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 9A2A1C433EF for ; Mon, 11 Apr 2022 14:13:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346990AbiDKOPw (ORCPT ); Mon, 11 Apr 2022 10:15:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232828AbiDKOPu (ORCPT ); Mon, 11 Apr 2022 10:15:50 -0400 Received: from NAM11-BN8-obe.outbound.protection.outlook.com (mail-bn8nam11on2056.outbound.protection.outlook.com [40.107.236.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD6E03204D for ; Mon, 11 Apr 2022 07:13:36 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=VP/L5HHkWDo6TSZA78HKxCvyOYKMu9IPqtxfjEJV+M7Nn/AK5rrI4XR4S9Ca36FzdAbrFkFMm6Ec5pzUbU2rOeKgYIU1ELWkRpYBxfrJtTFUitxCHWZ6pdpp5inynibYfxXJ0jHJ5jwjRzUTu1x2KZtslzxFYchcBOyJ3u2vSXhHwLrfrEVbIM69Vvq8bEjCe/ZoJPhETS+pQGGujOVOYAIjnTx8Lcy5Zc0pXjMk2Fe1774GCnWByS4SE2XgQP5LQ+9Zb9j6J9OCuiXtmCQGklF+L9GQl/IcL+JBcAJUak2psxSbMiCdG4XqVjddXWspc2jLSCO3BEY4CGqBtpaxpw== 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=josvuwXSee1or+V4uJYKAd8Gog0QImST4G8WwRzlcHk=; b=Bqoq94QfvN6PDEJzOGRcEGKmUisveV98WE38PQsCuYQF97mIbWmoiqA8VGd+phcO4+XpDLap29XPe+qd3J3aGEYV1NhgBQPVzQpg/ZHgFYCHPbwF3FQXt2gJ8ufrrgxKF8p+PT+PtMpLaiy8P0qYyHzv3BfyZ/rWVxnKNAJ/qzIXqh3xN8TgdSUsa7VPiJhqj5CKYaHRc97d7IlyZpvck94MFSjkjXZq5wXhsY53VCV8/EeGHygT44geviRgROMrnS3EF2w32gMB0oas5Ae6btuH7Ny3mirzIVzJrAPI1UdlTBf88bCfI0+kdx4h2J1Ta7p9kq6ySz+xWXRo90dtBQ== 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=josvuwXSee1or+V4uJYKAd8Gog0QImST4G8WwRzlcHk=; b=NK6VRIUeU88Lq5QS6ih47fcgtRWSHLuCWUG3LoA/yLbNPqWFQ6AGUg/GOxPxMgZkSP8j+SLo3JWZYQUXgTn4Wu44vSFSTTSQj9xb+7XuB18LUazBm2lU0c6srT8DSnqzHh3COoDbcL+fmfmSJQqzkiU6tyakhe2kPOWRg5ednABNCAnXmMfRPZHgwfzNyNuEXcZhXV5BHbJphejtvh617JdT+mDCRY1gSPi0ooTJeFQsmiNLGiqh05IA8t3F4xkEZpI7iWfh+HkqhOkEzjr1Pa6QKMlLky/sVs4mSVPRzW084OuY40OfcfV6BX0Wnez247+ijfR0UJ1oKmfZeoQbmw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from MN2PR12MB4192.namprd12.prod.outlook.com (2603:10b6:208:1d5::15) by MWHPR1201MB2526.namprd12.prod.outlook.com (2603:10b6:300:ec::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5144.29; Mon, 11 Apr 2022 14:13:35 +0000 Received: from MN2PR12MB4192.namprd12.prod.outlook.com ([fe80::cdfb:f88e:410b:9374]) by MN2PR12MB4192.namprd12.prod.outlook.com ([fe80::cdfb:f88e:410b:9374%6]) with mapi id 15.20.5144.029; Mon, 11 Apr 2022 14:13:34 +0000 Date: Mon, 11 Apr 2022 11:13:33 -0300 From: Jason