From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 225AFC3DA7F for ; Tue, 13 Aug 2024 02:57:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:In-Reply-To:From:References:CC:To: Subject:Date:Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zkHI70nbNbyTdN9bXqyo4v/CKoFxlSq2XfL0V5qeLpc=; b=Jl1zvJd6pQ+NrjaJ+D/ESBDpVQ OnpTWCECULt6RfZzhlfeFWfw5myvR6QsB3dShnEi9gboY/tRUchIhY7P78M0kDPhjx7B4W9Dho6Zj rIAf39JL1F4RuSd1sJs3GPEMZ1AOibYAsmeYH/3G6ZiDLywMimG+oUF0t26M5udSgLXLi/JTShXZ7 gh+L8RmB5GCxYNnWTWHDvbZO8Lt8c0izF+HKSEgmhiN13ffE5w2vqMsJgl9AjnymBZZ3sBKu04vt3 WHQb6to14iuct1Jpt27fUguyPXRus03s1yNu22sTYw+yxZP+npqC1erhv5ez212mmNjLQzR5JlYOw qUDVca7A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdhin-0000000298o-2d94; Tue, 13 Aug 2024 02:57:17 +0000 Received: from mgamail.intel.com ([192.198.163.18]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sdhiB-0000000293x-2yJB for linux-arm-kernel@lists.infradead.org; Tue, 13 Aug 2024 02:56:41 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1723517800; x=1755053800; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=UTjJNkznowLsc7Umy9GZnfwBSD1nb51ZQRUpos7Fmy4=; b=ERT5FcakcDPp1Yhbcu4/jBkxqSEnG1oIy8EYKUcyVSmkwSvrQ60R9j3B zL72QcJxPKJnauz6MmQ69GDzlPVNcokGhRDIbMGiOxOeQsbmwmo8yXNZ2 3MbLCDu/Of6QA45r4Yfa9OcX5yhaGe6WLQF6Tl7dCYlwZF59vGbmAwkww fMzIhhfz4Qui9WYRo5IrlzE+GDgAiaLgXjTepWxXCqY6HftVaaBiOSCxO 7aFCGYR1hKYQyuYnncRtRwWuQu/dceLbqr1DV0X2hfShSTUZPFV8Q6PfS uPuBMNjUPF4msaLjuNLOS6UF/nfFmqSb6UsB623MGIVxcaewJNktniFsE A==; X-CSE-ConnectionGUID: DlrB3tGyQROPBA9WHju+xw== X-CSE-MsgGUID: 0FZkF5BLQWaMEiAE04s+hQ== X-IronPort-AV: E=McAfee;i="6700,10204,11162"; a="21218869" X-IronPort-AV: E=Sophos;i="6.09,284,1716274800"; d="scan'208";a="21218869" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2024 19:56:35 -0700 X-CSE-ConnectionGUID: iiaLH/UsTZyMrN6/vE82PA== X-CSE-MsgGUID: Hu3jrnOUQfC9ZnxmF92Fmw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,284,1716274800"; d="scan'208";a="59255898" Received: from fmsmsx602.amr.corp.intel.com ([10.18.126.82]) by orviesa008.jf.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 12 Aug 2024 19:56:34 -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; Mon, 12 Aug 2024 19:56:33 -0700 Received: from fmsmsx601.amr.corp.intel.com (10.18.126.81) 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; Mon, 12 Aug 2024 19:56:33 -0700 Received: from fmsedg602.ED.cps.intel.com (10.1.192.136) by fmsmsx601.amr.corp.intel.com (10.18.126.