Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 607 insertions, 0 deletions

diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c
new file mode 100644
index 000000000..003281dbf
--- /dev/null
+++ b/drivers/vfio/container.c
@@ -0,0 +1,607 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
+ *
+ * VFIO container (/dev/vfio/vfio)
+ */
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/capability.h>
+#include <linux/iommu.h>
+#include <linux/miscdevice.h>
+#include <linux/vfio.h>
+#include <uapi/linux/vfio.h>
+
+#include "vfio.h"
+
+struct vfio_container {
+	struct kref			kref;
+	struct list_head		group_list;
+	struct rw_semaphore		group_lock;
+	struct vfio_iommu_driver	*iommu_driver;
+	void				*iommu_data;
+	bool				noiommu;
+};
+
+static struct vfio {
+	struct list_head		iommu_drivers_list;
+	struct mutex			iommu_drivers_lock;
+} vfio;
+
+static void *vfio_noiommu_open(unsigned long arg)
+{
+	if (arg != VFIO_NOIOMMU_IOMMU)
+		return ERR_PTR(-EINVAL);
+	if (!capable(CAP_SYS_RAWIO))
+		return ERR_PTR(-EPERM);
+
+	return NULL;
+}
+
+static void vfio_noiommu_release(void *iommu_data)
+{
+}
+
+static long vfio_noiommu_ioctl(void *iommu_data,
+			       unsigned int cmd, unsigned long arg)
+{
+	if (cmd == VFIO_CHECK_EXTENSION)
+		return vfio_noiommu && (arg == VFIO_NOIOMMU_IOMMU) ? 1 : 0;
+
+	return -ENOTTY;
+}
+
+static int vfio_noiommu_attach_group(void *iommu_data,
+		struct iommu_group *iommu_group, enum vfio_group_type type)
+{
+	return 0;
+}
+
+static void vfio_noiommu_detach_group(void *iommu_data,
+				      struct iommu_group *iommu_group)
+{
+}
+
+static const struct vfio_iommu_driver_ops vfio_noiommu_ops = {
+	.name = "vfio-noiommu",
+	.owner = THIS_MODULE,
+	.open = vfio_noiommu_open,
+	.release = vfio_noiommu_release,
+	.ioctl = vfio_noiommu_ioctl,
+	.attach_group = vfio_noiommu_attach_group,
+	.detach_group = vfio_noiommu_detach_group,
+};
+
+/*
+ * Only noiommu containers can use vfio-noiommu and noiommu containers can only
+ * use vfio-noiommu.
+ */
+static bool vfio_iommu_driver_allowed(struct vfio_container *container,
+				      const struct vfio_iommu_driver *driver)
+{
+	if (!IS_ENABLED(CONFIG_VFIO_NOIOMMU))
+		return true;
+	return container->noiommu == (driver->ops == &vfio_noiommu_ops);
+}
+
+/*
+ * IOMMU driver registration
+ */
+int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops)
+{
+	struct vfio_iommu_driver *driver, *tmp;
+
+	if (WARN_ON(!ops->register_device != !ops->unregister_device))
+		return -EINVAL;
+
+	driver = kzalloc_obj(*driver);
+	if (!driver)
+		return -ENOMEM;
+
+	driver->ops = ops;
+
+	mutex_lock(&vfio.iommu_drivers_lock);
+
+	/* Check for duplicates */
+	list_for_each_entry(tmp, &vfio.iommu_drivers_list, vfio_next) {
+		if (tmp->ops == ops) {
+			mutex_unlock(&vfio.iommu_drivers_lock);
+			kfree(driver);
+			return -EINVAL;
+		}
+	}
+
+	list_add(&driver->vfio_next, &vfio.iommu_drivers_list);
+
+	mutex_unlock(&vfio.iommu_drivers_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_register_iommu_driver);
+
+void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops)
+{
+	struct vfio_iommu_driver *driver;
+
+	mutex_lock(&vfio.iommu_drivers_lock);
+	list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) {
+		if (driver->ops == ops) {
+			list_del(&driver->vfio_next);
+			mutex_unlock(&vfio.iommu_drivers_lock);
+			kfree(driver);
+			return;
+		}
+	}
+	mutex_unlock(&vfio.iommu_drivers_lock);
+}
+EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver);
+
+/*
+ * Container objects - containers are created when /dev/vfio/vfio is
+ * opened, but their lifecycle extends until the last user is done, so
+ * it's freed via kref.  Must support container/group/device being
+ * closed in any order.
