Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1891 insertions, 0 deletions

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
new file mode 100644
index 000000000..6e8804fe0
--- /dev/null
+++ b/drivers/vfio/vfio_main.c
@@ -0,0 +1,1891 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VFIO core
+ *
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ */
+
+#include <linux/cdev.h>
+#include <linux/compat.h>
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/anon_inodes.h>
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/iommu.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include <linux/wait.h>
+#include <linux/sched/signal.h>
+#include <linux/pm_runtime.h>
+#include <linux/interval_tree.h>
+#include <linux/iova_bitmap.h>
+#include "vfio.h"
+
+#define DRIVER_VERSION	"0.3"
+#define DRIVER_AUTHOR	"Alex Williamson <alex.williamson@redhat.com>"
+#define DRIVER_DESC	"VFIO - User Level meta-driver"
+
+static struct vfio {
+	struct class			*class;
+	struct list_head		group_list;
+	struct mutex			group_lock; /* locks group_list */
+	struct ida			group_ida;
+	dev_t				group_devt;
+	struct class			*device_class;
+	struct ida			device_ida;
+} vfio;
+
+static DEFINE_XARRAY(vfio_device_set_xa);
+static const struct file_operations vfio_group_fops;
+
+int vfio_assign_device_set(struct vfio_device *device, void *set_id)
+{
+	unsigned long idx = (unsigned long)set_id;
+	struct vfio_device_set *new_dev_set;
+	struct vfio_device_set *dev_set;
+
+	if (WARN_ON(!set_id))
+		return -EINVAL;
+
+	/*
+	 * Atomically acquire a singleton object in the xarray for this set_id
+	 */
+	xa_lock(&vfio_device_set_xa);
+	dev_set = xa_load(&vfio_device_set_xa, idx);
+	if (dev_set)
+		goto found_get_ref;
+	xa_unlock(&vfio_device_set_xa);
+
+	new_dev_set = kzalloc(sizeof(*new_dev_set), GFP_KERNEL);
+	if (!new_dev_set)
+		return -ENOMEM;
+	mutex_init(&new_dev_set->lock);
+	INIT_LIST_HEAD(&new_dev_set->device_list);
+	new_dev_set->set_id = set_id;
+
+	xa_lock(&vfio_device_set_xa);
+	dev_set = __xa_cmpxchg(&vfio_device_set_xa, idx, NULL, new_dev_set,
+			       GFP_KERNEL);
+	if (!dev_set) {
+		dev_set = new_dev_set;
+		goto found_get_ref;
+	}
+
+	kfree(new_dev_set);
+	if (xa_is_err(dev_set)) {
+		xa_unlock(&vfio_device_set_xa);
+		return xa_err(dev_set);
+	}
+
+found_get_ref:
+	dev_set->device_count++;
+	xa_unlock(&vfio_device_set_xa);
+	mutex_lock(&dev_set->lock);
+	device->dev_set = dev_set;
+	list_add_tail(&device->dev_set_list, &dev_set->device_list);
+	mutex_unlock(&dev_set->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_assign_device_set);
+
+static void vfio_release_device_set(struct vfio_device *device)
+{
+	struct vfio_device_set *dev_set = device->dev_set;
+
+	if (!dev_set)
+		return;
+
+	mutex_lock(&dev_set->lock);
+	list_del(&device->dev_set_list);
+	mutex_unlock(&dev_set->lock);
+
+	xa_lock(&vfio_device_set_xa);
+	if (!--dev_set->device_count) {
+		__xa_erase(&vfio_device_set_xa,
+			   (unsigned long)dev_set->set_id);
+		mutex_destroy(&dev_set->lock);
+		kfree(dev_set);
+	}
+	xa_unlock(&vfio_device_set_xa);
+}
+
+unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
+{
+	struct vfio_device *cur;
+	unsigned int open_count = 0;
+
+	lockdep_assert_held(&dev_set->lock);
+
+	list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
+		open_count += cur->open_count;
+	return open_count;
+}
+EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
+
+/*
+ * Group objects - create, release, get, put, search
+ */
+static struct vfio_group *
+__vfio_group_get_from_iommu(struct iommu_group *iommu_group)
+{
+	struct vfio_group *group;
+
+	/*
+	 * group->iommu_group from the vfio.group_list cannot be NULL
+	 * under the vfio.group_lock.
+	 */
+	list_for_each_entry(group, &vfio.group_list, vfio_next) {
+		if (group->iommu_group == iommu_group) {
+			refcount_inc(&group->drivers);
+			return group;
+		}
+	}
+	return NULL;
+}
+
+static struct vfio_group *
+vfio_group_get_from_iommu(struct iommu_group *iommu_group)
+{
+	struct vfio_group *group;
+
+	mutex_lock(&vfio.group_lock);
+	group = __vfio_group_get_from_iommu(iommu_group);
+	mutex_unlock(&vfio.group_lock);
+	return group;
+}
+
+static void vfio_group_release(struct device *dev)
+{
+	struct vfio_group *group = container_of(dev, struct vfio_group, dev);
+
+	mutex_destroy(&group->device_lock);
+	mutex_destroy(&group->group_lock);
+	WARN_ON(group->iommu_group);
+	ida_free(&vfio.group_ida, MINOR(group->dev.devt));
+	kfree(group);
+}
+
+static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
+					   enum vfio_group_type type)
+{
+	struct vfio_group *group;
+	int minor;
+
+	group = kzalloc(sizeof(*group), GFP_KERNEL);
+	if (!group)
+		return ERR_PTR(-ENOMEM);
+
+	minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
+	if (minor < 0) {
+		kfree(group);
+		return ERR_PTR(minor);
+	}
+
+	device_initialize(&group->dev);
+	group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
+	group->dev.class = vfio.class;
+	group->dev.release = vfio_group_release;
+	cdev_init(&group->cdev, &vfio_group_fops);
+	group->cdev.owner = THIS_MODULE;
+
+	refcount_set(&group->drivers, 1);
+	mutex_init(&group->group_lock);
+	INIT_LIST_HEAD(&group->device_list);
+	mutex_init(&group->device_lock);
+	group->iommu_group = iommu_group;
+	/* put in vfio_group_release() */
+	iommu_group_ref_get(iommu_group);
+	group->type = type;
+	BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
+
+	return group;
+}
+
+static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
+		enum vfio_group_type type)
+{
+	struct vfio_group *group;
+	struct vfio_group *ret;
+	int err;
+
+	group = vfio_group_alloc(iommu_group, type);
+	if (IS_ERR(group))
+		return group;
+
+	err = dev_set_name(&group->dev, "%s%d",
+			   group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
+			   iommu_group_id(iommu_group));
+	if (err) {
+		ret = ERR_PTR(err);
+		goto err_put;
+	}
+
+	mutex_lock(&vfio.group_lock);
+
+	/* Did we race creating this group? */
+	ret = __vfio_group_get_from_iommu(iommu_group);
+	if (ret)
+		goto err_unlock;
+
+	err = cdev_device_add(&group->cdev, &group->dev);
+	if (err) {
+		ret = ERR_PTR(err);
+		goto err_unlock;
+	}
+
+	list_add(&group->vfio_next, &vfio.group_list);
+
+	mutex_unlock(&vfio.group_lock);
+	return group;
+
+err_unlock:
+	mutex_unlock(&vfio.group_lock);
+err_put:
+	put_device(&group->dev);
+	return ret;
+}
+
+static void vfio_device_remove_group(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+	struct iommu_group *iommu_group;
+
+	if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
+		iommu_group_remove_device(device->dev);
+
+	/* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
+	if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
+		return;
+	list_del(&group->vfio_next);
+
+	/*
+	 * We could concurrently probe another driver in the group that might
+	 * race vfio_device_remove_group() with vfio_get_group(), so we have to
+	 * ensure that the sysfs is all cleaned up under lock otherwise the
+	 * cdev_device_add() will fail due to the name aready existing.
