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 5511AC77B78 for ; Wed, 26 Apr 2023 15:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240731AbjDZPDw (ORCPT ); Wed, 26 Apr 2023 11:03:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241084AbjDZPDw (ORCPT ); Wed, 26 Apr 2023 11:03:52 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E43085279; Wed, 26 Apr 2023 08:03:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1682521425; x=1714057425; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0GeMScAV8YWi1uvkmiQ+6Qx5YIKhXkweNIZBaAjQdAw=; b=hOPnyLweuq3z6PzmhjtW6L3SQk/iWMKf4/urv69zc4ydm+gg5mq3BnTb iDi31X1xWv0IDZxq1YR8yFBS0Aq3YjJl/UJtYI1PsKzDBa/mxEswjZ0/G nz6giDxEjwXS+f/bT2ZeDWwViwq3KDoJ0KeUBnVe4pwnkasn54PDOClW/ f+gxb17pVJZOu9ROiVZQDFUcCaUJ341KbdV0EMCADnYZNrN4rFpvgtZi0 5Q1SIMLoJkKeYNjtGCEtQG1E+JLLmJ7l4gBMfy45KE13VKYAISdJTQNfk 6OMGFiCFAL3zfU5+Xny4T8LlcIyMs+cqUsq7L+Ev7aRiHGVOuB7VjjJ20 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10692"; a="349944510" X-IronPort-AV: E=Sophos;i="5.99,228,1677571200"; d="scan'208";a="349944510" 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 08:03:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10692"; a="805544097" X-IronPort-AV: E=Sophos;i="5.99,228,1677571200"; d="scan'208";a="805544097" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga002.fm.intel.com with ESMTP; 26 Apr 2023 08:03:43 -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 Subject: [PATCH v10 08/22] vfio: Add cdev_device_open_cnt to vfio_group Date: Wed, 26 Apr 2023 08:03:07 -0700 Message-Id: <20230426150321.454465-9-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 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. 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 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 95a2d67153f5..763de54d441f 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 aad94bf60ee2..68260535dc18 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