From patchwork Wed Oct 18 17:14:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dragos Tatulea X-Patchwork-Id: 13427522 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 DD582CDB484 for ; Wed, 18 Oct 2023 17:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231518AbjJRRQB (ORCPT ); Wed, 18 Oct 2023 13:16:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230018AbjJRRP4 (ORCPT ); Wed, 18 Oct 2023 13:15:56 -0400 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2055.outbound.protection.outlook.com [40.107.243.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 141AAB0; Wed, 18 Oct 2023 10:15:55 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=HmJYR5A8aNs1/qlTyBiaF8H4uFSbrnjmuVtRv82VGjOX2Cwwz/k29fdJoVxpm0bzkN7Wc2BjBdA5D4NcXm2tZJKgvnggRK8/slYp0mKA2rj6eQoVgadwEEHPch/N6WrOfG2icEaFKCDI22nXKkNzW4NbCv6NqnXFQhU8dfhlCCJJQCDzxTfVUnZdRpH1Zsv+Mhtb3l05SIRWr9MxJmh/Ay/4if4rSmoK5qSQALk1u0LdmtslaeAv3R5Re8jFGHfhoQ0FirME+QJGPjJPdOHDungUGqUf9gyc+iixkqojx1CeWaCPT3Y/yCWk62Uyidtumjfu1HRPPbDV2rA3GuddMw== 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=Zs2p5Im8kifm/aJ1lEAfNpIB6nh0RoaB6CA/cNIHKDA=; b=YJEZzKdlqNSSVBxtOeftWp6F+IYm1anjd92kkxaOW/AXMjMJwMt9TqlYWudhGkZA7niWOYCAAIWDMnV1UB1tnc0O4erb+dv63Lx7RvFSG0X757Y95aKOm/a6Lfz4Ael8pyXY5a+YiNx/Qnu96LCFGw/a/rW0dNsMqxWUgdVoXIt1NlcAZgDEA60LECVVRajhJK6YO30VxLaFsLR/xTsATwzMy6Li9RtY7PZvt5LgMG7MJiLMWk1ZfM95t/mUtTJhHpagLOAe9l7fQdPkeEYE75bcNb2pGC5i27dv2EQZnVUe+daOcVb7wVs1qUNh0VupBvcXkuHQ3IV7XbyKz8K8eQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.161) smtp.rcpttodomain=redhat.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); 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=Zs2p5Im8kifm/aJ1lEAfNpIB6nh0RoaB6CA/cNIHKDA=; b=lZtmCB4T5+OptN5sueNbgxReNPY/IQnUGw0wFPIs5WOBBWDpZjE7X23CDZ85Skzl28oXsIHOprOjB4Tmsehi7aVz0HKBcdm1JeTMtuHfu/LdKLkAbJNsVQnoG/4D4RGpdZUQvO7QnzWpy1FL9rCvSp6MoOSCwtQtR2DTl3e85/HdPWlvuqMzr55qWAxnbF7rDBbpIffNzmwpH5wjQM/9e199i2+P0BHDHa5ljC2spNSvL7EHVuCBiA79s/d3b5wG9DnVI5z9/0WV2VEFyhurZHcu51sW632Oh63nB8oovDoIR5Bv5AW1ihmJ6mKXNZQrt++TyXPFyrWpOzSeYNf6wA== Received: from DM6PR08CA0025.namprd08.prod.outlook.com (2603:10b6:5:80::38) by SA3PR12MB7857.namprd12.prod.outlook.com (2603:10b6:806:31e::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6886.36; Wed, 18 Oct 2023 17:15:53 +0000 Received: from CY4PEPF0000FCC4.namprd03.prod.outlook.com (2603:10b6:5:80:cafe::79) by DM6PR08CA0025.outlook.office365.com (2603:10b6:5:80::38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6907.23 via Frontend Transport; Wed, 18 Oct 2023 17:15:52 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.117.161) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.161 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.161; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.161) by CY4PEPF0000FCC4.mail.protection.outlook.com (10.167.242.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6907.22 via Frontend Transport; Wed, 18 Oct 2023 17:15:52 +0000 Received: from rnnvmail204.nvidia.com (10.129.68.6) by mail.nvidia.com (10.129.200.67) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.41; Wed, 18 Oct 2023 10:15:34 -0700 Received: from rnnvmail201.nvidia.com (10.129.68.8) by rnnvmail204.nvidia.com (10.129.68.6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.41; Wed, 18 Oct 2023 10:15:34 -0700 Received: from c-237-113-220-225.mtl.labs.mlnx (10.127.8.12) by mail.nvidia.com (10.129.68.8) with Microsoft SMTP Server id 15.2.986.41 via Frontend Transport; Wed, 18 Oct 2023 10:15:31 -0700 From: Dragos Tatulea To: "Michael S . Tsirkin" , Jason Wang , Eugenio Perez Martin , Si-Wei Liu , Saeed Mahameed , Leon Romanovsky , CC: Dragos Tatulea , , , Parav Pandit , Xuan Zhuo Subject: [PATCH vhost v4 02/16] vdpa: introduce dedicated descriptor group for virtqueue Date: Wed, 18 Oct 2023 20:14:41 +0300 Message-ID: <20231018171456.1624030-4-dtatulea@nvidia.