From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SJ2PR03CU001.outbound.protection.outlook.com (mail-westusazon11012061.outbound.protection.outlook.com [52.101.43.61]) (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 C8C44361DDF; Wed, 28 Jan 2026 14:59:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.43.61 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769612355; cv=fail; b=MYX5aC9czvegUSDgZ9CRwAyUCL5o66lUEG93o32N/xkyYiEy+YdUQUJzd7DgOklTy2oD25R/hna4+telwW2b5+tx7vNXRI6A6B5ovHaftJKWeWmltZxiPq0o/lzFWrVXsYYH3hJFs5IPOHx1toAg7Rxio0yPcwcl1YijzABV9t4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769612355; c=relaxed/simple; bh=xdCImewoo/iTSMJ2rFFctkcziC/mFygCHxbrMjH82ps=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=Qx74mmmJY3AH1zfwxjzYEykF94v8/1YkHBAFOikXsf6UZjWAT0x/IBLVkvuh7uI9/AZNgq+DH+9cRCOuPcIhmAYyQvHXnpSlx3VMnl+AewKXK/8jdqWwDknqMWrFbQnFqLUo2EMpEA2ekj7OF3xeebXyUVB2y0Nyq0QlOxc4a+s= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=svmKzlhO; arc=fail smtp.client-ip=52.101.43.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="svmKzlhO" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=B7ntfzupkut9xYWQNg6p3h355xUsIdUCogqiw1kSRIKsm2euU9fAltJ91beAAB7waMpvt2iB7YcSU/YWNqJQ+KrmqU9DVru9AHVVEFdi6+Xj27hBL8f5mGQ8g6tjLzblzTQxQ8sKmJOOVKLkTAjVb/N0/lRUXL1k4m4+fYkptlpGo3AOo9PUKNctJ3TCod6Zhu7pttFXU9gp17z/LvcCjFWT6fDxZRskqsClJRqaao4wX2YbIL0cdDfhiWcv0hgKYVtFArB/FcZ3sYCPeMJ4NaRbfNkepWT0fUaD86GaPpD+IsafMLfA9FjhdNHgr5ZabStwzqBoo41XrOrWR3Zd8Q== 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=SiSzgLlIFHwLmhCa8wS5kwNKKj8PVeYclFl2nK4RIVk=; b=gUxPNyYYeo9l906ung7+HBle0SCPw956w5QM8BjWVnbI+zkuTxnMIy5CSLT07V2aYyQzg8V0zZZWICd5rHtZX8HmAxUfp9RRpPjYyfJi+jxZEGgBzW/AS4pDuIjdD8/fLHVePrQrEGBznPQXRPobqkK5P1DYhsTk2RlhMtQd5Cnzj7o/xyAElRPQEPEUTFsQhQARuvUudzAsJLS/crukzya8V/iwugygUzlLEgzVq/YrpPa+qPTEVnSDL+SSnXAjNFUxLpEZj3JqWpg6nlodWTinD0/wryvrGfe7a7tdpWck3fC75Cb5FCBVjrERkuOZiPXITfFDodORNdJuueiruw== 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=SiSzgLlIFHwLmhCa8wS5kwNKKj8PVeYclFl2nK4RIVk=; b=svmKzlhOYjCq+VvzgBgdLjHjTj6SR94e9xyk8klq6rHTU+uMSxMgZlOzDHESTcSHQwbM2jK45mHbe+KFr/MKT1McTOZ2C9LLepau6FZcJTpL8TLJ7TeHplgD4WScIWICF6sgcDVEkTsq5Lzi+oObDPDCsHZv/Q/UHjQ2eFYLCC0GnWA+AGWQ4tOg/gInOJDzgu6DPZmha7Y18h2+YpEqhQNqocX5ApchWaugIRLQkikdkcPbSvNPIkLbWPQaUYIFQvMBi0WtNvZIqcEUdJjkUGQvJzkZl/WscCqNIF0+9IscVlHfcAGEdy6NLUIdJScCL4ESh2eLxbdzecD6Hwi00Q== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by