1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
6 * Author: Alex Williamson <alex.williamson@redhat.com>
8 * Derived from original vfio:
9 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
10 * Author: Tom Lyon, pugs@cisco.com
13 #include <linux/cdev.h>
14 #include <linux/compat.h>
15 #include <linux/device.h>
16 #include <linux/file.h>
17 #include <linux/anon_inodes.h>
19 #include <linux/idr.h>
20 #include <linux/iommu.h>
21 #include <linux/list.h>
22 #include <linux/miscdevice.h>
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <linux/pci.h>
26 #include <linux/rwsem.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 #include <linux/stat.h>
30 #include <linux/string.h>
31 #include <linux/uaccess.h>
32 #include <linux/vfio.h>
33 #include <linux/wait.h>
34 #include <linux/sched/signal.h>
36 #define DRIVER_VERSION "0.3"
37 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
38 #define DRIVER_DESC "VFIO - User Level meta-driver"
42 struct list_head iommu_drivers_list;
43 struct mutex iommu_drivers_lock;
44 struct list_head group_list;
46 struct mutex group_lock;
47 struct cdev group_cdev;
51 struct vfio_iommu_driver {
52 const struct vfio_iommu_driver_ops *ops;
53 struct list_head vfio_next;
56 struct vfio_container {
58 struct list_head group_list;
59 struct rw_semaphore group_lock;
60 struct vfio_iommu_driver *iommu_driver;
65 struct vfio_unbound_dev {
67 struct list_head unbound_next;
73 atomic_t container_users;
74 struct iommu_group *iommu_group;
75 struct vfio_container *container;
76 struct list_head device_list;
77 struct mutex device_lock;
79 struct notifier_block nb;
80 struct list_head vfio_next;
81 struct list_head container_next;
82 struct list_head unbound_list;
83 struct mutex unbound_lock;
85 wait_queue_head_t container_q;
87 unsigned int dev_counter;
89 struct blocking_notifier_head notifier;
92 #ifdef CONFIG_VFIO_NOIOMMU
93 static bool noiommu __read_mostly;
94 module_param_named(enable_unsafe_noiommu_mode,
95 noiommu, bool, S_IRUGO | S_IWUSR);
96 MODULE_PARM_DESC(enable_unsafe_noiommu_mode, "Enable UNSAFE, no-IOMMU mode. This mode provides no device isolation, no DMA translation, no host kernel protection, cannot be used for device assignment to virtual machines, requires RAWIO permissions, and will taint the kernel. If you do not know what this is for, step away. (default: false)");
100 * vfio_iommu_group_{get,put} are only intended for VFIO bus driver probe
101 * and remove functions, any use cases other than acquiring the first
102 * reference for the purpose of calling vfio_add_group_dev() or removing
103 * that symmetric reference after vfio_del_group_dev() should use the raw
104 * iommu_group_{get,put} functions. In particular, vfio_iommu_group_put()
105 * removes the device from the dummy group and cannot be nested.
107 struct iommu_group *vfio_iommu_group_get(struct device *dev)
109 struct iommu_group *group;
110 int __maybe_unused ret;
112 group = iommu_group_get(dev);
114 #ifdef CONFIG_VFIO_NOIOMMU
116 * With noiommu enabled, an IOMMU group will be created for a device
117 * that doesn't already have one and doesn't have an iommu_ops on their
118 * bus. We set iommudata simply to be able to identify these groups
119 * as special use and for reclamation later.
