpP+9bT?= =?us-ascii?Q?hmxuUG1b3w/JrfEGbVY3OnIsQYadYbKz1lLH964kemw54TGCB3LqU+KW23Dz?= =?us-ascii?Q?p3Y5q0mjAFnJ+JGo+lKtnWOsrpG2u/74D+pbrIQTcioG172AFMb4sWz2P6Xl?= =?us-ascii?Q?BFLO/DSbd77W7PLT34oXJnvaidYp1S1P7lInTpJpZV2D5c2qkd668KKmrQOC?= =?us-ascii?Q?7t2JnDJLhAOsOsplprxDQx9NMSIqQpMAognq34/E0diYTZVA1WmmXgeL937J?= =?us-ascii?Q?yYWAR7AC/PS3z8bsTDOL5k80qZX49Q1fUJlxrZuHS/o+rf9QDzu+jmFoJFHM?= =?us-ascii?Q?5UiWu7ou/Ow9vE3boMQ2fwn/3g6cyMu1OamLFsklsfOV3WVyUXd/X+uu5fLk?= =?us-ascii?Q?xk3nd4nJ1KfQ3XSE/cmBYK/4ROuj0/LublHSRDjCtblwaPi9DgZ8Tzz5gaWX?= =?us-ascii?Q?wfG2RSc5OynMDJVK3vfyWEWm/UCzY71yjBFam4mdHNncKM8WnPA5PRJ76OgT?= =?us-ascii?Q?C/osDrCsbomqqaf43SCuYn1geH+y1Ww0vj/5xgBpPNhWkSQBDIophwKBywII?= =?us-ascii?Q?bCavRTT+HxjpBulf8DJzXdNDR3HKETf8ERDeHnzlHLhX76NxUHezMg9jC+3b?= =?us-ascii?Q?rKEBhg8bQVtHuqBEf3ZjgN1Ad7N32klmWnTINBde4SyJXlHh9f3IvhDLHbVV?= =?us-ascii?Q?00bzvhyBRZp9IUA057jqUyT9/ajEvbPYFbz0sR/gVu6wkjuvXKJPZj+BXXr2?= =?us-ascii?Q?i7obr5uvsD2rxg4ok90buPViqe2fLPdcQxFqE1rRvSO6Zz/YCuzeQka3Mx3Q?= =?us-ascii?Q?AgFu0oX/FqwvTUwXBaW++gyUP/14fGqZD+0PxS1nReEXMB0kfjV+UYvGmlaP?= =?us-ascii?Q?IEGIB38WtXGdupWCzBZtDelUqbvHK+VoKXZv+VpNWcQxb1HL31QTZa2tYveX?= =?us-ascii?Q?Y5ml0tim9wsp+9DmCz1IVcM6QpSOdxswn8YM/w4wqVRBqMVQ4DWmywTAIm1z?= =?us-ascii?Q?XXOshPM+Hg3I9GTdeObPSL6Sl1TbmMnHy1mfDS+5aCT7b2NWZCj9LJKAB+nG?= =?us-ascii?Q?8z5AamGMd8pku3p3ZUc005vEGog1q4Y83U3tcBS7PctzjeTbY3Q2fLJnXqEe?= =?us-ascii?Q?PHikWbcaNEOGHoHc23FDfuCAyAd91DsdmezDuTnP0kbdJNIHlZfciMsSy5LW?= =?us-ascii?Q?aVTUHMzBi6Whl+8OPsbrF76LAznkJnAtarkcA1osIvYbhJBCYzfOf9ddTn1l?= =?us-ascii?Q?VGNSxw3QR/0aJQBbdWV4iPSmTNnDfYV0cUd0cQwHWBHrGg=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR11MB5966.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(376014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?GMvygpzf2Vq8dTYj8bSi/qTm685twXfxDlygMHXrbjlzNd+gj2Xjyw7HXkwW?= =?us-ascii?Q?kYNCQuYkY8yLfCYQUqLFzfc1NxsEzXtee6wq+Z/aX8YJZfF4pz3cu+lzRmm+?= =?us-ascii?Q?fXiREPeO47sFRBzCRgEOY+/9yP3mRh3nJQuOZ0/V0CB3UQE4peH6z4SKtC84?= =?us-ascii?Q?EULqcblZUHbs33ud/8b80TpmglNnA5dYKxqnCHHIZpZ6DKFLTejQGCswB0pt?= =?us-ascii?Q?Ko/0tNGD5fqzQ/sp0CbAQn4D+LjjEuA+VF14RDD2kBDFxHcIRjO93C1pxNUQ?= =?us-ascii?Q?ON4zCLwK8aN9BKmmeeMKAF4ad0hh58BgbpWH2Dsqen/jDm68tvvEwC4ziL4r?= =?us-ascii?Q?LEoR/FQQ9B6Uafb+ViNBaZ3eELAtQY5RfG2SIZRL0EEh8kapqYr8ltPCkzsQ?= =?us-ascii?Q?qjcGXeGMDMgd+WCJkjQ0RRlFfHBIEPewaYBZ+SxSkPF+NorXth8IPVvg7zba?= =?us-ascii?Q?Zprb5BdcZfJXbFQCqrHDwTmsn5m5kKrGNjzVN+IXicBCltrUyCNhn70Tyjnd?= =?us-ascii?Q?xo3bCg90AaWJkoiWwtLa5F9sMFpSB++vnDpAI5z8hoxElahCi2wYBrj3968x?= =?us-ascii?Q?s50zBI1brzYaZtCyLxqys6oRNQuWWb2ewEIjQA6+rez5YUlvvJjfCUS+MJZZ?= =?us-ascii?Q?fzjo7hwUk6XgIaax4sXOK76ePRHymu+wG+NlGZ/szsNmR7nSypRfNt9qC8cP?= =?us-ascii?Q?h5K9Lnz1d6CsocHWh+jFc1XwLSDuGfEyaK9DrzrY4S6n4B7JGB+eWu7d97pv?