From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM04-DM6-obe.outbound.protection.outlook.com (mail-dm6nam04on2053.outbound.protection.outlook.com [40.107.102.53]) (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 AF76217578 for ; Wed, 9 Jul 2025 18:54:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.102.53 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752087257; cv=fail; b=iauPFKuSZIDWY2C+AKaYO2fV06bMZLhYjhLRcI9vKxFW1Y0VnsBJOFiNYY5WBl7bIRJ6ODF6Vx+HjiBRjwtxE89S5z+1Rgp77xlUKwze1MG53AicMgw6Kn2EmvlCQqkq5PKMN840PbG5G/0IKnm9OV99UdWFDHC+wCyAODgvJA4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752087257; c=relaxed/simple; bh=dz66vuwNEKtY0awqg9xi+zmcTBYGekcVgscsw/9A5P0=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=m9//V1f0iPpt/nNXXSZXRmBp6zYMwMDKPWicnZHam4HXFmlLw3B3xHLkEw9lvlhUZdPZmyKl4S4z7qdWyiFKPIFvubcjsHjsPxkwKiJaRuQACBwld79OupiYSFNBQQxtz3fB1DMDB//Gkgd7k632JesDPKHjzpyGaTyHe1ykAHs= 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=Wun486qS; arc=fail smtp.client-ip=40.107.102.53 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="Wun486qS" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=WoW4Ik1rJyPVwEb+7bG/fczUXKs/jbTP9EB/gE1ZC1xanS75wr1Z7oi35D7UUpbwghdeP/9odVuONIyFzkdmQZWqXPdHjyLSzoz+wxvOX5M9PgxPlp25zSA3s66MPtqOyx0L6Txi740GYdaXGcABU5fcsiqbkWQzJ6edhknmxk8nWfrLCAGD7oy3FLA2ghqUvEec9FkimV4aelialGihQG14ZDNW8A0NAZSCx4tExdt6rT8R3FK79DLhLCFJB7hxpU2LoXb7EgXNrjoFtaKyJR5E2RwLb+2fEoir1PvHC43pqkfyu+ypSDhugnu5TfFQUtEMT5C+nRDhrw0d5sjZ7g== 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=dz66vuwNEKtY0awqg9xi+zmcTBYGekcVgscsw/9A5P0=; b=ie8L+KrGSeLIhnhgdqhA4y0gH5fYdrVHF7eSJi8tL/r54k9zdrMaSYXez6J6JnpJ9zBoG9uuVgKzVpCdQfAQMowR2+qU9xwusKj5oZYMISQVSDjRNJhBf+5MF3sBfSt1l9O5iU2yY7mzPm1L02vX/wqY848BnpH1D9iNA4UAkqB+XG8JMnyoZ2ViclTAzLBC+1ftrwIHtoN8JSWgfIl2+bbSO6DQcUN7Ki+5OXZNHTV6KIkR2qSCZbfqRSPll7otfqU82467y15aq0Xx+7RDJPfyWcKjci9KPRYT/XLBOfm7871mFKJAwUSgc96miYhJHi7sZCZ5NuaG6/Los2/85A== 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=dz66vuwNEKtY0awqg9xi+zmcTBYGekcVgscsw/9A5P0=; b=Wun486qSDhpl+4ENxepxdJhUYspsVdhMpjvWpSEp3eAPp7DA3cxHJ5OeXAOLZKbRcc023oG2TVJZ3hyujB6qdZioNMy6q0dKrxPWs4TxK3k/9BL3ble+gO6lax1F6qfR/wepUaiDwnu1YINBzsVnIVvmWsNHO9hiQcc4E27fMTMOdSX9LyGo2HSHa8Q64sHi7SopViwbfwfGJHyihVWcECG5KmbK03a8o5+c2mjjYCADqOutGFhr0VHHIyeLf5N83zfPC5kTzCZalJ7J76yN/v9MeKnbZ2MRCklpwfyS1FJfw6vNxBrPrm71EnDxoD7Z4ja/I/tBa26mgyIVZLvGZg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) by