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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3762C63797 for ; Wed, 11 Jan 2023 13:41:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232339AbjAKNlU (ORCPT ); Wed, 11 Jan 2023 08:41:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239351AbjAKNkJ (ORCPT ); Wed, 11 Jan 2023 08:40:09 -0500 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2042.outbound.protection.outlook.com [40.107.244.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA4DD639A for ; Wed, 11 Jan 2023 05:38:42 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=KgJNk/OfP5/sgu0QN9gxPPobP408t6U+wpyciqzfSNHkJRGrVJvtPQVRf3CmHu3hmuZ7TUQW1jsDcHzwa0MNAIbyZ9/oZ1lhuvdeecgh7eoqiV1Y1x5gkIM3TQBB4cMwN7gHOCi9R6mVgwoLPGD2EoACgbb6w/EKV9Jm6kEao7Gk3Tb0rGF0Pg9qEkCVt0GKItI09ph+T+JbAJYmldRc1hMAPct0ldHBqDFmk+a8GX/La/6lPqeZN/2CEhwR56hNxhvayKdEIbMNRA+kgENi3J9rqNdzDaKhVctCH+yyzFnTjs6W+gylGJE3n/EVC+CY5xMAO0I2oiVIL8rNIQZQww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=RrvlZAdzuwKa5hrj+EjQhRDwCkiwN/+I+C9fbt64n64=; b=B2IMMymg6ilOKdgt9kly3gApRFLHt05R9kvDLw+XQjJb58eCkAshBxi5+OHJLHlMhQO1A8IvlgFxCAL+18NhMv4H8EX3Odr1hQtxhV16zd6C7qA9OAHZ+kGT8rqYWDtQcUq9P31D3rLKw/mgJX+JiEfx1yM8DYGLyst/g5kjLoSiThj7M2b1YOsnhU8kfF7+BGDDkAzjSD9PZKCJzWopIp43dTkPjonKhIm0paip/YF1kTM4QpzgjDevjDegW3rgW29YgAH8+6COCKUt1z7NrjRwX2I8tpMK/iUHf763yYOJS6viHSTNX2Z9Jg2zR9KjhfO03UaqO06l39+ruYemQw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=RrvlZAdzuwKa5hrj+EjQhRDwCkiwN/+I+C9fbt64n64=; b=Cxx693mbixh2InKRxkCKGYH3boW97wMM2w4YfGStEUlrnTu1JFRNsnmDuVo2TwlNpfRaoXX6I3w6RRxqu8tZl7XYk3Fu/Mj6hKuLWBwED15vm9MNG53VOdP7HQlbgzQ9qryr8BjeqlevVDoX2ncU9Xz4SOoHX9EAhM9vRnRdemk= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BN8PR12MB3587.namprd12.prod.outlook.com (2603:10b6:408:43::13) by DM4PR12MB7693.namprd12.prod.outlook.com (2603:10b6:8:103::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5986.18; Wed, 11 Jan 2023 13:38:41 +0000 Received: from BN8PR12MB3587.namprd12.prod.outlook.com ([fe80::80d8:934f:caa7:67b0]) by BN8PR12MB3587.namprd12.prod.outlook.com ([fe80::80d8:934f:caa7:67b0%3]) with mapi id 15.20.5986.018; Wed, 11 Jan 2023 13:38:41 +0000 Message-ID: <0da0f213-5d6a-c692-b9f7-9babb40adc96@amd.com> Date: Wed, 11 Jan 2023 14:38:34 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: [PATCH] PCI: revert "Enable PASID only when ACS RR & UF enabled on upstream path" Content-Language: en-US To: Jason Gunthorpe , =?UTF-8?Q?Christian_K=c3=b6nig?= Cc: linux-pci@vger.kernel.org, Kevin Tian , Lu Baolu , Bjorn Helgaas , Tony Zhu , Joerg Roedel References: <20230111085745.401710-1-christian.koenig@amd.com> From: =?UTF-8?Q?Christian_K=c3=b6nig?= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: FR2P281CA0048.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:92::19) To BN8PR12MB3587.namprd12.prod.outlook.com (2603:10b6:408:43::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN8PR12MB3587:EE_|DM4PR12MB7693:EE_ X-MS-Office365-Filtering-Correlation-Id: 7dfdefeb-8017-41ac-6631-08daf3d926c9 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BN8PR12MB3587.