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39 via Frontend Transport; Mon, 12 Aug 2024 19:56:33 -0700 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (104.47.66.44) 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; Mon, 12 Aug 2024 19:56:32 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=eDihqw9mSPrqE3OckF6XwZbEYSTOpQgT/Hf38EkgJsmmWZqHHQ71gOgrzE9oZdrEKMpagoLJ+akAPkDFTQf0vaomj3CQvFyuwnOVhopDS6ge58dYyKqz4GaKRJ37Z0mEQKcudNcA+SJu82s7Wh47Cqt5caGnjWnx1B5twLeutZGC+YK4xDZQzgKnU8GbJEsZHPaC8HAsGo15nVG1F+1Ma5QdKLPwxmCi1fAxvDotWxLI4v6REKnW6jNBlmkw1Zut8ZMn8D+sr/GbTGMeO4B91hYM90FHlQZ51oOZRGaQ+YjUWm8FkRrjfNDOQokzFYXuRVsI6KZS6wf1qS0SQDplTA== 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=zkHI70nbNbyTdN9bXqyo4v/CKoFxlSq2XfL0V5qeLpc=; b=T2zJUNiyy+UccnNZkwm7WpA0vPRxCdKReYmqxMZRatipg/69lIOl4c6IbWyDOVhyM/uqEt019p3TZJHW6RdultXJVU9cV73j4MGwR4zzogNlF3UqNJcQrXDJWQSOLerg0QPpsHQulgTCB+jTiCCBjbXWZ3BHgrExznG+78WLNXVXniJzi0zupBhzpp77oUCz7+GwTpG5HeZqGAMGy8qh2ml0KgAOiYCgFUxRmxjnfob1QmLzusS2m/uwSwWwyAm3g3urFUwuBOzW/UGYyswqpyyGMJtu9u0sj5RUp6Ot7qqBGlXPDrnEHYQ/0KVqPdMVSkB94W5zYdF5GN0E2okEOg== 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 DS0PR11MB7529.namprd11.prod.outlook.com (2603:10b6:8:141::20) by CY8PR11MB7083.namprd11.prod.outlook.com (2603:10b6:930:51::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7828.31; Tue, 13 Aug 2024 02:56:31 +0000 Received: from DS0PR11MB7529.namprd11.prod.outlook.com ([fe80::d244:15cd:1060:941a]) by DS0PR11MB7529.namprd11.prod.outlook.com ([fe80::d244:15cd:1060:941a%3]) with mapi id 15.20.7828.030; Tue, 13 Aug 2024 02:56:30 +0000 Message-ID: <77197bcb-574e-4f46-87b5-1b1fe4a75e7f@intel.com> Date: Tue, 13 Aug 2024 11:00:43 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] iommu: Allow ATS to work on VFs when the PF uses IDENTITY To: Jason Gunthorpe CC: "Tian, Kevin" , Lu Baolu , Bjorn Helgaas , David Woodhouse , "iommu@lists.linux.dev" , Joerg Roedel , "kvm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-pci@vger.kernel.org" , Robin Murphy , "Suravee Suthikulpanit" , Will Deacon , "patches@lists.linux.dev" References: <0-v1-0fb4d2ab6770+7e706-ats_vf_jgg@nvidia.com> <20240809132845.GG8378@nvidia.com> <880c1858-afee-4c30-aac5-5da2925aaf11@intel.com> <20240812113555.GP8378@nvidia.com> Content-Language: en-US From: Yi Liu In-Reply-To: <20240812113555.GP8378@nvidia.