DS7PR12MB9527.namprd12.prod.outlook.com (2603:10b6:8:251::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8901.27; Wed, 9 Jul 2025 18:54:12 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%7]) with mapi id 15.20.8901.024; Wed, 9 Jul 2025 18:54:12 +0000 Date: Wed, 9 Jul 2025 15:54:11 -0300 From: Jason Gunthorpe To: Jacob Pan Cc: Dave Hansen , Lu Baolu , Joerg Roedel , Will Deacon , Robin Murphy , Kevin Tian , Jann Horn , Vasant Hegde , Alistair Popple , Peter Zijlstra , Uladzislau Rezki , Jean-Philippe Brucker , Andy Lutomirski , iommu@lists.linux.dev, security@kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 1/1] iommu/sva: Invalidate KVA range on kernel TLB flush Message-ID: <20250709185411.GJ1599700@nvidia.com> References: <20250704133056.4023816-1-baolu.lu@linux.intel.com> <20250709085158.0f050630@DESKTOP-0403QTC.> <20250709162724.GE1599700@nvidia.com> <20250709111527.5ba9bc31@DESKTOP-0403QTC.> <42c500b8-6ffb-4793-85c0-d3fbae0116f1@intel.com> <20250709114432.294425ff@DESKTOP-0403QTC.> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250709114432.294425ff@DESKTOP-0403QTC.> X-ClientProxiedBy: BL1PR13CA0196.namprd13.prod.outlook.com (2603:10b6:208:2be::21) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|DS7PR12MB9527:EE_ X-MS-Office365-Filtering-Correlation-Id: 36d3e276-f177-4b15-c21a-08ddbf19febf X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?qKQvoJu5dCAphwvuzQHUZgut6Wat5ENbQDBjbpt1N4TnQm3LtAa09yjjWmmy?= =?us-ascii?Q?W0ac/Cieb6Rc9pyp2tYMFwi+LeLhzH9GpRx83pDPFGfc9q38OQIi9Tb11Cj+?= =?us-ascii?Q?q4ArJ9UAz2WnT6fuifrvC9hLxx0jhZXn6oW3J0/PPlxO+okR/w7tv8j8FnxC?= =?us-ascii?Q?oZkYQMtw6J+v9Cit20MvzwKoG95VFepaiTNu/dSwpf+n6ufOmGbwhgQ1WzVa?= =?us-ascii?Q?47ALZ1r/+PUVNoa4yQqSZCPJOGMvIiY+eOQOTGZZdvaIwxT+ZpjGLgllUDNk?= =?us-ascii?Q?48PnJkTOiio1tfgHNIRF6ou1JjxlluMgZ3lgixD1pr7eh6HsQ55Ys0+cAJd5?= =?us-ascii?Q?09O8kgasFf/vG0foPmrLXAK+x1CNejbvg6knIYRdzYAx3rarzrTNWxrvwKtA?= =?us-ascii?Q?0erusGbGQpSZP73F7z3gHttovcs0xNZx+IJDGdqHa731pOl71fh+4goVfpNP?= =?us-ascii?Q?z9rOPRC4bxR3uNBj0+B907qRzBH70hcn1muKw6W0BMEVTNAT2/c/kfZdNoQP?= =?us-ascii?Q?DQ9RlUTYjl5u73ALt1fgM14d0aQmr9hjUc+hWRt1LwjgAbjo8uPXPb/Yn6zg?