From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CH4PR04CU002.outbound.protection.outlook.com (mail-northcentralusazon11013070.outbound.protection.outlook.com [40.107.201.70]) (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 6884BE55C; Sat, 3 Jan 2026 02:15:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.201.70 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767406516; cv=fail; b=uFj84l6jfbz8uEP6rtQZQDQ2BuVzYgByoPs/htCA+b0SGbrQrmRnd63SWJ8vkypBnHRqB0DU0u3MIwE3lgyxw1dzeuVM+2FrF1KZsoDmt8KVO4uIafgJbHZhoV21CVSvJ6AMC2Ls9Z8awlWuYhzvFHTJoDVvm6tV2hyUqXxu99c= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767406516; c=relaxed/simple; bh=VwsdLqtIwGz6yWAoDG1OdUpDRD6U6HeiO63QJGX2Jyw=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=e3kuJMCkSTJJ+WW/zxuTyDKkuhY6OWI6JunBdNkywg0MdSQKNnspPnULkXX0aYJ7Ij1LHbwDqWjf3ZQEo2Cl8vodBTbT+CRyBGzkxA3ZzYRi2Y+h7USl9Yh4ZRPR4p1qQhlJfIQUjJrcmNbA5PcDdkIXO1KQqa7k1IIE58qxW7c= 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=stF57MOc; arc=fail smtp.client-ip=40.107.201.70 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="stF57MOc" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=KJbUIr4Hw2Sze4zzoz9Nsots8my/vqmxlFCsFP1kKwGiF68zMtZ8XEq5PT6S8bGCC5cKOhKiy5ZdKU/QW4/BwWz1xs3QzKVvBtP6Y9XpaJicMobt2qbRk8e7Mgs5DZ+WMv4shbbDTJMc4PekQzlyMNz+TJ4yO4wCSmI2Z19YBUph5vYhIXBX3PwDtbT8UumO6E571FIhhZHq+GkhaPL4sYtycFp676alh3mniI4Y0qEfeQs9Xh4RY7FfXkMJM1uwwFKfVQd0UkGl+stL8QJE7AdU2++FQORW0pO2myKK2QotPpSryXd/d75E4nz+XSrpdeOKPQ96VDrLQXvJ79zBRQ== 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=i+/IZtwVk4t617Di/of8pripzQnYR6vUYJhtYIZZ1Zw=; b=sXBLw4HdKsc4mR8hJcUlN3+vQcTn1lNu9U6/258imPFO2wyfcM5pjnrZ31xIT/tKK7InrkL411tfvPUOFuNSQOiemomYJvUv/nVSEVl0ewt+X3mmbJl5P35zMRjo9scK7NbTYLenkHsgPv7At5C0suQ3kfjuqqUAHeXW1D1cDx3XxXud3sBqWa6ZeNlIWpPb83/I8fKt5udjLmms3OUPusHx3mLgqXz8xW0h0tpA2p37f+kShV9onfaF6v9hAYPt+fgsz7HAgoXmlv+dqQzz81ZUR4Lm8fnwiL/t/3EvN6tbfhWX+bQUhcuUBbq5CNjU3PvCfOYkv/ET/GOmNuBFoA== 