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(4636009)(376002)(366004)(39860400002)(136003)(346002)(396003)(451199015)(86362001)(31686004)(2906002)(5660300002)(6666004)(36756003)(8936002)(41300700001)(66556008)(66476007)(38100700002)(8676002)(4326008)(66946007)(83380400001)(66574015)(6512007)(31696002)(316002)(2616005)(110136005)(54906003)(186003)(6486002)(478600001)(6506007)(43740500002)(45980500001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QTR4a2hWYmpFeDRmT2lNa2RtQVZrbVNCSm9aNmxQQVRoVnptaGRhRU51OEts?= =?utf-8?B?SWRJZXZoQkFXQ1MydFo1dnZiYVM5VDYxaDliMlhyRUhVN2tabVZPUWV1eUJO?= =?utf-8?B?ZkNKNWZkQ3pxdWNMcVhRemxNc0RWNlhBSTNXQ3cvSE9SVE4rMDlOSENhbUor?= =?utf-8?B?aVhpV0RiaHR0Ly8zZzNsUUg4UjdqaGlYL0VxcWRCb3k3YTl3eWRjSEhrb2Qy?= =?utf-8?B?N05MUUdnQzdIMDBhTE1vdEc1Slg4djdod3RYMUE5a1Z3WDU2VENUOCt3SWhM?= =?utf-8?B?ZG54bFN0UWUzVmlCWTFrZnJTdHpGNFlPMS9naUtUOERieFlMZkpmWlRUM09K?= =?utf-8?B?R2hRMVltUnczcmZnNE91VHFyV0xzUkNPMTJGdEx0bm9lcUZJN0VKekw3SWsr?= =?utf-8?B?N0VyWG9JYmovMERzZlFOMHRqa0xjZWlvcDBpdi9kUWpLT0R3QmUrR0EvN1Jv?= =?utf-8?B?a0NCK3NUOVlHNGYxSDhObFBwdWJ0WGIwQml2M3VyQ0dobnpMTFpKdysyLzlK?= =?utf-8?B?dUdwc3ptb01xa09YUGFTR0N0dndaNWlLOU1RKzNKd3oxS1k1b0VRZk16bEpG?= =?utf-8?B?Y01kUUtlSVRmYlZ4Q2VRS3BJbFk2MEVpeW9VZG0rUW9tOWRxOCtOZXZaRHE5?= =?utf-8?B?QlI0dG1Hb1Npbmp0aWdMcnBWWGVaVURiVEorMlJDSGxxbFZpeWdHTXpveUgr?= =?utf-8?B?cHZrMTdEdnYxWXhRQ3hEdlozaWhmTE9WWThkTjk0NXFDc1FPaFhrWGlVaXBk?= =?utf-8?B?WmdBSXdhd05zeStzRllNTWdFTUJ6NmkrQ0V5aktKVk94NzVDYVRnMjJ4b2hH?= =?utf-8?B?TG93bTVsTlNXaUY5QXArWWt6aDE5OGx3ZWhUS0tpRmpzV2NLK1UrL0cwQnM3?= =?utf-8?B?WSsyRC85citaQnFrYThBbzZBUHlsZHZrbVc5cDE5N1B1cFhMNWZIS2tyYytQ?= =?utf-8?B?ZU1pcVl4WVZtazk1K3N1UkpvNU5UbG9vNzFwNi9ZQ0dsODlkdG1IdWNvbVZ0?= =?utf-8?B?bTVsdHlXYy9sVzVCamczKy92elBtN0ZEbFllQ2lDdjV6QkhzZ3NPd3dXcnpG?= =?utf-8?B?T0FWZEE4d2lqTlRSTWxqdmVsRHI0cWFEbmZ5WHZrREVrL2lwQ0VoMUs0V3NJ?= =?utf-8?B?YmM3amV6R3VydjR5UEI0RThkNkU4aHdGVGRuNVYvSTRJemJZUWhKUy8yMWNJ?= =?utf-8?B?aDdHdGUvNGRVVW53RTU3Q0xXRm9xREx2MHZOYXVwRGhFUGU5OTVhcDBudWF1?= =?utf-8?B?QjR1eGFvTS9SaWM2VGlnaTltcTUwd1Q2dS92alpKUVp6MCtrcDUybG5MdjE2?= =?utf-8?B?VFZlci8wTVI1RmlZd1lSYUJBdXhJSU9iSzMxOE1wU3hhcXRpWDY5TVFQVmp5?= =?utf-8?B?NlM5UUVubzdvak1RaFNFeWYxQWhqTHJWaXdoNTZybXFQUHJnNEFKWlNSSTA4?= =?utf-8?B?YnhBK251dVFiaFF1Nk5LK3FEbHhmWWM0US9jMWN5OHg3QnZhTVNveXpkQ0pn?= =?utf-8?B?M2FpYTREQ1YydHZmSVFOOEo0WDBxK2E3OXV1dWFjQWdlSnJ5SEVhb2xROUpu?= =?utf-8?B?SG1aQmtZMHpIL3NNc2FHMDI0b2d4T0hhMFJSdDlnTkJRbkNQMXYwTE42L0Vp?= =?utf-8?B?VjFOWjFzK2RSOWU5aVhha1VFOTNNZEdNNWpkWkt4WnNrT3pQK1R3czFKOWNn?= =?utf-8?B?QlJQS09yL0hNa3N6bERDR09jelV1RWtHTXZwbjlUclFranhzczBLNEFWdUxn?= =?utf-8?B?MFJ5YVhENWdVM0F3dW5yK0ViSHB1V1d0bXJaWlRoVmhHQ2YvdiszTytPMlA1?= =?utf-8?B?WGthd3pMb01WVDgrUENwZmoxTURqVGRuZUdvUFZCMHdXakxBbUlVZU9LemtZ?= =?utf-8?B?RE54VmlUWEtOUnJEUWY3RjFDNjNnbjZVb09US2hYakluTnhrZFBENW14RlA5?