+	 */
+	cdev_device_del(&group->cdev, &group->dev);
+
+	mutex_lock(&group->group_lock);
+	/*
+	 * These data structures all have paired operations that can only be
+	 * undone when the caller holds a live reference on the device. Since
+	 * all pairs must be undone these WARN_ON's indicate some caller did not
+	 * properly hold the group reference.
+	 */
+	WARN_ON(!list_empty(&group->device_list));
+	WARN_ON(group->notifier.head);
+
+	/*
+	 * Revoke all users of group->iommu_group. At this point we know there
+	 * are no devices active because we are unplugging the last one. Setting
+	 * iommu_group to NULL blocks all new users.
+	 */
+	if (group->container)
+		vfio_group_detach_container(group);
+	iommu_group = group->iommu_group;
+	group->iommu_group = NULL;
+	mutex_unlock(&group->group_lock);
+	mutex_unlock(&vfio.group_lock);
+
+	iommu_group_put(iommu_group);
+	put_device(&group->dev);
+}
+
+/*
+ * Device objects - create, release, get, put, search
+ */
+/* Device reference always implies a group reference */
+static void vfio_device_put_registration(struct vfio_device *device)
+{
+	if (refcount_dec_and_test(&device->refcount))
+		complete(&device->comp);
+}
+
+static bool vfio_device_try_get_registration(struct vfio_device *device)
+{
+	return refcount_inc_not_zero(&device->refcount);
+}
+
+static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
+						 struct device *dev)
+{
+	struct vfio_device *device;
+
+	mutex_lock(&group->device_lock);
+	list_for_each_entry(device, &group->device_list, group_next) {
+		if (device->dev == dev &&
+		    vfio_device_try_get_registration(device)) {
+			mutex_unlock(&group->device_lock);
+			return device;
+		}
+	}
+	mutex_unlock(&group->device_lock);
+	return NULL;
+}
+
+/*
+ * VFIO driver API
+ */
+/* Release helper called by vfio_put_device() */
+static void vfio_device_release(struct device *dev)
+{
+	struct vfio_device *device =
+			container_of(dev, struct vfio_device, device);
+
+	vfio_release_device_set(device);
+	ida_free(&vfio.device_ida, device->index);
+
+	/*
+	 * kvfree() cannot be done here due to a life cycle mess in
+	 * vfio-ccw. Before the ccw part is fixed all drivers are
+	 * required to support @release and call vfio_free_device()
+	 * from there.
+	 */
+	device->ops->release(device);
+}
+
+/*
+ * Allocate and initialize vfio_device so it can be registered to vfio
+ * core.
+ *
+ * Drivers should use the wrapper vfio_alloc_device() for allocation.
+ * @size is the size of the structure to be allocated, including any
+ * private data used by the driver.
+ *
+ * Driver may provide an @init callback to cover device private data.
+ *
+ * Use vfio_put_device() to release the structure after success return.
+ */
+struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
+				       const struct vfio_device_ops *ops)
+{
+	struct vfio_device *device;
+	int ret;
+
+	if (WARN_ON(size < sizeof(struct vfio_device)))
+		return ERR_PTR(-EINVAL);
+
+	device = kvzalloc(size, GFP_KERNEL);
+	if (!device)
+		return ERR_PTR(-ENOMEM);
+
+	ret = vfio_init_device(device, dev, ops);
+	if (ret)
+		goto out_free;
+	return device;
+
+out_free:
+	kvfree(device);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(_vfio_alloc_device);
+
+/*
+ * Initialize a vfio_device so it can be registered to vfio core.
+ *
+ * Only vfio-ccw driver should call this interface.
+ */
+int vfio_init_device(struct vfio_device *device, struct device *dev,
+		     const struct vfio_device_ops *ops)
+{
+	int ret;
+
+	ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
+	if (ret < 0) {
+		dev_dbg(dev, "Error to alloc index\n");
+		return ret;
+	}
+
+	device->index = ret;
+	init_completion(&device->comp);
+	device->dev = dev;
+	device->ops = ops;
+
+	if (ops->init) {
+		ret = ops->init(device);
+		if (ret)
+			goto out_uninit;
+	}
+
+	device_initialize(&device->device);
+	device->device.release = vfio_device_release;
+	device->device.class = vfio.device_class;
+	device->device.parent = device->dev;
+	return 0;
+
+out_uninit:
+	vfio_release_device_set(device);
+	ida_free(&vfio.device_ida, device->index);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_init_device);
+
+/*
+ * The helper called by driver @release callback to free the device
+ * structure. Drivers which don't have private data to clean can
+ * simply use this helper as its @release.
