From patchwork Tue Jul 11 02:59:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13308038 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 23060EB64DA for ; Tue, 11 Jul 2023 03:01:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229637AbjGKDBA (ORCPT ); Mon, 10 Jul 2023 23:01:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229845AbjGKDA4 (ORCPT ); Mon, 10 Jul 2023 23:00:56 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB8411728; Mon, 10 Jul 2023 20:00:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689044422; x=1720580422; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=1sQkWuUWd1EgQZC0VeeoQ5zSEsWEi8gzSk5vg+yuDhg=; b=CxC4b0odMJVFFYxie2CcrXvvmMmYCdRL+Sj5jMrNhlYa0S7R5G5t9Q5J Gn5n2mNqoMok95IbU9XYCSCpG8iuLhxdwV2FIkQ0w7mdOa/AllVhhqx7V qxkhoxM54EgpcWgkb7c9hbiJtSdFqDGVA8HVWFrc3FvH/dvl8iNPoiDzT OPFyC/vwBfChdrDj9Bgw2PImVcTG2z1mPHsNVBsdK0RX22mIcoJ2iJR/l rihDo4Itr01c67cgWed37rIyneJQ0Ogb4zUCGSxTTALHZpLHIiAUL4NPk 3wggmi+62Kqeu9rz3DkZCP5XeZ/yKad02hAgd2PMGnnspYPScWaZxKldI A==; X-IronPort-AV: E=McAfee;i="6600,9927,10767"; a="361973148" X-IronPort-AV: E=Sophos;i="6.01,195,1684825200"; d="scan'208";a="361973148" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2023 19:59:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10767"; a="724250901" X-IronPort-AV: E=Sophos;i="6.01,195,1684825200"; d="scan'208";a="724250901" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga007.fm.intel.com with ESMTP; 10 Jul 2023 19:59:47 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Cc: 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.l.liu@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: [PATCH v14 17/26] vfio: Move device_del() before waiting for the last vfio_device registration refcount Date: Mon, 10 Jul 2023 19:59:19 -0700 Message-Id: <20230711025928.6438-18-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230711025928.6438-1-yi.l.liu@intel.com> References: <20230711025928.6438-1-yi.l.liu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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. Signed-off-by: Yi Liu Reviewed-by: Jason Gunthorpe --- 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); }