= =?utf-8?B?RmNyVWVIY3doVWgzMkc5VUk1c2lsSlBIT0xMODZqN0Y5dURLSkN6QUQwQmgv?= =?utf-8?B?MXhXMmR2bElaS2RidC9uckEycUN1UzR0RzFJVEpzUjI2U0hJVFhkaDRVdGNx?= =?utf-8?B?emlDc3hrK0w4bFQvbTdKWld2dnBrUlN0ZnlVb3JtUC9xM2dIYU52WWJrUDAy?= =?utf-8?B?NFluL0JhdjNzNEVCMlZDTkphTTBKclBRbXRabXB4M2JSRkRTUVl1Z3BLV252?= =?utf-8?Q?cIZfhOZI5iDFncQPXmfiz9igFn03cEkweZ02lXopdeUJ?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 7dfdefeb-8017-41ac-6631-08daf3d926c9 X-MS-Exchange-CrossTenant-AuthSource: BN8PR12MB3587.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Jan 2023 13:38:41.1782 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: IgFJunyEAHKyQT6XRO6dg33vMSIdM/Q3po7ZTj1ZZ4TiR1SqHN9hR/U1GAJrq2Rn X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR12MB7693 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Am 11.01.23 um 14:07 schrieb Jason Gunthorpe: > On Wed, Jan 11, 2023 at 09:57:45AM +0100, Christian König wrote: >> This reverts commit 201007ef707a8bb5592cd07dd46fc9222c48e0b9. >> >> It's correct that the PCIe fabric routes Memory Requests based on the >> TLP address, but enabling the PASID mapping doesn't necessary mean that >> Memory Requests will have a PASID associated with them. > It is true, the routine assumes the device will use untranslated > requests with the PASID. > >> The alternative is ATS which lets the device resolve the PASID+addr pair >> before a memory request is made into a routeable TLB address through the >> TA. Those resolved addresses are then cached on the device instead of >> in the IOMMU TLB. > We should pass in a flag "device always sets the translated bit for > PASID" and skip the ACS check in that case. > > The ACS check is not wrong, and it is definately necessary for devices > that do not guarentee ATS and PASID are used together, we should not > be removing it. > > Given adding the flag is trivial we should just fix it, not revert this. Well exactly that's the point, adding this flag is absolutely not trivial as far as I can see. We need to go through multiple layers of abstraction since this is the low level function and nothing high level. Additional to that the check doesn't seem to make much sense to me. pci_enable_pasid() is called by three functions: pdev_pri_ats_enable() in the AMD IOMMU driver while enabling ATS. As far as I can see we absolutely don't need the ACS check here because ATS is a must have. iommu_enable_pci_caps() in the Intel IOMMU driver. This also does some handling for ATS, so here we could check the info->ats_supported flag if ACS needs to be checked or not. arm_smmu_enable_pasid() in the ARM IOMMU driver code. No idea what this one does with ATS. Here is the only place where the ACS check might make sense. So even if we have some need for this check this seems to be the wrong place for the check since not all necessary information from the higher level is available. Regards, Christian. > > Jason