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 smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 E325FC433F5 for ; Sun, 12 Dec 2021 23:34:39 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 771A060EDE; Sun, 12 Dec 2021 23:34:39 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id IeoK6VRWLbii; Sun, 12 Dec 2021 23:34:38 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTPS id 6181560A8E; Sun, 12 Dec 2021 23:34:38 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 25E0BC001E; Sun, 12 Dec 2021 23:34:38 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 93EAEC0012 for ; Sun, 12 Dec 2021 23:34:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 7B365402DC for ; Sun, 12 Dec 2021 23:34:36 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp4.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=nvidia.com Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id w-09eKo98B26 for ; Sun, 12 Dec 2021 23:34:35 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on20627.outbound.protection.outlook.com [IPv6:2a01:111:f400:7eab::627]) by smtp4.osuosl.org (Postfix) with ESMTPS id 77041402D3 for ; Sun, 12 Dec 2021 23:34:35 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=BIVQkiHGhwTzCGqmw6NDN02BbP1tdOo8ccsuZmM6n78S+ZBu54uSpPzNTRrwarOKXkfXmDk/BtW+ODGdPL0molGsrwl6dHEHcMTnOftE79CeCgkLvkYBCAMVVEy7qGxzWc4fdC0xFFPxzdkNSI4x4Nw49hAczpWzBDcE9YG41sthx99Lnq3EavTNxVdLxWU0p2O1yvxHmhChkjpsfM0N97Gib8Scea90fAt+eKvXcsljms3SPr09JZNbPjQL2vm/jwf9cL6iwQL4Dlgm76jUt4sqG1Kfo/UWxC1zbgQoeBdvhi87tSZ5XeWhnfRR0GRXBwmOh68ZkEIED/0KKw7p3Q== 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=jSXm3V4EUDq6ippmmJvI2c2rchvv0sU9WxGskmACnd4=; b=nBFaqQO5vd32e2K2v6RwKWFysUIzZaUh7yLAKyEtgOc3jRrB+tFEH/mdBVbISZSAGyUjnzeP9AttVrGqph1m9tr+uEoI+ajnzh0Up6flsTLzUkLBYT3JLZsBIvyY4MrZHPmxMWrjwBPBvQGgJXp0gCS28vbxCxMixBf8KIT+RgWljXmCPKGrE+xtMrIcanYbXSaWIXWBc9bH3x2Cm3INIZKGQgzlVbwVQyJ9g4f8VUJgplvAniUkFHJY+yd2D/XeC+DURRT1/oKVsTVf9jqhBINYMU+w0TEVbk2CkOkrI0Pfj9XAKT1Zsb+m7Ha/SXUoPozoTE3M3GM+8PD1OYo+6w== 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=jSXm3V4EUDq6ippmmJvI2c2rchvv0sU9WxGskmACnd4=; b=q3+5EBNg2NHYLtHnhDJpAT16w2YKmmaWfIw88PrnIZN/925mi+i3sNsEY7+IODheKOVki2sBxXOud/7SDaE/jiiFc0fllGTpziR4iSHHpnYOKrb76ypzUBsE1r03BdnWZgD48OflJC9EqZLHHt8+oBDqzJoNeVFN06q0HwCSRuKBXBS1iDsxuFvHxJliHdcLNc9uLBvCCGVdk3QN7/XmuG6Ex92SoAT87CoU2/3iA+qQnsMHXDwaynBpTI7X152gHe/sufGL4yaV+cnPkUcvSo90ztSxDp9OmpP6QVVTbZesREiC1XSuW1ywAKkQ0u/PE344sqjMA/QnbBSwbm4Gog== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from