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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5B5AC63697 for ; Mon, 16 Nov 2020 21:44:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 660672225B for ; Mon, 16 Nov 2020 21:44:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amdcloud.onmicrosoft.com header.i=@amdcloud.onmicrosoft.com header.b="U7VxG78d" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728030AbgKPVoA (ORCPT ); Mon, 16 Nov 2020 16:44:00 -0500 Received: from mail-dm6nam10on2079.outbound.protection.outlook.com ([40.107.93.79]:55300 "EHLO NAM10-DM6-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726235AbgKPVoA (ORCPT ); Mon, 16 Nov 2020 16:44:00 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=MufFQT5tWrr/0BNSKjJODF19KA3cFzI860vx1PTKZbFgNROkrKToOjQXYT0Nchf/sAP6SvpFZJWedMR+p+Ol5zeHMvid9kBYO8Jk9c+/UQGmypQPArDyNe1V/PwEPP5K4b7IrbutyzU2qEfI/2M1vkgB7w6/NxATEHAbFaszg8WOXk6rLdCTuG0z99jyeK4SZqF4RqjA+z/gfSu+iLkrCW4l1oRjoWTPabwTg2w9grWRVTFjpXmp9d2S91perMfvbLwMcDPQzzbvMpbPWh82BnTN829DHC6nL1OlSWf+3yr/v0pc9k2v6kDD8IImVnDIkiZfKrJtMvQ71W/nBcenxQ== 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-SenderADCheck; bh=lQs7p82GluW2+sg18GuS78FbsUo7rmdcyxxxCa42nQQ=; b=L+7WrlsJwA40gp1ueWrXkJTOqou0znEjwCvyE5fQHAAwo8fBPh3uB+xT90Rh4nDLMWu1HO9ypIumc0wh7F9VCVNTJWxBKNbGfKVo75bH8VIb6NgHzEzMvt4mDGeh9aKVEhP4Rx1Sq2NT5paCvaF3F7e6Sd9mkAQuGZLwNY0cYjFZ7/fdZB5C6LJohqQbbDneenhHekcR7IK41HPx/lMfgMuZDQ+2hbuIkzl/XLeJe5ar4rqxGcnY2mM1xKL4afF8/Wvmk+Ri0NVT0OCZP7zExGfPNs874xZpKAxqzTYBmomZyWzUXd2zuPNYvv+EgDcH+yGbtMOshf81ndmKPxMcrw== 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=amdcloud.onmicrosoft.com; s=selector2-amdcloud-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=lQs7p82GluW2+sg18GuS78FbsUo7rmdcyxxxCa42nQQ=; b=U7VxG78dydRocMv2jjXwRywvVKAzk6MjZYyLwEPsSPEUYEjlZzdDWzA0mngcHSPDwrbFs/foxLpABQg+F80B3gxIHgluDC0KRiW+kpqNJMPmTyuLf5qxcmZOpXWp3LX96RbyaAQCwgEYmij1KzA8r1LECGjXIbu4knVsbRNtbe8= Authentication-Results: redhat.com; dkim=none (message not signed) header.d=none;redhat.com; dmarc=none action=none header.from=amd.com; Received: from DM5PR12MB1355.namprd12.prod.outlook.com (2603:10b6:3:6e::7) by DM6PR12MB2828.namprd12.prod.outlook.com (2603:10b6:5:77::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3499.18; Mon, 16 Nov 2020 21:43:54 +0000 Received: from DM5PR12MB1355.namprd12.prod.outlook.com ([fe80::dcda:c3e8:2386:e7fe]) by DM5PR12MB1355.namprd12.prod.outlook.com ([fe80::dcda:c3e8:2386:e7fe%12]) with mapi id 15.20.3564.028; Mon, 16 Nov 2020 21:43:54 +0000 Subject: Re: [PATCH] vfio-pci: Use io_remap_pfn_range() for PCI IO memory To: Jason Gunthorpe , Peter Xu Cc: Cornelia Huck , kvm@vger.kernel.org, Alex Williamson References: <0-v1-331b76591255+552-vfio_sme_jgg@nvidia.com> <20201105233949.GA138364@xz-x1> <20201116155341.GL917484@nvidia.com> From: Tom Lendacky Message-ID: <02bd74bb-b672-da91-aae7-6364c4bf555f@amd.com> Date: Mon, 16 Nov 2020 15:43:53 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 In-Reply-To: <20201116155341.GL917484@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [165.204.77.1] X-ClientProxiedBy: DM5PR07CA0033.namprd07.prod.outlook.com (2603:10b6:3:16::19) To DM5PR12MB1355.namprd12.prod.outlook.com (2603:10b6:3:6e::7) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [10.236.30.118] (165.204.77.1) by DM5PR07CA0033.namprd07.prod.outlook.com (2603:10b6:3:16::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3564.28 via Frontend Transport; Mon, 16 Nov 2020 21:43:54 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-HT: Tenant X-MS-Office365-Filtering-Correlation-Id: 61e62423-d07b-43f9-b774-08d88a78b6f5 X-MS-TrafficTypeDiagnostic: DM6PR12MB2828: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:7691; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 4qtCUUvDTS7ZTEeNC3Dv6pWNMMH10gLhGiEwir+Q02LJHyiX4aVfdbqeIp6KQUd/iyCsGxA7EzQzjvkZrvFFW/vLdquaKUBOubMiGdeIBEs8Mbgyt2o3LjonZy8LcdFbAGi2qgC/0fmZrb8TpF8cB2qMjq+SVuFq1JhQBHhBwA8n9UsVJrsNKHdS25i+OUIoAjHqAiDzeSz0x4BhRPQTNZzEOdXja++ZqUyp08taOHSpwcBJI+ErUQBMsmOl+QAslHGycGI4KrCiuHLNdOI0NOAaLFyvcGwfDMQX6mWVCWxEU2TLpsSkHaYX7s5rlWQyBQVps79ZdsdBWOLT4W89m+XdGZXu7z1TqNbiw3vcpDOTzFX//fWm7xceRd2QrqB1 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM5PR12MB1355.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(396003)(366004)(346002)(39860400002)(376002)(136003)(2616005)(956004)(316002)(5660300002)(36756003)(110136005)(53546011)(16576012)(52116002)(26005)(54906003)(478600001)(186003)(16526019)(86362001)(8676002)(8936002)(66476007)(66556008)(66946007)(6486002)(4326008)(31696002)(31686004)(2906002)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: 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 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 61e62423-d07b-43f9-b774-08d88a78b6f5 X-MS-Exchange-CrossTenant-AuthSource: DM5PR12MB1355.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Nov 2020 21:43:54.5649 (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: 8vU/is/oLZcEl/hv1HvnE5o6qH9sAjlwzLsSlH5jjA2/Ta0yLQ+zRVxKbNNwr+ygw3X19GHZGMQ4vXFCXi7BXw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB2828 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 11/16/20 9:53 AM, Jason Gunthorpe wrote: > On Thu, Nov 05, 2020 at 06:39:49PM -0500, Peter Xu wrote: >> On Thu, Nov 05, 2020 at 12:34:58PM -0400, Jason Gunthorpe wrote: >>> Tom says VFIO device assignment works OK with KVM, so I expect only things >>> like DPDK to be broken. >> >> Is there more information on why the difference? Thanks, > > I have nothing, maybe Tom can explain how it works? IIUC, the main differences would be along the lines of what is performing the mappings or who is performing the MMIO. For device passthrough using VFIO, the guest kernel is the one that ends up performing the MMIO in kernel space with the proper encryption mask (unencrypted). I'm not familiar with how DPDK really works other than it is userspace based and uses polling drivers, etc. So it all depends on how everything gets mapped and by whom. For example, using mmap() to get a mapping to something that should be mapped unencrypted will be an issue since the userspace mappings are created encrypted. Extending mmap() to be able to specify a new flag, maybe MAP_UNENCRYPTED, might be something to consider. Thanks, Tom > > Jason >