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SI1PR02CA0029.apcprd02.prod.outlook.com (2603:1096:4:1f4::20) To DS0PR11MB7529.namprd11.prod.outlook.com (2603:10b6:8:141::20) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR11MB7529:EE_|CY8PR11MB7083:EE_ X-MS-Office365-Filtering-Correlation-Id: 857e391f-3e6c-49b4-34c0-08dcbb438860 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|7416014|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?RG45bTcwUlNWWjlodUNBSTdWN0UzQ2o0dTRoQ2N2TzZuZGxkWEhIb0xnRDN6?= =?utf-8?B?UmZOd3U5aDV6RnZSTFhwUVdmalg2aWh0MGJMY3VjWkhJbnhhM0lvYXdkWlpI?= =?utf-8?B?QTd1UGdrc0RNTld6TmpRUzQ1VzcyRFZyTjF6ekcrd0tic2VrL1dtNmZsbkF0?= =?utf-8?B?bUV3d2ZYaXltdVp0TXlacUIxMUgrKzhNakhMN2dqVVFvMS9td1NHczRFY1I0?= =?utf-8?B?Z054bitEQ1JZVk5vWjRudVJSRmdKMUZ5azlFVWNzTEE4emRRU1h1TWh1Ylhx?= =?utf-8?B?elBNbVVjVmFPcXVvc1Ivd2ROYzd3aVRyZHBTOG1XRXlYeGFnM083bEZhd2po?= =?utf-8?B?bFdlcTNBbHNoNjNMWEdmOGhCSFlnQVhaWjBPMHJVTU1nc1VrTzVsaVBOOVg0?= =?utf-8?B?clk2c1dDSnV1QmJ0K2MzcEYxcWk5TjNqNFFhREN3ejdzSzJ3dm1kQUZ1WEQz?= =?utf-8?B?THRnUTk3bkRIeG5nOC9pVis2OEQyU1Jaa3JCZlhWUEhHZS9qZlEwT2VZT0lH?= =?utf-8?B?ZmRJZ1hMQmpHSzZsRzE4NjFaeFRmeGJaSFB2OWgvTXRHMy9CV3FiV21aWXhj?= =?utf-8?B?SWExaGV1UVEyNlpHVGVFeWdSL3VJaFhoWE1qMjJKTkJZK002OHMzWVZwUTRk?= =?utf-8?B?ZTVwZFRwMngxQkluMld4V2ZXbTErN1h4cXRLRE45R3FTTDdBU3dEZWNLVGZZ?= =?utf-8?B?L0U2Z3ZFVEhJZEVLeVVSSkY1OXo3aEtSUXJQeE1zQWVVUjA2R0FRNFFNcHhN?= =?utf-8?B?b0pPa3dGd1lWZ3N5YTEyUDRyckVtVzBLbnFjQ3liVktYaTNHVG5RRUhTcXpw?= =?utf-8?B?dVAxM0Z3QlRPYUk5K2Yrd2F4RTBWdUJpcUI0T21lREhJcCs3Y0ViaDBvRjRh?= =?utf-8?B?alkrYkxaUHVCVVQyVHB2MzAyTmZmSm9RUkZsQUNnMk5tZENPVUY2S21aN2dJ?= =?utf-8?B?WDBEUFhkMy9xbHdoZEFDMU9zUHY2KzBqaTZoUkRKbDlMaDJzZmpBVDFORW54?= =?utf-8?B?M3kwdWdSQURidTdsNkYwSlZNK09Ib1RkR3EvYldWZE1Mc1pDOXcrZTRUcHE5?= =?utf-8?B?UUpMYlN0Q3Bnc3krVjN4aVhaaFV0RmxhWnlyazlMT2JpMmFraUJNdXJXOVpR?= =?utf-8?B?ZDFuS0RRUUxsemY0QWg4UmVFQXUxb1ljaVNKM2NCdVFra0p0TlZESUhiNXV0?= =?utf-8?B?TG0zaWc1RkNvdFNFUHRUYVNhR2JVOVQ2MU5FVDBSRUdMOHZ1bTd6cnJqVFdJ?= =?utf-8?B?NENhZ0txRllxRyt6eG5LR3hBa0hMZHFyaHhqaEhRRFk2dEF5MWx1RHY0ZDln?= =?utf-8?B?V0hTYkRYbFAwZVh1RkFEdjJxZnZpdnVwMkIzVzcwRFN3enJtZWRqL1hma2Iz?= =?utf-8?B?SnI5bExRWGlZYmxnb3p5QzFYU0tiSmtMbzlnajN4WDl5OHU4N0wydDRKNGpo?= =?utf-8?B?eGlMV3BPanBreEJtSEJRSFFMZ0hadlZFUGdabkRRVWxCVkNka3A5VG83bURK?= =?utf-8?B?aHB1R0YwYW1SWFZ4aTNrSVBvdFhsNWZkOEpaOTIxenljRldmSVVJQzNHNXhs?= =?utf-8?B?ZGJXMVVzVzB5aFRLc3hNd3N3NnRWNjJhS2hneGhwenp0cjZOMW4wWjBJdzRO?= =?utf-8?B?Z2xndnpLeXF5aE9nS2hhaU9jK1VpNUdPSXY3YUNSSzVlOEdMN09ScHhqOVlG?= =?utf-8?B?akhsdXphdHN5aGp2c2ZVR0dzV3F1ZkpUVGlPMlZoTWZ1MnBITzc4VTJrQ1M3?