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 22C84C7EE2C for ; Fri, 2 Jun 2023 12:17:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232570AbjFBMRZ (ORCPT ); Fri, 2 Jun 2023 08:17:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235160AbjFBMRQ (ORCPT ); Fri, 2 Jun 2023 08:17:16 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 001E81A8; Fri, 2 Jun 2023 05:17:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685708234; x=1717244234; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=lHlyhZUd8KT70M+Qp16dcKXUh4IvKR/hyIG9XKd2Ozw=; b=IojvsqjuEon1/YXwZD96FbdSaeKzKxf3TBAjhK/IueMvusnYFJretbv0 Ahthn7wk//mYBca96NAsHQEBPT2VaiklNaHWUaitiOvDUctVxQ5fJYtS4 2g2aWwYc2CqZeUyRrktyvC7hyt1W4CoBz5lu193PjoM71zkrObVLZMuGc k1k8V8acX4ak0ShFssyuanbE7JVFOp6fJa2SulftpxqiXF1hP3yzTGetB Fm1coIGLJhM00K3pQ/uQj096a4nxrsZ4sB765T3Xe+MMhznbp+X7czPfB LSzzK3uD2RTNOYcLn/s3ngaJrdH8z0fc44VhIPQFZS6kDBQTlEvzn8vmb w==; X-IronPort-AV: E=McAfee;i="6600,9927,10728"; a="384136564" X-IronPort-AV: E=Sophos;i="6.00,212,1681196400"; d="scan'208";a="384136564" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2023 05:17:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10728"; a="1037947306" X-IronPort-AV: E=Sophos;i="6.00,212,1681196400"; d="scan'208";a="1037947306" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga005.fm.intel.com with ESMTP; 02 Jun 2023 05:17:04 -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 v12 08/24] vfio: Add cdev_device_open_cnt to vfio_group Date: Fri, 2 Jun 2023 05:16:37 -0700 Message-Id: <20230602121653.80017-9-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230602121653.80017-1-yi.l.liu@intel.com> References: <20230602121653.80017-1-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 This is 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 Reviewed-by: Eric Auger Tested-by: Terrence Xu Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Signed-off-by: Yi Liu --- 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 088dd34c8931..2751d61689c4 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 fdf2fc73f880..de17bdd16df5 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