121 if (group || !noiommu || iommu_present(dev->bus))
124 group = iommu_group_alloc();
128 iommu_group_set_name(group, "vfio-noiommu");
129 iommu_group_set_iommudata(group, &noiommu, NULL);
130 ret = iommu_group_add_device(group, dev);
132 iommu_group_put(group);
137 * Where to taint? At this point we've added an IOMMU group for a
138 * device that is not backed by iommu_ops, therefore any iommu_
139 * callback using iommu_ops can legitimately Oops. So, while we may
140 * be about to give a DMA capable device to a user without IOMMU
141 * protection, which is clearly taint-worthy, let's go ahead and do
144 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
145 dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
150 EXPORT_SYMBOL_GPL(vfio_iommu_group_get);
152 void vfio_iommu_group_put(struct iommu_group *group, struct device *dev)
154 #ifdef CONFIG_VFIO_NOIOMMU
155 if (iommu_group_get_iommudata(group) == &noiommu)
156 iommu_group_remove_device(dev);
159 iommu_group_put(group);
161 EXPORT_SYMBOL_GPL(vfio_iommu_group_put);
163 #ifdef CONFIG_VFIO_NOIOMMU
164 static void *vfio_noiommu_open(unsigned long arg)
166 if (arg != VFIO_NOIOMMU_IOMMU)
167 return ERR_PTR(-EINVAL);
168 if (!capable(CAP_SYS_RAWIO))
169 return ERR_PTR(-EPERM);
174 static void vfio_noiommu_release(void *iommu_data)
178 static long vfio_noiommu_ioctl(void *iommu_data,
179 unsigned int cmd, unsigned long arg)
181 if (cmd == VFIO_CHECK_EXTENSION)
182 return noiommu && (arg == VFIO_NOIOMMU_IOMMU) ? 1 : 0;
187 static int vfio_noiommu_attach_group(void *iommu_data,
188 struct iommu_group *iommu_group)
190 return iommu_group_get_iommudata(iommu_group) == &noiommu ? 0 : -EINVAL;
193 static void vfio_noiommu_detach_group(void *iommu_data,
194 struct iommu_group *iommu_group)
198 static const struct vfio_iommu_driver_ops vfio_noiommu_ops = {
199 .name = "vfio-noiommu",
200 .owner = THIS_MODULE,
201 .open = vfio_noiommu_open,
202 .release = vfio_noiommu_release,
203 .ioctl = vfio_noiommu_ioctl,
204 .attach_group = vfio_noiommu_attach_group,
205 .detach_group = vfio_noiommu_detach_group,
211 * IOMMU driver registration
213 int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops)
215 struct vfio_iommu_driver *driver, *tmp;
217 driver = kzalloc(sizeof(*driver), GFP_KERNEL);
223 mutex_lock(&vfio.iommu_drivers_lock);
225 /* Check for duplicates */
226 list_for_each_entry(tmp, &vfio.iommu_drivers_list, vfio_next) {
227 if (tmp->ops == ops) {
228 mutex_unlock(&vfio.iommu_drivers_lock);
234 list_add(&driver->vfio_next, &vfio.iommu_drivers_list);
236 mutex_unlock(&vfio.iommu_drivers_lock);
240 EXPORT_SYMBOL_GPL(vfio_register_iommu_driver);
242 void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops)
244 struct vfio_iommu_driver *driver;
246 mutex_lock(&vfio.iommu_drivers_lock);
247 list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) {
248 if (driver->ops == ops) {
249 list_del(&driver->vfio_next);
250 mutex_unlock(&vfio.iommu_drivers_lock);
255 mutex_unlock(&vfio.iommu_drivers_lock);
257 EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver);
260 * Group minor allocation/free - both called with vfio.group_lock held
262 static int vfio_alloc_group_minor(struct vfio_group *group)
264 return idr_alloc(&vfio.group_idr, group, 0, MINORMASK + 1, GFP_KERNEL);
267 static void vfio_free_group_minor(int minor)
269 idr_remove(&vfio.group_idr, minor);
272 static int vfio_iommu_group_notifier(struct notifier_block *nb,
273 unsigned long action, void *data);
274 static void vfio_group_get(struct vfio_group *group);
277 * Container objects - containers are created when /dev/vfio/vfio is
278 * opened, but their lifecycle extends until the last user is done, so
279 * it's freed via kref. Must support container/group/device being
280 * closed in any order.