= =?us-ascii?Q?ZMLfTzkY5q+sb+0x6QHa7fA8mTLFAXWQzc8DXbFSJqcckOOObZaSaDPLZ+aL?= =?us-ascii?Q?pc3xPSBtwNqIuwnByvdK1nm19kO8NhNE2d5UuthIapLyKzmIZwOiDCzYN9oq?= =?us-ascii?Q?cfIUuMimNyumYsWIQSOdd/GXwaZFwAZ5NGHNNnU71x6vebrHUdXVf7xONiL3?= =?us-ascii?Q?Jj1pqjn2bfOwiCjzzuyK2wmhfKmVenhxKTSyn3RsqMCDRsh2XdGzzr2zkHCe?= =?us-ascii?Q?CFR4aSnNXgdWn3cpCTNuisVFfwoZtK+4Pj0YIABANexehdvJKGnjliMbm9ET?= =?us-ascii?Q?tMNLL/0qz9GRE/Oby7NGF7WUque7+/oPnFdNQ0XXRLN1c3Ek50D/NefTuVc3?= =?us-ascii?Q?eaZXviEr5+r7XtGDyI3SXg34qu+jWh3n9UGZ59K3ehfzbPAE5R6pZhS+D08N?= =?us-ascii?Q?ZU6rIbiDowAV2jArd1bTFHLDpWkxX+LjyYhu+rb6dlloVQB/f3xBqpUAp9gg?= =?us-ascii?Q?puQC4cjFDynOf+AcGSKpx4ez2f0myDXFW0hgX4eJhz/W+owvENZ+FnMs99QL?= =?us-ascii?Q?IyMjkkhOl6qUKIqRZCczTb0UVUEqkp6pIwcGu8pky8u0mH1fztLDOrvHC2Ed?= =?us-ascii?Q?YaYjbEtbC3VPldCfNw23GQFoZSzMJ4fJNoDfwnpgm+yb878rVGKoQcnYiKLE?= =?us-ascii?Q?PgTDt5tXZvOCSlVQdQ9DLHqGjz4B8PZGK7AYpFmCpyLLVMc4KHhDZ+KmqzTW?= =?us-ascii?Q?l/l3eBkwNFANfHnG0RFrEGYgXvdrxtl53PoBT2BacK5voGf0dm+zERBzsWlS?= =?us-ascii?Q?nWn3NGgfZ1mY4IVicp4KHczcX5lDbxCBMktR9XMO?= X-MS-Exchange-CrossTenant-Network-Message-Id: 432f27c8-f184-45d4-8bcd-08dca23259dc X-MS-Exchange-CrossTenant-AuthSource: DS7PR11MB5966.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jul 2024 05:20:32.0558 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Higr0w5StbMGVGVDz9AjYaPQhKKYvHGx3GMDsf7RrASx9u97gW1UFNxdRbvrOzf6nDuexZ429GOtNRlg1aC64A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR11MB4538 X-OriginatorOrg: intel.com On Wed, Jul 10, 2024 at 11:40:44AM -0300, Jason Gunthorpe wrote: > On Mon, Jul 01, 2024 at 01:48:07PM +0800, Yan Zhao wrote: > > > No, I don't have such a need. > > I just find it's confusing to say "Only the group path allows the device to be > > opened multiple times. The device cdev path doesn't have a secure way for it", > > since it's still doable to achieve the same "secure" level in cdev path and the > > group path is not that "secure" :) > > It is more that the group path had an API that allowed for multiple > FDs without an actual need to ever use that. You can always make more > FDs with dup. > > There is no reason for this functionality, we just have to keep it > working as a matter of uABI compatability and we are being more strict > in the new APIs. Thanks for clarification. Regarding to uABI compatability, even after being more strict and returning error when opening the second FD in group path, the uABI compatability is still maintained? e.g. QEMU would correctly reports "Verify all devices in group xxx are bound to vfio- or pci-stub and not already in use" in that case. Given there's no actual users, could we also remove the support of multiple FDs in group path to simplify code?