From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CH1PR05CU001.outbound.protection.outlook.com (mail-northcentralusazon11010010.outbound.protection.outlook.com [52.101.193.10]) (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 3AC38282F08; Mon, 2 Mar 2026 21:19:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.193.10 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772486348; cv=fail; b=g3R4RLPCcx8klD2inIS2iQ7wEWs4y8sTe5VChKBYpPXDUKIaih0wAdJTaMh6tT5qevk/4Dux30l1IwuNYCEuqxbvM6KybmWZLnp7MUT/gLZ1jB7GGRzujinXmCdst5sfbIqYzmoj2IcZwZ6H9WDEDkMZ52Pfb++ze4bHwTgoboA= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772486348; c=relaxed/simple; bh=uildwec5WRBRWgIdIheAxkC9mCO8EBhEzEDC+Dnj6Io=; h=Message-ID:Date:From:Subject:To:Cc:References:In-Reply-To: Content-Type:MIME-Version; b=ACT17kIMTNtkof0zN+s/9N1ec89T929TUdHRayQ9OV3/NWqH03fCtSsnswJqUI5jHFOA6Dg6BQ+Puj0424su6BdbHxM7EIiic5hoVN4OkrJnDEHz8tqVSix/NbHj09pbqfiJbD3wNk1uf3yZqYJACIHybbrxssKIZcpy1WTb+JU= 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=sEp0/zPP; arc=fail smtp.client-ip=52.101.193.10 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="sEp0/zPP" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=UDQv/LPFzERYG155gJ1z4aVPhmuy3Mk9OlwPX+PvzexLAq7WiWkxLYo8+P+pB93bYSyH/OCiVd/M+mLAGYYerWQOtflvTnuOgeXN30a87ra4Q/dfKSE57Tf/Zn40bVnTNtHySQtAan3YamhWd1KCYkYIiX3UzwbrYZRDyFRYx7fE3nwIzA8568cX6nTBsIXgW2Th41ommg8wForR9CoMz1ukhkiiLCdrElAaFtWdJ7HwJdVwyXFWF3z/o515JB8dMkGTczA6/1A2o/Tn+h2sglbe++Y7bZB2IfjOXrII58Uv7k6nqemB1ZDcMPL+kBfQttmjxNXzeF3xtPiZTRXNoQ== 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=pOQmMXo5C3WJmUBAdjBvhCpEzy4haUJs6C4FtTWL4DI=; b=YlR3+FjSPrk5vuYhthsoRbiKxXHGkZmTVS1advtpZ44XLS8RAUx6nsDczwZ7x2tmT0L8UqkmaEgg9aRS6z5AoD1h55tk/+S5rV/Qa5igRswgDer3Wkn9Qwm7p+cYb4J2NV9EqTtqUWBf++JgMswmoWlekYFHRaETGO6oUV2WJc0XWFzzBHl1EGCqpFjIpPa7brty/0CG9PolLSm+ep279MAr40rxgKgSakU07B5sr1aaS3EeSTPQMH8PKfukI3YFR+F9USTyKn2H6ckJYbv0VKr2XYnconCKUrwvH2S5htc5sHjkS9YCAHiGpCYJTNBJc+5ETGei2gGlg4kgcsBEEw== 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=pOQmMXo5C3WJmUBAdjBvhCpEzy4haUJs6C4FtTWL4DI=; b=sEp0/zPPfK9X15JRlAXtN9JOEOAw+jYFDOikwch3F1fvzk02LXkPHvOPRDRbtwu8Hpu9rbrNpJeGsdUYJ5EEMoBnB29KR4qbQETds03ikN5241g2lZNR3/iLyMldwB5OrsBOs9lUbmZqYiGQEtQnHaP+82XWWfWtrBR5cNfr58EUsrKOhM+3d4SyRmcodHf/zNcyIXNiyY8sN7abmHbeqesL5j7brgNZQR7e8hOBH1PoztZiY3iH6Ko3vaksPs4EdYa3EqWxXW7dphrbuzO2MXHAPGzKeL2ag5P6Sxm2eBHzXOi970Wr54MTPKdYXn6z0oaVaQlREsAqmDLh/mK0gQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DS0PR12MB6486.namprd12.prod.outlook.com (2603:10b6:8:c5::21) by DS7PR12MB8081.namprd12.prod.outlook.com (2603:10b6:8:e6::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9654.20; Mon, 2 Mar 2026 21:18:58 +0000 Received: from DS0PR12MB6486.namprd12.prod.outlook.com ([fe80::88a9:f314:c95f:8b33]) by DS0PR12MB6486.namprd12.prod.outlook.com ([fe80::88a9:f314:c95f:8b33%4]) with mapi id 15.20.9654.015; Mon, 2 Mar 2026 21:18:58 +0000 Message-ID: <7b3146c1-ce5a-4bf9-9837-57c19b24ada9@nvidia.com> Date: Mon, 2 Mar 2026 16:18:56 -0500 User-Agent: Mozilla Thunderbird From: Joel Fernandes Subject: Re: [PATCH v11 4/4] rust: gpu: Add GPU buddy allocator bindings To: Danilo Krummrich Cc: linux-kernel@vger.kernel.org, Miguel Ojeda , Boqun Feng , Gary Guo , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Dave Airlie , dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, rust-for-linux@vger.kernel.org, Alexandre Courbot , arunpravin.paneerselvam@amd.com, joel@joelfernandes.org References: <20260224224005.3232841-1-joelagnelf@nvidia.com> <20260224224005.3232841-5-joelagnelf@nvidia.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BLAPR03CA0177.namprd03.prod.outlook.com (2603:10b6:208:32f::30) To DS0PR12MB6486.namprd12.prod.outlook.com (2603:10b6:8:c5::21) 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: DS0PR12MB6486:EE_|DS7PR12MB8081:EE_ X-MS-Office365-Filtering-Correlation-Id: 307943e5-22c3-4ddf-0eaf-08de78a15122 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016; X-Microsoft-Antispam-Message-Info: cFB/r/fATCI+FAkCJOhmsCL6NbJulqyIk4Gj0ydq82rY6fGQ0kGcVicTUOSlEOSJomsndWn0zDWAwO0+j0H+qt+tIzctd+eRPqjkp+2XWlAwpgGHVXFyDnde/KeK73ov1xcTlJVJ1qKG+fYNjkP8NTYKjmQAE6QEuGISBldO80lwia31+7E4ziIunUSggpw8jTPpvTcbOdicVN4grNGhvzuzjrnLuCH2p6DWLTXc+f+WR2yMotZzGQH2u047KF72E1RPDjrz/IHSP5lEQEyzczIcP92cVlm5uFNzrPwyE+gBjY0L/GWfr7x7xNlXSN/MzhPIyS1HsiJ2buApezYm8qz1+2FvIaImNV1/LWE1b1a5AXD8K1V2dSV3Zd0nnhuuzRyIyLc2FulwdHTqWvBB3R+X04pid34L1qjJmHm7Uubbl4MbYHcR7qrKEnh9/BsP3rlfYl1m8rXLbWJCCKyRQbtP2ERJdoCzRO+FYfrxJl1HBpYvw5MKv1yXN8GhIDKZh3DrOGn1oeDxWH9O/n9BPHWP5M7pRUXH5FgkZiYflFP9i+jDe8ZvaNvRS4AHIUS9cuTVwXl2S9hfa1SgW14U6XZed+Y3b4c3bOSVwr85nNqjS+HRRnUgWqzbmOUCFhYcQWBPhQz4JGdW8wZOTiXkaKo7ch4Y/j26p0PLDyxG2GHPxvZFOUFVqfemk2bFSd3woC0+8CTGFDudpQBgruh9dXNshBXTfojIrcBcUjMjZEM= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR12MB6486.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SUtZSnJEWkJlS0U0UHZSQ3ZXYldXQVBTVndlNnd6Y3BiNmRmOTFPbVJoeTdS?= =?utf-8?B?Ry9HWHdNWDBQeFltU0htdXliT2tOVkVwQ2VzdSsyRHZ5L1owK01OTENQZ2Rm?= =?utf-8?B?WFNHQ0duNFFTcm5pRWpRYjdYMllMMGpCZkNaOUtIQXU4NUlwd09hRW1ia2gx?= =?utf-8?B?WWdPZDd1NXBzYW9JWTRtQkUrOE42cTh3NERERnZWZlJzbTZyOHJCejVFMTVL?= =?utf-8?B?N05ZNkdWZERUS1p0Qm9iOHU5aE5qZCtyaTYyeHlMTC9QRkhBTmpDeFV1SkN3?= =?utf-8?B?N1RxRzFQYTZOekhjVjUrM1duSGJ5eThzMWxWc2duMEluUjVLVGFLUWhsODN5?= =?utf-8?B?STR1ZERoNVU3bUNCVkRxdGV5WTE5aU5jTTZDbGtOSmlKT0FLY1lWQTdpdGF3?= =?utf-8?B?RVV4RGJQRW1vbTNzQytRbkNNT1gwSjhkTmZuMXBMUTZaT1V6YzVwU05aa25E?= =?utf-8?B?OTFqTGxkQjNVZHpsNFNMRGtiaXd0YnZzNW94WUhIWUZZekg5a0lTWW5HWmRl?= =?utf-8?B?ZzU1ZkRVZmw5UnZJRkY3UVNZME5ydy9SdXNtN0x5L1FzUmRFSlAzcGJ5TnJl?= =?utf-8?B?U2grWjZEUVpaK296dytmYzJubzN2NnROc1RkbmZYL3NuQ0tubmpmcThmSnhO?= =?utf-8?B?enVLcU4zUWRTNVBkV2IvUkRpWENaT0ZQaXE4eU81YUNBTldHdi93QUR4MEYr?= =?utf-8?B?TGN0R1FqOXd0UjFzRlN2V0tjUEJzQlRjMnJ2bldya1Zsa2RMemE5RzhoY2JU?