From patchwork Tue Jul 18 13:55:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13317293 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 D10DCEB64DC for ; Tue, 18 Jul 2023 13:56:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 224BB10E366; Tue, 18 Jul 2023 13:56:28 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5F12810E36A; Tue, 18 Jul 2023 13:56:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689688567; x=1721224567; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Tro7ldK39c/D+P73wAYl8xylrR+MAx9kksAZpQYgz6M=; b=iyHfL0Du9XX6kjWxMrEwa+OKll6ljmlANPy2yAt02h8Yex6Dun5w669k C/kOVx/dS4+aAngeaZRp/2G7tnkXxtiEmoRpYIs96Q7uctTp6LJ5TNK9N aIJqnjDLbPcYXHTHdH18SLdLUpiX0OR1eecj4UN7wCETofCyv4vg9IqOC cStbK/U8CEhcLu+dfoiYzP5YVnWkcy9u2EKxUGmktGoTL/FMsMz0BcGew Xx2uMXJquvLFNkZB8mYj/fzWmjlDJLIuTkVmSAiiKS/RAgKWDn9g7xDQ8 dqf5tTdSvpbB6JFHFwZCn7JFkDI2RchTlApzqzgUORjPz5wikHCD5cdHU A==; X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="452590744" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="452590744" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 06:56:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="970251060" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="970251060" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga006.fm.intel.com with ESMTP; 18 Jul 2023 06:56:06 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Tue, 18 Jul 2023 06:55:42 -0700 Message-Id: <20230718135551.6592-18-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230718135551.6592-1-yi.l.liu@intel.com> References: <20230718135551.6592-1-yi.l.liu@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v15 17/26] vfio: Move device_del() before waiting for the last vfio_device registration refcount 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" device_del() destroys the vfio-dev/vfioX under the sysfs for vfio_device. There is no reason to keep it while the device is going to be unregistered. This movement is also a preparation for adding vfio_device cdev. Kernel should remove the cdev node of the vfio_device to avoid new registration refcount increment while the device is going to be unregistered. Reviewed-by: Jason Gunthorpe Tested-by: Zhenzhong Duan Signed-off-by: Yi Liu --- drivers/vfio/vfio_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 6d45caa1f9a0..294bb5ecfc1c 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -338,6 +338,9 @@ void vfio_unregister_group_dev(struct vfio_device *device) */ vfio_device_group_unregister(device); + /* Balances device_add in register path */ + device_del(&device->device); + vfio_device_put_registration(device); rc = try_wait_for_completion(&device->comp); while (rc <= 0) { @@ -361,9 +364,6 @@ void vfio_unregister_group_dev(struct vfio_device *device) } } - /* Balances device_add in register path */ - device_del(&device->device); - /* Balances vfio_device_set_group in register path */ vfio_device_remove_group(device); }