+ */
+static void vfio_container_release(struct kref *kref)
+{
+	struct vfio_container *container;
+	container = container_of(kref, struct vfio_container, kref);
+
+	kfree(container);
+}
+
+static void vfio_container_get(struct vfio_container *container)
+{
+	kref_get(&container->kref);
+}
+
+static void vfio_container_put(struct vfio_container *container)
+{
+	kref_put(&container->kref, vfio_container_release);
+}
+
+void vfio_device_container_register(struct vfio_device *device)
+{
+	struct vfio_iommu_driver *iommu_driver =
+		device->group->container->iommu_driver;
+
+	if (iommu_driver && iommu_driver->ops->register_device)
+		iommu_driver->ops->register_device(
+			device->group->container->iommu_data, device);
+}
+
+void vfio_device_container_unregister(struct vfio_device *device)
+{
+	struct vfio_iommu_driver *iommu_driver =
+		device->group->container->iommu_driver;
+
+	if (iommu_driver && iommu_driver->ops->unregister_device)
+		iommu_driver->ops->unregister_device(
+			device->group->container->iommu_data, device);
+}
+
+static long
+vfio_container_ioctl_check_extension(struct vfio_container *container,
+				     unsigned long arg)
+{
+	struct vfio_iommu_driver *driver;
+	long ret = 0;
+
+	down_read(&container->group_lock);
+
+	driver = container->iommu_driver;
+
+	switch (arg) {
+		/* No base extensions yet */
+	default:
+		/*
+		 * If no driver is set, poll all registered drivers for
+		 * extensions and return the first positive result.  If
+		 * a driver is already set, further queries will be passed
+		 * only to that driver.
+		 */
+		if (!driver) {
+			mutex_lock(&vfio.iommu_drivers_lock);
+			list_for_each_entry(driver, &vfio.iommu_drivers_list,
+					    vfio_next) {
+
+				if (!list_empty(&container->group_list) &&
+				    !vfio_iommu_driver_allowed(container,
+							       driver))
+					continue;
+				if (!try_module_get(driver->ops->owner))
+					continue;
+
+				ret = driver->ops->ioctl(NULL,
+							 VFIO_CHECK_EXTENSION,
+							 arg);
+				module_put(driver->ops->owner);
+				if (ret > 0)
+					break;
+			}
+			mutex_unlock(&vfio.iommu_drivers_lock);
+		} else
+			ret = driver->ops->ioctl(container->iommu_data,
+						 VFIO_CHECK_EXTENSION, arg);
+	}
+
+	up_read(&container->group_lock);
+
+	return ret;
+}
+
+/* hold write lock on container->group_lock */
+static int __vfio_container_attach_groups(struct vfio_container *container,
+					  struct vfio_iommu_driver *driver,
+					  void *data)
+{
+	struct vfio_group *group;
+	int ret = -ENODEV;
+
+	list_for_each_entry(group, &container->group_list, container_next) {
+		ret = driver->ops->attach_group(data, group->iommu_group,
+						group->type);
+		if (ret)
+			goto unwind;
+	}
+
+	return ret;
+
+unwind:
+	list_for_each_entry_continue_reverse(group, &container->group_list,
+					     container_next) {
+		driver->ops->detach_group(data, group->iommu_group);
+	}
+
+	return ret;
+}
+
+static long vfio_ioctl_set_iommu(struct vfio_container *container,
+				 unsigned long arg)
+{
+	struct vfio_iommu_driver *driver;
+	long ret = -ENODEV;
+
+	down_write(&container->group_lock);
+
+	/*
+	 * The container is designed to be an unprivileged interface while
+	 * the group can be assigned to specific users.  Therefore, only by
+	 * adding a group to a container does the user get the privilege of
+	 * enabling the iommu, which may allocate finite resources.  There
+	 * is no unset_iommu, but by removing all the groups from a container,
+	 * the container is deprivileged and returns to an unset state.
+	 */
+	if (list_empty(&container->group_list) || container->iommu_driver) {
+		up_write(&container->group_lock);
+		return -EINVAL;
+	}
+
+	mutex_lock(&vfio.iommu_drivers_lock);
+	list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) {
+		void *data;
+
+		if (!vfio_iommu_driver_allowed(container, driver))
+			continue;
+		if (!try_module_get(driver->ops->owner))
+			continue;
+
+		/*
+		 * The arg magic for SET_IOMMU is the same as CHECK_EXTENSION,
+		 * so test which iommu driver reported support for this
+		 * extension and call open on them.  We also pass them the
+		 * magic, allowing a single driver to support multiple
+		 * interfaces if they'd like.