+ */
+void vfio_free_device(struct vfio_device *device)
+{
+	kvfree(device);
+}
+EXPORT_SYMBOL_GPL(vfio_free_device);
+
+static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
+		enum vfio_group_type type)
+{
+	struct iommu_group *iommu_group;
+	struct vfio_group *group;
+	int ret;
+
+	iommu_group = iommu_group_alloc();
+	if (IS_ERR(iommu_group))
+		return ERR_CAST(iommu_group);
+
+	ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
+	if (ret)
+		goto out_put_group;
+	ret = iommu_group_add_device(iommu_group, dev);
+	if (ret)
+		goto out_put_group;
+
+	group = vfio_create_group(iommu_group, type);
+	if (IS_ERR(group)) {
+		ret = PTR_ERR(group);
+		goto out_remove_device;
+	}
+	iommu_group_put(iommu_group);
+	return group;
+
+out_remove_device:
+	iommu_group_remove_device(dev);
+out_put_group:
+	iommu_group_put(iommu_group);
+	return ERR_PTR(ret);
+}
+
+static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
+{
+	struct iommu_group *iommu_group;
+	struct vfio_group *group;
+
+	iommu_group = iommu_group_get(dev);
+	if (!iommu_group && vfio_noiommu) {
+		/*
+		 * With noiommu enabled, create an IOMMU group for devices that
+		 * don't already have one, implying no IOMMU hardware/driver
+		 * exists.  Taint the kernel because we're about to give a DMA
+		 * capable device to a user without IOMMU protection.
+		 */
+		group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
+		if (!IS_ERR(group)) {
+			add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+			dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
+		}
+		return group;
+	}
+
+	if (!iommu_group)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
+	 * restore cache coherency. It has to be checked here because it is only
+	 * valid for cases where we are using iommu groups.
+	 */
+	if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
+		iommu_group_put(iommu_group);
+		return ERR_PTR(-EINVAL);
+	}
+
+	group = vfio_group_get_from_iommu(iommu_group);
+	if (!group)
+		group = vfio_create_group(iommu_group, VFIO_IOMMU);
+
+	/* The vfio_group holds a reference to the iommu_group */
+	iommu_group_put(iommu_group);
+	return group;
+}
+
+static int __vfio_register_dev(struct vfio_device *device,
+		struct vfio_group *group)
+{
+	struct vfio_device *existing_device;
+	int ret;
+
+	/*
+	 * In all cases group is the output of one of the group allocation
+	 * functions and we have group->drivers incremented for us.
+	 */
+	if (IS_ERR(group))
+		return PTR_ERR(group);
+
+	/*
+	 * If the driver doesn't specify a set then the device is added to a
+	 * singleton set just for itself.
+	 */
+	if (!device->dev_set)
+		vfio_assign_device_set(device, device);
+
+	existing_device = vfio_group_get_device(group, device->dev);
+	if (existing_device) {
+		/*
+		 * group->iommu_group is non-NULL because we hold the drivers
+		 * refcount.
+		 */
+		dev_WARN(device->dev, "Device already exists on group %d\n",
+			 iommu_group_id(group->iommu_group));
+		vfio_device_put_registration(existing_device);
+		ret = -EBUSY;
+		goto err_out;
+	}
+
+	/* Our reference on group is moved to the device */
+	device->group = group;
+
+	ret = dev_set_name(&device->device, "vfio%d", device->index);
+	if (ret)
+		goto err_out;
+
+	ret = device_add(&device->device);
+	if (ret)
+		goto err_out;
+
+	/* Refcounting can't start until the driver calls register */
+	refcount_set(&device->refcount, 1);
+
+	mutex_lock(&group->device_lock);
+	list_add(&device->group_next, &group->device_list);
+	mutex_unlock(&group->device_lock);
+
+	return 0;
+err_out:
+	vfio_device_remove_group(device);
+	return ret;
+}
+
+int vfio_register_group_dev(struct vfio_device *device)
+{
+	return __vfio_register_dev(device,
+		vfio_group_find_or_alloc(device->dev));
+}
+EXPORT_SYMBOL_GPL(vfio_register_group_dev);
+
+/*
+ * Register a virtual device without IOMMU backing.  The user of this
+ * device must not be able to directly trigger unmediated DMA.
+ */
+int vfio_register_emulated_iommu_dev(struct vfio_device *device)
+{
+	return __vfio_register_dev(device,
+		vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU));
+}
+EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
+
+static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
+						     char *buf)
+{
+	struct vfio_device *it, *device = ERR_PTR(-ENODEV);
+
+	mutex_lock(&group->device_lock);
+	list_for_each_entry(it, &group->device_list, group_next) {
+		int ret;
+
+		if (it->ops->match) {
+			ret = it->ops->match(it, buf);
+			if (ret < 0) {
+				device = ERR_PTR(ret);
+				break;
+			}
+		} else {
+			ret = !strcmp(dev_name(it->dev), buf);
+		}
+
+		if (ret && vfio_device_try_get_registration(it)) {
+			device = it;
+			break;
+		}
+	}
+	mutex_unlock(&group->device_lock);
+
+	return device;
+}
+
+/*
+ * Decrement the device reference count and wait for the device to be
+ * removed.  Open file descriptors for the device... */
+void vfio_unregister_group_dev(struct vfio_device *device)
+{
+	struct vfio_group *group = device->group;
+	unsigned int i = 0;
+	bool interrupted = false;
+	long rc;
+
+	vfio_device_put_registration(device);
+	rc = try_wait_for_completion(&device->comp);
+	while (rc <= 0) {
+		if (device->ops->request)
+			device->ops->request(device, i++);
+
+		if (interrupted) {
+			rc = wait_for_completion_timeout(&device->comp,
+							 HZ * 10);
+		} else {
+			rc = wait_for_completion_interruptible_timeout(
+				&device->comp, HZ * 10);
+			if (rc < 0) {
+				interrupted = true;
+				dev_warn(device->dev,
+					 "Device is currently in use, task"
+					 " \"%s\" (%d) "
+					 "blocked until device is released",
+					 current->comm, task_pid_nr(current));
+			}
+		}
+	}
+
+	mutex_lock(&group->device_lock);
+	list_del(&device->group_next);
+	mutex_unlock(&group->device_lock);
+
+	/* Balances device_add in register path */
+	device_del(&device->device);
+
+	vfio_device_remove_group(device);
+}
+EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
+
+/*
+ * VFIO Group fd, /dev/vfio/$GROUP
+ */
+/*
+ * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
+ * if there was no container to unset.  Since the ioctl is called on
+ * the group, we know that still exists, therefore the only valid
+ * transition here is 1->0.
