From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH8PR06CU001.outbound.protection.outlook.com (mail-westus3azon11012044.outbound.protection.outlook.com [40.107.209.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82BF11A4F3C for ; Mon, 6 Apr 2026 11:47:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.209.44 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775476062; cv=fail; b=mdOm2J9gzZ0xFqkwAv/pvBH6/T6EWjRZKRjJSjY1tlyrfsqy0TKkACC8PHbTpf2TYr9lg1XaBCXR6jwdK2mIJHvXB5tSWxNX7rWutfziSrOhigJnj0mbUB8tDm3ypPnvzZ1X2r3bOM32S3W0QOBK4z4OVUboE/cxVwNo9tP/gww= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775476062; c=relaxed/simple; bh=dofm73A1BK5mQ+Gg8pQYGRWdDRzbuTkwAp1ORPRdwF4=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=cefkNjfko9DeRO0v8EcbTgJZ+zGnwrJ1j1giip3sT5rSWnJfrK83AFgEzXZtkqRAm0klCqy2bHH3oY6Lm3L38gvJ+UOJdwhE+foy5tGVB+t5C9mwyMIi+/OndQw35dO4H18vB8L/zkQIuwcqR2FBps1CuxP/sYO/RrDUy2OClgU= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=kI1Evp55; arc=fail smtp.client-ip=40.107.209.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="kI1Evp55" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=r5W6mVbGW9wUTpdkqPLX6imSBo4a9ouYAwJdzMHLS7BbclCbJGPodz8eEIOaBY64g7FY3OQ5gpx/rJgiGWezRX7q5PIE4Ky14wx9h9ySGJwn2TbU1vLPWqkqqGY6sMFsY8A9OFzHVC/fJkU+3xgjO26udSlGhlQHofeftTitWm9zuT/uMzZk9XZsfg6kZ8e+bzCwbBgtJNGyiiFh0W8xLYopG2uFvTXUqbKDzhJ/YR5h6Evlj5yhwPzRxlGvRiVSHIjkxbZxnKLO9iG2u7KHJy/FPf/ZOvkdZ1VbUrfACDB8t3BJsjumWCNZnGh/ZImzeWUjOiYR71pnlvHAh2VQ+g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=fsJwVL5Je6Ow/R+Js1w81PW3bKFJOeGN2tosJrhSPZQ=; b=yNs/ompj5Ls8eRa6VwKXtWnm9oQjVZsFso8MiaJR7fpXZjV6Qa3yatJIncv1KxrYiJKSM7LzfS1sDKsKI6hCkew6deY7T9ZyGMqwBVxtG4q69xow6eP6Xbkf54fEueiej/n9ouVGn0jWM/RX4go0KAsUf4yLzBi4So3uPbAN9KejebKJR8I5VnCKrJZJ57EI62HcZSpShpRhxtNzXT+MeVMAHaRVP3WgVYximFkO6iofvzIj92Bi3C+7P7s9fTSQRJwkqlr/hc/sh5Xifw61VZ9A8DZi52rpdYqBd3itWEWzdGWoaY5pq/T/b6We9fTk0R+gvICyGS+xwK7IGfHbpA== 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=fsJwVL5Je6Ow/R+Js1w81PW3bKFJOeGN2tosJrhSPZQ=; b=kI1Evp55P7wl4lIk2Th56rmQQA8Uo2nk5Rc70Xw2NgbTuY8ijflMyZPAmBTAtd9CrW0TLAvq4lUd+JiTxU3Df+uL3TSx5VKZEy9CpCc2e70Ka41ZPmWuLg1aAjb7tWgYc9yKcLZ/ZsciYE6sFvaQh84RWO+OLxkJjzLlmuEYmqdlsVaNTuZjj8Y8emlrWb73AXhOMCtcYCXYFvL2WdaekTOC2TK93wY5jyllZPqosgpo4cPOsAwzSYogoj5akNTKJSOBK6vVgiZecYrLTnR16MP7IQR+OmOgSZx15+v5wheM6CszSDz7kPjbukgDq9MK6vHqf5LQ/tJjks+LtxYAyw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by DS0PR12MB9422.namprd12.prod.outlook.com (2603:10b6:8:1bb::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9769.20; Mon, 6 Apr 2026 11:47:37 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%5]) with mapi