= =?us-ascii?Q?VPApd0on17LXbEmLuYDJlyJ4UoL4ENq8WojxZ0YeeqyGfOoGja+8GuTWCsdl?= =?us-ascii?Q?I7SC8aBn3+C96VZGsc1ceN968nhIMe6cS4WtNC0/3Lu7GhTCrhAQoGmeY4br?= =?us-ascii?Q?1Z7QtFFofLtzXK4bwuRASo6zQ1BPrIkDPZrsNf2w0FFxkwKdyLSTD3UggNWb?= =?us-ascii?Q?q+ctjNhGmRt944LRecBiPagKjfhiG31xArSiGIW1tI3ut2LnOYo0yvDPfn2K?= =?us-ascii?Q?9HmPJGPBgnj2+Vh1DZjDIIffP9lozOp+MgQ3OsNrJ8UtaEtwvJ6oYzC36HV3?= =?us-ascii?Q?5bp7ueLYgDw9uuZ9tpXAfdRRV+KvOQPKxqMUL3nwVmmgbZ8KL5w8kPeoiHrD?= =?us-ascii?Q?hJTTT7TJxYqFGnZrap7yvA42jqbFGTPrbT9UmMYDLENGtxjhbXDJfHKgG6jb?= =?us-ascii?Q?57vv/1Cb8V/igv/UL7met1mlHIuQePgB5BsdmPGRhuJE2FwCGDKjs2H0qLuE?= =?us-ascii?Q?wxFUZIPbz/G812zNMDYEe7/cPdPLTcy72xFrpI2ZWiJd/cR007iqji2HUqJ/?= =?us-ascii?Q?bwviWi4aGv9Jmz1WCTb7NBVOKQrHneJOhTDgN/wXqyhvW9j01Zc7xKlzWQVX?= =?us-ascii?Q?n3FFOAGXkDP+OYYvpfD9ssIs4NCprETxWH2aGhpS+K9Pii6G4DCiKKqpnQsN?= =?us-ascii?Q?D27ZIqfE4obIGsl6u5FC/LkaU1/Dxm9RIPzQU2J7AUCXVfu4dE4BPN1hE3Oe?= =?us-ascii?Q?J3ejH5oZzen09RKd359qh9oQLk6RJbIp9VDyFlaBgKCNpPgZ1JMrXDVbfBr6?= =?us-ascii?Q?CKiFl0XI0b/2fBSxP+n8cAjNyvzxYITrRjZpmdmumrDKUDj7lw6rJpvQRQK2?= =?us-ascii?Q?EqCmmYMUx24=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB8659.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(7416014)(376014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?tAVZuC82iverkdQdRewuKC1ZAZep5QFXgWpSO4LRErjVuMWySR2Upgz/VXYR?= =?us-ascii?Q?16jx3ZjvpfbFXb6wQBSx2jK/quU9X20NHrKEOkHFicz1JM1mdH9rTM2I9bWR?= =?us-ascii?Q?uDxbJ6yxMu8fzZp47fUWeCsGI246Fa+C6wEgQdQHXEhzvF3so2hHHXBvpFvD?= =?us-ascii?Q?bHdWSilPWV0+DxoxBzCBG5a4hZu3VF3irezBqcI+8Ijk7vNxWLFhwTreIi9e?= =?us-ascii?Q?cqy/aASo7PsjC7WobAVIxsJwBHHPaNFyPNNZV5wiO90dMWF5I27U7Chfrn9m?= =?us-ascii?Q?hHh2yvUcg+xKGM0xi6LUSEzVLgb/mlR4b9MCrWN9I2wZYhwuyX2khUUHOVDp?= =?us-ascii?Q?NjAtHw2mSN6zFNKhDb/yjKmd7pRdGgwkB/Z475NGJ1hG4qrdm1Jj/XyZnM3C?= =?us-ascii?Q?3pHVOa0MewC7ZcxWqsSVNBn8av1aaSf6ZspJYU7DKO1XciaoME1jAvwORkgG?= =?us-ascii?Q?j1EF0nP6uoCvynIMT0gfcBIetjTsAxGCZAHKNNod+OHXs8AfJ3JVTvdaHkba?= =?us-ascii?Q?RoMOIfchMExuaYxgCbxf5b+3RAL0/HtBJZlPx+CngrILPKmE5IYBhuKMoHy8?= =?us-ascii?Q?p4PuxhwipZs1I8vQwe9Fymp2q+c86zsR6ik0e7yyAbqwUf8odsEAYom6yqIW?= =?us-ascii?Q?HTT+tNse+f2B6qV0vpJb0CZx8ldwVXPsf5/MeoLTqT9c7e5gkyIboY5Me0WB?= =?us-ascii?Q?2USrTzTN3QWKvgBAPZpyMywP4egRe1CWIGCTdq582y/6EKWC3zF5ASh/HE+9?