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 6CB5FD3A678 for ; Tue, 29 Oct 2024 17:37:00 +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:In-Reply-To:Content-Type: MIME-Version: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=+nc3oOAYkIVH2K+Vb1WyqN9ZvBvS4TANHUyo0vFFgxE=; b=xRQFDyinBncNd4RMcGVrhss7eo a2N+dSncPv3V0An9M7VAAvpRF5KCVbO1JqwmUMefhsgiHvYmaUwjj0hmCXiaWPy+9MNhrdosRTy/j fa5TG1Br0Eu7V1hANUJTm0Eb/ueu16jsAbhJQzwW8Ga1/vfPZbkPAbEG31Mkn996gR75YUpnITuj9 FFzVRAruh4Ob3jK1cAlyZbJXTRAXPLYn95xX8niwooyrUzE8vyT3geSc+DFfiSTeXg/dVmvQ+pxAa aY4wDvEG17X81XFe5NRBelV5+p7vZLLqozDcXaEM0mdPAva0cwx1x1Hek9g0NURAUQRe3xbzx6C4P upp6oVuw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t5q97-0000000FIY5-2vPY; Tue, 29 Oct 2024 17:36:45 +0000 Received: from mail-dm6nam11on20611.outbound.protection.outlook.com ([2a01:111:f403:2415::611] helo=NAM11-DM6-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t5ogv-0000000F3AI-1z4C for linux-arm-kernel@lists.infradead.org; Tue, 29 Oct 2024 16:03:35 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=CoQqQCIwkJTrpsvdVKadwCVY7S1yPr0mygX+WEbGiBl1su01GGkQ7DejmWH9XQAGbBGF/4jPkHyo3OHS5rw7sBVOY+xHaFUhoe6LoeOZfKtwymtnuKS1kI6X3t4XDOhsyXjCXYPX6cmy4Aexj4ggZiX+P+1q92bTBtA1GhH3YfdqAUqKtffRojjefk/n9v7hvXkHktWurzkT7ILNNoPiWo5tcJzu3egm/tHKG/BpA0udHFzelXjB7YLDPM0pzjQAulL5rrSF7qqy5G9H4rOiYQEpW+DDfenpy+fsyNw9W7CT4MtjBDgs3dGNKWuONfXH61vmz133tmT4H9zcH7jdOA== 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=+nc3oOAYkIVH2K+Vb1WyqN9ZvBvS4TANHUyo0vFFgxE=; b=UAzy6iJZCZKc3Ir9mib5RziBsNbRCB9YLyLPPq4/Fs13owyXDCDa2rvLROR3o1vS/OkdvzNZhOBBiSzNta5hmVD8V+u5+GfZuNhNoZ+H+ITJ3sSsVFCQJpoerhzIEdi5NhkdeU+0BDb8ZRG+4zFD2d6ToRY+41V7APrBomc+PS1hutYjPEtJnb7XS6gQUUNYYXfbyR/LRflz9O6jq/5oFsscTAt7FUyFlDIwcwSo6rLOnTrhJzzUD95PsEevtau21v5HgCESInZNjIxZCO9eqs//vsLLxUNEAYSRUkCkiJC87aPPwOFyjAgUFqxLQiLoKMX0TJyhzf7/QZbd0sSkAw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.161) smtp.rcpttodomain=amd.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 (0) 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=+nc3oOAYkIVH2K+Vb1WyqN9ZvBvS4TANHUyo0vFFgxE=; b=ICWS85dslu8O6CQPmlgh19DufP/+7E7NjrRWbf+7jRGmA7fJQ9PHtfMAQxRZuWAZzFOaKzNk55DlHiTQ80lbJH3b8i7947eCPwTmpVRc+Y7CcWd+HNVWRZrEQFxi3eMpXzDyTSe+HuDPRsI8dV9tGotZTp08/sV43PB49GkG+fs2kC4k7JFOk24YqctgrbE5JfZhG1+CWrQX9POlr2sq8g1nBrR2roe8cDY1HjKVogNFt6xRotDYSOrPlp3aiV0djd1N9d3y7+TNQZhJxh+K0Ga5Db+LsIkh8Tev2Wpq/yx12XH8JSl0vFfB9VNgzMJGBYeB/jlKji5jvIBl9+8mxg== Received: from MN2PR08CA0017.namprd08.prod.outlook.com (2603:10b6:208:239::22) by MN0PR12MB5836.namprd12.prod.outlook.com (2603:10b6:208:37b::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8093.23; Tue, 29 Oct 2024 16:03:25 +0000 Received: from BL6PEPF0001AB55.namprd02.prod.outlook.com (2603:10b6:208:239:cafe::f9) by MN2PR08CA0017.outlook.office365.com (2603:10b6:208:239::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8093.25 via Frontend Transport; Tue, 29 Oct 2024 16:03:25 +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 BL6PEPF0001AB55.mail.protection.outlook.com (10.167.241.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8114.16 via Frontend Transport; Tue, 29 Oct 2024 16:03:25 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) 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 15.2.1544.4; Tue, 29 Oct 2024 09:03:02 -0700 Received: from rnnvmail204.nvidia.com (10.129.68.6) by rnnvmail201.nvidia.com (10.129.68.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.4; Tue, 29 Oct 2024 09:03:01 -0700 Received: from Asurada-Nvidia (10.127.8.12) by mail.nvidia.com (10.129.68.6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.4 via Frontend Transport; Tue, 29 Oct 2024 09:03:00 -0700 Date: Tue, 29 Oct 2024 09:02:58 -0700 From: Nicolin Chen To: Jason Gunthorpe CC: , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v5 09/13] iommufd/selftest: Add refcount to mock_iommu_device Message-ID: References: <20241029153438.GH209124@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20241029153438.GH209124@nvidia.com> X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL6PEPF0001AB55:EE_|MN0PR12MB5836:EE_ X-MS-Office365-Filtering-Correlation-Id: 5ac85655-8b1e-45d2-f70e-08dcf833388e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|1800799024|36860700013|82310400026; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?+UizP5ad71aOc3Ex5+H7I8lb4MuZiqouHVFjEf8OLK1GvUKh4zOJTZfWsdhJ?= =?us-ascii?Q?0t8u/nHKrRbt6u/rwCVf2qsrgoztQYfqjLd9F+INu/NLUGRlmS+/5VM7wBaf?= =?us-ascii?Q?xxL47hD3QlMJOUnb57bbGu7gwU4aHEkO09a2cFS8tyZG2eUlVmFYLK71QXTF?= =?us-ascii?Q?Da1ruScnElvPPWs9UIjDmTDl8acytSc6E9zvlVuMszUNA4uGtLx8Gn9MrW7c?= =?us-ascii?Q?qTGII/KdGWZY69PWxOKkQjW1qtuTT8q9dyAEn2SNPjye2SfKdwF516jIXEaY?= =?us-ascii?Q?Q3mDKAoTZ3jJ//PblkCbvze0HTajREF5h/cPwUJhuezzL9OWujF9ExABW0G9?= =?us-ascii?Q?lxxjaxd+W8WCYx5mgIVTlze8GP99t57lqRwneUNy6ozGUJfAZBtAOS2VO7cE?= =?us-ascii?Q?bjo3XCZgfLb3QgPYORrT1o3SJSFvx4EBH3cNxYS26veLKBjHdXvlxjLPALrs?= =?us-ascii?Q?AhmjccjX0AAMT77+JJc+cZmfZvXpE8puxhyO2kZ0gahT6rJB1Tjaia8I3GQM?= =?us-ascii?Q?FNJTGcEe7usJeJcT9icKXWkI36jHwIs0Kz/W/b0RNuMA8c3cBzjzUoXhk0Qb?= =?us-ascii?Q?itDPQVhZnYE+kt0aHGdHZ/iiTHM0cSAFwrWmBmgyt6AHS1Z48xIlUG0zrIGY?