From patchwork Sat Apr 1 15:18:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13197126 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 05F97C77B6E for ; Sat, 1 Apr 2023 15:19:26 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EDC5010E2FB; Sat, 1 Apr 2023 15:19:24 +0000 (UTC) Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id A9E8810E10B; Sat, 1 Apr 2023 15:18:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680362321; x=1711898321; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DUxZkfCi6OQ0x/puexaodV/sQy1kiF7rc8iDtDgi5ZI=; b=aBmZ9m7EvlfO5PNQ2K59qywNsWleQWyxmdniNhkjO91epuDEjl9d3Q0j 3e9RAH5MGi7hpKhX9yMuutPL7XxZtB0RlyeIUwGKVVuJ/BJRjODKedjUQ mD/JfrCUZxLdcO3Gp1btLpnhuEvY5nSssUkrcLrkpejUCS30sF4oIgWK0 rN35nfo3QNhgpz/fV13A8rZBm6tPmgRDSdcI9ApymWeUkyyzHvwM8VT3L sUwSRSV5+1sG8KibatweBTsPQ1FrQEVvoLeG5AtOZdkPqu8XqvRfATja9 cm//UdmJt7xE/eENraPpU+h2Otc5uIZBLh6gyAek2gk3mvRMzX0/rLSVT A==; X-IronPort-AV: E=McAfee;i="6600,9927,10667"; a="404411257" X-IronPort-AV: E=Sophos;i="5.98,310,1673942400"; d="scan'208";a="404411257" 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="678937186" X-IronPort-AV: E=Sophos;i="5.98,310,1673942400"; d="scan'208";a="678937186" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by orsmga007.jf.intel.com with ESMTP; 01 Apr 2023 08:18:40 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Sat, 1 Apr 2023 08:18:17 -0700 Message-Id: <20230401151833.124749-10-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 09/25] vfio: Add cdev_device_open_cnt to vfio_group 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" 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. Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Terrence Xu Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Signed-off-by: Yi Liu Reviewed-by: Eric Auger --- 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 71f0a9a4016e..d55ce3ca44b7 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -383,6 +383,33 @@ 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 = @@ -405,6 +432,11 @@ 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. */ @@ -479,6 +511,7 @@ 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 854f2c97cb9a..b2f20b78a707 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);