From patchwork Wed Apr 26 15:03:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13224714 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 D3660C77B7C for ; Wed, 26 Apr 2023 15:04:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CD4DD10EA0D; Wed, 26 Apr 2023 15:04:02 +0000 (UTC) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTPS id 18EC710EA05; Wed, 26 Apr 2023 15:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1682521437; x=1714057437; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rNbdnFNXhsfKnZiSnsZQt++FoYI+cmxvGCKsSVRHz8M=; b=VqR6L1XgiU8Xqdwuec3rEmWtypPa8OHwLkfeuY7Rq6vfulVfKMbAXkQO UK2Sg9eF4xdjCL0tNdQ/K9/oxohcaxapncr/eRJCjkFaCtD1mtegXDLFg z+sl0IOs5FD2triDm1UA7FOGJtgSDQT0zupPhADV8wvDfR5CO/zgwxDGy riN4N/tQmI1EIIfU41cSGKhQVkwt7NKNR5zrVfLhzOxbJYRw/7Eg5VL4f i205LSBRTdwuYSxdyq6wiPJsVsV/3DyfEcc7EN8a/aFXDVpdTHumu/6Wv r8/6ZgOObnrP5oAxRpizxAhKbBGLU7TbzTf1UWADcmTpjDi29L8qFf1aD g==; X-IronPort-AV: E=McAfee;i="6600,9927,10692"; a="349944648" X-IronPort-AV: E=Sophos;i="5.99,228,1677571200"; d="scan'208";a="349944648" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2023 08:03:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10692"; a="805544283" X-IronPort-AV: E=Sophos;i="5.99,228,1677571200"; d="scan'208";a="805544283" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga002.fm.intel.com with ESMTP; 26 Apr 2023 08:03:55 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Wed, 26 Apr 2023 08:03:16 -0700 Message-Id: <20230426150321.454465-18-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230426150321.454465-1-yi.l.liu@intel.com> References: <20230426150321.454465-1-yi.l.liu@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v10 17/22] 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, 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(). 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 c0459872d79a..c3263cb2ea75 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -322,6 +322,12 @@ 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) { @@ -345,8 +351,6 @@ void vfio_unregister_group_dev(struct vfio_device *device) } } - vfio_device_group_unregister(device); - /* Balances device_add in register path */ device_del(&device->device);