id 15.20.9769.017; Mon, 6 Apr 2026 11:47:37 +0000 Date: Mon, 6 Apr 2026 08:47:35 -0300 From: Jason Gunthorpe To: "Suthikulpanit, Suravee" Cc: linux-kernel@vger.kernel.org, iommu@lists.linux.dev, joro@8bytes.org, yi.l.liu@intel.com, kevin.tian@intel.com, nicolinc@nvidia.com, vasant.hegde@amd.com, jon.grimm@amd.com, santosh.shukla@amd.com, sairaj.arunkodilkar@amd.com, jay.chen@amd.com, wvw@google.com, wnliu@google.com, dantuluris@google.com, chriscli@google.com, kpsingh@google.com Subject: Re: [PATCH 09/22] iommu/amd: Introduce domain for IOMMU Private Address (IPA) region Message-ID: <20260406114735.GL310919@nvidia.com> References: <20260330084206.9251-1-suravee.suthikulpanit@amd.com> <20260330084206.9251-10-suravee.suthikulpanit@amd.com> <20260330122012.GG310919@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: YT4PR01CA0424.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:10b::24) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|DS0PR12MB9422:EE_ X-MS-Office365-Filtering-Correlation-Id: b90288b2-b9f9-4a7a-78f5-08de93d24c77 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|1800799024|366016|18002099003|22082099003|56012099003; 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:LV8PR12MB9620.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(1800799024)(366016)(18002099003)(22082099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?TNv7UbhNOP4lDyXSzwbnMP6Sks5CNu6bIinxV/Qddorf61SAAP2blP18aKxq?= =?us-ascii?Q?XRwTVeLR8GnmgdLwvunCf1NJmxUs9I6kjqifnnGaAfCpRtUpv/YOja5Y+37/?= =?us-ascii?Q?hZjml7HfRGRFtcza2LluU5hswCJi30KZyGcQh/olbFl1DUbfchLV9w67Ui/F?= =?us-ascii?Q?37tQcr4V9c2jAaQL0Gx3e/9xY924sLLiGnDfqxyx6vAg91EsOSwb4B6YKx0Z?= =?us-ascii?Q?41HRGMFbLkh41EL2G9qKThp2PUt4cnvc7IGILKVcj88I1Ep4q1rs9fXK9imW?= =?us-ascii?Q?Rlpbt4qTF/LDGwjBpknbR3MlvcwVbgDleOReOy5HIb8chgmdqXzQPGkdZVIy?= =?us-ascii?Q?ZmamdEIukWVRQZHe/KVDIP/+bQ4W5oldWRuJUfXGrwa9q5g5omBwvVq6uJJw?= =?us-ascii?Q?iGA+XxajUwAAK1V/63b90YC6AntVqLuhzF1mkerrC58mvBzbcWecrStHhrmO?= =?us-ascii?Q?K3+bJ8RTCjQwZoMC1lEos4tRZWdW+/FA9fmb0oDYprOBiXyyDLg3+SfQvhAX?= =?us-ascii?Q?ecRjuZcC4m04xMCoGyoyOaD6yziXwrn/JX8Secegs5JtA3N7FjJnetLxKNfk?= =?us-ascii?Q?pr68A8PMa7aTCusUctEu17IhTRPJQMMPNhqBQ6XYtzbtLhceWpfUZPo12DlZ?= =?us-ascii?Q?b9BmURftZY7LiB280d3bMm/btUf4pQj3x2nBNyVgjGiVVL7HhVyzz4KbRrf8?= =?us-ascii?Q?RD0BAPy6CFq+GKdpOfo2QhVAJxaR1twUZm9SwGFSMHw4r+aLz1CS7V0MS8fT?= =?us-ascii?Q?wOh7K9UWKYzSet49ATkx7Vxydv4I7WHSqRfyRyGnuiwp4ABGknv1tk79s7hu?= =?us-ascii?Q?G/m3nPd0CAmvPUTnUypLVKSNii4cY2jQtoah+hZ7m8BI9d+ZYF1IQzT02pwC?= =?us-ascii?Q?R+7vwWVdUJrkw9dlsRyaSYZBILKRUeN6wB8bqSBmQWevMN1bhMIORImhOzcC?= =?us-ascii?Q?cxf/vQoPyY2gDMNZSwhVqQ0m/FpBmJwLxbvWoY60IGCql3Ut3a+cKyPLOu14?