+ */
+static int vfio_group_ioctl_unset_container(struct vfio_group *group)
+{
+	int ret = 0;
+
+	mutex_lock(&group->group_lock);
+	if (!group->container) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+	if (group->container_users != 1) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+	vfio_group_detach_container(group);
+
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	return ret;
+}
+
+static int vfio_group_ioctl_set_container(struct vfio_group *group,
+					  int __user *arg)
+{
+	struct vfio_container *container;
+	struct fd f;
+	int ret;
+	int fd;
+
+	if (get_user(fd, arg))
+		return -EFAULT;
+
+	f = fdget(fd);
+	if (!f.file)
+		return -EBADF;
+
+	mutex_lock(&group->group_lock);
+	if (group->container || WARN_ON(group->container_users)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+	if (!group->iommu_group) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	container = vfio_container_from_file(f.file);
+	ret = -EINVAL;
+	if (container) {
+		ret = vfio_container_attach_group(container, group);
+		goto out_unlock;
+	}
+
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	fdput(f);
+	return ret;
+}
+
+static const struct file_operations vfio_device_fops;
+
+/* true if the vfio_device has open_device() called but not close_device() */
+bool vfio_assert_device_open(struct vfio_device *device)
+{
+	return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
+}
+
+static struct file *vfio_device_open(struct vfio_device *device)
+{
+	struct file *filep;
+	int ret;
+
+	mutex_lock(&device->group->group_lock);
+	ret = vfio_device_assign_container(device);
+	mutex_unlock(&device->group->group_lock);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (!try_module_get(device->dev->driver->owner)) {
+		ret = -ENODEV;
+		goto err_unassign_container;
+	}
+
+	mutex_lock(&device->dev_set->lock);
+	device->open_count++;
+	if (device->open_count == 1) {
+		/*
+		 * Here we pass the KVM pointer with the group under the read
+		 * lock.  If the device driver will use it, it must obtain a
+		 * reference and release it during close_device.
+		 */
+		mutex_lock(&device->group->group_lock);
+		device->kvm = device->group->kvm;
+
+		if (device->ops->open_device) {
+			ret = device->ops->open_device(device);
+			if (ret)
+				goto err_undo_count;
+		}
+		vfio_device_container_register(device);
+		mutex_unlock(&device->group->group_lock);
+	}
+	mutex_unlock(&device->dev_set->lock);
+
+	/*
+	 * We can't use anon_inode_getfd() because we need to modify
+	 * the f_mode flags directly to allow more than just ioctls
+	 */
+	filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
+				   device, O_RDWR);
+	if (IS_ERR(filep)) {
+		ret = PTR_ERR(filep);
+		goto err_close_device;
+	}
+
+	/*
+	 * TODO: add an anon_inode interface to do this.
+	 * Appears to be missing by lack of need rather than
+	 * explicitly prevented.  Now there's need.
+	 */
+	filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
+
+	if (device->group->type == VFIO_NO_IOMMU)
+		dev_warn(device->dev, "vfio-noiommu device opened by user "
+			 "(%s:%d)\n", current->comm, task_pid_nr(current));
+	/*
+	 * On success the ref of device is moved to the file and
+	 * put in vfio_device_fops_release()
+	 */
+	return filep;
+
+err_close_device:
+	mutex_lock(&device->dev_set->lock);
+	mutex_lock(&device->group->group_lock);
+	if (device->open_count == 1) {
+		if (device->ops->close_device)
+			device->ops->close_device(device);
+
+		vfio_device_container_unregister(device);
+	}
+err_undo_count:
+	mutex_unlock(&device->group->group_lock);
+	device->open_count--;
+	if (device->open_count == 0 && device->kvm)
+		device->kvm = NULL;
+	mutex_unlock(&device->dev_set->lock);
+	module_put(device->dev->driver->owner);
+err_unassign_container:
+	vfio_device_unassign_container(device);
+	return ERR_PTR(ret);
+}
+
+static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
+					  char __user *arg)
+{
+	struct vfio_device *device;
+	struct file *filep;
+	char *buf;
+	int fdno;
+	int ret;
+
+	buf = strndup_user(arg, PAGE_SIZE);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	device = vfio_device_get_from_name(group, buf);
+	kfree(buf);
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	fdno = get_unused_fd_flags(O_CLOEXEC);
+	if (fdno < 0) {
+		ret = fdno;
+		goto err_put_device;
+	}
+
+	filep = vfio_device_open(device);
+	if (IS_ERR(filep)) {
+		ret = PTR_ERR(filep);
+		goto err_put_fdno;
+	}
+
+	fd_install(fdno, filep);
+	return fdno;
+
+err_put_fdno:
+	put_unused_fd(fdno);
+err_put_device:
+	vfio_device_put_registration(device);
+	return ret;
+}
+
+static int vfio_group_ioctl_get_status(struct vfio_group *group,
+				       struct vfio_group_status __user *arg)
+{
+	unsigned long minsz = offsetofend(struct vfio_group_status, flags);
+	struct vfio_group_status status;
+
+	if (copy_from_user(&status, arg, minsz))
+		return -EFAULT;
+
+	if (status.argsz < minsz)
+		return -EINVAL;
+
+	status.flags = 0;
+
+	mutex_lock(&group->group_lock);
+	if (!group->iommu_group) {
+		mutex_unlock(&group->group_lock);
+		return -ENODEV;
+	}
+
+	if (group->container)
+		status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
+				VFIO_GROUP_FLAGS_VIABLE;
+	else if (!iommu_group_dma_owner_claimed(group->iommu_group))
+		status.flags |= VFIO_GROUP_FLAGS_VIABLE;
+	mutex_unlock(&group->group_lock);
+
+	if (copy_to_user(arg, &status, minsz))
+		return -EFAULT;
+	return 0;
+}
+
+static long vfio_group_fops_unl_ioctl(struct file *filep,
+				      unsigned int cmd, unsigned long arg)
+{
+	struct vfio_group *group = filep->private_data;
+	void __user *uarg = (void __user *)arg;
+
+	switch (cmd) {
+	case VFIO_GROUP_GET_DEVICE_FD:
+		return vfio_group_ioctl_get_device_fd(group, uarg);
+	case VFIO_GROUP_GET_STATUS:
+		return vfio_group_ioctl_get_status(group, uarg);
+	case VFIO_GROUP_SET_CONTAINER:
+		return vfio_group_ioctl_set_container(group, uarg);
+	case VFIO_GROUP_UNSET_CONTAINER:
+		return vfio_group_ioctl_unset_container(group);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static int vfio_group_fops_open(struct inode *inode, struct file *filep)
+{
+	struct vfio_group *group =
+		container_of(inode->i_cdev, struct vfio_group, cdev);
+	int ret;
+
+	mutex_lock(&group->group_lock);
+
+	/*
+	 * drivers can be zero if this races with vfio_device_remove_group(), it
+	 * will be stable at 0 under the group rwsem
+	 */
+	if (refcount_read(&group->drivers) == 0) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+
+	/*
+	 * Do we need multiple instances of the group open?  Seems not.