+		 */
+		if (driver->ops->ioctl(NULL, VFIO_CHECK_EXTENSION, arg) <= 0) {
+			module_put(driver->ops->owner);
+			continue;
+		}
+
+		data = driver->ops->open(arg);
+		if (IS_ERR(data)) {
+			ret = PTR_ERR(data);
+			module_put(driver->ops->owner);
+			continue;
+		}
+
+		ret = __vfio_container_attach_groups(container, driver, data);
+		if (ret) {
+			driver->ops->release(data);
+			module_put(driver->ops->owner);
+			continue;
+		}
+
+		container->iommu_driver = driver;
+		container->iommu_data = data;
+		break;
+	}
+
+	mutex_unlock(&vfio.iommu_drivers_lock);
+	up_write(&container->group_lock);
+
+	return ret;
+}
+
+static long vfio_fops_unl_ioctl(struct file *filep,
+				unsigned int cmd, unsigned long arg)
+{
+	struct vfio_container *container = filep->private_data;
+	struct vfio_iommu_driver *driver;
+	void *data;
+	long ret = -EINVAL;
+
+	if (!container)
+		return ret;
+
+	switch (cmd) {
+	case VFIO_GET_API_VERSION:
+		ret = VFIO_API_VERSION;
+		break;
+	case VFIO_CHECK_EXTENSION:
+		ret = vfio_container_ioctl_check_extension(container, arg);
+		break;
+	case VFIO_SET_IOMMU:
+		ret = vfio_ioctl_set_iommu(container, arg);
+		break;
+	default:
+		driver = container->iommu_driver;
+		data = container->iommu_data;
+
+		if (driver) /* passthrough all unrecognized ioctls */
+			ret = driver->ops->ioctl(data, cmd, arg);
+	}
+
+	return ret;
+}
+
+static int vfio_fops_open(struct inode *inode, struct file *filep)
+{
+	struct vfio_container *container;
+
+	container = kzalloc_obj(*container, GFP_KERNEL_ACCOUNT);
+	if (!container)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&container->group_list);
+	init_rwsem(&container->group_lock);
+	kref_init(&container->kref);
+
+	filep->private_data = container;
+
+	return 0;
+}
+
+static int vfio_fops_release(struct inode *inode, struct file *filep)
+{
+	struct vfio_container *container = filep->private_data;
+
+	filep->private_data = NULL;
+
+	vfio_container_put(container);
+
+	return 0;
+}
+
+static const struct file_operations vfio_fops = {
+	.owner		= THIS_MODULE,
+	.open		= vfio_fops_open,
+	.release	= vfio_fops_release,
+	.unlocked_ioctl	= vfio_fops_unl_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+};
+
+struct vfio_container *vfio_container_from_file(struct file *file)
+{
+	struct vfio_container *container;
+
+	/* Sanity check, is this really our fd? */
+	if (file->f_op != &vfio_fops)
+		return NULL;
+
+	container = file->private_data;
+	WARN_ON(!container); /* fget ensures we don't race vfio_release */
+	return container;
+}
+
+static struct miscdevice vfio_dev = {
+	.minor = VFIO_MINOR,
+	.name = "vfio",
+	.fops = &vfio_fops,
+	.nodename = "vfio/vfio",
+	.mode = S_IRUGO | S_IWUGO,
+};
+
+int vfio_container_attach_group(struct vfio_container *container,
+				struct vfio_group *group)
+{
+	struct vfio_iommu_driver *driver;
+	int ret = 0;
+
+	lockdep_assert_held(&group->group_lock);
+
+	if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO))
+		return -EPERM;
+
+	down_write(&container->group_lock);
+
+	/* Real groups and fake groups cannot mix */
+	if (!list_empty(&container->group_list) &&
+	    container->noiommu != (group->type == VFIO_NO_IOMMU)) {
+		ret = -EPERM;
+		goto out_unlock_container;
+	}
+
+	if (group->type == VFIO_IOMMU) {
+		ret = iommu_group_claim_dma_owner(group->iommu_group, group);
+		if (ret)
+			goto out_unlock_container;
+	}
+
+	driver = container->iommu_driver;
+	if (driver) {
+		ret = driver->ops->attach_group(container->iommu_data,
+						group->iommu_group,
+						group->type);
+		if (ret) {
+			if (group->type == VFIO_IOMMU)
+				iommu_group_release_dma_owner(
+					group->iommu_group);
+			goto out_unlock_container;
+		}
+	}
+
+	group->container = container;
+	group->container_users = 1;
+	container->noiommu = (group->type == VFIO_NO_IOMMU);
+	list_add(&group->container_next, &container->group_list);
+