BL0PR12MB5506.namprd12.prod.outlook.com (2603:10b6:208:1cb::22) by BL1PR12MB5157.namprd12.prod.outlook.com (2603:10b6:208:308::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4778.17; Sun, 12 Dec 2021 23:34:31 +0000 Received: from BL0PR12MB5506.namprd12.prod.outlook.com ([fe80::d8be:e4e4:ce53:6d11]) by BL0PR12MB5506.namprd12.prod.outlook.com ([fe80::d8be:e4e4:ce53:6d11%7]) with mapi id 15.20.4778.017; Sun, 12 Dec 2021 23:34:31 +0000 Date: Sun, 12 Dec 2021 19:34:28 -0400 To: "Tian, Kevin" Subject: Re: [PATCH 1/4] ioasid: Reserve a global PASID for in-kernel DMA Message-ID: <20211212233428.GM6385@nvidia.com> References: <1638884834-83028-1-git-send-email-jacob.jun.pan@linux.intel.com> <1638884834-83028-2-git-send-email-jacob.jun.pan@linux.intel.com> <20211209101404.6aefbe1c@jacob-builder> <20211210123109.GE6385@nvidia.com> <20211210100545.373c30d1@jacob-builder> Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BYAPR06CA0011.namprd06.prod.outlook.com (2603:10b6:a03:d4::24) To BL0PR12MB5506.namprd12.prod.outlook.com (2603:10b6:208:1cb::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 40fe12c8-d9ff-4e4f-4649-08d9bdc7f239 X-MS-TrafficTypeDiagnostic: BL1PR12MB5157:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:7691; 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:BL0PR12MB5506.namprd12.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(366004)(6506007)(66556008)(186003)(26005)(66946007)(66476007)(6486002)(6916009)(2616005)(4744005)(5660300002)(6666004)(1076003)(33656002)(6512007)(83380400001)(8936002)(54906003)(86362001)(36756003)(8676002)(7416002)(316002)(38100700002)(508600001)(2906002)(4326008); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Wk52bkpsQStpenFCdEliQTRDUkFZL2pKdnhSakR0SngwL0o1V29rdzB4WlZI?= =?utf-8?B?UHc1bVlZOVkvUmphT09jbTR6R2gzY1FKT2psRzVRbXBYSDhiclg3UzJMOHQ1?= =?utf-8?B?UTZrQmVhRjYrQks1aXlRS3IzZ3paZXVWTnJ4aFIwMlYvZ2FnTDBWc0RSYkdV?= =?utf-8?B?c3pyOE9UVExOUWVoQkJycmFJTUtzYXErN0VpaElrU0g1djNNbms0UUEzQkp6?= =?utf-8?B?bERlT0xIUlBIN1JmUjhFRllZdXdiYlNKZHFFVjROWHpDUG9iSEF4aHNOMVFw?= =?utf-8?B?eWg0NjhiZXdaZjlKYXRXNTl6WmlzY2s3NVdhK3ZmazFIS1ZYQnpxZndoVS9O?= =?utf-8?B?VjNQakMvTGYzWEkvUnN0SDY4OFZ0YlVKdnkyLzlJcjlYZWpOK3NxNk5PWHAx?= =?utf-8?B?QkV5S1ZPNWU1YWoxemZBQmlxY0llbmVVRkpleVZpWUMrZFJIaDhuK0tOZWtT?