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charset=UTF-8 Date: Wed, 08 Jul 2026 23:13:08 +0900 Message-Id: Cc: , , , , , , , , , , , , , , , , , , , , , , , , , , , "Bjorn Helgaas" , "David Laight" , Subject: Re: [PATCH v3 2/8] rust: pci: add sriov_get_totalvfs() helper From: "Alexandre Courbot" To: "Zhi Wang" References: <20260701062622.3499033-1-zhiw@nvidia.com> <20260701062622.3499033-3-zhiw@nvidia.com> In-Reply-To: X-ClientProxiedBy: TYCP301CA0028.JPNP301.PROD.OUTLOOK.COM (2603:1096:400:381::11) To CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) 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: CH2PR12MB3990:EE_|IA1PR12MB7520:EE_ X-MS-Office365-Filtering-Correlation-Id: f4217523-4898-4297-7cf5-08dedcfb0b42 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|10070799003|23010399003|366016|7416014|376014|11063799006|6133799003|56012099006|18002099003|4143699003|22082099003; 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>> + >> + // CAST: The C helper returns `unsigned int`, but the value ori= ginates >> + // from TotalVFs/driver_max_VFs, so this cast cannot truncate. > > nit: "from TotalVFs/driver_max_VFs (which are defined as `u16`), ..." > > With that, > > Reviewed-by: Alexandre Courbot ... with an additional item for thought: in a previous revision [1], I had raised the question of making the return type `Option>`, as I think it better encodes "0 if SR-IOV is not available" - callers are then forced to consider the dichotomy of the result, and not interpret a particular value as having a special meaning. OTOH, for all practical purposes 0 VFs also seems to be strictly equivalent to "SR-IOV is not available", so please take this as a nit to consider, not a blocker. [1] https://lore.kernel.org/rust-for-linux/DETDILPA1GFY.27WND0TEC5352@nvidi= a.com/