+	 */
+	if (group->opened_file) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+	group->opened_file = filep;
+	filep->private_data = group;
+	ret = 0;
+out_unlock:
+	mutex_unlock(&group->group_lock);
+	return ret;
+}
+
+static int vfio_group_fops_release(struct inode *inode, struct file *filep)
+{
+	struct vfio_group *group = filep->private_data;
+
+	filep->private_data = NULL;
+
+	mutex_lock(&group->group_lock);
+	/*
+	 * Device FDs hold a group file reference, therefore the group release
+	 * is only called when there are no open devices.
+	 */
+	WARN_ON(group->notifier.head);
+	if (group->container)
+		vfio_group_detach_container(group);
+	group->opened_file = NULL;
+	mutex_unlock(&group->group_lock);
+	return 0;
+}
+
+static const struct file_operations vfio_group_fops = {
+	.owner		= THIS_MODULE,
+	.unlocked_ioctl	= vfio_group_fops_unl_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.open		= vfio_group_fops_open,
+	.release	= vfio_group_fops_release,
+};
+
+/*
+ * Wrapper around pm_runtime_resume_and_get().
+ * Return error code on failure or 0 on success.
+ */
+static inline int vfio_device_pm_runtime_get(struct vfio_device *device)
+{
+	struct device *dev = device->dev;
+
+	if (dev->driver && dev->driver->pm) {
+		int ret;
+
+		ret = pm_runtime_resume_and_get(dev);
+		if (ret) {
+			dev_info_ratelimited(dev,
+				"vfio: runtime resume failed %d\n", ret);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Wrapper around pm_runtime_put().
+ */
+static inline void vfio_device_pm_runtime_put(struct vfio_device *device)
+{
+	struct device *dev = device->dev;
+
+	if (dev->driver && dev->driver->pm)
+		pm_runtime_put(dev);
+}
+
+/*
+ * VFIO Device fd
+ */
+static int vfio_device_fops_release(struct inode *inode, struct file *filep)
+{
+	struct vfio_device *device = filep->private_data;
+
+	mutex_lock(&device->dev_set->lock);
+	vfio_assert_device_open(device);
+	mutex_lock(&device->group->group_lock);
+	if (device->open_count == 1) {
+		if (device->ops->close_device)
+			device->ops->close_device(device);
+
+		vfio_device_container_unregister(device);
+	}
+	mutex_unlock(&device->group->group_lock);
+	device->open_count--;
+	if (device->open_count == 0)
+		device->kvm = NULL;
+	mutex_unlock(&device->dev_set->lock);
+
+	module_put(device->dev->driver->owner);
+
+	vfio_device_unassign_container(device);
+
+	vfio_device_put_registration(device);
+
+	return 0;
+}
+
+/*
+ * vfio_mig_get_next_state - Compute the next step in the FSM
+ * @cur_fsm - The current state the device is in
+ * @new_fsm - The target state to reach
+ * @next_fsm - Pointer to the next step to get to new_fsm
+ *
+ * Return 0 upon success, otherwise -errno
+ * Upon success the next step in the state progression between cur_fsm and
+ * new_fsm will be set in next_fsm.
+ *
+ * This breaks down requests for combination transitions into smaller steps and
+ * returns the next step to get to new_fsm. The function may need to be called
+ * multiple times before reaching new_fsm.
+ *
+ */
+int vfio_mig_get_next_state(struct vfio_device *device,
+			    enum vfio_device_mig_state cur_fsm,
+			    enum vfio_device_mig_state new_fsm,
+			    enum vfio_device_mig_state *next_fsm)
+{
+	enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_RUNNING_P2P + 1 };
+	/*
+	 * The coding in this table requires the driver to implement the
+	 * following FSM arcs:
+	 *         RESUMING -> STOP
+	 *         STOP -> RESUMING
+	 *         STOP -> STOP_COPY
+	 *         STOP_COPY -> STOP
+	 *
+	 * If P2P is supported then the driver must also implement these FSM
+	 * arcs:
+	 *         RUNNING -> RUNNING_P2P
+	 *         RUNNING_P2P -> RUNNING
+	 *         RUNNING_P2P -> STOP
+	 *         STOP -> RUNNING_P2P
+	 * Without P2P the driver must implement:
+	 *         RUNNING -> STOP
+	 *         STOP -> RUNNING
+	 *
+	 * The coding will step through multiple states for some combination
+	 * transitions; if all optional features are supported, this means the
+	 * following ones:
+	 *         RESUMING -> STOP -> RUNNING_P2P
+	 *         RESUMING -> STOP -> RUNNING_P2P -> RUNNING
+	 *         RESUMING -> STOP -> STOP_COPY
+	 *         RUNNING -> RUNNING_P2P -> STOP
+	 *         RUNNING -> RUNNING_P2P -> STOP -> RESUMING
+	 *         RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY
+	 *         RUNNING_P2P -> STOP -> RESUMING
+	 *         RUNNING_P2P -> STOP -> STOP_COPY
+	 *         STOP -> RUNNING_P2P -> RUNNING
+	 *         STOP_COPY -> STOP -> RESUMING
+	 *         STOP_COPY -> STOP -> RUNNING_P2P
+	 *         STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING
+	 */
+	static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = {
+		[VFIO_DEVICE_STATE_STOP] = {
+			[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
+			[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
+			[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+		},
+		[VFIO_DEVICE_STATE_RUNNING] = {
+			[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
+			[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+		},
+		[VFIO_DEVICE_STATE_STOP_COPY] = {
+			[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
+			[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+		},
+		[VFIO_DEVICE_STATE_RESUMING] = {
+			[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
+			[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+		},
+		[VFIO_DEVICE_STATE_RUNNING_P2P] = {
+			[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
+			[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
+			[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
+			[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+		},
+		[VFIO_DEVICE_STATE_ERROR] = {
+			[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR,
+			[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR,
+			[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR,
+			[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR,
+			[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR,
+			[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
+		},
+	};
+
+	static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = {
+		[VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY,
+		[VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY,
+		[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY,
+		[VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY,
+		[VFIO_DEVICE_STATE_RUNNING_P2P] =
+			VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P,
+		[VFIO_DEVICE_STATE_ERROR] = ~0U,
+	};
+
+	if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
+		    (state_flags_table[cur_fsm] & device->migration_flags) !=
+			state_flags_table[cur_fsm]))
+		return -EINVAL;
+
+	if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
+	   (state_flags_table[new_fsm] & device->migration_flags) !=
+			state_flags_table[new_fsm])
+		return -EINVAL;
+
+	/*
+	 * Arcs touching optional and unsupported states are skipped over. The
+	 * driver will instead see an arc from the original state to the next
+	 * logical state, as per the above comment.