282 static void vfio_container_get(struct vfio_container *container)
284 kref_get(&container->kref);
287 static void vfio_container_release(struct kref *kref)
289 struct vfio_container *container;
290 container = container_of(kref, struct vfio_container, kref);
295 static void vfio_container_put(struct vfio_container *container)
297 kref_put(&container->kref, vfio_container_release);
300 static void vfio_group_unlock_and_free(struct vfio_group *group)
302 mutex_unlock(&vfio.group_lock);
304 * Unregister outside of lock. A spurious callback is harmless now
305 * that the group is no longer in vfio.group_list.
307 iommu_group_unregister_notifier(group->iommu_group, &group->nb);
312 * Group objects - create, release, get, put, search
314 static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
316 struct vfio_group *group, *tmp;
320 group = kzalloc(sizeof(*group), GFP_KERNEL);
322 return ERR_PTR(-ENOMEM);
324 kref_init(&group->kref);
325 INIT_LIST_HEAD(&group->device_list);
326 mutex_init(&group->device_lock);
327 INIT_LIST_HEAD(&group->unbound_list);
328 mutex_init(&group->unbound_lock);
329 atomic_set(&group->container_users, 0);
330 atomic_set(&group->opened, 0);
331 init_waitqueue_head(&group->container_q);
332 group->iommu_group = iommu_group;
333 #ifdef CONFIG_VFIO_NOIOMMU
334 group->noiommu = (iommu_group_get_iommudata(iommu_group) == &noiommu);
336 BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
338 group->nb.notifier_call = vfio_iommu_group_notifier;
341 * blocking notifiers acquire a rwsem around registering and hold
342 * it around callback. Therefore, need to register outside of
343 * vfio.group_lock to avoid A-B/B-A contention. Our callback won't
344 * do anything unless it can find the group in vfio.group_list, so
345 * no harm in registering early.
347 ret = iommu_group_register_notifier(iommu_group, &group->nb);
353 mutex_lock(&vfio.group_lock);
355 /* Did we race creating this group? */
356 list_for_each_entry(tmp, &vfio.group_list, vfio_next) {
357 if (tmp->iommu_group == iommu_group) {
359 vfio_group_unlock_and_free(group);
364 minor = vfio_alloc_group_minor(group);
366 vfio_group_unlock_and_free(group);
367 return ERR_PTR(minor);
370 dev = device_create(vfio.class, NULL,
371 MKDEV(MAJOR(vfio.group_devt), minor),
372 group, "%s%d", group->noiommu ? "noiommu-" : "",
373 iommu_group_id(iommu_group));
375 vfio_free_group_minor(minor);
376 vfio_group_unlock_and_free(group);
377 return ERR_CAST(dev);
380 group->minor = minor;
383 list_add(&group->vfio_next, &vfio.group_list);
385 mutex_unlock(&vfio.group_lock);
390 /* called with vfio.group_lock held */
391 static void vfio_group_release(struct kref *kref)
393 struct vfio_group *group = container_of(kref, struct vfio_group, kref);
394 struct vfio_unbound_dev *unbound, *tmp;
395 struct iommu_group *iommu_group = group->iommu_group;
397 WARN_ON(!list_empty(&group->device_list));
398 WARN_ON(group->notifier.head);
400 list_for_each_entry_safe(unbound, tmp,
401 &group->unbound_list, unbound_next) {
402 list_del(&unbound->unbound_next);
406 device_destroy(vfio.class, MKDEV(MAJOR(vfio.group_devt), group->minor));
407 list_del(&group->vfio_next);
408 vfio_free_group_minor(group->minor);
409 vfio_group_unlock_and_free(group);
410 iommu_group_put(iommu_group);
413 static void vfio_group_put(struct vfio_group *group)
415 kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock);
418 struct vfio_group_put_work {
419 struct work_struct work;
420 struct vfio_group *group;
423 static void vfio_group_put_bg(struct work_struct *work)
425 struct vfio_group_put_work *do_work;
427 do_work = container_of(work, struct vfio_group_put_work, work);
429 vfio_group_put(do_work->group);
433 static void vfio_group_schedule_put(struct vfio_group *group)
435 struct vfio_group_put_work *do_work;
437 do_work = kmalloc(sizeof(*do_work), GFP_KERNEL);
438 if (WARN_ON(!do_work))
441 INIT_WORK(&do_work->work, vfio_group_put_bg);
442 do_work->group = group;
443 schedule_work(&do_work->work);
446 /* Assume group_lock or group reference is held */
447 static void vfio_group_get(struct vfio_group *group)
449 kref_get(&group->kref);
453 * Not really a try as we will sleep for mutex, but we need to make
454 * sure the group pointer is valid under lock and get a reference.