PH7PR12MB5925.namprd12.prod.outlook.com (2603:10b6:510:1d8::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9564.7; Wed, 28 Jan 2026 14:59:07 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::1b59:c8a2:4c00:8a2c]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::1b59:c8a2:4c00:8a2c%3]) with mapi id 15.20.9542.015; Wed, 28 Jan 2026 14:59:07 +0000 Date: Wed, 28 Jan 2026 10:59:06 -0400 From: Jason Gunthorpe To: Danilo Krummrich Cc: Zhi Wang , rust-for-linux@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, aliceryhl@google.com, bhelgaas@google.com, kwilczynski@kernel.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, tmgross@umich.edu, markus.probst@posteo.de, helgaas@kernel.org, cjia@nvidia.com, smitra@nvidia.com, ankita@nvidia.com, aniketa@nvidia.com, kwankhede@nvidia.com, targupta@nvidia.com, acourbot@nvidia.com, joelagnelf@nvidia.com, jhubbard@nvidia.com, zhiwang@kernel.org, daniel.almeida@collabora.com Subject: Re: [PATCH v2 1/2] rust: introduce abstractions for fwctlg Message-ID: <20260128145906.GZ1134360@nvidia.com> References: <20260122204232.15988-1-zhiw@nvidia.com> <20260122204232.15988-2-zhiw@nvidia.com> <20260126181912.GA2131321@nvidia.com> <20260127215744.332380fe.zhiw@nvidia.com> <20260128000410.GT1134360@nvidia.com> <20260128132029.GX1134360@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: IA1P220CA0021.NAMP220.PROD.OUTLOOK.COM (2603:10b6:208:464::14) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|PH7PR12MB5925:EE_ X-MS-Office365-Filtering-Correlation-Id: b94ab512-0897-4060-4f2d-08de5e7dc956 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?2yvLZhii7W//FYYUoVbnNtGQ7hAsFmUTJV/fv7arKmZiWTwJC2Vm5ZQvpnDA?= =?us-ascii?Q?8iTT/fdJlewESY5/g+Pinh+of86KVGB/zMKYOPUxZfv3sB7Bfa8lwp/eAB1n?= =?us-ascii?Q?dOHTYexBRzt+7EuAgI3M6dNxfpyBoYGWfool6bU2skDIKub4M+K+UrhBZ7xT?= =?us-ascii?Q?s13sG2QBU9kov83iIkWsDpXOhjXIyK7zOrP6hxeo6PABlBAi+dj12X9M65/t?= =?us-ascii?Q?eFCR7pp+riurGhvo57waVscHytMi8JQR53bVsyueZDqtTKr+6rI0h8TG5+09?= =?us-ascii?Q?2L0jaFdJAOIQukP5uaipgFifVN2UcmMAGisUsl4e4B9eUqsM/x2HtucRYybm?= =?us-ascii?Q?fbYSzB6Vf7eb/9eYjVCZ2rSYiEbY8nM5kzr1Rs8maJj7IUZmV8PyLOigGAgK?= =?us-ascii?Q?HVxobC0La9uOo9Na5ZxEoYXSH8RGc8XBm0PK3Vd+Nch4MOY38DoZ9QBC1XXX?= =?us-ascii?Q?pdaj1JIIlRG+DF/cVt1zfUgWDsPKRYL79IugmfolSGBjoSlJaoASJYaOIFsx?