= =?utf-8?B?anpRajFidk9vUEpWckpoTjFqNFR5NVNqdHhIbUx1ZGgvRk9DZmJYbG9qUUh6?= =?utf-8?B?Y2huRUhnZzQ2bDJyWDA4Z1JvV1VtYjdVUEg0QVIrZ2hVTmhHaW0vSGhubWdN?= =?utf-8?B?eEVHUnZBalJuM0gxeHd3Q0tMSmtSL0YzZUo4RERac203bk1KUGZZQ21RdVNY?= =?utf-8?B?MzVsRXhrQnBvbFloWTlaQ2RHaldBUDFsNS9MRjVuYUxHdHlGZzJ6Qy9SbDJt?= =?utf-8?B?UmJPQXhXa1hiNWJaT3M2MHlHcW4vdzRmN0JtVlBPUnhzK2tyQnQ3a2hHUHY2?= =?utf-8?B?b2RjdE1CQUR6cXFPMFpnWEk4d1pJL2tkU3dkMjJEeWNMT2lTNzB2VHZPSHNt?= =?utf-8?B?eUw0TFJBc1Y3SW1SK0pxMTRCaks3WHAvek5LVEY0Zm9nMVdrNnhNcDVCeGpR?= =?utf-8?B?azRQY1QzVnFYREQzcG1NWUdIM25vQ2t3aHhZMDhET0VVMnFlNDNuZ1JPa0I5?= =?utf-8?B?ejVHNHNJZVFRZk1KQjU5WUMvSXEvMlkvUzJsSFd5MXZhNk5nYXl6em90V0FM?= =?utf-8?B?YkZuVyt2RTE1bUNWT21kNmY2Ui94MG5MaGN5ODhBMXpmeWo0WHZqZk02SFpm?= =?utf-8?B?RGpaKzE4M2JQZU5lNm5CemFKeXRrcU5iNjVqclpvbXhwWmV5cU5iTUtuTzAr?= =?utf-8?B?YnR0WXRHRnNUN3QvbTNhV1YzeVpnMGo1dHVsM0NvUG1PYkgyYTNkU3FRdllD?= =?utf-8?B?YUpScVZoWjBHR0QraysySGdtb1hlOGpoZTVZUnpkZjFiaGhVMnkwdkxJOUY0?= =?utf-8?B?WnRweHhYeWxzWVYyQ2cvTXB1WDdYSlBRMEQyS01FazRNMFdlNFA4cUtnOUpk?= =?utf-8?B?aFcyR3hHdWlQbE5OYWlDSHpRcFRhYzBVUHJMcGw2SXo5RU9CN3JJaytLWmFk?= =?utf-8?B?WW1aaVlxSFJWeEhqSjlQS0tMSFNST1Z1VTh4TzFrSElRZUZ0TlVsZ3dubEor?= =?utf-8?B?elloU1JBWjNGN0Zabm9SdWZoS1AxMHUrNXRVaURWQzlWOHNPSDhoUE5Va2x0?= =?utf-8?B?blowRFQrUERZWGxOU2VabStkcDNGM2ZOZUVTL2g5aTMvK1FIL1o2N0prMCtT?= =?utf-8?B?Uzl6ZzByOEpYT1dPT1VnZlpEVlNlR3hxWVlkOHJ3YjZwclBXcFRPWlB0OXRR?= =?utf-8?B?UzVtK3RGN2hCSGx3b3RPWWI4WW1PalRhWnJVamc4MG83WE1RZThoaVQ3OWtS?= =?utf-8?B?S3YwcG9HLzRWY2RNcnZSanpEdmVhb2hUMFl2Z20vRXg0OHRldi9zaGp3M1lo?= =?utf-8?B?VGgxVkRhbFp5b2l5L092UHJwY1N1andiZXJ4SEZEdnVueGxCTEVZVTdqYVNP?= =?utf-8?B?WnZ0Sks4NElsVXdoSWFkSTZTOHJTN0xUWkVwelhNVGtmRUVmZncwWHk2Ujkx?= =?utf-8?B?eXFTSzFZUW1sdHhqZ1FCa0E3UXJicGl1TTFGVmMzb3VzeWNsOGRCZi9UT1Zz?= =?utf-8?B?SmtFck9yRFcyV3MwK1Q3bC91VWVFTmVlQXFWc0NUR0liSXpBQldOZHN2UFNo?= =?utf-8?B?Q3Q3QnNFNHdBcG1QN0pFbmZmaHJVWk1qUlFWa292U0s3ZGF2b2prUT09?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 307943e5-22c3-4ddf-0eaf-08de78a15122 X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB6486.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Mar 2026 21:18:58.2593 (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: H6Mf2HgQ8w8dibest2PI9Zd+Tjya8ookiVAncbvBftJGJOekJ3oc/+tzznblIpaeKKWRw7PANatWsfh9gPMhFQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB8081 Hi Danilo, On Fri, Feb 27, 2026 at 12:30:20PM +0100, Danilo Krummrich wrote: > > > > +RUST [GPU BUDDY] > > +M: Joel Fernandes > > +L: dri-devel@lists.freedesktop.org > > +L: rust-for-linux@vger.kernel.org > > +S: Maintained > > +F: rust/helpers/gpu.c > > +F: rust/kernel/gpu/ > > What about adding this to the existing GPU BUDDY ALLOCATOR entry? Maybe you can > offer Matthew and Arun your help. > > Also, this wouldn't be a subentry of "RUST", but the rust version of GPU BUDDY, > so it would be "GPU BUDDY [RUST]". > > Also, please add rust/kernel/gpu/ to the "DRM DRIVERS AND COMMON INFRASTRUCTURE > [RUST]" entry. Both these additions sound good to me. Just to list all the options below so we save time on what we all agree on: 1. New GPU BUDDY [RUST] entry. 