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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B462C6FD20 for ; Wed, 8 Mar 2023 13:32:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230106AbjCHNcc (ORCPT ); Wed, 8 Mar 2023 08:32:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231575AbjCHNcL (ORCPT ); Wed, 8 Mar 2023 08:32:11 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C57D39BBF; Wed, 8 Mar 2023 05:30:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678282223; x=1709818223; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=p0+sdiJRsT1CFvbgXCytRESDpwjpnnBYhpkQpIa3C7k=; b=bZh22pw5SnoPAMyxJTcsb32qP0FxFNJ9AFWWCN8cRpKxkKbAbdrQRhzo SW9ppg1a9Ly2lhAObqFftF0g4lySMI4NPD6LtyDtJ7sT9PNunQIOqBQxx KZdEBCnNlZ/Q+FmZxoF0K8VTughxZbCuvKtXfJyqw/+aLv2z3B45k33FJ 6xuWwvPT8v0Gi/q8iifWtCSHzT3q1wVmK6nY6MvmF03j3kDVriZ2KtgmD xuqGx44a0kM26/ObBHlHt+mWfeOjayh9g+sxtkMLsnT6Yc/jcIywnxgft 6wPYnloMpa66edWE/Ysg06sFmKSjmBd/VclGS5a5tWJNnGTwzaWV37RZm A==; X-IronPort-AV: E=McAfee;i="6500,9779,10642"; a="336165243" X-IronPort-AV: E=Sophos;i="5.98,244,1673942400"; d="scan'208";a="336165243" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2023 05:29:30 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10642"; a="922789400" X-IronPort-AV: E=Sophos;i="5.98,244,1673942400"; d="scan'208";a="922789400" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga006.fm.intel.com with ESMTP; 08 Mar 2023 05:29:29 -0800 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 Subject: [PATCH v6 14/24] vfio: Add cdev_device_open_cnt to vfio_group Date: Wed, 8 Mar 2023 05:28:53 -0800 Message-Id: <20230308132903.465159-15-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230308132903.465159-1-yi.l.liu@intel.com> References: <20230308132903.465159-1-yi.l.liu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org for counting the devices that are opened via the cdev path. This count is increased and decreased by the cdev path. The group path checks it to achieve exclusion with the cdev path. With this, only one path (group path or cdev path) will claim DMA ownership. This avoids scenarios in which devices within the same group may be opened via different paths. Signed-off-by: Yi Liu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Terrence Xu Tested-by: Nicolin Chen Tested-by: Matthew Rosato --- drivers/vfio/group.c | 33 +++++++++++++++++++++++++++++++++ drivers/vfio/vfio.h | 3 +++ 2 files changed, 36 insertions(+) diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index 555d68aefa71..63aafd59278d 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -392,6 +392,33 @@ static long vfio_group_fops_unl_ioctl(struct file *filep, } } +int vfio_device_block_group(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + int ret = 0; + + mutex_lock(&group->group_lock); + if (group->opened_file) { + ret = -EBUSY; + goto out_unlock; + } + + group->cdev_device_open_cnt++; + +out_unlock: + mutex_unlock(&group->group_lock); + return ret; +} + +void vfio_device_unblock_group(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + + mutex_lock(&group->group_lock); + group->cdev_device_open_cnt--; + mutex_unlock(&group->group_lock); +} + static int vfio_group_fops_open(struct inode *inode, struct file *filep) { struct vfio_group *group = @@ -414,6 +441,11 @@ static int vfio_group_fops_open(struct inode *inode, struct file *filep) goto out_unlock; } + if (group->cdev_device_open_cnt) { + ret = -EBUSY; + goto out_unlock; + } + /* * Do we need multiple instances of the group open? Seems not. */ @@ -488,6 +520,7 @@ static void vfio_group_release(struct device *dev) mutex_destroy(&group->device_lock); mutex_destroy(&group->group_lock); WARN_ON(group->iommu_group); + WARN_ON(group->cdev_device_open_cnt); ida_free(&vfio.group_ida, MINOR(group->dev.devt)); kfree(group); } diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index 3356321805e9..e1b8763e443e 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -83,8 +83,11 @@ struct vfio_group { struct blocking_notifier_head notifier; struct iommufd_ctx *iommufd; spinlock_t kvm_ref_lock; + unsigned int cdev_device_open_cnt; }; +int vfio_device_block_group(struct vfio_device *device); +void vfio_device_unblock_group(struct vfio_device *device); int vfio_device_set_group(struct vfio_device *device, enum vfio_group_type type); void vfio_device_remove_group(struct vfio_device *device); -- 2.34.1