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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8936EB64D7 for ; Fri, 23 Jun 2023 14:22:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231433AbjFWOWu (ORCPT ); Fri, 23 Jun 2023 10:22:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230491AbjFWOWs (ORCPT ); Fri, 23 Jun 2023 10:22:48 -0400 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2077.outbound.protection.outlook.com [40.107.244.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FA54A2; Fri, 23 Jun 2023 07:22:46 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=j4lUBHyIGSB+MK5r0c65lJQfaV6iTJPJ5AXjYr84MI6+W7InKEGEoKYTw3pGR+7pCvcZyaaU6MDx2tfZ6R1WWJE85GOeY1NPSFmzMqNKi2VLIHuVTzbpgHO9Ycqn3c8kYqaE1xQZrhhDX5gJCnQfLnnVhyIDjOlx4G//kkrQFDP6tR8WNq6e/NkOtDnBqFq/TA7TsTkRTMzx/r29qS5UBmnluOXMVcmObQzPbaJVYfd4IPzklE7sSEbp/PpFov6gC8gltbDC8ok49xUMel251oEFRUvL+MOPEBClw90IuishMRVG1fY61znOig09Ocfo4DSlsgtiWTCP8ZOGCTJtPw== 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=LMRaTDl2dBA3njqhP91fAVbvd61tK0oSfUWmkOogNBc=; b=T16MHpRN3FwKAC5KmtVxBBli91PMnveYpapyssgRkcbwVJGkhIdaku972KAzcEzIGi8kUHtsAM1fmkE69ZEPPdpnrmRpJWSHAEtL98ywaZh6BWIopkrA1fXiRR+tn4olwayzIiIBBz98gDi13XcTBh0+DuuIi8uK2mnE0wMuX+JsFh3DUzEKIgVl8RDzgV6vSSg5ZUpi9NlSme8TDFaM/nXxbnLzSvIWgn8ZZ4e84j+OiTVuqXUUmqUnjPcPBJeNowwqHLSYICglDOngXo1iKklPgqlu6BV/HQD2TvlCYnfc8Aj8K75IrhupqcYGnTKlU0xMAE8G995ja38H1NgzuQ== 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=LMRaTDl2dBA3njqhP91fAVbvd61tK0oSfUWmkOogNBc=; b=cwhUvg/a2cxWqlybFmUGnB+9ZBFHs78kwhz6eLNVTDKVyk2RBxLi3B8YA81Tme/rjHf72v45hnYj+apWAzucnJudMvPW3XK3E9Fiwwt+DVAP9fofLTkbhWwU+V1+qVOR3V2WlC5SqUL4ZITDfejHLpWZbXLUvGjBEzNEp+0Mjw8xW4ksTY3CJZFfftewa76r+kXuZhsRLKKqYc3SFr4XucP0wLxJVh5ZEaqwZJY/sAKs+Wl2HzgFFgQlqm7HYl5TO1oquEKcILdF5lTLoZwpDvr6NXjXDCy12+zADtEKiQaL40oVfDkN4e7xLnbAQ5sh2x5GhxFAP8Q7YQeFTYu9FQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) by BY5PR12MB4178.namprd12.prod.outlook.com (2603:10b6:a03:20e::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6521.26; Fri, 23 Jun 2023 14:22:44 +0000 Received: from LV2PR12MB5869.namprd12.prod.outlook.com ([fe80::f7a7:a561:87e9:5fab]) by LV2PR12MB5869.namprd12.prod.outlook.com ([fe80::f7a7:a561:87e9:5fab%7]) with mapi id 15.20.6521.024; Fri, 23 Jun 2023 14:22:44 +0000 Date: Fri, 23 Jun 2023 11:22:42 -0300 From: Jason Gunthorpe To: Yi Liu Cc: alex.williamson@redhat.com, kevin.tian@intel.com, joro@8bytes.org, robin.murphy@arm.com, cohuck@redhat.com, eric.auger@redhat.com, nicolinc@nvidia.com, kvm@vger.kernel.org, mjrosato@linux.ibm.com, chao.p.peng@linux.intel.com, yi.y.sun@linux.intel.com, peterx@redhat.com, jasowang@redhat.com, shameerali.kolothum.thodi@huawei.com, lulu@redhat.com, suravee.suthikulpanit@amd.com, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-s390@vger.kernel.org, xudong.hao@intel.com, yan.y.zhao@intel.com, terrence.xu@intel.com, yanting.jiang@intel.com, zhenzhong.duan@intel.com, clegoate@redhat.com Subject: Re: [PATCH v12 16/24] vfio: Move vfio_device_group_unregister() to be the first operation in unregister Message-ID: References: <20230602121653.80017-1-yi.l.liu@intel.com> <20230602121653.80017-17-yi.l.liu@intel.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230602121653.80017-17-yi.l.liu@intel.com> X-ClientProxiedBy: CH2PR14CA0031.namprd14.prod.outlook.com (2603:10b6:610:56::11) To LV2PR12MB5869.namprd12.prod.outlook.com (2603:10b6:408:176::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV2PR12MB5869:EE_|BY5PR12MB4178:EE_ X-MS-Office365-Filtering-Correlation-Id: c60fa397-9442-4ee7-e660-08db73f54f90 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:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LV2PR12MB5869.