= =?utf-8?B?ZFZ3VzRpQnJJTFRGeFRmRWdQU292bVlQSCtxRjNLRHZwTzFyNXZTd3NYVUQv?= =?utf-8?B?VFltMUNmakg4emFsM1IrQXRkbE8vWnJMNE1lR01Gekxsd1IrRnRZUklFN0U2?= =?utf-8?B?MllvOWU4akNFR3FBNFFhdHVmdGdnN3h3aVJJK2hQajB3ZXNobXRzWTlONkRL?= =?utf-8?B?N1M5WWVwMDg3bXpFS0lzUnJLYlc0MWRGU21VeGtEaU1LSGpza21JYUNNemxP?= =?utf-8?B?dGx2M1NkVGJSNGlZNEQ4SnptVTdsQ3Jpc0hyTmlCcVRsTDJhVSs1aU5yaWhY?= =?utf-8?B?bGRCLzhDMnQ5c3JQclpCN281RzZqZ2l0QTl4VkVMUUZQR3NCbG1NMTUyQ0Vt?= =?utf-8?B?TTMydUJnK2REQndmRVpreDNGT3FvOTZhSkczZVV4UXV6ZmMxblVtZWhpU2dK?= =?utf-8?B?Nzc4bFBaeDh6QXJxTmNBM0hVcGIvZUdRaWdzVUEwWS9tREFCYzEvQUd6R2pS?= =?utf-8?B?STVWbEVPTlJnamFhcmNzbDd4dGY5ZXA4ZUlMSXcvaW9XTXNFZ205M3NhUFpj?= =?utf-8?B?OW5DblMxK1FRSC91OXkwdC82Wm9ES2NidzhmZm1kNXBQcWs4a1M1TUZRMGlC?= =?utf-8?B?RkpiLzVFdkl5ZWJLUVdQdEFYWm5KRmQwZWR2a1NwOHBlOVd0YWQ4amNlT1hF?= =?utf-8?B?VHJkNkI3dStTZmUxbnNPRWptVTF4dC8vWEFaTXNzQWdwTVdBVFV4SG9Nc2Fl?= =?utf-8?B?SUVOVy9SMHF1K3JQUEJuUjdaNUxWQ2lZbzkrdXJnNnhrSG41cFExOUZNdnFi?= =?utf-8?B?aEZjK0xLbjFvVUFWc3NGK3BZMmlZNjZlOTlaMDA4K0hDMkUzRng5OFptcEFk?= =?utf-8?B?UlR2bU9GUDh5cUoyNVlZa1M5Rld2V3hCQWladFl4VnVWcUcveDJ5dEpLL2VD?= =?utf-8?B?MG5pTk5HTHp5dXVmR2NibFBENTZ4clhCMEZHV1l6U3FRK3VPd3hhaERkdUFa?= =?utf-8?B?dEdTTFg2N1JRcEErQTNTUEE4ZHNSYkgvQ1VRaXR0eEtiRTJvQVlnUThCQlRB?= =?utf-8?B?eHhXTzMzbzU3VWZGQTAwRlp1TTJWREhYcVc0V2loYzdTL05yS0xDc212MzZh?= =?utf-8?B?bnhQNmxEcFN3czRhSmJTVVFWdzRkVk4zeXZmOEJEY1FqOVNuRWxoU1RUS1h2?= =?utf-8?B?MnpNOURyU1dRRklKUUVFdE1nN05hMk52QXBWRENwcWRWVHdyMWtERlBXV3lE?= =?utf-8?B?aWFORlljT0JCNitiNlBkUVRXSEpyMnRnbUhFK3N6YUVuOXcxZW5xZ01LcGpo?= =?utf-8?B?QmhZWjBFQlFLTUVIUXVFZnFqVzdaT1dQbTc4QTVlVjVDcWxzTzdnR1Z6dU55?= =?utf-8?B?OENvNzBxTXZ2Z0pvbGI1VElMQ3NpWEY5Z0haY2ZEdHdyV1lIMGlZRERBTkJE?= =?utf-8?B?ME5qRVdneWJWY2djaWV4TnRoa3huQjJkLzJCRkkwMEIveTY3NGdHRzlQZUlH?= =?utf-8?B?T0dtMjdYWTJHMnBDTndGMkErRU1hUnVVbTFhNUdVNkhyUEpBQ1Z0UXM4MEpV?= =?utf-8?B?QWI1bDcrTThVc05paFMvTjN1UmU0dFhQVytuTjBndUFFWlVMdnh6UStOMDlI?= =?utf-8?B?UEt3Z1YyeWFrRmtEVG0yUXFDNnpON1FXSWFRL3F1M295NFBTaEQ3RDFUTmdv?= =?utf-8?Q?L6GM=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 40fe12c8-d9ff-4e4f-4649-08d9bdc7f239 X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB5506.