From patchwork Sat May 13 13:28:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13240231 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 1A2D4C7EE24 for ; Sat, 13 May 2023 13:29:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239131AbjEMN3s (ORCPT ); Sat, 13 May 2023 09:29:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239160AbjEMN3q (ORCPT ); Sat, 13 May 2023 09:29:46 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97A7746A9; Sat, 13 May 2023 06:29:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1683984567; x=1715520567; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=XZqHF42zwcmP7zlF0QkPpOxHtNXyFN10NVkmRvgrLJY=; b=GuNalFhnR8T1texwVawI92YkmE3bpLne99uleR/4xg/rtXBJ5lL4X9Ks ebseK8vmuIYh2xWDoBogfve0BrZcNB9dY/uy7rYRmHRMInLi6QVgunILu fhCNCKtnGZfo0iNaUzztlchzr+eiXCxqZPBNz2UkQ0O/zeR20Y2IRnzle 9fir1EThTOI1LEOmfAdo8yQac063yR23mELeGJeUCrbUpRpdkxdh+c+EN tT9AlSBtST7p7eiJUQzQY+Eaml/s+Dzq+IT+RI44ZbOJZrATaMOSZD+EE sLi0LGzFZWbky/waUAHkSsrUTWuUrfnZPIJvpPY49Px2sov5zij1uBWf0 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10708"; a="354100827" X-IronPort-AV: E=Sophos;i="5.99,272,1677571200"; d="scan'208";a="354100827" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2023 06:28:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10708"; a="703459525" X-IronPort-AV: E=Sophos;i="5.99,272,1677571200"; d="scan'208";a="703459525" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga007.fm.intel.com with ESMTP; 13 May 2023 06:28:56 -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 v11 19/23] vfio: Add VFIO_DEVICE_BIND_IOMMUFD Date: Sat, 13 May 2023 06:28:23 -0700 Message-Id: <20230513132827.39066-20-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230513132827.39066-1-yi.l.liu@intel.com> References: <20230513132827.39066-1-yi.l.liu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This adds ioctl for userspace to bind device cdev fd to iommufd. VFIO_DEVICE_BIND_IOMMUFD: bind device to an iommufd, hence gain DMA control provided by the iommufd. open_device op is called after bind_iommufd op. Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Signed-off-by: Yi Liu --- drivers/vfio/device_cdev.c | 130 +++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio.h | 13 ++++ drivers/vfio/vfio_main.c | 5 ++ include/linux/vfio.h | 3 +- include/uapi/linux/vfio.h | 28 ++++++++ 5 files changed, 178 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c index 1c640016a824..291cc678a18b 100644 --- a/drivers/vfio/device_cdev.c +++ b/drivers/vfio/device_cdev.c @@ -3,6 +3,7 @@ * Copyright (c) 2023 Intel Corporation. */ #include +#include #include "vfio.h" @@ -44,6 +45,135 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep) return ret; } +static void vfio_device_get_kvm_safe(struct vfio_device_file *df) +{ + spin_lock(&df->kvm_ref_lock); + if (df->kvm) + _vfio_device_get_kvm_safe(df->device, df->kvm); + spin_unlock(&df->kvm_ref_lock); +} + +void vfio_device_cdev_close(struct vfio_device_file *df) +{ + struct vfio_device *device = df->device; + + /* + * In the time of close, there is no contention with another one + * changing this flag. So read df->access_granted without lock + * and no smp_load_acquire() is ok. + */ + if (!df->access_granted) + return; + + mutex_lock(&device->dev_set->lock); + vfio_device_close(df); + vfio_device_put_kvm(device); + iommufd_ctx_put(df->iommufd); + device->cdev_opened = false; + mutex_unlock(&device->dev_set->lock); + vfio_device_unblock_group(device); +} + +static struct iommufd_ctx *vfio_get_iommufd_from_fd(int fd) +{ + struct iommufd_ctx *iommufd; + struct fd f; + + f = fdget(fd); + if (!f.file) + return ERR_PTR(-EBADF); + + iommufd = iommufd_ctx_from_file(f.file); + + fdput(f); + return iommufd; +} + +long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, + struct vfio_device_bind_iommufd __user *arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_bind_iommufd bind; + unsigned long minsz; + int ret; + + static_assert(__same_type(arg->out_devid, df->devid)); + + minsz = offsetofend(struct vfio_device_bind_iommufd, out_devid); + + if (copy_from_user(&bind, arg, minsz)) + return -EFAULT; + + if (bind.argsz < minsz || bind.flags || bind.iommufd < 0) + return -EINVAL; + + /* BIND_IOMMUFD only allowed for cdev fds */ + if (df->group) + return -EINVAL; + + if (vfio_device_is_noiommu(device) && !capable(CAP_SYS_RAWIO)) + return -EPERM; + + ret = vfio_device_block_group(device); + if (ret) + return ret; + + mutex_lock(&device->dev_set->lock); + /* one device cannot be bound twice */ + if (df->access_granted) { + ret = -EINVAL; + goto out_unlock; + } + + df->iommufd = vfio_get_iommufd_from_fd(bind.iommufd); + if (IS_ERR(df->iommufd)) { + ret = PTR_ERR(df->iommufd); + df->iommufd = NULL; + goto out_unlock; + } + + /* + * Before the device open, get the KVM pointer currently + * associated with the device file (if there is) and obtain + * a reference. This reference is held until device closed. + * Save the pointer in the device for use by drivers. + */ + vfio_device_get_kvm_safe(df); + + ret = vfio_device_open(df); + if (ret) + goto out_put_kvm; + + ret = copy_to_user(&arg->out_devid, &df->devid, + sizeof(df->devid)) ? -EFAULT : 0; + if (ret) + goto out_close_device; + + /* + * Paired with smp_load_acquire() in vfio_device_fops::ioctl/ + * read/write/mmap + */ + smp_store_release(&df->access_granted, true); + device->cdev_opened = true; + mutex_unlock(&device->dev_set->lock); + + if (vfio_device_is_noiommu(device)) + dev_warn(device->dev, "noiommu device is bound to iommufd by user " + "(%s:%d)\n", current->comm, task_pid_nr(current)); + return 0; + +out_close_device: + vfio_device_close(df); +out_put_kvm: + vfio_device_put_kvm(device); + iommufd_ctx_put(df->iommufd); + df->iommufd = NULL; +out_unlock: + mutex_unlock(&device->dev_set->lock); + vfio_device_unblock_group(device); + return ret; +} + static char *vfio_device_devnode(const struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "vfio/devices/%s", dev_name(dev)); diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index 6861f8ebb64d..8b359a7794be 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -279,6 +279,9 @@ static inline void vfio_device_del(struct vfio_device *device) void vfio_init_device_cdev(struct vfio_device *device); int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep); +void vfio_device_cdev_close(struct vfio_device_file *df); +long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, + struct vfio_device_bind_iommufd __user *arg); int vfio_cdev_init(struct class *device_class); void vfio_cdev_cleanup(void); #else @@ -302,6 +305,16 @@ static inline int vfio_device_fops_cdev_open(struct inode *inode, return 0; } +static inline void vfio_device_cdev_close(struct vfio_device_file *df) +{ +} + +static inline long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, + struct vfio_device_bind_iommufd __user *arg) +{ + return -EOPNOTSUPP; +} + static inline int vfio_cdev_init(struct class *device_class) { return 0; diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index c87cc7afe92c..c9fa39ac4b02 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -574,6 +574,8 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) if (df->group) vfio_device_group_close(df); + else + vfio_device_cdev_close(df); vfio_device_put_registration(device); @@ -1147,6 +1149,9 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, struct vfio_device *device = df->device; int ret; + if (cmd == VFIO_DEVICE_BIND_IOMMUFD) + return vfio_device_ioctl_bind_iommufd(df, (void __user *)arg); + /* Paired with smp_store_release() following vfio_device_open() */ if (!smp_load_acquire(&df->access_granted)) return -EINVAL; diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 873275419f13..cf9d082a623c 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -67,6 +67,7 @@ struct vfio_device { struct iommufd_device *iommufd_device; bool iommufd_attached; #endif + bool cdev_opened:1; }; /** @@ -169,7 +170,7 @@ vfio_iommufd_physical_devid(struct vfio_device *vdev) static inline bool vfio_device_cdev_opened(struct vfio_device *device) { - return false; + return device->cdev_opened; } /** diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 24858b650562..07c917de31e9 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -194,6 +194,34 @@ struct vfio_group_status { /* --------------- IOCTLs for DEVICE file descriptors --------------- */ +/* + * VFIO_DEVICE_BIND_IOMMUFD - _IOR(VFIO_TYPE, VFIO_BASE + 19, + * struct vfio_device_bind_iommufd) + * + * Bind a vfio_device to the specified iommufd. + * + * User is restricted from accessing the device before the binding operation + * is completed. + * + * Unbind is automatically conducted when device fd is closed. + * + * @argsz: User filled size of this data. + * @flags: Must be 0. + * @iommufd: iommufd to bind. + * @out_devid: The device id generated by this bind. devid is a handle for + * this device/iommufd bond and can be used in IOMMUFD commands. + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_device_bind_iommufd { + __u32 argsz; + __u32 flags; + __s32 iommufd; + __u32 out_devid; +}; + +#define VFIO_DEVICE_BIND_IOMMUFD _IO(VFIO_TYPE, VFIO_BASE + 19) + /** * VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 7, * struct vfio_device_info)