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(4636009)(39860400002)(396003)(366004)(136003)(376002)(346002)(451199021)(478600001)(6512007)(26005)(6506007)(6486002)(7416002)(5660300002)(2906002)(36756003)(4744005)(4326008)(66556008)(66476007)(6916009)(66946007)(86362001)(8936002)(8676002)(41300700001)(83380400001)(316002)(38100700002)(2616005)(186003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?VAvzj10wnhwnTL29sIphu5pl9qOsIiEZ7NglYHkmpDbqCDSEbJ0x702khVz3?= =?us-ascii?Q?6odiA0lm1EH0bJu6kC2aPItpxRmBG+2STVj7hXi/CAAtDaDXb64Ac9bovsES?= =?us-ascii?Q?0r2UTJ3UG11SGyGQp+VWeo09Ojub4U4id+7U51RhWQpqjIoDZKHwCJYkU09F?= =?us-ascii?Q?EfRtgEXKng/HyrZZ1fan1qhfyUufmSgIy+71qfCoFCJ/5gYzGGHk61KQZVuR?= =?us-ascii?Q?0mOW2z4MX3/zxTwa2Am6Hpbr+jMPvH5es8IK7NE5RXlD1lMQNv4DD0IP2Z8q?= =?us-ascii?Q?3kS2fU/XsiV/oghWTDmIql4miomPy8LG7E0LJSzlBAg5HTCusn6Stz4YTVZN?= =?us-ascii?Q?/BK9BjmZBvjzpaXeVH3TaHHUR2htu3Setlr+Pl8fWcNhWioL47WkxwEBItdm?= =?us-ascii?Q?6Das4RWZlJWa7i5cGMcNUzPQ9Hf1c8X6S7XNILylXpPcCL3gASsiL/m80DIv?= =?us-ascii?Q?eAKc8SGTxg6hoAMTIj+hYwlRli0P3kowSsqaT2eTkhanxPkgcRS8llcJdGpx?= =?us-ascii?Q?SRmhktiqVJauxv0IVSN/VlX3moBNAcVHUOmsb1o2AhIeW1siaQBGdwi0LsLn?= =?us-ascii?Q?KUeRiYC33lNMbyTCCT5THrMiLezGLORBCwQdWPe2G7OvTSrVWBlBpuH+tdL6?= =?us-ascii?Q?EKw0wDMHCSc4rtF0ZHNe3dY3+lhpzh49VSgRu+i9PJ8QaXfFX3BlbsKKDV48?= =?us-ascii?Q?/KowCIp80EhIrjaslXTfF8+MP7DOHW0lfNjYNhPFsa8M4BdalKDnPtfQb4qh?= =?us-ascii?Q?G+24AOSk/FNemFlSsCrqyIchDRixcEYWeEragExlWWPdLhz2ZmCXJBLITa/Y?= =?us-ascii?Q?GnCeHUJKBm+7xrC3ARMg3hTYssNZrxR6vzPLFbhzW4dXulcvYomDlNT2kFG2?= =?us-ascii?Q?qdd0WxNQkmTYXvnOEDkx93F3LHHgu1yLfpmEK69+N2esjZf0fVbVjCuDPFFq?= =?us-ascii?Q?zSSHPxFIcO6qz+fux2magmcjLa+OoE/tlDjF27RMGTE8w7MGHs2cmlTBMPqf?= =?us-ascii?Q?snVrnvFSUfMJJxJGQLzLRffgtey0Uj4xINPw/SDfQ3CLpTzS/jSqTXW9QZjN?= =?us-ascii?Q?gOX4fGTjZCQYYOirXbtzJlHs0YlUbU0W3T47ucfEyNREmu2c7FHLCkKbknY/?= =?us-ascii?Q?vXQVQYCkxQun0Takaxei097IcroXxS7Wrq+cYgFydOg6OWV5DOqO01LYDj3x?= =?us-ascii?Q?4GAWsW7tu52R7O+bZUdtiUu6YwLjQTYVVtVFk+Oc2P1OkZhQhDMpSbVfxOH5?= =?us-ascii?Q?6BDWzcm8ZCkzz0NCwH5sxyIDQft9iExsgqx7nziJ+zSRNALxyaQVgGayfHg0?= =?us-ascii?Q?5OPRrOTzxwUDJA3ATUEb32/iJ48sQzsC76bGCwksNC061D8VJmS65m7BEhus?= =?us-ascii?Q?A+KCN0SbH1EaMAo/ztVxeNJoNO49BMxu53Z8Y7kYzP7lgpE9wuyTGL0VZdUs?= =?us-ascii?Q?+LyK63PSK/a38YFmueJU2kqTSbAzlnv6g9KQGMWoiF5awIebX3Gwyh5g6JFq?= =?us-ascii?Q?oO20KIVjKg28CBXfHo9V0l48OGURIRlTQbo6SMV7+5DSnz90wxmat70F23fh?= =?us-ascii?Q?8AUHkGC7lW+YCvpycOKfhELkDkSHoV7TEP5jncsE?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c60fa397-9442-4ee7-e660-08db73f54f90 X-MS-Exchange-CrossTenant-AuthSource: LV2PR12MB5869.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Jun 2023 14:22:44.3505 (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: o24aE7aGsqEpzAITWmMpXMRDqRSaZeap7B0EdUH06xQINkRsu7bSGYgeoAN+oX9K X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR12MB4178 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Jun 02, 2023 at 05:16:45AM -0700, Yi Liu wrote: > This avoids endless vfio_device refcount increasement by userspace, > which would keep blocking the vfio_unregister_group_dev(). > > Tested-by: Yanting Jiang > Tested-by: Shameer Kolothum > Tested-by: Terrence Xu > Signed-off-by: Yi Liu > --- > drivers/vfio/vfio_main.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) Reviewed-by: Jason Gunthorpe It looks OK, at least I couldn't find a reason why the group list would need to continue to be valid while we are waiting for the registration lock to release. Jason