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=i+/IZtwVk4t617Di/of8pripzQnYR6vUYJhtYIZZ1Zw=; b=stF57MOcME3pn17ZIa+342rEr5QaRQvGpEEhbwTsreJfwpJDX1ykP9mvwNCbN7svF2dCYrcrOnfNyDPtHEMCUQjyl8iiFUPzS6s4q3y2wzybPUjft8ub18XhNTc9NKx/te7yhd9HQu54XfkgChcmMMPZdcCTO00oA4mutt6S42u+FiVivtXQBE9mS34gIVZS5MAu+xdAz7+RsozlKp0vZaA9/d31k8WewnXmnDEuXFMHGneaOSyvcQOxGgyhAFPSDZ5UN7JAnvru+60yyY53NoS2S/a5qUtsAZrMyWpPGot3HUGZZJQogsNtGDj2zUSkCsbtEWG4uyBrkN6aAt+C7w== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DM3PR12MB9416.namprd12.prod.outlook.com (2603:10b6:0:4b::8) by MW4PR12MB7358.namprd12.prod.outlook.com (2603:10b6:303:22b::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9478.4; Sat, 3 Jan 2026 02:15:11 +0000 Received: from DM3PR12MB9416.namprd12.prod.outlook.com ([fe80::8cdd:504c:7d2a:59c8]) by DM3PR12MB9416.namprd12.prod.outlook.com ([fe80::8cdd:504c:7d2a:59c8%7]) with mapi id 15.20.9478.004; Sat, 3 Jan 2026 02:15:10 +0000 Message-ID: <2603ab3c-98aa-43cb-9d7a-525c7df3616d@nvidia.com> Date: Fri, 2 Jan 2026 18:15:06 -0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 16/31] gpu: nova-core: Hopper/Blackwell: add FSP message infrastructure To: Joel Fernandes , Danilo Krummrich Cc: Alexandre Courbot , Timur Tabi , Alistair Popple , Edwin Peer , Zhi Wang , David Airlie , Simona Vetter , Bjorn Helgaas , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , nouveau@lists.freedesktop.org, rust-for-linux@vger.kernel.org, LKML References: <20251203055923.1247681-1-jhubbard@nvidia.com> <20251203055923.1247681-17-jhubbard@nvidia.com> <37a85b2e-603c-44ad-a346-783842e9c829@nvidia.com> Content-Language: en-US From: John Hubbard In-Reply-To: <37a85b2e-603c-44ad-a346-783842e9c829@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BYAPR02CA0038.namprd02.prod.outlook.com (2603:10b6:a03:54::15) To DM3PR12MB9416.namprd12.prod.outlook.com (2603:10b6:0:4b::8) 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: DM3PR12MB9416:EE_|MW4PR12MB7358:EE_ X-MS-Office365-Filtering-Correlation-Id: 5fb2b5f7-0658-45f5-c0f4-08de4a6dec29 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|7416014|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?U2dvUFZhL3BYWjVqV09VenJ2UmJrTEtZeHdVL3B2ZzAzSDh1b3gzdTR0U1dk?