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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 28672C77B7D for ; Sat, 13 May 2023 13:29:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4C37210E0F3; Sat, 13 May 2023 13:28:59 +0000 (UTC) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8C69910E0E6; Sat, 13 May 2023 13:28:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1683984534; x=1715520534; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TWV894DTZrYaN7h4aj49YReKCmOsfie/espg2ZPGgRk=; b=SLSmh3tt+hbOtn+aRG+4Y1dSmC+tj7M/314uTYgZtc7XJei0pBmsY4qm 4RR8/9JgcBJnuPrp+HmR05uh5mWTNCictbpwMfWpU3XGm2/8ZNweqAmvS ZMBzPFRPOkoiSnxcw6nApOQ7PkStP263EMP2xA6slnVXvWkH5SW5A4LXQ KQ5Oya1MOIFqOxxPPUAKJ1YgSD92r/6fb//YnWiIyEZE+ba0lmCz7g0PO kWvh13o7x7JMLSaS6QRqafqa32WOdl0KxZnNxknDNekcfqqQKW9wpBCSM bUI3PDEQwo14ZclsDAFjLBADKVK2UFs7vc3s9bQ3s2LZJUQO3JwF5yquO Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10708"; a="354100811" X-IronPort-AV: E=Sophos;i="5.99,272,1677571200"; d="scan'208";a="354100811" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2023 06:28:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10708"; a="703459516" X-IronPort-AV: E=Sophos;i="5.99,272,1677571200"; d="scan'208";a="703459516" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga007.fm.intel.com with ESMTP; 13 May 2023 06:28:53 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Sat, 13 May 2023 06:28:21 -0700 Message-Id: <20230513132827.39066-18-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230513132827.39066-1-yi.l.liu@intel.com> References: <20230513132827.39066-1-yi.l.liu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [PATCH v11 17/23] vfio: Move vfio_device_group_unregister() to be the first operation in unregister X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mjrosato@linux.ibm.com, jasowang@redhat.com, xudong.hao@intel.com, zhenzhong.duan@intel.com, peterx@redhat.com, terrence.xu@intel.com, chao.p.peng@linux.intel.com, linux-s390@vger.kernel.org, yi.l.liu@intel.com, kvm@vger.kernel.org, lulu@redhat.com, yanting.jiang@intel.com, joro@8bytes.org, nicolinc@nvidia.com, yan.y.zhao@intel.com, intel-gfx@lists.freedesktop.org, eric.auger@redhat.com, intel-gvt-dev@lists.freedesktop.org, yi.y.sun@linux.intel.com, clegoate@redhat.com, cohuck@redhat.com, shameerali.kolothum.thodi@huawei.com, suravee.suthikulpanit@amd.com, robin.murphy@arm.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" This can avoid endless vfio_device refcount increasement by userspace, which would keep blocking the vfio_unregister_group_dev(). Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Signed-off-by: Yi Liu --- drivers/vfio/vfio_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 89720b73fa30..541bfd9ce004 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -333,6 +333,12 @@ void vfio_unregister_group_dev(struct vfio_device *device) bool interrupted = false; long rc; + /* + * Prevent new device opened by userspace via the + * VFIO_GROUP_GET_DEVICE_FD in the group path. + */ + vfio_device_group_unregister(device); + vfio_device_put_registration(device); rc = try_wait_for_completion(&device->comp); while (rc <= 0) { @@ -356,8 +362,6 @@ void vfio_unregister_group_dev(struct vfio_device *device) } } - vfio_device_group_unregister(device); - /* Balances device_add in register path */ device_del(&device->device); -- 2.34.1