= =?us-ascii?Q?+LKf0NAsNFflN32nEFgtUgeTKr4nKKBLT2JeKmY413qrY08hx6lGuzWs9KVR?= =?us-ascii?Q?I98AyDCzWJefsW+hpOfVl3Z3WCXwI5zvm0/NyQoOgOF1iPKNXx5QP0KFeEUv?= =?us-ascii?Q?p2bOIrifT/XwKb/zCEmm8rY8o7DIiZ2067lECYWD+8iEQQK8FJ84l6Fmjqx1?= =?us-ascii?Q?cCeC/I4dDUvtoNBj0AH+YL4vfrCfmq1BV5rLDd2hFVz8f8mQYqVUHJhuzE+x?= =?us-ascii?Q?0z0qlwTP4qiumORFGlbDOKVTT5qkrcLQpjaisG3yeMxD2ZVEBeiDa67ycHyb?= =?us-ascii?Q?QJfx5cDvdVUtR+qDqAzXb0VekjbKDpYvuGTXGFcpztCWwyPq1NN3EP88gbTJ?= =?us-ascii?Q?DVTohDIfyLMsl0a9pb8Se2EgS9OytrXRMJp7a87ulIZtBXuMhj4yS+YmmL9+?= =?us-ascii?Q?WFecbJ4mgM4YASFFx2nPNHa0VOBl2p6TT+WTlneURsOe1FzxNe7tsWEg3S3b?= =?us-ascii?Q?OtNUA46xUSAkC+7arzmWltVNEoEFHYl/f6vhmEMabJzaFUVeL97l+dgZ/VZO?= =?us-ascii?Q?+Fhrn4LOWyc3qr4paNHXoQfEvte7+wrzghGdpsEOQyOoFayS3MuZSj5nnx1n?= =?us-ascii?Q?Uu+ZEOWIeBSJbySwZfTCbhNMwzKH6GknOPScztkVVwLsf5nxcAPWzKla5MKU?= =?us-ascii?Q?cGNgUp5CnXWK5NODDhUgqPSYcAeaIHcg/cwaviGzWxFq5/dgj3DgNuoGzMde?= =?us-ascii?Q?xbDAa1wgmy7K+j/JsaEe/v2QK/LHHuVEXCje1wv5W6ZXpztF378b9+Ar4o1x?= =?us-ascii?Q?uI7/KlRb6uPWqJgKqtAGvWYLEVM3udsc60WVNTZ+tF8G52VSce1E7nnI17q0?= =?us-ascii?Q?Oy7GhkNUYwBVkR4LcgWVfcWX/vBnbG7UxNDtz7roQY52tZwCGh/oCqcB4bbj?= =?us-ascii?Q?s1B+KigUqlm8oWUjA1OHR+cqEl1wMJzrN+dcEwo3axKpldloxDGWtUK90PpX?= =?us-ascii?Q?fB41Oz/rEXE0q7MpxmDX4G3991rEqI/rc/hgpPWaKBzOz2tvdFScBvcpOJrO?= =?us-ascii?Q?HgCijXN81hJj/t+aiaU=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV8PR12MB9620.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?az6gIMFpgJT8mk+8iwFECNDuoy4WDYbk3LevkXeQI2U0rVjFRc8nvoADpZks?= =?us-ascii?Q?OVN/p+2Bz3v25xiUj2b2FAfRvhgd7Be0bBqA5TGg6dISnclOzh2l83D39t65?= =?us-ascii?Q?Yt5tqifJKYNYR/vwxotyfhWXaexO4Tt6T4gw4+q3dGZ4JNC7t0OkVtnd26GN?= =?us-ascii?Q?aSDTp3KvA195jVLeP9E4UciLTuSgchWtYPh9zw2sTRf3yqElBJnWB7smI+xj?= =?us-ascii?Q?ggIr3cGqzLYijkphzbpoAZWYPzVir0Zb2wMWWGpkZTb125BGW8QoC3JQI+Wv?= =?us-ascii?Q?RD59FqsRfPJbhGFVBHNtYc8OCTr07RBBea4uxxXxc7PeLAdpML/XyywZvHde?= =?us-ascii?Q?kMlaQeohgW7gCmU1lEXTYdQzX9JZUNeaWqqhBD0MvMa+xjpDXtPYgl0tgL1F?= =?us-ascii?Q?mOA1jQofVUa/mPptzbyhKJGHQJN+V3Sgw6h3UX4tO0empuxqihVNEfAhq1la?= =?us-ascii?Q?FOaxmp3TXC2+lxO1Ygp1P46a1d4zh0+BNZ8VfEoJo0RjvwPKpgpQ2yW5+Mkb?= =?us-ascii?Q?2xDK/C3iB9z5svEpmtTlDdkp7lP23EyROkd+tXE7IolSFgVdrUcrZMqDZXm/?= =?us-ascii?Q?bAb2t4xir/t4Zvu1l1uf6Eg3c8XS/Gxi9rRG5gVLkTeUo0vcx21mA9EdvPbN?= =?us-ascii?Q?HisHW87cPoOzXvMF+i3knbg6KMMvrOd1uPJJCK8DaUajjcdOUimWMOTm7oUE?