= =?utf-8?B?VWphQjRORmt0VjJKUFRUUUpvVFJYTnZoNjBLWTdhcUNTbXZhREhJM1ppcmxt?= =?utf-8?B?c2owRVhLOXJScUp2dFBHY0pocFE2SWw0cU5mN2lHUEh0WlcwZkdVSCttWTZ6?= =?utf-8?B?YjRFYXVxcXJQR2JNcThveGxsYXRZTjF0VVoyeEsvWEx6N1hPMUF2d1VYOEVt?= =?utf-8?B?NXRjNzgxQnU4bG1tbzVMaHBOWmVzKzJxLzdhWUhhekJ2ZFQxWmNDVXM4bC9l?= =?utf-8?B?RnB3QjdieVQ4cUp5TmVQZ0lyM1FjNXRUL3h1SktkcWw3ZFQ2bFFXUzNKTVVR?= =?utf-8?B?OUFVakkvWlVoeXZDRDlkMXpsY0EvS1Y3djFvTWtqTEhOVGJSNEhSNmdUeDVl?= =?utf-8?B?WTVoMm5XRi9WVUQxT1U4THNDSi9SbzZQV2x0U3RiUHhBVGlMWjltZDJoSzMr?= =?utf-8?B?RlhjbWdtbERIaVd5cm5YRXp1ZnVQUjh0cVFFWGdVVHVwQTl4QytyRXJtWk11?= =?utf-8?B?b2cvd1JaTkdXT3pZSnc2Qm5pL0xtcWRMbWd3MjJrTUh6eEt1K0QxVno0cTIv?= =?utf-8?B?Uld0TTJXcVR3c1poS1BTWWZ5QlMrK3BaQmc2Z1F4NHZQS1pObVZJNHZIVnV6?= =?utf-8?B?NmhycDBuM0cxUXdsNkZNNTA5QldobG42NjNLUkIxVFg1dTA0WTR0K2JjdzNq?= =?utf-8?B?d1ZoQTY2VG1nZ3ZkVjlWVmhzS3JDc2hyQjNYQUNPcTEremU4YXF1WnVBNE5D?= =?utf-8?B?eTRFUnhMV1dUVlhBZGdtYnNpdHZLRnVMZGZjRzV3NjJDNmtmZE9YSE01TjI0?= =?utf-8?B?WFYwQjQ5NXNiUjlNUE9oSzljSzF6eUVXY3h5YUJyQW16b2c1enFtUm1GcmRX?= =?utf-8?B?NVg3VGhkSTIxelBBQ1pnVkZ0dmVVVnE2ZEswd21rclVWc1NZUG1vbGhTaEtC?= =?utf-8?B?Ly9pSnZRY0JFb3AxVnVoRURSYnpxcW5CUFpYK1dHUFJEZzBqVzBsQWZlL2hJ?= =?utf-8?B?Y25JRzRmQnVJYVRTbllyZkdsU1FLcjNuSHdUT042aFV2Q3NXN0FKeVQ2cS9M?= =?utf-8?B?eVB4bTgwcmY4YzhWbUpIT0F3YWhHOXIyazMxYVI1cTlKaEhNNWIyVVFSMDlB?= =?utf-8?B?Y2xMc1ZzRWNldllYSTFKRnBzemFvOEMwN3A1U0dpQUxTdjNHYXVyQ200Q00y?= =?utf-8?B?VVdtejlYOXRmUWFHSTB5QWpLMXVJSHhpU3BucnVOTGZmY2p6RksycXVic1BD?= =?utf-8?B?eWdobEhRK1A4d25EWnJsOG52UU9ISmc2ZEF5S3JqT0tTZ1RUMzBHQi80Q2Ru?= =?utf-8?B?QzBSbHdwRi9Tc093cjJEQ2Jac2lLanhlc0tzV2JxdVJlalZwVVZaR0lpTmg5?= =?utf-8?B?Zml6bzFISC9JS0ZHTFBDQlpVdS93akxhSnpRWnMyRHA0Qlg1WFlVb3BMUnFZ?= =?utf-8?B?ekZGWTVzWDdWZCtLYWtlMzJFOTRQSVFsRjdES0tmQUUrRC9DQzE5ZEZha0hj?= =?utf-8?B?WlZJMFd1YlBSWHRjQ2xERjBzWkRUSmxmekpWU2w0NlY5blFwYWJCN1dTOXpo?= =?utf-8?B?Y3hiRHlMYmpOamVkeXc2dUo3cHRORDhjQXRJSjdyeWRZWGZCV1ZSU2p1dTRy?= =?utf-8?B?Q3hYYkNPQzMrMEc3L0VuUzl3QkFJb01xeURhMmtTdE54MGhlVytBaDVJZURI?= =?utf-8?B?WUZLakFGd1JuZFhEakNPTk1qYVp3S0ZzckJBZFdrZDYySUN5VDdrMy9iUXRO?