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Dec 2021 23:34:31.1491 (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: p77fnnE5tx/5TZGE2x6PZhCD3L91wI+8AM2P/dAFWtoYZA4Q9aKBVtoEPPeX3vdI X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5157 Cc: Jean-Philippe Brucker , "Jiang, Dave" , "Raj, Ashok" , Greg Kroah-Hartman , "Kumar, Sanjay K" , LKML , Christoph Hellwig , "iommu@lists.linux-foundation.org" , "Luck, Tony" , "Pan, Jacob jun" , Barry Song <21cnbao@gmail.com>, "Williams, Dan J" , Jean-Philippe Brucker , "Zanussi, Tom" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Jason Gunthorpe via iommu Reply-To: Jason Gunthorpe Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" T24gU2F0LCBEZWMgMTEsIDIwMjEgYXQgMDg6Mzk6MTJBTSArMDAwMCwgVGlhbiwgS2V2aW4gd3Jv dGU6Cgo+IFVuaXF1ZW5lc3MgaXMgbm90IHRoZSBtYWluIGFyZ3VtZW50IG9mIHVzaW5nIGdsb2Jh bCBQQVNJRHMgZm9yCj4gU1dRLCBzaW5jZSBpdCBjYW4gYmUgZGVmaW5lZCBlaXRoZXIgaW4gcGVy LVJJRCBvciBpbiBnbG9iYWwgUEFTSUQKPiBzcGFjZS4gTm8gU1ZBIGFyY2hpdGVjdHVyZSBjYW4g YWxsb3cgdHdvIHByb2Nlc3NlcyB0byB1c2UgdGhlCj4gc2FtZSBQQVNJRCB0byBzdWJtaXQgd29y ayB1bmxlc3MgdGhleSBzaGFyZSBtbSEg8J+Yigo+IAo+IElNTyB0aGUgcmVhbCByZWFzb24gaXMg dGhhdCBTV1EgZm9yIHVzZXIgU1ZBIG11c3QgYmUgYWNjZXNzZWQgCj4gdmlhIEVOUUNNRCBpbnN0 cnVjdGlvbiB3aGljaCBmZXRjaGVzIHRoZSBQQVNJRCBmcm9tIGEgQ1BVIE1TUgoKVGhpcyByZWFs bHkgc2hvdWxkIGhhdmUgYmVlbiBpbnNpZGUgYSBjb21tZW50IGluIHRoZSBzdHJ1Y3QgbW0KCiJw YXNpZCBpcyB0aGUgdmFsdWUgdXNlZCBieSB4ODYgRU5RQ01EIgoKKGFuZCBpZiB3ZSBwaHJhc2Ug aXQgdGhhdCB3YXkgSSB3b25kZXIgd2h5IGl0IGlzIGluIGEgc3RydWN0IG1tIG5vdApzb21lIHBy b2Nlc3Mgb3IgdGFzayByZWxhdGVkIHN0cnVjdCwgc2luY2UgaXQgaGFzIG5vdGhpbmcgdG8gZG8g d2l0aApwYWdlIHRhYmxlcykKCkFuZCwgSU1ITywgdGhlIElPTU1VIHBhcnQgb2YgdGhlIGNvZGUg c2hvdWxkIGF2b2lkIHVzaW5nIHRoaXMKZmllbGQuIElPTU1VIHNob3VsZCBiZSBhYmxlIHRvIGNy ZWF0ZSBhcmJpdGFyaWx5IG1hbnkgIlNWQSIKaW9tbXVfZG9tYWlucyBmb3IgdXNlIGJ5IFBBU0lE IGV2ZW4gaWYgdGhleSBjYW4ndCBiZSB1c2VkIHdpdGgKRU5RQ01ELiBTdWNoIGlzIHByb3BlciBs YXllcmluZy4KCkphc29uCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fCmlvbW11IG1haWxpbmcgbGlzdAppb21tdUBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9y ZwpodHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby9pb21t dQ== 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 2CE1CC433EF for ; Sun, 12 Dec 2021 23:35:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229921AbhLLXef (ORCPT ); Sun, 12 Dec 2021 18:34:35 -0500 Received: from mail-co1nam11on2056.outbound.protection.outlook.com ([40.107.220.56]:25025 "EHLO NAM11-CO1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S229579AbhLLXee (ORCPT ); Sun, 12 Dec 2021 18:34:34 