+	 */
+	*next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm];
+	while ((state_flags_table[*next_fsm] & device->migration_flags) !=
+			state_flags_table[*next_fsm])
+		*next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm];
+
+	return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(vfio_mig_get_next_state);
+
+/*
+ * Convert the drivers's struct file into a FD number and return it to userspace
+ */
+static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg,
+				   struct vfio_device_feature_mig_state *mig)
+{
+	int ret;
+	int fd;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0) {
+		ret = fd;
+		goto out_fput;
+	}
+
+	mig->data_fd = fd;
+	if (copy_to_user(arg, mig, sizeof(*mig))) {
+		ret = -EFAULT;
+		goto out_put_unused;
+	}
+	fd_install(fd, filp);
+	return 0;
+
+out_put_unused:
+	put_unused_fd(fd);
+out_fput:
+	fput(filp);
+	return ret;
+}
+
+static int
+vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device,
+					   u32 flags, void __user *arg,
+					   size_t argsz)
+{
+	size_t minsz =
+		offsetofend(struct vfio_device_feature_mig_state, data_fd);
+	struct vfio_device_feature_mig_state mig;
+	struct file *filp = NULL;
+	int ret;
+
+	if (!device->mig_ops)
+		return -ENOTTY;
+
+	ret = vfio_check_feature(flags, argsz,
+				 VFIO_DEVICE_FEATURE_SET |
+				 VFIO_DEVICE_FEATURE_GET,
+				 sizeof(mig));
+	if (ret != 1)
+		return ret;
+
+	if (copy_from_user(&mig, arg, minsz))
+		return -EFAULT;
+
+	if (flags & VFIO_DEVICE_FEATURE_GET) {
+		enum vfio_device_mig_state curr_state;
+
+		ret = device->mig_ops->migration_get_state(device,
+							   &curr_state);
+		if (ret)
+			return ret;
+		mig.device_state = curr_state;
+		goto out_copy;
+	}
+
+	/* Handle the VFIO_DEVICE_FEATURE_SET */
+	filp = device->mig_ops->migration_set_state(device, mig.device_state);
+	if (IS_ERR(filp) || !filp)
+		goto out_copy;
+
+	return vfio_ioct_mig_return_fd(filp, arg, &mig);
+out_copy:
+	mig.data_fd = -1;
+	if (copy_to_user(arg, &mig, sizeof(mig)))
+		return -EFAULT;
+	if (IS_ERR(filp))
+		return PTR_ERR(filp);
+	return 0;
+}
+
+static int vfio_ioctl_device_feature_migration(struct vfio_device *device,
+					       u32 flags, void __user *arg,
+					       size_t argsz)
+{
+	struct vfio_device_feature_migration mig = {
+		.flags = device->migration_flags,
+	};
+	int ret;
+
+	if (!device->mig_ops)
+		return -ENOTTY;
+
+	ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
+				 sizeof(mig));
+	if (ret != 1)
+		return ret;
+	if (copy_to_user(arg, &mig, sizeof(mig)))
+		return -EFAULT;
+	return 0;
+}
+
+/* Ranges should fit into a single kernel page */
+#define LOG_MAX_RANGES \
+	(PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range))
+
+static int
+vfio_ioctl_device_feature_logging_start(struct vfio_device *device,
+					u32 flags, void __user *arg,
+					size_t argsz)
+{
+	size_t minsz =
+		offsetofend(struct vfio_device_feature_dma_logging_control,
+			    ranges);
+	struct vfio_device_feature_dma_logging_range __user *ranges;
+	struct vfio_device_feature_dma_logging_control control;
+	struct vfio_device_feature_dma_logging_range range;
+	struct rb_root_cached root = RB_ROOT_CACHED;
+	struct interval_tree_node *nodes;
+	u64 iova_end;
+	u32 nnodes;
+	int i, ret;
+
+	if (!device->log_ops)
+		return -ENOTTY;
+
+	ret = vfio_check_feature(flags, argsz,
+				 VFIO_DEVICE_FEATURE_SET,
+				 sizeof(control));
+	if (ret != 1)
+		return ret;
+
+	if (copy_from_user(&control, arg, minsz))
+		return -EFAULT;
+
+	nnodes = control.num_ranges;
+	if (!nnodes)
+		return -EINVAL;
+
+	if (nnodes > LOG_MAX_RANGES)
+		return -E2BIG;
+
+	ranges = u64_to_user_ptr(control.ranges);
+	nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
+			      GFP_KERNEL);
+	if (!nodes)
+		return -ENOMEM;
+
+	for (i = 0; i < nnodes; i++) {
+		if (copy_from_user(&range, &ranges[i], sizeof(range))) {
+			ret = -EFAULT;
+			goto end;
+		}
+		if (!IS_ALIGNED(range.iova, control.page_size) ||
+		    !IS_ALIGNED(range.length, control.page_size)) {
+			ret = -EINVAL;
+			goto end;
+		}
+
+		if (check_add_overflow(range.iova, range.length, &iova_end) ||
+		    iova_end > ULONG_MAX) {
+			ret = -EOVERFLOW;
+			goto end;
+		}
+
+		nodes[i].start = range.iova;
+		nodes[i].last = range.iova + range.length - 1;
+		if (interval_tree_iter_first(&root, nodes[i].start,
+					     nodes[i].last)) {
+			/* Range overlapping */
+			ret = -EINVAL;
+			goto end;
+		}
+		interval_tree_insert(nodes + i, &root);
+	}
+
+	ret = device->log_ops->log_start(device, &root, nnodes,
+					 &control.page_size);
+	if (ret)
+		goto end;
+
+	if (copy_to_user(arg, &control, sizeof(control))) {
+		ret = -EFAULT;
+		device->log_ops->log_stop(device);
+	}
+
+end:
+	kfree(nodes);
+	return ret;
+}
+
+static int
+vfio_ioctl_device_feature_logging_stop(struct vfio_device *device,
+				       u32 flags, void __user *arg,
+				       size_t argsz)
+{
+	int ret;
+
+	if (!device->log_ops)
+		return -ENOTTY;
+
+	ret = vfio_check_feature(flags, argsz,
+				 VFIO_DEVICE_FEATURE_SET, 0);
+	if (ret != 1)
+		return ret;
+
+	return device->log_ops->log_stop(device);
+}
+
+static int vfio_device_log_read_and_clear(struct iova_bitmap *iter,
+					  unsigned long iova, size_t length,
+					  void *opaque)
+{
+	struct vfio_device *device = opaque;
+
+	return device->log_ops->log_read_and_clear(device, iova, length, iter);
+}
+
+static int
+vfio_ioctl_device_feature_logging_report(struct vfio_device *device,
+					 u32 flags, void __user *arg,
+					 size_t argsz)
+{
+	size_t minsz =
+		offsetofend(struct vfio_device_feature_dma_logging_report,
+			    bitmap);
+	struct vfio_device_feature_dma_logging_report report;
+	struct iova_bitmap *iter;
+	u64 iova_end;
+	int ret;
+
+	if (!device->log_ops)
