From patchwork Sat Apr 1 15:18:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13197110 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 E80FDC761AF for ; Sat, 1 Apr 2023 15:18:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 77E5C10E1BE; Sat, 1 Apr 2023 15:18:45 +0000 (UTC) Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2361C10E0F6; Sat, 1 Apr 2023 15:18:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680362322; x=1711898322; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=XUStM8T02ZrjFFH8fi8mvUfbLcVIWY8ixRTVzSOKiDE=; b=IcAtNifk/cCZKFL6V75Hpn44nmYK80EqVcWgnt0ihWho5qmy4g6gRDQl jtB/yBgzHfaJ6Uqz4rF+QDmmpwfQVnD4ERPd6vEQBQz3Uvf3zy5T4gi0B CL6wFMsw7u0Li9i85Z0j3od0oY5Ci3zNfpsenEmYdOddBhsA+uYPbosym hSH8MjvtvoNjJ8KFVqvlm8wqA6iw7tylUGTzsUM4wze0Zl7t+45cAh+AZ 0NyRDiHauE5e+rBn7FRkQFZ3p1WqKWnS7DW9/eCEc3nhcoEfQym9CIbT/ iriLigrsdjAPd7779pjJdxrj/S06BGfBEVrJu10k2L7TL4jGk6j9yUVnZ Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10667"; a="404411268" X-IronPort-AV: E=Sophos;i="5.98,310,1673942400"; d="scan'208";a="404411268" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2023 08:18:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10667"; a="678937190" X-IronPort-AV: E=Sophos;i="5.98,310,1673942400"; d="scan'208";a="678937190" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by orsmga007.jf.intel.com with ESMTP; 01 Apr 2023 08:18:41 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Sat, 1 Apr 2023 08:18:18 -0700 Message-Id: <20230401151833.124749-11-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230401151833.124749-1-yi.l.liu@intel.com> References: <20230401151833.124749-1-yi.l.liu@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v9 10/25] vfio: Make vfio_device_open() single open for device cdev path 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, 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" VFIO group has historically allowed multi-open of the device FD. This was made secure because the "open" was executed via an ioctl to the group FD which is itself only single open. However, no known use of multiple device FDs today. It is kind of a strange thing to do because new device FDs can naturally be created via dup(). When we implement the new device uAPI (only used in cdev path) there is no natural way to allow the device itself from being multi-opened in a secure manner. Without the group FD we cannot prove the security context of the opener. Thus, when moving to the new uAPI we block the ability of opening a device multiple times. Given old group path still allows it we store a vfio_group pointer in struct vfio_device_file to differentiate. Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Terrence Xu Tested-by: Nicolin Chen Tested-by: Yanting Jiang Signed-off-by: Yi Liu Reviewed-by: Eric Auger --- drivers/vfio/group.c | 2 ++ drivers/vfio/vfio.h | 2 ++ drivers/vfio/vfio_main.c | 7 +++++++ 3 files changed, 11 insertions(+) diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index d55ce3ca44b7..1af4b9e012a7 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -245,6 +245,8 @@ static struct file *vfio_device_open_file(struct vfio_device *device) goto err_out; } + df->group = device->group; + ret = vfio_device_group_open(df); if (ret) goto err_free; diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index b2f20b78a707..f1a448f9d067 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -18,6 +18,8 @@ struct vfio_container; struct vfio_device_file { struct vfio_device *device; + struct vfio_group *group; + bool access_granted; spinlock_t kvm_ref_lock; /* protect kvm field */ struct kvm *kvm; diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 6d5d3c2180c8..c8721d5d05fa 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -477,6 +477,13 @@ int vfio_device_open(struct vfio_device_file *df) lockdep_assert_held(&device->dev_set->lock); + /* + * Only the group path allows the device opened multiple times. + * The device cdev path doesn't have a secure way for it. + */ + if (device->open_count != 0 && !df->group) + return -EINVAL; + device->open_count++; if (device->open_count == 1) { ret = vfio_device_first_open(df);