= =?us-ascii?Q?GwxhmWuox8WtMZrjIBo7obpAXpPc0x5SW3EQq/tCE999m0UoEu3Yoiilh7pv?= =?us-ascii?Q?qV3NkN1EodQp62YQ9ENaAiZmOF3ggyCMz4/GT3iU7oWN7tgDvygiGzzNn7DY?= =?us-ascii?Q?fGHqIk2XqD+sEwOzW5E6Fl+GrlurHgupU0a1haJ0plZ3Jv2QzLCrc9Tqo89J?= =?us-ascii?Q?42AU28pGQmn0JQOr836ZyplElqwiAzd+mcxQRnST5KIRpuw6//fJnw6m+6Mg?= =?us-ascii?Q?gtF/2WWGK8OQlI0UXYQ8Lz+QYLXE6DA7ejwkREHxtqbmXdDRcsZb+g9iEGtB?= =?us-ascii?Q?auleUc2ffcVLx/CAbDyqr09tppx9H32yCeAI4qB/SWLcj6VpCroc/sRNL45E?= =?us-ascii?Q?aFY/pMwmP4PhSn+c1fsU3j0kIxw4qSO7ZU8cxUm850a76pcDVpMMHCdujC7o?= =?us-ascii?Q?9nlfTOeNPdbDZBvz/8L2VjzmfZTpVBWk2DjHhfKcMp4mQtpfzpahp7s1r8sI?= =?us-ascii?Q?focd5CuvSIQj8BFPnaGxDajPZrRWOELFixyzC16DkAFK6DQcCVpn8Oxm+RIe?= =?us-ascii?Q?wTkjjh2Vj451OYAhGua2iy6sfdtFGVQEe2rA3EipDGJhLL7QHHtOS6D67hV+?= =?us-ascii?Q?GEtlD3k+neRVQQllbeGGyBzIEZOfWqxWp2eYAjthoVlVav6C0gJszTZ6MqyX?= =?us-ascii?Q?wrch1wGK2EqrCF4tQiKbUrvZch+2Fn8Pal8gQEOl8pvN0e5P3YHkS0vjerft?= =?us-ascii?Q?xnIgKZPyvjMnxs7gybJZzLlr5XCVQff7vESXzP/pPTFyZPi7lQau+YMaWsYW?= =?us-ascii?Q?JKK/aPRik7F0PJMnSOftuEZ0eyYgdfJa20MPnw8Q?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 36d3e276-f177-4b15-c21a-08ddbf19febf X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jul 2025 18:54:12.7925 (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: dwJiDrc3et1mCWkwNguamcBkiU95auSw0fExlwtBEU5/9obazwpSIsdK6mvLTGlg X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB9527 On Wed, Jul 09, 2025 at 11:44:32AM -0700, Jacob Pan wrote: > So you are saying IOMMU can cache user DMA initiated walks and cache > with supervisor privilige? Since the SVA PASID is a user PASID, even if > IOMMU uses the cache later on, how could it get supervior privilege? The walk cache (aka paging structure cache) and IOTLB cache are different things. The walk cache has no concept of privilege. All memory holding page tables can be loaded into the walk cache. Meaning any table in the radix tree is eligible to reside in the walk cache. So we point the IOMMU at the CR3 of a MM struct with KVA's mapped into it and the walk cache is permitted to somehow cache every single 4k page that comprises that radix tree. Supervisor does not come into it at all. I had hoped the U/S bits within the table structure itself would effect the walk cache but it was confirmed that it does not. Jason