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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 84D87C43458 for ; Thu, 2 Jul 2026 14:42:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To: Content-Type:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5Is8eINyeAVVB+DLIHgXjkqR8cN2aETcY+mCrmiLpgo=; b=VLXEj3IZ7odraxqXR0KCHK/vVh hK28eX3Yq3xEnHi4jDqM/rKhTRPwygl2YhbAec/CBi9SGl43bpQuGcrcy3x+/n2Uu0cIJSwaJ9v/S dm7NBaXKtboj9nHPx84uLVagocJtgM/zUn/nwaO96EhANxSHW8Lqva2iqtP1VeChvif97lyrpQJug VM93mx6AmiZzhZFXvLmAqRYL0Lr1XZGMRrkUsj629K4w5sr3pX9YZuP31eQE/H1Pd1G6QULS57G9q X91vK/tK/HY+24b3m7vEvAvMChm0PvlSWEh9tC59PY6bhk6pX7IM0v52BWiQZkuVolS8DA4S593JJ tCwePTDA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wfIcF-00000004eIb-1ht5; Thu, 02 Jul 2026 14:42:11 +0000 Received: from mail-westus3azon11010008.outbound.protection.outlook.com ([52.101.201.8] helo=PH7PR06CU001.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wfIcC-00000004eHx-2CjY for linux-arm-kernel@lists.infradead.org; Thu, 02 Jul 2026 14:42:09 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=c7MIwxXnn4Xvv25uG255cgiVDXhqxhJZpaHmC1MbxY4T6P5CCu/aq03C3y72eAakt4UO8saIC1NKs5QfYcgBcwrrwllBJIAkSeLiCiHMLkUJsoP0d/T3FBrvfcqol3cH9Ks8yKPtRRVS6qC4g/3JO8eVELkJfPugzestNIvh7stXWkrFJxw9sxoMCOUXZdwh2CJjYgYYi2SX0XZ3UvPBil/tTMdrcQ+kEub/1SoQPWFHTYKuHesP+yC1HPDqaCuJQE8Wrfbdf+bU9m4vyp51zM3uf+4uXCN9MDquzf9Vb5DMuvBJNp/TkFqKkJi7iPvSmqEcdgYbV92krPaiN4cg/Q== 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=5Is8eINyeAVVB+DLIHgXjkqR8cN2aETcY+mCrmiLpgo=; b=KmCZeDO9O94qn95YUAjj9U1FiNRl3NMxDcatasbM36AFEKWO2yCTY2b3dF8XOITriqQUsunRBr2Z5U71OCqmREyL+vH9/jqkoWjo73+5laSZrM1bq8iN50/d3ihSM1zFDBtAl66gAiTo2b1QPF9xJ10JYIZTp1FDAtD2DueGtQm3ZvHvCgMTqt40u+RtZegeUDXS3yVbdKBmfeBlwAYDIDemsN+o1nxZKxQcC/dgPiyGjogqnuX1CUXTPb0rjOMHBj72YOSiFcrmzFEnayjTNg+dTjrX/hCJmg4t54cyo2+v8n32n40ozswZmwO+HtU287U41v7boyfe28l2AlqnOg== 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=5Is8eINyeAVVB+DLIHgXjkqR8cN2aETcY+mCrmiLpgo=; b=oEmIpVhUtoyb3x/ZSNuhbrCMC0m0gyHalD534J9qmUwj1BTmuClCP+81JKT+ex2Wjv+URldIR0buDvThSwDfNhzoR492nZTelGbelsQZA/sGbreRkV2ynI5DVaYs9i/BxKbuykxtanyVMMLI2W7Y7SN/dGJLDsmwUm0TvrN8GqEcO8W0uVfvO6j0FCuuXaBZ+DCvs/pyEZ4G6+9PkLeZ6+kj3lkgrwrLHXgWLWlMYceTtwCwLzkS4mqe2Kd/Yv2vomENgDXrErjPEAViG/41pEaK26VVF6aHWPUeE69nzkktdnvrOF5fEnnSPPxdlVKszR96YRXtxQGFU5HXuH6M/Q== 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 DS7PR12MB5813.namprd12.prod.outlook.com (2603:10b6:8:75::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.181.10; Thu, 2 Jul 2026 14:41:59 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%4]) with mapi id 15.21.0181.008; Thu, 2 Jul 2026 14:41:59 +0000 Date: Thu, 2 Jul 2026 11:41:57 -0300 From: Jason Gunthorpe To: Pranjal Shrivastava Cc: Mostafa Saleh , Nicolin Chen , will@kernel.org, robin.murphy@arm.com, joro@8bytes.org, kees@kernel.org, baolu.lu@linux.intel.com, kevin.tian@intel.com, miko.lenczewski@arm.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, jamien@nvidia.com Subject: Re: [PATCH rc v7 0/7] iommu/arm-smmu-v3: Fix device crash on kdump kernel Message-ID: <20260702144157.GM7481@nvidia.com> References: <20260630185942.GF7481@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: YT4PR01CA0250.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:10f::22) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|DS7PR12MB5813:EE_ X-MS-Office365-Filtering-Correlation-Id: d7570ea1-5d2b-4313-58c0-08ded8481240 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|23010399003|1800799024|376014|366016|18002099003|22082099003|11063799006|4143699003|6133799003|56012099006; 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)(23010399003)(1800799024)(376014)(366016)(18002099003)(22082099003)(11063799006)(4143699003)(6133799003)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?uL6iBiLfzQ1EEmHEPUtS7NBIkNYI2zzDA8CBa9I6gLEQwSamdYP8oVBKoX7S?= =?us-ascii?Q?4g9JLOlLrc5PEGsE3/LW/qtJAxoCZ8bJu29mxDRHYuwmRGp+31ykQXy/uom4?= =?us-ascii?Q?n5Z6i+/ygQaAUdQKK/jM9FeadyfWkVhYIBW2Oj2JZjxOCk68KdUVG+3RFrUx?= =?us-ascii?Q?QfHRSeOLEMQ6LVKu+7yzc7CbQ8HWq8EqmXBeFoRphET+QvLdvxAbl67Wnp92?= =?us-ascii?Q?KWmVd6Hgef91DgyGD4jQz5fdLRn0i+PayDngXxi+EHy6od0Z0sxHxKUUsljG?= =?us-ascii?Q?toyCk2OTGjC6mg1DWOgX+ABstieFQQBDbkFvpIxjZPpSW4u7ypbZrWqdFIG3?= =?us-ascii?Q?1S1MWw5aumcMOE9IK/+KGIv2/Dv5j8asoXDk7f+vzXbUslQGJcBY8KL78+Mw?= =?us-ascii?Q?XfQ7GAyORIy/adX3rXeAs+g+8DbRlCcXReBsW8pzBOH79rj+5X2tBGgMlHnb?= =?us-ascii?Q?GJvzivsVOVT7FtROsOb+29zH5ER5/BZsAgohvHvLjHKe3W730K3kZ4EbUQU8?= =?us-ascii?Q?yaL58pqPXCMVyaB+/7CbDYhKGRuo8U439uBWXcHvA+X4OtKFabUz97aykXpE?= =?us-ascii?Q?kgZgQRyFqqJvEBa9/u22l6hLScO0iZYTLN3SMpQsyCzCAcQU9cds6xNhpF9l?= =?us-ascii?Q?VDqxDOjO0MEJ7UQnPbgnhsSZ9g+G2mMBzeQCeB6CfqoP9BSIJmC7Sw/9Bz71?= =?us-ascii?Q?Fnf+04mBohw4H7yMfWcH/zRabW5iNNakGKHMRRsZ6kPeBgmQyTPZljtHojod?= =?us-ascii?Q?on6y7xatHvZ+CVI2xvtXbMhWzcM3ssfcAyOk6UskBKXlabuOG+BwNDJ/ByLn?= =?us-ascii?Q?I3/Zsjni+wSGU8TufwJIkZHjtdBBtAsZINzzZqYyTOEGj8ZFJKINKIdXuXXL?