2. Add it under the existing "DRM DRIVERS AND COMMON INFRASTRUCTURE [RUST]" 3. Add the rust files under the existing "GPU BUDDY ALLOCATOR" and add myself and Alex as R:/M: Which of these options make sense? Personally, I think #2 makes sense since we are already suggesting to add it to the existing DRM RUST entry anyway - we can just drop the new record and add rust/helpers/gpu.c there as well. That's what I've done for now. Does that work for you/others? > > +/// # Invariants > > +/// > > +/// The inner [`Opaque`] contains a valid, initialized buddy allocator. > > The invariant should be justified in the constructor. Also, where is it used? Done. Added `// INVARIANT:` justification in `GpuBuddyInner::new()` and cited at all usage sites (ex, alloc_blocks). > > +// SAFETY: GpuBuddyInner is `Sync` because the internal GpuBuddyGuard > > +// serializes all access to the C allocator, preventing data races. > > I think it's more precise to refer to GpuBuddyInner::lock. Agreed. Fixed to reference `GpuBuddyInner::lock`. > > +/// # Invariants > > +/// > > +/// The inner [`Arc`] points to a valid, initialized GPU buddy allocator. > > Do we need this invariant? Isn't this implied by the GpuBuddyInner type? Right, removed. > > + // SAFETY: list contains gpu_buddy_block items linked via __bindgen_anon_1.link. > > + let clist = clist_create!(unsafe { > > This macro has three separate safety requirements, please justify all of them. > Also, please also use markdown in safety comments. Done. Expanded to justify all three safety requirements. > > +pub struct Block(Opaque); > > Does this need to be public? I don't see it being exposed by any API. You're right. Made it private. > > +/// An allocated block with access to the GPU buddy allocator. > > This needs a better description, i.e. what makes an `AllocatedBlock different > compared to a "normal" Block. Updated to the following: /// A [`Block`] paired with its owning [`AllocatedBlocks`] context. /// /// Unlike a raw [`Block`], which only knows its offset within the buddy address /// space, an [`AllocatedBlock`] also has access to the allocator's /// `base_offset` and `chunk_size`, enabling it to compute absolute offsets and /// byte sizes. /// /// Returned by [`AllocatedBlocks::iter()`]. pub struct AllocatedBlock<'a> { this: &'a Block, blocks: &'a AllocatedBlocks, } > > +/// - `block` is a valid reference to an allocated [`Block`]. > > +/// - `alloc` is a valid reference to the [`AllocatedBlocks`] that owns this block. > > References should always be valid, no need to mention that. Removed. > > + block: &'a Block, > > NIT: What about just naming it "this" and > > > + alloc: &'a AllocatedBlocks, > > "blocks"? Done, that's better. thanks, -- Joel Fernandes