+		return -ENOTTY;
+
+	ret = vfio_check_feature(flags, argsz,
+				 VFIO_DEVICE_FEATURE_GET,
+				 sizeof(report));
+	if (ret != 1)
+		return ret;
+
+	if (copy_from_user(&report, arg, minsz))
+		return -EFAULT;
+
+	if (report.page_size < SZ_4K || !is_power_of_2(report.page_size))
+		return -EINVAL;
+
+	if (check_add_overflow(report.iova, report.length, &iova_end) ||
+	    iova_end > ULONG_MAX)
+		return -EOVERFLOW;
+
+	iter = iova_bitmap_alloc(report.iova, report.length,
+				 report.page_size,
+				 u64_to_user_ptr(report.bitmap));
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	ret = iova_bitmap_for_each(iter, device,
+				   vfio_device_log_read_and_clear);
+
+	iova_bitmap_free(iter);
+	return ret;
+}
+
+static int vfio_ioctl_device_feature(struct vfio_device *device,
+				     struct vfio_device_feature __user *arg)
+{
+	size_t minsz = offsetofend(struct vfio_device_feature, flags);
+	struct vfio_device_feature feature;
+
+	if (copy_from_user(&feature, arg, minsz))
+		return -EFAULT;
+
+	if (feature.argsz < minsz)
+		return -EINVAL;
+
+	/* Check unknown flags */
+	if (feature.flags &
+	    ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET |
+	      VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE))
+		return -EINVAL;
+
+	/* GET & SET are mutually exclusive except with PROBE */
+	if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
+	    (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
+	    (feature.flags & VFIO_DEVICE_FEATURE_GET))
+		return -EINVAL;
+
+	switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
+	case VFIO_DEVICE_FEATURE_MIGRATION:
+		return vfio_ioctl_device_feature_migration(
+			device, feature.flags, arg->data,
+			feature.argsz - minsz);
+	case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE:
+		return vfio_ioctl_device_feature_mig_device_state(
+			device, feature.flags, arg->data,
+			feature.argsz - minsz);
+	case VFIO_DEVICE_FEATURE_DMA_LOGGING_START:
+		return vfio_ioctl_device_feature_logging_start(
+			device, feature.flags, arg->data,
+			feature.argsz - minsz);
+	case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP:
+		return vfio_ioctl_device_feature_logging_stop(
+			device, feature.flags, arg->data,
+			feature.argsz - minsz);
+	case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT:
+		return vfio_ioctl_device_feature_logging_report(
+			device, feature.flags, arg->data,
+			feature.argsz - minsz);
+	default:
+		if (unlikely(!device->ops->device_feature))
+			return -EINVAL;
+		return device->ops->device_feature(device, feature.flags,
+						   arg->data,
+						   feature.argsz - minsz);
+	}
+}
+
+static long vfio_device_fops_unl_ioctl(struct file *filep,
+				       unsigned int cmd, unsigned long arg)
+{
+	struct vfio_device *device = filep->private_data;
+	int ret;
+
+	ret = vfio_device_pm_runtime_get(device);
+	if (ret)
+		return ret;
+
+	switch (cmd) {
+	case VFIO_DEVICE_FEATURE:
+		ret = vfio_ioctl_device_feature(device, (void __user *)arg);
+		break;
+
+	default:
+		if (unlikely(!device->ops->ioctl))
+			ret = -EINVAL;
+		else
+			ret = device->ops->ioctl(device, cmd, arg);
+		break;
+	}
+
+	vfio_device_pm_runtime_put(device);
+	return ret;
+}
+
+static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
+				     size_t count, loff_t *ppos)
+{
+	struct vfio_device *device = filep->private_data;
+
+	if (unlikely(!device->ops->read))
+		return -EINVAL;
+
+	return device->ops->read(device, buf, count, ppos);
+}
+
+static ssize_t vfio_device_fops_write(struct file *filep,
+				      const char __user *buf,
+				      size_t count, loff_t *ppos)
+{
+	struct vfio_device *device = filep->private_data;
+
+	if (unlikely(!device->ops->write))
+		return -EINVAL;
+
+	return device->ops->write(device, buf, count, ppos);
+}
+
+static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
+{
+	struct vfio_device *device = filep->private_data;
+
+	if (unlikely(!device->ops->mmap))
+		return -EINVAL;
+
+	return device->ops->mmap(device, vma);
+}
+
+static const struct file_operations vfio_device_fops = {
+	.owner		= THIS_MODULE,
+	.release	= vfio_device_fops_release,
+	.read		= vfio_device_fops_read,
+	.write		= vfio_device_fops_write,
+	.unlocked_ioctl	= vfio_device_fops_unl_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.mmap		= vfio_device_fops_mmap,
+};
+
+/**
+ * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
+ * @file: VFIO group file
+ *
+ * The returned iommu_group is valid as long as a ref is held on the file. This
+ * returns a reference on the group. This function is deprecated, only the SPAPR
+ * path in kvm should call it.
+ */
+struct iommu_group *vfio_file_iommu_group(struct file *file)
+{
+	struct vfio_group *group = file->private_data;
+	struct iommu_group *iommu_group = NULL;
+
+	if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
+		return NULL;
+
+	if (!vfio_file_is_group(file))
+		return NULL;
+
+	mutex_lock(&group->group_lock);
+	if (group->iommu_group) {
+		iommu_group = group->iommu_group;
+		iommu_group_ref_get(iommu_group);
+	}
+	mutex_unlock(&group->group_lock);
+	return iommu_group;
+}
+EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
+
+/**
+ * vfio_file_is_group - True if the file is usable with VFIO aPIS
+ * @file: VFIO group file
+ */
+bool vfio_file_is_group(struct file *file)
+{
+	return file->f_op == &vfio_group_fops;
+}
+EXPORT_SYMBOL_GPL(vfio_file_is_group);
+
+/**
+ * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
+ *        is always CPU cache coherent
+ * @file: VFIO group file
+ *
+ * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
+ * bit in DMA transactions. A return of false indicates that the user has
+ * rights to access additional instructions such as wbinvd on x86.