456 static struct vfio_group *vfio_group_try_get(struct vfio_group *group)
458 struct vfio_group *target = group;
460 mutex_lock(&vfio.group_lock);
461 list_for_each_entry(group, &vfio.group_list, vfio_next) {
462 if (group == target) {
463 vfio_group_get(group);
464 mutex_unlock(&vfio.group_lock);
468 mutex_unlock(&vfio.group_lock);
474 struct vfio_group *vfio_group_get_from_iommu(struct iommu_group *iommu_group)
476 struct vfio_group *group;
478 mutex_lock(&vfio.group_lock);
479 list_for_each_entry(group, &vfio.group_list, vfio_next) {
480 if (group->iommu_group == iommu_group) {
481 vfio_group_get(group);
482 mutex_unlock(&vfio.group_lock);
486 mutex_unlock(&vfio.group_lock);
491 static struct vfio_group *vfio_group_get_from_minor(int minor)
493 struct vfio_group *group;
495 mutex_lock(&vfio.group_lock);
496 group = idr_find(&vfio.group_idr, minor);
498 mutex_unlock(&vfio.group_lock);
501 vfio_group_get(group);
502 mutex_unlock(&vfio.group_lock);
507 static struct vfio_group *vfio_group_get_from_dev(struct device *dev)
509 struct iommu_group *iommu_group;
510 struct vfio_group *group;
512 iommu_group = iommu_group_get(dev);
516 group = vfio_group_get_from_iommu(iommu_group);
517 iommu_group_put(iommu_group);
523 * Device objects - create, release, get, put, search
525 /* Device reference always implies a group reference */
526 void vfio_device_put(struct vfio_device *device)
528 if (refcount_dec_and_test(&device->refcount))
529 complete(&device->comp);
531 EXPORT_SYMBOL_GPL(vfio_device_put);
533 static bool vfio_device_try_get(struct vfio_device *device)
535 return refcount_inc_not_zero(&device->refcount);
538 static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
541 struct vfio_device *device;
543 mutex_lock(&group->device_lock);
544 list_for_each_entry(device, &group->device_list, group_next) {
545 if (device->dev == dev && vfio_device_try_get(device)) {
546 mutex_unlock(&group->device_lock);
550 mutex_unlock(&group->device_lock);
555 * Some drivers, like pci-stub, are only used to prevent other drivers from
556 * claiming a device and are therefore perfectly legitimate for a user owned
557 * group. The pci-stub driver has no dependencies on DMA or the IOVA mapping
558 * of the device, but it does prevent the user from having direct access to
559 * the device, which is useful in some circumstances.
561 * We also assume that we can include PCI interconnect devices, ie. bridges.
562 * IOMMU grouping on PCI necessitates that if we lack isolation on a bridge
563 * then all of the downstream devices will be part of the same IOMMU group as
564 * the bridge. Thus, if placing the bridge into the user owned IOVA space
565 * breaks anything, it only does so for user owned devices downstream. Note
566 * that error notification via MSI can be affected for platforms that handle
567 * MSI within the same IOVA space as DMA.
569 static const char * const vfio_driver_allowed[] = { "pci-stub" };
571 static bool vfio_dev_driver_allowed(struct device *dev,
572 struct device_driver *drv)
574 if (dev_is_pci(dev)) {
575 struct pci_dev *pdev = to_pci_dev(dev);
577 if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
581 return match_string(vfio_driver_allowed,
582 ARRAY_SIZE(vfio_driver_allowed),
587 * A vfio group is viable for use by userspace if all devices are in
588 * one of the following states:
590 * - bound to a vfio driver
591 * - bound to an otherwise allowed driver
592 * - a PCI interconnect device
594 * We use two methods to determine whether a device is bound to a vfio
595 * driver. The first is to test whether the device exists in the vfio
596 * group. The second is to test if the device exists on the group
597 * unbound_list, indicating it's in the middle of transitioning from
598 * a vfio driver to driver-less.