= =?utf-8?B?bEl3dzk1NEQzdHBsQ3BwNk4xcEs3Q1B5YjNtTy9wRmpCZ1oyS0xab1pHbUdB?= =?utf-8?B?ZzR0TVFTL1Zsd29EL2F6KzZGL2JOS0VwKytDajJZSnRsWWRHdEExRFNCNmNl?= =?utf-8?B?U1Y2UXEwTlVvWk9FMy9xcVArZC9IUHpnUzcxUmtnYU9kN1BuSkwwOWhEczlt?= =?utf-8?Q?g63kicqDpBS56afvcFpWC9yELOBEZYoi?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM3PR12MB9416.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?MzNTU0Z0T3hIZVdMNzFVWE9ST3ZwZU52OUd3WlVRL0tuMmV6VVFUVFY4RjMw?= =?utf-8?B?NDVUcXVMSk1xeUpQZW81UkNZT0ZWUzJ6QjFhMGVwWU1qdzlKZXJlelVndGh6?= =?utf-8?B?dENVdFdFdldIb0N4S1lPNGQxNUVnLzFlZk1lc0svUGpEYXFtSDkwRStFRUVj?= =?utf-8?B?NWplYi9VQnFTWDF3ckg2eHBsMkpKWXhhWEsxREFaSVpHcjZiM01hMEFLV0hX?= =?utf-8?B?R3hpSnJDKzFod09SclllNWpLdTFib0FrYjhkQ3VkV3BKcnZrWVB0ajZXTTNC?= =?utf-8?B?Z29kQnZwakEwbWM4TjFLQXhDay9CcGRNSGJVMitMb2dOYmVieUo3Zk1qR3Ey?= =?utf-8?B?TG1lNHlsemtHeHY1MUphenhtWHU2a0xQQXhHWDRsSk5mZnRhY0s2RkdCVTA0?= =?utf-8?B?cWpaQ1FzZVVsOUs2UFlWSmpwZ0JuK2F1dEdGbzJZM3M3SlZRYTVRUFczdE53?= =?utf-8?B?eGUyQ0Z2eXZDWFk2OTlPeS85OFhFTlFDWDcwa3dOQk51d3ViQXVyS2hEem9w?= =?utf-8?B?aFRKYnR4aUZYbWNjR0dDaXU1b2UzaTN2YXhYRWlVamduSkYwaGdvWGxRVFBz?= =?utf-8?B?ZUd4TDdFclVKT2lvNm1ZK0QwNmIxaVBycy80YStRRC9TSUFlNnhFNnV2d3hB?= =?utf-8?B?aHlmRjBkYzB6eE51RWl6bGl0dks1aVNVQzlEaW1tZE1rRGxVRDhKRnhGYkd3?= =?utf-8?B?ZHBqOXRqZXdjYXJ3NnpqS3RTTU5OMUVhaC9vZjR4QVQ1Zm9sby9WcUk5MzZp?= =?utf-8?B?TElEOXpyUmpqeHlaQ3p2NmwwakhZVDVTU2I5OGlZdFZsc0ozWTBGOWpTQUtU?= =?utf-8?B?bVFBK0gyZmh0dS8vSkZIbW4yVEpMYUo2V2l3U2NMbFViUWxQbkpHMkJXSi85?= =?utf-8?B?ZExYVUQ2Y0gvcm8wT1c2RFJWbWZOVExTTmd4ZGdlaDhtVXpGL3R6SGlSR0Vz?= =?utf-8?B?UGdVZFA0U3pKVVYwajBUN2pnbnphc09qRWNGTzJoQkM4cDR1Uk1wY2IvNXht?= =?utf-8?B?TnA0bUV6Tkk3R2lRT3kyRkIzSGFpTjdWeHllVlk1djdnZnUxbWtReUpmUW5k?= =?utf-8?B?aUU2a0V5ZWhiR0xBalludUszVksvSldhUXhlcWQ5ZG4zNHF3Qy9pOHNyUWJU?= =?utf-8?B?ZVpSY05tNUZUeGp1Y2tzNDlYZ1pGOWlkMEFIOE1ReGxHM21jeWRlejZHbXFQ?= =?utf-8?B?MHRwWjNVVnlLWDdHc1dHQWVtajVqTFF5T1IzTEJnenQyK2x2VjZOSE5pQ3dm?= =?utf-8?B?VkhUV29qYVpnSHU5UnVCdWpZWWN6VmoxODNMaitIQ0JZbGpXNE5hU2Z1WEti?= =?utf-8?B?TWpra3ovbEx6NExROWhsSjQxR2lxSlZqWHJVMVBvZDJPK3JXeXlKNEpsY2V5?= =?utf-8?B?c0ZRWEVuRjNISnU2Y2VOK2MvanJBWnBzSXJKaUJzTGpLaHVlYmdLQWlVeFd3?