+ */
+bool vfio_file_enforced_coherent(struct file *file)
+{
+	struct vfio_group *group = file->private_data;
+	bool ret;
+
+	if (!vfio_file_is_group(file))
+		return true;
+
+	mutex_lock(&group->group_lock);
+	if (group->container) {
+		ret = vfio_container_ioctl_check_extension(group->container,
+							   VFIO_DMA_CC_IOMMU);
+	} else {
+		/*
+		 * Since the coherency state is determined only once a container
+		 * is attached the user must do so before they can prove they
+		 * have permission.
+		 */
+		ret = true;
+	}
+	mutex_unlock(&group->group_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
+
+/**
+ * vfio_file_set_kvm - Link a kvm with VFIO drivers
+ * @file: VFIO group file
+ * @kvm: KVM to link
+ *
+ * When a VFIO device is first opened the KVM will be available in
+ * device->kvm if one was associated with the group.
+ */
+void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+{
+	struct vfio_group *group = file->private_data;
+
+	if (!vfio_file_is_group(file))
+		return;
+
+	mutex_lock(&group->group_lock);
+	group->kvm = kvm;
+	mutex_unlock(&group->group_lock);
+}
+EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
+
+/**
+ * vfio_file_has_dev - True if the VFIO file is a handle for device
+ * @file: VFIO file to check
+ * @device: Device that must be part of the file
+ *
+ * Returns true if given file has permission to manipulate the given device.
+ */
+bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
+{
+	struct vfio_group *group = file->private_data;
+
+	if (!vfio_file_is_group(file))
+		return false;
+
+	return group == device->group;
+}
+EXPORT_SYMBOL_GPL(vfio_file_has_dev);
+
+/*
+ * Sub-module support
+ */
+/*
+ * Helper for managing a buffer of info chain capabilities, allocate or
+ * reallocate a buffer with additional @size, filling in @id and @version
+ * of the capability.  A pointer to the new capability is returned.
+ *
+ * NB. The chain is based at the head of the buffer, so new entries are
+ * added to the tail, vfio_info_cap_shift() should be called to fixup the
+ * next offsets prior to copying to the user buffer.
+ */
+struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
+					       size_t size, u16 id, u16 version)
+{
+	void *buf;
+	struct vfio_info_cap_header *header, *tmp;
+
+	buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
+	if (!buf) {
+		kfree(caps->buf);
+		caps->buf = NULL;
+		caps->size = 0;
+		return ERR_PTR(-ENOMEM);
+	}
+
+	caps->buf = buf;
+	header = buf + caps->size;
+
+	/* Eventually copied to user buffer, zero */
+	memset(header, 0, size);
+
+	header->id = id;
+	header->version = version;
+
+	/* Add to the end of the capability chain */
+	for (tmp = buf; tmp->next; tmp = buf + tmp->next)
+		; /* nothing */
+
+	tmp->next = caps->size;
+	caps->size += size;
+
+	return header;
+}
+EXPORT_SYMBOL_GPL(vfio_info_cap_add);
+
+void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
+{
+	struct vfio_info_cap_header *tmp;
+	void *buf = (void *)caps->buf;
+
+	for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
+		tmp->next += offset;
+}
+EXPORT_SYMBOL(vfio_info_cap_shift);
+
+int vfio_info_add_capability(struct vfio_info_cap *caps,
+			     struct vfio_info_cap_header *cap, size_t size)
+{
+	struct vfio_info_cap_header *header;
+
+	header = vfio_info_cap_add(caps, size, cap->id, cap->version);
+	if (IS_ERR(header))
+		return PTR_ERR(header);
+
+	memcpy(header + 1, cap + 1, size - sizeof(*header));
+
+	return 0;
+}
+EXPORT_SYMBOL(vfio_info_add_capability);
+
+int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
+				       int max_irq_type, size_t *data_size)
+{
+	unsigned long minsz;
+	size_t size;
+
+	minsz = offsetofend(struct vfio_irq_set, count);
+
+	if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
+	    (hdr->count >= (U32_MAX - hdr->start)) ||
+	    (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
+				VFIO_IRQ_SET_ACTION_TYPE_MASK)))
+		return -EINVAL;
+
+	if (data_size)
+		*data_size = 0;
+
+	if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
+		return -EINVAL;
+
+	switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+	case VFIO_IRQ_SET_DATA_NONE:
+		size = 0;
+		break;
+	case VFIO_IRQ_SET_DATA_BOOL:
+		size = sizeof(uint8_t);
+		break;
+	case VFIO_IRQ_SET_DATA_EVENTFD:
+		size = sizeof(int32_t);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (size) {
+		if (hdr->argsz - minsz < hdr->count * size)
+			return -EINVAL;
+
+		if (!data_size)
+			return -EINVAL;
+
+		*data_size = hdr->count * size;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
+
+/*
+ * Module/class support
+ */
+static char *vfio_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
+}
+
+static int __init vfio_init(void)
+{
+	int ret;
+
+	ida_init(&vfio.group_ida);
+	ida_init(&vfio.device_ida);
+	mutex_init(&vfio.group_lock);
+	INIT_LIST_HEAD(&vfio.group_list);
+
+	ret = vfio_container_init();
+	if (ret)
+		return ret;
+
+	/* /dev/vfio/$GROUP */
+	vfio.class = class_create(THIS_MODULE, "vfio");
+	if (IS_ERR(vfio.class)) {
+		ret = PTR_ERR(vfio.class);
+		goto err_group_class;
+	}
+
+	vfio.class->devnode = vfio_devnode;
+
+	/* /sys/class/vfio-dev/vfioX */
+	vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
+	if (IS_ERR(vfio.device_class)) {
+		ret = PTR_ERR(vfio.device_class);
+		goto err_dev_class;
+	}
+
+	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
+	if (ret)
+		goto err_alloc_chrdev;
+
+	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
+	return 0;
+
+err_alloc_chrdev:
+	class_destroy(vfio.device_class);
+	vfio.device_class = NULL;
+err_dev_class:
+	class_destroy(vfio.class);
+	vfio.class = NULL;
+err_group_class:
+	vfio_container_cleanup();
+	return ret;
+}
+
+static void __exit vfio_cleanup(void)
+{
+	WARN_ON(!list_empty(&vfio.group_list));
+
+	ida_destroy(&vfio.device_ida);
+	ida_destroy(&vfio.group_ida);
+	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
+	class_destroy(vfio.device_class);
+	vfio.device_class = NULL;
+	class_destroy(vfio.class);
+	vfio_container_cleanup();
+	vfio.class = NULL;
+	xa_destroy(&vfio_device_set_xa);
+}
+
+module_init(vfio_init);
+module_exit(vfio_cleanup);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_ALIAS_MISCDEV(VFIO_MINOR);
+MODULE_ALIAS("devname:vfio/vfio");
+MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");