= =?utf-8?B?RjdpcEpkWWtpdDFLMnFJekV1cWZkTkhDSmdyREdNbm9ySUVIZmhuVGN2RTFG?= =?utf-8?B?Mk01V3FLM1NyT09VRHNudz09?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR11MB7529.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(7416014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?WTQ5QTRESGJkUEJmVWJaSkFsZWl6cmNuTEd2a0dRZlFnWjliWUY3RTdRdnhI?= =?utf-8?B?SG14U3I2ZVJWdlhKZ01xcDZHWnNrRENuTXFLZm92c011Yk5NeXV0dXlrSEIv?= =?utf-8?B?NDUreC9qUUVlV1dBNFVQeTZQcUVVNXhwb2pYOGlPVFJqYXZXMHlISDlMMXZS?= =?utf-8?B?a0szY1ZrUWxCcXFZdVNyYzRrVndzN0RmWkkvMUdCeDh6ZzA5VThyOXNOM2xF?= =?utf-8?B?ZE9JR0pDZDZLd3cyR2NtYzFDYnV1OFFSbGpLMVhoVWg5R3NSWGVjRHJJY0dS?= =?utf-8?B?V0VEWHRZdkF6VERCQnA1YnhNc0J4eldteEVrbmYzRWM2WmtRNFlNMmFldFpj?= =?utf-8?B?UW82WW9MZjFjVU5JWmlCQnY4ZVdpMFRiV3J4ajE3bzJramN3UWt1cnhMYk55?= =?utf-8?B?YkFRb0dBNktTVmJQV2VUbTlqOWtjTTZ3Sm9TTTR3NnBUcW9nckhXU25RRXZl?= =?utf-8?B?KzNxczBpaVcxd0IrRVFnYmVzRUZWNVBPMnVYTkhwUjltbldxL2dQWEtFUlRT?= =?utf-8?B?czdRaHFtYWZDNG1BdEZBL21yVTFkT3BudHpZTjR5L09aQmZlT1FvWEFqem5m?= =?utf-8?B?dm12RVhRZlNUZU5NdnFCVHRLQjl2OWRKZE1iQVlBYXZ5SGtMVWRENnJFWkdH?= =?utf-8?B?N2VOWldzWGtFM011MElNREc5dlQzWkpROGUrTkZxcStGUmpkcTVvdW9jUGk0?= =?utf-8?B?eXN6SnV2Zng3emJubFZpQzUzV3kvekhyeldtZDhKbHhad2NselRuUXJxMmVK?= =?utf-8?B?OGtqMXFCRkhGc3F6TDJ1VDF4Mmdkd29laldGaWNxYUo5VjVGYVVBaXVwT2Jl?= =?utf-8?B?QUJTTjhtc2lzVXlLbzdwR1NZZTdNNnZHU0NhWHVUeEFtMHNJWW5vZTFyMXRK?= =?utf-8?B?MDBjMHo2ZXlFeVViWEJRNU4wV1RYYzdNSUprS00wWkswbEUwcEZNRmNLd3hW?= =?utf-8?B?TjlEWTdiVGpFS2x3NHZ6YkN5UkFjWkwxVDFKQjlaUDhQTmFNVU8rcmlkNXlG?= =?utf-8?B?L2xtekxibjh4Z2NmcFQ1bjFJbUpoeTlpVmR3RU8vK1hIOEhmVThqL2lvZFJC?= =?utf-8?B?STFLWEIzVFBBd1oyS2ZNUUF2YTV4amFRNlNpUitld3ZCdm5aNC9CNTAvUnNp?= =?utf-8?B?OXRHdURucE44aG1raytWVXdsNmYrQS9SSnJBQk82M2Q2VHRGOW5kRkhwajU0?= =?utf-8?B?Q1VTUHBUTFU4TFI2WXFGUGpEUnJYMWVkSzBtMUhjU0t5YzdCeHpUZ2p1bEd0?= =?utf-8?B?ZDNlUXhNUGtlaERGZ0hjN0NjN2tYNW1QamM3Z0ZUOGlZRndmSkRvRml6T2tH?= =?utf-8?B?K3ZuTVZ2ckdvTjJMeFJzcklwaDJKWlh1UUx5MHFiRVB4b3hZRWJYMUlKTWlR?= =?utf-8?B?TkQ2cWhXay9PbUtEQWtEdURpbkRmTmphOG1IQ0cydS9Nc3lnQWtQU1ZzN2JN?= =?utf-8?B?WDdBUU5neW1zdHNwN0RQYzlUVmtyS3JyaGZFN1IrUUx6YTR6Q09SSGNaeExW?= =?utf-8?B?Y3c2V3B3NGRBNXdmTjZWZkh6aTFwbHJlNTVuZVBYY0t2RGpwTzRiRTJReXRM?= =?utf-8?B?S0RSK05yNm01VC9LQVQxbGYzWnIxNFBNeWxVeW5BeUhKZ1ozMEpSVVZ0ZHI0?= =?utf-8?B?NHk3M0JPZnF4WUlTZzVQYU15d2hXK2dCUWk3aEVHRDYvN0lKbll2ZlFDMGd4?= =?utf-8?B?QnRHKzUxK1FrdnZtc3l6SmRlYWxYbmNKL1o4aU00a2poUXMvYVhDMWxIUFI3?= =?utf-8?B?bDVEME5KRXZ2bEdDUWdSVWh2WGtvSzJTUzZDRzlKc0hyZnNOR0lpT3RhaThu?