= =?us-ascii?Q?KjH53pugwhtqjAKXX5Id0ZX6+VaDP8dY479KB4OZQo/wFP8j73fLEwj+MLzo?= =?us-ascii?Q?/6d1wzuVKeol9TuzKSPUpgybXIYnv9R7VZ8Ohx6ShvrTek8Q2d8o+THY8y1s?= =?us-ascii?Q?+A2iCFwkp40MfTxqwksOfYhC5aK4USszfU+cZZdZY15AmNvJuQCQd6gqfdA0?= =?us-ascii?Q?M6U/IzwbSKofFCxVzGs1myw3O3PFEs4sBBvJMByhBuK8YpztU+/HsA6TY2Co?= =?us-ascii?Q?5NB/ubW2jj77Xa1NUOdq2xkJBIpVIdCa2tg9KrJ4+xNK7n3nFIVzCOSRVogf?= =?us-ascii?Q?7ozeC8AYOKZxYX0MgH14WJ+avU2REoJ9GCjbklxgH/V3Vycrvh0fp8mIRhPi?= =?us-ascii?Q?O+iL874joDd7QOxDXGTwE19yUhPgyHPjekMGwcaD7+9p+S3aEuu8Ym0GhTtn?= =?us-ascii?Q?V5s9uod2Ec2dc+yyipDjwjnDUhPy6JMtkhgYHTDtzQ105bitm8YOu/HB/Fbc?= =?us-ascii?Q?jVN92n4CY1VJyV80b+ovNROFV5ly5Zh7uhSkU/oE2SChQQqAdV87Z3qby1Hm?= =?us-ascii?Q?SEUHIqcGQFC8rLTzwajcsjUbCg/EInB+yYE/3S4imZuiaTjmjo8g0vMenEpB?= =?us-ascii?Q?6ZTzlGPESHttIKrea+42dJfOCYYCUyuleJn55CAsOh0bv/K4PKm0d+cX58Tn?= =?us-ascii?Q?mQ7w/PbVDPQRuJHLNDV1s5tfH7FF5zgN2UbeR5tTWo7wCkq81fmoAta2Faxq?= =?us-ascii?Q?cZsoHeXJ3oi/gyuvrqSNfNYlL5hxYbwlVDOPeNLyKMyULH3tISYdGrQ39In9?= =?us-ascii?Q?AR0qoebSZ4Vda5WWX1c935+ONjegfWJtUQwKYl/Coj5XZNfR?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: d7570ea1-5d2b-4313-58c0-08ded8481240 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jul 2026 14:41:59.0588 (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: ylMJV0lnIGhiHgaU/QqPAsdNLGXl1XJbtpqZtAZaOpjMJdOCro0s0agmHtyBa1Xy X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB5813 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260702_074208_564286_1E3EABC8 X-CRM114-Status: GOOD ( 12.95 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jul 01, 2026 at 01:36:29PM +0000, Pranjal Shrivastava wrote: > However, I agree with the overall problem, i.e. IF an active device > unmaps the DMA addr after the transaction in the previous kernel, > (with the SMMU powered ON) but the TLBI was missed due to a crash/panic, > Any new DMA in the new kernel may alias onto a memory in the previous > (crashed) kernel, not the kdump kernel. It looks like there is an issue in this series, it isn't doing anything with the VMIDs. The VMIDs that are in-used by the adopted stream table have to be removed from the idr as well (and similarly for ASID if we don't have VMID HW support). Then the VMIDs that may be dirtied by the prior kernel remain isolated and are never re-used by the new kernel. When the new kernel wants to do DMA it will replace the STE with a new, clean VMID, and there is no problem. Jason