600 static int vfio_dev_viable(struct device *dev, void *data)
602 struct vfio_group *group = data;
603 struct vfio_device *device;
604 struct device_driver *drv = READ_ONCE(dev->driver);
605 struct vfio_unbound_dev *unbound;
608 mutex_lock(&group->unbound_lock);
609 list_for_each_entry(unbound, &group->unbound_list, unbound_next) {
610 if (dev == unbound->dev) {
615 mutex_unlock(&group->unbound_lock);
617 if (!ret || !drv || vfio_dev_driver_allowed(dev, drv))
620 device = vfio_group_get_device(group, dev);
622 vfio_device_put(device);
630 * Async device support
632 static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev)
634 struct vfio_device *device;
636 /* Do we already know about it? We shouldn't */
637 device = vfio_group_get_device(group, dev);
638 if (WARN_ON_ONCE(device)) {
639 vfio_device_put(device);
643 /* Nothing to do for idle groups */
644 if (!atomic_read(&group->container_users))
647 /* TODO Prevent device auto probing */
648 dev_WARN(dev, "Device added to live group %d!\n",
649 iommu_group_id(group->iommu_group));
654 static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev)
656 /* We don't care what happens when the group isn't in use */
657 if (!atomic_read(&group->container_users))
660 return vfio_dev_viable(dev, group);
663 static int vfio_iommu_group_notifier(struct notifier_block *nb,
664 unsigned long action, void *data)
666 struct vfio_group *group = container_of(nb, struct vfio_group, nb);
667 struct device *dev = data;
668 struct vfio_unbound_dev *unbound;
671 * Need to go through a group_lock lookup to get a reference or we
672 * risk racing a group being removed. Ignore spurious notifies.
674 group = vfio_group_try_get(group);
679 case IOMMU_GROUP_NOTIFY_ADD_DEVICE:
680 vfio_group_nb_add_dev(group, dev);
682 case IOMMU_GROUP_NOTIFY_DEL_DEVICE:
684 * Nothing to do here. If the device is in use, then the
685 * vfio sub-driver should block the remove callback until
686 * it is unused. If the device is unused or attached to a
687 * stub driver, then it should be released and we don't
688 * care that it will be going away.
691 case IOMMU_GROUP_NOTIFY_BIND_DRIVER:
692 dev_dbg(dev, "%s: group %d binding to driver\n", __func__,
693 iommu_group_id(group->iommu_group));
695 case IOMMU_GROUP_NOTIFY_BOUND_DRIVER:
696 dev_dbg(dev, "%s: group %d bound to driver %s\n", __func__,
697 iommu_group_id(group->iommu_group), dev->driver->name);
698 BUG_ON(vfio_group_nb_verify(group, dev));
700 case IOMMU_GROUP_NOTIFY_UNBIND_DRIVER:
701 dev_dbg(dev, "%s: group %d unbinding from driver %s\n",
702 __func__, iommu_group_id(group->iommu_group),
705 case IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER:
706 dev_dbg(dev, "%s: group %d unbound from driver\n", __func__,
707 iommu_group_id(group->iommu_group));
709 * XXX An unbound device in a live group is ok, but we'd
710 * really like to avoid the above BUG_ON by preventing other
711 * drivers from binding to it. Once that occurs, we have to
712 * stop the system to maintain isolation. At a minimum, we'd
713 * want a toggle to disable driver auto probe for this device.
716 mutex_lock(&group->unbound_lock);
717 list_for_each_entry(unbound,
718 &group->unbound_list, unbound_next) {
719 if (dev == unbound->dev) {
720 list_del(&unbound->unbound_next);
725 mutex_unlock(&group->unbound_lock);
730 * If we're the last reference to the group, the group will be
731 * released, which includes unregistering the iommu group notifier.