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231018171456.1624030-2-dtatulea@nvidia.com> References: <20231018171456.1624030-2-dtatulea@nvidia.com> MIME-Version: 1.0 X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000FCC4:EE_|SA3PR12MB7857:EE_ X-MS-Office365-Filtering-Correlation-Id: 6355522f-8b05-4ef0-9aac-08dbcffde20b 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:216.228.117.161;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge2.nvidia.com;CAT:NONE;SFS:(13230031)(4636009)(376002)(346002)(136003)(396003)(39860400002)(230922051799003)(1800799009)(82310400011)(186009)(451199024)(64100799003)(46966006)(40470700004)(36840700001)(40480700001)(40460700003)(36756003)(426003)(110136005)(316002)(70206006)(7636003)(86362001)(70586007)(54906003)(82740400003)(356005)(1076003)(47076005)(83380400001)(478600001)(36860700001)(8936002)(336012)(26005)(6666004)(66574015)(2906002)(5660300002)(41300700001)(2616005)(4326008)(8676002);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Oct 2023 17:15:52.7737 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 6355522f-8b05-4ef0-9aac-08dbcffde20b X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.161];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000FCC4.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR12MB7857 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Si-Wei Liu In some cases, the access to the virtqueue's descriptor area, device and driver areas (precluding indirect descriptor table in guest memory) may have to be confined to a different address space than where its buffers reside. Without loss of simplicity and generality with already established terminology, let's fold up these 3 areas and call them as a whole as descriptor table group, or descriptor group for short. Specifically, in case of split virtqueues, descriptor group consists of regions for Descriptor Table, Available Ring and Used Ring; for packed virtqueues layout, descriptor group contains Descriptor Ring, Driver and Device Event Suppression structures. The group ID for a dedicated descriptor group can be obtained through a new .get_vq_desc_group() op. If driver implements this op, it means that the descriptor, device and driver areas of the virtqueue may reside in a dedicated group than where its buffers reside, a.k.a the default virtqueue group through the .get_vq_group() op. In principle, the descriptor group may or may not have same group ID as the default group. Even if the descriptor group has a different ID, meaning the vq's descriptor group areas can optionally move to a separate address space than where guest memory resides, the descriptor group may still start from a default address space, same as where its buffers reside. To move the descriptor group to a different address space, .set_group_asid() has to be called to change the ASID binding for the group, which is no different than what needs to be done on any other virtqueue group. On the other hand, the .reset() semantics also applies on descriptor table group, meaning the device reset will clear all ASID bindings and move all virtqueue groups including descriptor group back to the default address space, i.e. in ASID 0. QEMU's shadow virtqueue is going to utilize dedicated descriptor group to speed up map and unmap operations, yielding tremendous downtime reduction by avoiding the full and slow remap cycle in SVQ switching. Signed-off-by: Si-Wei Liu Acked-by: Eugenio Pérez Acked-by: Jason Wang --- include/linux/vdpa.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index 0e652026b776..d376309b99cf 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -204,6 +204,16 @@ struct vdpa_map_file { * @vdev: vdpa device * @idx: virtqueue index * Returns u32: group id for this virtqueue + * @get_vq_desc_group: Get the group id for the descriptor table of + * a specific virtqueue (optional) + * @vdev: vdpa device + * @idx: virtqueue index + * Returns u32: group id for the descriptor table + * portion of this virtqueue. Could be different + * than the one from @get_vq_group, in which case + * the access to the descriptor table can be + * confined to a separate asid, isolating from + * the virtqueue's buffer address access. * @get_device_features: Get virtio features supported by the device * @vdev: vdpa device * Returns the virtio features support by the @@ -360,6 +370,7 @@ struct vdpa_config_ops { /* Device ops */ u32 (*get_vq_align)(struct vdpa_device *vdev); u32 (*get_vq_group)(struct vdpa_device *vdev, u16 idx); + u32 (*get_vq_desc_group)(struct vdpa_device *vdev, u16 idx); u64 (*get_device_features)(struct vdpa_device *vdev); u64 (*get_backend_features)(const struct vdpa_device *vdev); int (*set_driver_features)(struct vdpa_device *vdev, u64 features);