= =?us-ascii?Q?YJkdjNUgl5n9lJQHWzaaSxrKLWb/TMZg1GRO4VA7kpLJ078Uyn+FtWCA00m/?= =?us-ascii?Q?yz8BlanzEzArKzI6LOjfqN8m4Yz9DUoZIcSzrrDvLtxSqzaF4I5qwZmgCPIH?= =?us-ascii?Q?g2uwRsjoPi3nqOFu+dkiMXgdgWIYhDkGnIxbAidIYoejxz6Xf0pHm3/x+BHZ?= =?us-ascii?Q?CNGcCKUfSzINv639cKgI0C5jfaobY4D/0jMbIS66B6u3okEHYVPJeQgPfvC1?= =?us-ascii?Q?dJOmTYDOxn+cMJjgbHcEKgYCSuyDNMQRY7JFSw4BB1Arnk1vuXLcXLBnxFuO?= =?us-ascii?Q?EEAcg+lOrNlArY00+L4ZiIaQ/HdxF8jhSq7aluXko7T71fs8hOyB/9gMAVE+?= =?us-ascii?Q?c/vYZ42oRimt3psk6la/WlKst0hxPq3bRsuu+BEyt6Omx/U+3edV0VpAZF1p?= =?us-ascii?Q?HN1K8FvIUFR4rZHVgdBZsnpjk221ILAigQDnR2ari6d8cDUkftD1r7MPYMVp?= =?us-ascii?Q?+NUxrMz854vx8AeK+wJv28u9rOKtR2TjAexQdInR+lFYM2jQdWNKdQ/XgVrz?= =?us-ascii?Q?NkFmP/mJ7OM2aWLRr1XY7vEBR9TUTYm/X8zmdJcUiIE3yoG15iD5XThfEFWj?= =?us-ascii?Q?CImJsPyWE4qwwJ4/PWjXKmlWDAl5XYx908fpFTKp3ySllxAucU28oWI/jUs9?= =?us-ascii?Q?wGUtPIbr6qtGuXdGHGrgoAQL5OMJpF8P321dTl16A6mgx81S?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: b90288b2-b9f9-4a7a-78f5-08de93d24c77 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Apr 2026 11:47:37.0142 (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: Q1Dn0BRaEGHotq5GiC2Qcj2FUVGpHbtjh3B9f9TpwnXgiTEqDHMPsGGs8K41KdLb X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB9422 On Mon, Apr 06, 2026 at 10:48:51AM +0700, Suthikulpanit, Suravee wrote: > > > On 3/30/2026 7:20 PM, Jason Gunthorpe wrote: > > On Mon, Mar 30, 2026 at 08:41:53AM +0000, Suravee Suthikulpanit wrote: > > > AMD vIOMMU introduces the IOMMU Private Address (IPA) region, which is > > > used to manage data structures necessary for IOMMU virtualization within > > > the guest. > > > > > > Introduce a new domain specifically for IPA region for each IOMMU, which > > > is stored in struct amd_iommu.viommu_pdom. This domain uses AMD IOMMU v1 > > > page table. > > > > Why can't you use a normal v1 domain with all the normal existing code? > > > > Afaict it is not special at all other than it has a specific dte index? > > > > Jason > > Actually, this is quite different from the normal GPA->SPA, but rather > IPA->SPA (for case GstBufferTRPMode=1). It is used specifically for vIOMMU. > > The current mapping is: > > IOMMU General Backing Storatge: IPA = 0x0 - 0x80_0000 (8MB) > Domain ID Mapping Table: IPA = 0x10_0000_0000 - 0x1F_FFFF_FFFF (64GB) > Device ID Mapping Table: IPA = 0x20_0000_0000 - 0x27_FFFF_FFFF (32GB) > > The v1 table containing this mapping is programmed onto the Device Table > Entry index of the IOMMU device ID. I understand what it is, I'm asking why so much code is duplicated when this is just a normal domain with a straightforward mapping put in it? Jason