= =?us-ascii?Q?me7XpHdAm2wYOO2rlqKlToaaX4Iyo3vfRgBfojfX3CYWehDYPCn60InlISS2?= =?us-ascii?Q?o7q8ExLXt4Ijc4eCW5GlX4sPhfvROK4G+VXOuPnM+bWkTWoOrj4uBJEabUXi?= =?us-ascii?Q?M+Pv9lSYF39ESZjf/Zoygd0tQHbq1nwz9ZXRKVjX1i6vZlwPfD8x5SjLIgLw?= =?us-ascii?Q?1U3wcFHAIRmG0JK8qpRcO9Mf8b3jh7RAi61OHV5B9aCJzJXHX0IaFvSKY28F?= =?us-ascii?Q?1iTy6yqR/pQI299udkDpS4wvAIhvdJMB+PzEndM+xD/TnjZ9LaMPl2bp9AeD?= =?us-ascii?Q?gobokkMSmkDwPnsj3d02UukalFAeu13tHVPV3ilzkT4iUJ5xGyLg2FWkA3tQ?= =?us-ascii?Q?b1o18Q3/T8M9++WM2/5GdKaWSlGguy3EsQnuyyuEWE9xYo5twtQYhY96nSIW?= =?us-ascii?Q?AaSxra3sheKbNjX45PNvByXfjbjsWhWTGpuySoQDs5Xptjwdhyjdgg3O2v49?= =?us-ascii?Q?RDuHlWl52o9Hgav8jEMKTG/F1oAJnfXm+VtzH5Jr/zHp6gARsgBy1hX7qsTs?= =?us-ascii?Q?89i0QLG/l24D9AK0ojiiOFiASkGpH2buxPAz8oYz+pIVGIFxfsZXeXKB4Gh4?= =?us-ascii?Q?P7ENqy3LxwpLna9mRoUKGnRSn5P+GIjVqaJm8iJKDbUYeuQRqBzn0qK8aTwU?= =?us-ascii?Q?/lSaTSXNu2wY0XGmA3eWr0suTSXYfRar8j6n47NLvRA/NEKdAt9RADkR8KZw?= =?us-ascii?Q?wjf8FfX6lKgO8iGHcmb+uwIylJ1S/6hRiDV6p1TdX+MU09MSXA=3D=3D?= 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:(13230040)(7416014)(376014)(1800799024)(36860700013)(82310400026);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Oct 2024 16:03:25.3963 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5ac85655-8b1e-45d2-f70e-08dcf833388e 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: BL6PEPF0001AB55.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN0PR12MB5836 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241029_090333_544029_77BD7883 X-CRM114-Status: GOOD ( 17.91 ) 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 Tue, Oct 29, 2024 at 12:34:38PM -0300, Jason Gunthorpe wrote: > On Fri, Oct 25, 2024 at 04:49:49PM -0700, Nicolin Chen wrote: > > For an iommu_dev that can unplug (so far only this selftest does so), the > > viommu->iommu_dev pointer has no guarantee of its life cycle after it is > > copied from the idev->dev->iommu->iommu_dev. > > > > Track the user count of the iommu_dev. Postpone the exit routine using a > > completion, if refcount is unbalanced. The refcount inc/dec will be added > > in the following patch. > > > > Signed-off-by: Nicolin Chen > > --- > > drivers/iommu/iommufd/selftest.c | 32 ++++++++++++++++++++++++-------- > > 1 file changed, 24 insertions(+), 8 deletions(-) > > Reviewed-by: Jason Gunthorpe > > Since this is built into the iommufd module it can't be unloaded > without also unloading iommufd, which is impossible as long as any > iommufd FDs are open. So I expect that the WARN_ON can never happen. Hmm, I assume we still need this patch then? Could a faulty "--force" possibly trigger it? Nicolin