= =?us-ascii?Q?0WRV/mmE36g9ja8QtVLYQogdpvWPOPJ5Gc5bt+KgdaRLrEA2nOs24oSnag9s?= =?us-ascii?Q?QYd7W+rfzf30dX6hUL4kTlovvxueRSdkIQJY54U5DDPNDoEvW6TbeAxMoriJ?= =?us-ascii?Q?X+dWol2mXLFK9xpQqdZ3WuycJkupcja3aALaxF/E3lp/YUdKD7zcCBulKnhp?= =?us-ascii?Q?GN6RVxw5HnC1N4fz3D5H1N8V3dDVW1m9Zfdl2P7Ut+KVRkSL27JZ6TXs+eFe?= =?us-ascii?Q?JQAMBk1mAu3t9+wEq+pgXUxrXJ01BrZQjbJIqBKYha46LdRRpwf+Ap3rg8+7?= =?us-ascii?Q?n5qL4o1Ehwgb0htjy05EJYTtsDybYYs9YuJl7rYf7pWzUfb71zFoEW1LvUBY?= =?us-ascii?Q?xUfWIFXH8Z0vfJvrcZnstm+yhQZ7MbaptXKyftbVXSnmOKLUcpeqrsVARCfF?= =?us-ascii?Q?kQR9w2i+SY/5jLqwP6miVXi9PJcJKFP5FaT8Pi0+Coi7yLjncfboEOmlJ2Ao?= =?us-ascii?Q?zlQ1wVzUwkbZvzAVpArJmV/7JrH4Qc69RODsDvTedJWibXMGvLH9Va3fyM1m?= =?us-ascii?Q?kdQvu6vLM9ED38LKqsXof+mHlhjqtBYPMgTrsdvkKwZ1Zx1/9gUd7L2AzcqX?= =?us-ascii?Q?0stSxhb4uUgLxTqSu1o8+zzu4NAC/dMeQBHbNwCt4gGcXPUoBRfXYd2eKOHh?= =?us-ascii?Q?Nrb2To/bpOU/+lZkzXVo4hm+eOfegZOTjzx4twSQBGyayWLSzmDvCf6NR4KG?= =?us-ascii?Q?Z/xzAqCWwSmGm+s+Db66cgDR0P3UTeNUayGX5ZvI8m+pb1He6dL2HtwNg6lF?= =?us-ascii?Q?hzq0/bcKNUKMhccsodvYlLtjXWBFzdWQBM81e8+2vqkSsQ3FMp0TAIqcDSLC?= =?us-ascii?Q?nnb1HuK/v+glm5wSO6A4G2MXYN/kH8vKCKBuvx6gWG2SyClPHXeNnCUC0FqK?= =?us-ascii?Q?FrrqMnPnRPw6QcaKZbOcKhAmI5T05B53y/RZE5YAj1m/N/jwjSihPHKMW7u2?= =?us-ascii?Q?Q5lnvilEo7cp0W/E9ymQudxs0FFF6muulsQpIT5tHIt+0eWfXlRFpyRFD0b1?= =?us-ascii?Q?ZMHmctBu1g=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: b94ab512-0897-4060-4f2d-08de5e7dc956 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Jan 2026 14:59:07.6509 (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: BcTbPPMQdxlttTcV9VaPtq4mvns/yZxPllHsyGDhraoVOsLWTuBFTTIEzMOLY/Ar X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB5925 On Wed, Jan 28, 2026 at 03:01:25PM +0100, Danilo Krummrich wrote: > There is no second memory allocation. In the implementation of > fwctl::Device::new() above we call _fwctl_alloc_device() with a size (and > layout) such that this allocation is suitable to initialize the second argument > (i.e. data: impl PinInit) within this allocation. You are talking about your suggestions now right? Because what I see in Zi's patch doesn't match any of this? + bindings::_fwctl_alloc_device( + parent.as_raw(), + ops, + core::mem::size_of::(), + ) That is not allocating any memory for driver use ... What you are explaining sounds good to me, though I don't quite get the PinInit<> flow but I trust you on that. :) Jason