Gunthorpe To: Alex Williamson Cc: Lu Baolu , Cornelia Huck , David Woodhouse , iommu@lists.linux-foundation.org, Joerg Roedel , kvm@vger.kernel.org, Suravee Suthikulpanit , Will Deacon , Christoph Hellwig , "Tian, Kevin" , Robin Murphy Subject: Re: [PATCH v2 2/4] vfio: Move the Intel no-snoop control off of IOMMU_CACHE Message-ID: <20220411141333.GB4085842@nvidia.com> References: <0-v2-f090ae795824+6ad-intel_no_snoop_jgg@nvidia.com> <2-v2-f090ae795824+6ad-intel_no_snoop_jgg@nvidia.com> <20220408094757.4f5765c8.alex.williamson@redhat.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220408094757.4f5765c8.alex.williamson@redhat.com> X-ClientProxiedBy: BLAP220CA0027.NAMP220.PROD.OUTLOOK.COM (2603:10b6:208:32c::32) To MN2PR12MB4192.namprd12.prod.outlook.com (2603:10b6:208:1d5::15) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: ff70b501-9978-4c7d-0e5c-08da1bc5770f X-MS-TrafficTypeDiagnostic: MWHPR1201MB2526:EE_ X-Microsoft-Antispam-PRVS: 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:MN2PR12MB4192.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(4636009)(366004)(6512007)(316002)(8936002)(36756003)(4744005)(2906002)(33656002)(7416002)(5660300002)(6506007)(38100700002)(6486002)(86362001)(54906003)(6916009)(66476007)(8676002)(4326008)(186003)(508600001)(66946007)(2616005)(66556008)(1076003)(26005);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?G0qoHAxmoYXcAVRM3rrY3kmh8Hy2krk2EuHDOqAhmyrhTbx4wqum0RbidRWn?= =?us-ascii?Q?10zY7MnNSodLdGfcVfHv5eZ8AJwXfNv8u+nbM6OI1aLCAnfPQtmUL68kQ3Oj?= =?us-ascii?Q?IAQSZDwmG5NqbckbeCQKWiS4EKfR5F/o0yMr47tXNv6+bUO89fK7tZKm0MWS?= =?us-ascii?Q?GDBvI6vkrl9GvhYGFWggMsT/fVeF2xflpm7+YYhTsuqzYRyykVztXeYSvNlk?= =?us-ascii?Q?EUxF4N9h1dug8kwCuy0lTZsQRJvv8yABKqHoIUSJCaiObVvHqbySXlfvVw4Q?= =?us-ascii?Q?bvpzcoOAXNcqmsGICuSeGwyCsGAIkFl8s4pQ92o00q5eZ7mtUXNTIWUiWSML?= =?us-ascii?Q?t9KajI6EOe55Lptt4Lgz6jQrbanmDmCGDLlmkJY1gPYFBZPhWZg2o2uuuuQt?= =?us-ascii?Q?w23nxGRH0rxkPrVeQACNQmR4aEHHObnA66L4kTZ8H636OZbKutc4yBvOgbjX?= =?us-ascii?Q?Xi7UHcr8IW06YL4AtNLHF60fEvGS7wY7UWIxhiK1ruV5LWa7w2JBfDneDYHD?= =?us-ascii?Q?X4uiCX8Px9rQh3gU3/N30nADMFzF1Wyv03L3/hxB99vfnnDJoZSVuDb4aEEr?= =?us-ascii?Q?pVUL9T+kYCbcJnahyh1A8UlfUnPaMxqIZiddKtkX5IDVPKFRRWzALY+gX/3g?= =?us-ascii?Q?pqx0tbFuTIgfNGlgqXygUvrcNeIfRt6l7eG9jV/29ac8aV9/H5PcuWQMAUhr?= =?us-ascii?Q?58YWr/0y/PjK/9Nl+w9BqphQUDcnKte9cl7Bj5v6rSsbuO0OLkKQ3R5ZsSEO?