+	/* Get a reference on the container and mark a user within the group */
+	vfio_container_get(container);
+
+out_unlock_container:
+	up_write(&container->group_lock);
+	return ret;
+}
+
+void vfio_group_detach_container(struct vfio_group *group)
+{
+	struct vfio_container *container = group->container;
+	struct vfio_iommu_driver *driver;
+
+	lockdep_assert_held(&group->group_lock);
+	WARN_ON(group->container_users != 1);
+
+	down_write(&container->group_lock);
+
+	driver = container->iommu_driver;
+	if (driver)
+		driver->ops->detach_group(container->iommu_data,
+					  group->iommu_group);
+
+	if (group->type == VFIO_IOMMU)
+		iommu_group_release_dma_owner(group->iommu_group);
+
+	group->container = NULL;
+	group->container_users = 0;
+	list_del(&group->container_next);
+
+	/* Detaching the last group deprivileges a container, remove iommu */
+	if (driver && list_empty(&container->group_list)) {
+		driver->ops->release(container->iommu_data);
+		module_put(driver->ops->owner);
+		container->iommu_driver = NULL;
+		container->iommu_data = NULL;
+	}
+
+	up_write(&container->group_lock);
+
+	vfio_container_put(container);
+}
+
+int vfio_group_use_container(struct vfio_group *group)
+{
+	lockdep_assert_held(&group->group_lock);
+
+	/*
+	 * The container fd has been assigned with VFIO_GROUP_SET_CONTAINER but
+	 * VFIO_SET_IOMMU hasn't been done yet.
+	 */
+	if (!group->container->iommu_driver)
+		return -EINVAL;
+
+	if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO))
+		return -EPERM;
+
+	get_file(group->opened_file);
+	group->container_users++;
+	return 0;
+}
+
+void vfio_group_unuse_container(struct vfio_group *group)
+{
+	lockdep_assert_held(&group->group_lock);
+
+	WARN_ON(group->container_users <= 1);
+	group->container_users--;
+	fput(group->opened_file);
+}
+
+int vfio_device_container_pin_pages(struct vfio_device *device,
+				    dma_addr_t iova, int npage,
+				    int prot, struct page **pages)
+{
+	struct vfio_container *container = device->group->container;
+	struct iommu_group *iommu_group = device->group->iommu_group;
+	struct vfio_iommu_driver *driver = container->iommu_driver;
+
+	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
+		return -E2BIG;
+
+	if (unlikely(!driver || !driver->ops->pin_pages))
+		return -ENOTTY;
+	return driver->ops->pin_pages(container->iommu_data, iommu_group, iova,
+				      npage, prot, pages);
+}
+
+void vfio_device_container_unpin_pages(struct vfio_device *device,
+				       dma_addr_t iova, int npage)
+{
+	struct vfio_container *container = device->group->container;
+
+	if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES))
+		return;
+
+	container->iommu_driver->ops->unpin_pages(container->iommu_data, iova,
+						  npage);
+}
+
+int vfio_device_container_dma_rw(struct vfio_device *device,
+				 dma_addr_t iova, void *data,
+				 size_t len, bool write)
+{
+	struct vfio_container *container = device->group->container;
+	struct vfio_iommu_driver *driver = container->iommu_driver;
+
+	if (unlikely(!driver || !driver->ops->dma_rw))
+		return -ENOTTY;
+	return driver->ops->dma_rw(container->iommu_data, iova, data, len,
+				   write);
+}
+
+int __init vfio_container_init(void)
+{
+	int ret;
+
+	mutex_init(&vfio.iommu_drivers_lock);
+	INIT_LIST_HEAD(&vfio.iommu_drivers_list);
+
+	ret = misc_register(&vfio_dev);
+	if (ret) {
+		pr_err("vfio: misc device register failed\n");
+		return ret;
+	}
+
+	if (IS_ENABLED(CONFIG_VFIO_NOIOMMU)) {
+		ret = vfio_register_iommu_driver(&vfio_noiommu_ops);
+		if (ret)
+			goto err_misc;
+	}
+	return 0;
+
+err_misc:
+	misc_deregister(&vfio_dev);
+	return ret;
+}
+
+void vfio_container_cleanup(void)
+{
+	if (IS_ENABLED(CONFIG_VFIO_NOIOMMU))
+		vfio_unregister_iommu_driver(&vfio_noiommu_ops);
+	misc_deregister(&vfio_dev);
+	mutex_destroy(&vfio.iommu_drivers_lock);
+}
+
+MODULE_ALIAS_MISCDEV(VFIO_MINOR);
+MODULE_ALIAS("devname:vfio/vfio");