= =?utf-8?B?amhhTDdBWVp6dTJ2ZnN5dWk1QUFLU01seFIxbnk5ZlI1R01SeWZyQzIxNmdq?= =?utf-8?B?eTAxYkFOeG00Y2dMdU5BNXJmbU82aDdsc1FwM1I4cmYzNko0Q29BYjV4b0Zw?= =?utf-8?B?OVFja3BMeE82c2p0Y0JtQTlLTkxEM3o4NWgwbDU5NkoxV3ZJdzc5TGd6UGo1?= =?utf-8?B?a1B5QllBTnhBRm8wditSVVJpbjBvbFN5bUYzN0hmdS9kc0JlWkEzZkwrQmZI?= =?utf-8?B?a093cmJYK1RoOGRJUytVcGpTbklTRTdwYlVJNUlIbE42UG5nRlFWQ3V3ZW92?= =?utf-8?Q?NP58YsXXvrP2J7NbIUFS4NYFe?= X-MS-Exchange-CrossTenant-Network-Message-Id: 857e391f-3e6c-49b4-34c0-08dcbb438860 X-MS-Exchange-CrossTenant-AuthSource: DS0PR11MB7529.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Aug 2024 02:56:30.7993 (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: 4Yvnpvo2jPg2OJiWmJWjz87R8kQ/TyFT0jyC+MKolSUSQAf9Ok+GoHRM9YFP8YuA5vVLmgLy51/i3nFq2IEeEQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR11MB7083 X-OriginatorOrg: intel.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240812_195639_801101_E1E7F9DA X-CRM114-Status: GOOD ( 18.67 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2024/8/12 19:35, Jason Gunthorpe wrote: > On Mon, Aug 12, 2024 at 05:03:37PM +0800, Yi Liu wrote: > >>> The PASID may require ATS to be enabled (ie SVA), but the RID may be >>> IDENTITY for performance. The poor device has no idea it is not >>> allowed to use ATS on the RID side :( >> >> If this is the only problematic case, the intel iommu driver in this >> patch could check the scalable mode before enabling ATS in the >> probe_device() op. In this way, the legacy mode iommu would keep the old >> ATS enable policy. > > At some point we will need to address this.. At least when we add > PASID support to mlx5 it will need something since mlx5 is using ATS > on the RID right now. > > Supporting ATS with the IDENTITY optimization is a good idea in the > IOMMU HW. The HW just has to answer the ATS with a 1:1 TA. looks like Intel scalable mode would allow ATS work even device uses IDENTITY. Below is what spec says when PGTT is PT. Chapter 9.6: Untranslated/Translation Requests (with or without PASID) referencing this scalable-mode PASID Table Entry bypass address translation and are processed as pass-through. > Next, telling the driver that ATS is enabled but doesn't work on the > RID would allow the driver to deal with it > > Finally, doing things like using IDENTITY through a paging domain > would be a last resort for troubled devices. yep. It's another issue then. -- Regards, Yi Liu