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=BIVQkiHGhwTzCGqmw6NDN02BbP1tdOo8ccsuZmM6n78S+ZBu54uSpPzNTRrwarOKXkfXmDk/BtW+ODGdPL0molGsrwl6dHEHcMTnOftE79CeCgkLvkYBCAMVVEy7qGxzWc4fdC0xFFPxzdkNSI4x4Nw49hAczpWzBDcE9YG41sthx99Lnq3EavTNxVdLxWU0p2O1yvxHmhChkjpsfM0N97Gib8Scea90fAt+eKvXcsljms3SPr09JZNbPjQL2vm/jwf9cL6iwQL4Dlgm76jUt4sqG1Kfo/UWxC1zbgQoeBdvhi87tSZ5XeWhnfRR0GRXBwmOh68ZkEIED/0KKw7p3Q== 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=jSXm3V4EUDq6ippmmJvI2c2rchvv0sU9WxGskmACnd4=; b=nBFaqQO5vd32e2K2v6RwKWFysUIzZaUh7yLAKyEtgOc3jRrB+tFEH/mdBVbISZSAGyUjnzeP9AttVrGqph1m9tr+uEoI+ajnzh0Up6flsTLzUkLBYT3JLZsBIvyY4MrZHPmxMWrjwBPBvQGgJXp0gCS28vbxCxMixBf8KIT+RgWljXmCPKGrE+xtMrIcanYbXSaWIXWBc9bH3x2Cm3INIZKGQgzlVbwVQyJ9g4f8VUJgplvAniUkFHJY+yd2D/XeC+DURRT1/oKVsTVf9jqhBINYMU+w0TEVbk2CkOkrI0Pfj9XAKT1Zsb+m7Ha/SXUoPozoTE3M3GM+8PD1OYo+6w== 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=jSXm3V4EUDq6ippmmJvI2c2rchvv0sU9WxGskmACnd4=; b=q3+5EBNg2NHYLtHnhDJpAT16w2YKmmaWfIw88PrnIZN/925mi+i3sNsEY7+IODheKOVki2sBxXOud/7SDaE/jiiFc0fllGTpziR4iSHHpnYOKrb76ypzUBsE1r03BdnWZgD48OflJC9EqZLHHt8+oBDqzJoNeVFN06q0HwCSRuKBXBS1iDsxuFvHxJliHdcLNc9uLBvCCGVdk3QN7/XmuG6Ex92SoAT87CoU2/3iA+qQnsMHXDwaynBpTI7X152gHe/sufGL4yaV+cnPkUcvSo90ztSxDp9OmpP6QVVTbZesREiC1XSuW1ywAKkQ0u/PE344sqjMA/QnbBSwbm4Gog== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from BL0PR12MB5506.namprd12.prod.outlook.com (2603:10b6:208:1cb::22) by BL1PR12MB5157.namprd12.prod.outlook.com (2603:10b6:208:308::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4778.17; Sun, 12 Dec 2021 23:34:31 +0000 Received: from BL0PR12MB5506.namprd12.prod.outlook.com ([fe80::d8be:e4e4:ce53:6d11]) by BL0PR12MB5506.namprd12.prod.outlook.com ([fe80::d8be:e4e4:ce53:6d11%7]) with mapi id 15.20.4778.017; Sun, 12 Dec 2021 23:34:31 +0000 Date: Sun, 12 Dec 2021 19:34:28 -0400 From: Jason Gunthorpe To: "Tian, Kevin" Cc: Jacob Pan , Jean-Philippe Brucker , "iommu@lists.linux-foundation.org" , LKML , Joerg Roedel , Christoph Hellwig , Greg Kroah-Hartman , Jean-Philippe Brucker , "Pan, Jacob jun" , Lu Baolu , "Raj, Ashok" , "Kumar, Sanjay K" , "Jiang, Dave" , "Luck, Tony" , "Liu, Yi L" , Barry Song <21cnbao@gmail.com>, "Zanussi, Tom" , "Williams, Dan J" Subject: Re: [PATCH 1/4] ioasid: Reserve a global PASID for in-kernel DMA Message-ID: <20211212233428.GM6385@nvidia.com> References: <1638884834-83028-1-git-send-email-jacob.jun.pan@linux.intel.com> <1638884834-83028-2-git-send-email-jacob.jun.pan@linux.intel.com> <20211209101404.6aefbe1c@jacob-builder> <20211210123109.GE6385@nvidia.com> <20211210100545.373c30d1@jacob-builder> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: BYAPR06CA0011.namprd06.prod.outlook.com (2603:10b6:a03:d4::24) To BL0PR12MB5506.namprd12.prod.outlook.com (2603:10b6:208:1cb::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 40fe12c8-d9ff-4e4f-4649-08d9bdc7f239 X-MS-TrafficTypeDiagnostic: BL1PR12MB5157:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:7691; 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:BL0PR12MB5506.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(6506007)(66556008)(186003)(26005)(66946007)(66476007)(6486002)(6916009)(2616005)(4744005)(5660300002)(6666004)(1076003)(33656002)(6512007)(83380400001)(8936002)(54906003)(86362001)(36756003)(8676002)(7416002)(316002)(38100700002)(508600001)(2906002)(4326008);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Wk52bkpsQStpenFCdEliQTRDUkFZL2pKdnhSakR0SngwL0o1V29rdzB4WlZI?= =?utf-8?B?UHc1bVlZOVkvUmphT09jbTR6R2gzY1FKT2psRzVRbXBYSDhiclg3UzJMOHQ1?= =?utf-8?B?UTZrQmVhRjYrQks1aXlRS3IzZ3paZXVWTnJ4aFIwMlYvZ2FnTDBWc0RSYkdV?= =?utf-8?B?c3pyOE9UVExOUWVoQkJycmFJTUtzYXErN0VpaElrU0g1djNNbms0UUEzQkp6?= =?utf-8?B?bERlT0xIUlBIN1JmUjhFRllZdXdiYlNKZHFFVjROWHpDUG9iSEF4aHNOMVFw?= =?utf-8?B?eWg0NjhiZXdaZjlKYXRXNTl6WmlzY2s3NVdhK3ZmazFIS1ZYQnpxZndoVS9O?= =?utf-8?B?VjNQakMvTGYzWEkvUnN0SDY4OFZ0YlVKdnkyLzlJcjlYZWpOK3NxNk5PWHAx?= =?utf-8?B?QkV5S1ZPNWU1YWoxemZBQmlxY0llbmVVRkpleVZpWUMrZFJIaDhuK0tOZWtT?= =?utf-8?B?ZFZ3VzRpQnJJTFRGeFRmRWdQU292bVlQSCtxRjNLRHZwTzFyNXZTd3NYVUQv?= =?utf-8?B?VFltMUNmakg4emFsM1IrQXRkbE8vWnJMNE1lR01Gekxsd1IrRnRZUklFN0U2?= =?utf-8?B?MllvOWU4akNFR3FBNFFhdHVmdGdnN3h3aVJJK2hQajB3ZXNobXRzWTlONkRL?= =?utf-8?B?N1M5WWVwMDg3bXpFS0lzUnJLYlc0MWRGU21VeGtEaU1LSGpza21JYUNNemxP?= =?utf-8?B?dGx2M1NkVGJSNGlZNEQ4SnptVTdsQ3Jpc0hyTmlCcVRsTDJhVSs1aU5yaWhY?= =?utf-8?B?bGRCLzhDMnQ5c3JQclpCN281RzZqZ2l0QTl4VkVMUUZQR3NCbG1NMTUyQ0Vt?= =?utf-8?B?TTMydUJnK2REQndmRVpreDNGT3FvOTZhSkczZVV4UXV6ZmMxblVtZWhpU2dK?= =?utf-8?B?Nzc4bFBaeDh6QXJxTmNBM0hVcGIvZUdRaWdzVUEwWS9tREFCYzEvQUd6R2pS?= =?utf-8?B?STVWbEVPTlJnamFhcmNzbDd4dGY5ZXA4ZUlMSXcvaW9XTXNFZ205M3NhUFpj?= =?utf-8?B?OW5DblMxK1FRSC91OXkwdC82Wm9ES2NidzhmZm1kNXBQcWs4a1M1TUZRMGlC?= =?utf-8?B?RkpiLzVFdkl5ZWJLUVdQdEFYWm5KRmQwZWR2a1NwOHBlOVd0YWQ4amNlT1hF?= =?utf-8?B?VHJkNkI3dStTZmUxbnNPRWptVTF4dC8vWEFaTXNzQWdwTVdBVFV4SG9Nc2Fl?= =?utf-8?B?SUVOVy9SMHF1K3JQUEJuUjdaNUxWQ2lZbzkrdXJnNnhrSG41cFExOUZNdnFi?