= =?utf-8?B?Snc3bFhidGRibi85blkxblZka0JISWwwMUh3OVUxc2VKbHkybStqM1A1Yy8z?= =?utf-8?B?eUhnVFdZT1B0YjJHUytBVEQvczRCbGhUYXdJTjdjZXlYQkRWSmthTjhxMlVN?= =?utf-8?B?Tm42ZEFMeVY0Nzc2TnY3MHBjOTYvUER0QkdTZmpPQlFtcDFIYlJzdnBGS2xo?= =?utf-8?B?cmgwS21xUEhZSWFFWkVtQUNmTXZEZkVrOGVRY2gzS096eVZVL24zd0xKWG9G?= =?utf-8?B?S2xCcGZsbERmMEl6TWJYbUdlaHFiTHRJMDZxMnBvb3hyNGdGVnNEYTcvUlJT?= =?utf-8?B?YVc2RmpJZ1BoNjBWUGJWdG04TFJiRi9DQnM3bHNWVkdNQmJzanJERzBLMnZq?= =?utf-8?B?NUFReTlaamptdndrSTFZYUhUaHdOM0UrR3JtUGJCZVRpSlpwaytZaFNranM3?= =?utf-8?B?TWFtQkxiakxPbjlNNEtDNWtNeUVtUFdsa1BSV1ZIQitNQUk5eWtOMS9XWmlw?= =?utf-8?B?QjFhbEZhdkhHVHMvSUh4YTNxRnhlUS9DL2tjcmh4VVEveFdmeFVzUE9QaGRE?= =?utf-8?B?K1ZsSjR0T0ZnUUZZT2ZBK2x3K2kzZmdsQStKUmJBUXpKNTZEUVI2KzQrMGNH?= =?utf-8?B?cnN2NVU0bENodXozUDNwaGhXYk8xaktQU3JXSm1Kb0svbXdUcHZsRnFoVXI4?= =?utf-8?B?MG5HU1ZwY0lQK1l6d2xxQ2JYNGJ6UnhWUjFKZktNdEtkSFdjZE5yUzRCdzhy?= =?utf-8?B?algzeU04WjQyc1UrTUNKRWR2Tkd2YVNlVURybnIxSXhjMUp3K0p1Qy93d0xr?= =?utf-8?B?elNCaTg4RnJpbnBvYnhDbjFnbXk4a0JoYVRjdnVlTXo3QkhaS21WaGJnb0RK?= =?utf-8?B?Qk54U3VlaGJuWlE3eXJkZkxCZGZEMXRzbDlaNy9yRmhuTzVvdEY3Zz09?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5fb2b5f7-0658-45f5-c0f4-08de4a6dec29 X-MS-Exchange-CrossTenant-AuthSource: DM3PR12MB9416.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Jan 2026 02:15:10.8679 (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: Mmf+ZUoiNHoNNmrv6kgEI+9F2ibp45JB3aPvcPwR/VOp04LINme4iwb39CNfC2lOnNjNJh5fnO5ZSNnpktUObg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB7358 On 12/5/25 8:47 AM, Joel Fernandes wrote: > On 12/3/2025 12:59 AM, John Hubbard wrote: ... >> + // TAIL points at last DWORD written, so add 4 to get total size >> + (tail - head) + 4 >> + } >> + > > Can we harden against integer underflow here? Even if tail is always >= head in > normal operation, I think we should prepare for underflow due to misbehaving HW > etc to avoid producing a massive integer, how about: > > tail.saturating_sub(head) + 4 Yes. Fixed in the next version, thanks for spotting that. thanks, -- John Hubbard