= =?us-ascii?Q?S0KxE60tay8kC5Rf6zdiu133WfreBFcWScDO3Ofe5H9X3RZi7jiNqwMcWTYU?= =?us-ascii?Q?jeRkD/ojxtUpu1RqmiLpJUdX9qTdbsmm9QkQpHulqX8geVMNQQP74/OlcMtg?= =?us-ascii?Q?FVsG0qPNxffwv+WY0yuUxiEwx7JE50WC79LW8DggdPpliJHgOU1U6ZekyduT?= =?us-ascii?Q?z8nUFIeJfP8HgzY3A+d3IEbhlriSyRVt7U+UAP03kEqtw90c0xJlVTUVA8TW?= =?us-ascii?Q?eJaeTqu3a583XiK4gERJMnaxcyQfvcSLGceRpQcALg4iANW+xoh0zncpP3WF?= =?us-ascii?Q?5Y09rL8iQGdje0Gw1iYode284u+Cn8SGhRhLCSDzskDsBUG/zJmqj8qWmuwV?= =?us-ascii?Q?P1MCjDwmXb7a8ZvOiixvVHONdKWs+ChFJ4hy+nlMwSSjGJbNHF4BoavMjUg+?= =?us-ascii?Q?9jQzZcKUGPB6X4ZkHkWnbpGgAD2T3mbU200IMDIyZ9P2rGRqczKVaD0tyXa2?= =?us-ascii?Q?IblNJCCo0VA6u8+B2nzcAUyzq8n5z64XkBGxQNPqT3MmYkh0L+Ko/7g3eF0Y?= =?us-ascii?Q?v5lY0OEhuOvzkvUrsMc38avnoQhfIH9bxbSM3CPYFyZ3l1euKrvovNESvrBk?= =?us-ascii?Q?iFP1LgFeLbYwIkEVGJNLbfJhG5/8P4VRoNdNQwlbGdEYHOBE5DwdnjH7BcGc?= =?us-ascii?Q?8b/f6WyX6faexejoxRpdALkb+CCfZFVO7s9YACl6h5sU0jTKrQTCfTYJ8DmZ?= =?us-ascii?Q?gwZL2TreKIRsDdNjHCOI29NK2nHm1XkP9wb8PUOm6PYsaDg/VzuDHvuBYWdH?= =?us-ascii?Q?PjJ2B3J2NL/X9fCXwTtrO+7aJ5Na8S3TAOugdW8WTy23zicVjBLz1b0ansfx?= =?us-ascii?Q?johMnZrY9HFPiJx+4ursSNFUHkTlKg382ZGXvLoKkxST2QTOHotzXsiSu0fq?= =?us-ascii?Q?1Lo0WugcOEHpExebYDVJ3FNHPNIPHaC07yfEKDXkGnCcDKplXn3VSxsYyw+4?= =?us-ascii?Q?iAdelWavPA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ff70b501-9978-4c7d-0e5c-08da1bc5770f X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Apr 2022 14:13:34.8203 (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: FOwRQGxWT41zyBRMtAonqciGEXHhrzrJwv0OWUkZKZ3tIZyAAo+yQC3LMqdm/IbC X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR1201MB2526 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Apr 08, 2022 at 09:47:57AM -0600, Alex Williamson wrote: > > Ultimately VFIO plumbs the result of enforce_cache_coherency() back into > > the x86 platform code through kvm_arch_register_noncoherent_dma() which > > controls if the WBINVD instruction is available in the guest. No other > > arch implements kvm_arch_register_noncoherent_dma(). > > I think this last sentence is alluding to it, but I wish the user > visible change to VFIO_DMA_CC_IOMMU on non-x86 were more explicit. > Perhaps for the last sentence: > > No other archs implement kvm_arch_register_noncoherent_dma() nor are > there any other known consumers of VFIO_DMA_CC_IOMMU that might be > affected by the user visible result change on non-x86 archs. Done Thanks, Jason