= =?utf-8?B?aEZjK0xLbjFvVUFWc3NGK3BZMmlZNjZlOTlaMDA4K0hDMkUzRng5OFptcEFk?= =?utf-8?B?UlR2bU9GUDh5cUoyNVlZa1M5Rld2V3hCQWladFl4VnVWcUcveDJ5dEpLL2VD?= =?utf-8?B?MG5pTk5HTHp5dXVmR2NibFBENTZ4clhCMEZHV1l6U3FRK3VPd3hhaERkdUFa?= =?utf-8?B?dEdTTFg2N1JRcEErQTNTUEE4ZHNSYkgvQ1VRaXR0eEtiRTJvQVlnUThCQlRB?= =?utf-8?B?eHhXTzMzbzU3VWZGQTAwRlp1TTJWREhYcVc0V2loYzdTL05yS0xDc212MzZh?= =?utf-8?B?bnhQNmxEcFN3czRhSmJTVVFWdzRkVk4zeXZmOEJEY1FqOVNuRWxoU1RUS1h2?= =?utf-8?B?MnpNOURyU1dRRklKUUVFdE1nN05hMk52QXBWRENwcWRWVHdyMWtERlBXV3lE?= =?utf-8?B?aWFORlljT0JCNitiNlBkUVRXSEpyMnRnbUhFK3N6YUVuOXcxZW5xZ01LcGpo?= =?utf-8?B?QmhZWjBFQlFLTUVIUXVFZnFqVzdaT1dQbTc4QTVlVjVDcWxzTzdnR1Z6dU55?= =?utf-8?B?OENvNzBxTXZ2Z0pvbGI1VElMQ3NpWEY5Z0haY2ZEdHdyV1lIMGlZRERBTkJE?= =?utf-8?B?ME5qRVdneWJWY2djaWV4TnRoa3huQjJkLzJCRkkwMEIveTY3NGdHRzlQZUlH?= =?utf-8?B?T0dtMjdYWTJHMnBDTndGMkErRU1hUnVVbTFhNUdVNkhyUEpBQ1Z0UXM4MEpV?= =?utf-8?B?QWI1bDcrTThVc05paFMvTjN1UmU0dFhQVytuTjBndUFFWlVMdnh6UStOMDlI?= =?utf-8?B?UEt3Z1YyeWFrRmtEVG0yUXFDNnpON1FXSWFRL3F1M295NFBTaEQ3RDFUTmdv?= =?utf-8?Q?L6GM=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 40fe12c8-d9ff-4e4f-4649-08d9bdc7f239 X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB5506.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Dec 2021 23:34:31.1491 (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: p77fnnE5tx/5TZGE2x6PZhCD3L91wI+8AM2P/dAFWtoYZA4Q9aKBVtoEPPeX3vdI X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5157 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 11, 2021 at 08:39:12AM +0000, Tian, Kevin wrote: > Uniqueness is not the main argument of using global PASIDs for > SWQ, since it can be defined either in per-RID or in global PASID > space. No SVA architecture can allow two processes to use the > same PASID to submit work unless they share mm! 😊 > > IMO the real reason is that SWQ for user SVA must be accessed > via ENQCMD instruction which fetches the PASID from a CPU MSR This really should have been inside a comment in the struct mm "pasid is the value used by x86 ENQCMD" (and if we phrase it that way I wonder why it is in a struct mm not some process or task related struct, since it has nothing to do with page tables) And, IMHO, the IOMMU part of the code should avoid using this field. IOMMU should be able to create arbitarily many "SVA" iommu_domains for use by PASID even if they can't be used with ENQCMD. Such is proper layering. Jason