732 * We hold a read-lock on that notifier list, unregistering needs
733 * a write-lock... deadlock. Release our reference asynchronously
734 * to avoid that situation.
736 vfio_group_schedule_put(group);
743 void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
744 const struct vfio_device_ops *ops, void *device_data)
746 init_completion(&device->comp);
749 device->device_data = device_data;
751 EXPORT_SYMBOL_GPL(vfio_init_group_dev);
753 int vfio_register_group_dev(struct vfio_device *device)
755 struct vfio_device *existing_device;
756 struct iommu_group *iommu_group;
757 struct vfio_group *group;
759 iommu_group = iommu_group_get(device->dev);
763 group = vfio_group_get_from_iommu(iommu_group);
765 group = vfio_create_group(iommu_group);
767 iommu_group_put(iommu_group);
768 return PTR_ERR(group);
772 * A found vfio_group already holds a reference to the
773 * iommu_group. A created vfio_group keeps the reference.
775 iommu_group_put(iommu_group);
778 existing_device = vfio_group_get_device(group, device->dev);
779 if (existing_device) {
780 dev_WARN(device->dev, "Device already exists on group %d\n",
781 iommu_group_id(iommu_group));
782 vfio_device_put(existing_device);
783 vfio_group_put(group);
787 /* Our reference on group is moved to the device */
788 device->group = group;
790 /* Refcounting can't start until the driver calls register */
791 refcount_set(&device->refcount, 1);
793 mutex_lock(&group->device_lock);
794 list_add(&device->group_next, &group->device_list);
795 group->dev_counter++;
796 mutex_unlock(&group->device_lock);
800 EXPORT_SYMBOL_GPL(vfio_register_group_dev);
802 int vfio_add_group_dev(struct device *dev, const struct vfio_device_ops *ops,
805 struct vfio_device *device;
808 device = kzalloc(sizeof(*device), GFP_KERNEL);
812 vfio_init_group_dev(device, dev, ops, device_data);
813 ret = vfio_register_group_dev(device);
816 dev_set_drvdata(dev, device);
823 EXPORT_SYMBOL_GPL(vfio_add_group_dev);
826 * Get a reference to the vfio_device for a device. Even if the
827 * caller thinks they own the device, they could be racing with a
828 * release call path, so we can't trust drvdata for the shortcut.
829 * Go the long way around, from the iommu_group to the vfio_group
830 * to the vfio_device.
832 struct vfio_device *vfio_device_get_from_dev(struct device *dev)
834 struct vfio_group *group;
835 struct vfio_device *device;
837 group = vfio_group_get_from_dev(dev);
841 device = vfio_group_get_device(group, dev);
842 vfio_group_put(group);
846 EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
848 static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
851 struct vfio_device *it, *device = ERR_PTR(-ENODEV);
853 mutex_lock(&group->device_lock);
854 list_for_each_entry(it, &group->device_list, group_next) {
857 if (it->ops->match) {
858 ret = it->ops->match(it->device_data, buf);
860 device = ERR_PTR(ret);
864 ret = !strcmp(dev_name(it->dev), buf);
867 if (ret && vfio_device_try_get(it)) {
872 mutex_unlock(&group->device_lock);
878 * Caller must hold a reference to the vfio_device
880 void *vfio_device_data(struct vfio_device *device)
882 return device->device_data;
884 EXPORT_SYMBOL_GPL(vfio_device_data);
887 * Decrement the device reference count and wait for the device to be
888 * removed. Open file descriptors for the device... */
889 void vfio_unregister_group_dev(struct vfio_device *device)
891 struct vfio_group *group = device->group;
892 struct vfio_unbound_dev *unbound;
894 bool interrupted = false;
898 * When the device is removed from the group, the group suddenly
899 * becomes non-viable; the device has a driver (until the unbind
900 * completes), but it's not present in the group. This is bad news
901 * for any external users that need to re-acquire a group reference
902 * in order to match and release their existing reference. To
903 * solve this, we track such devices on the unbound_list to bridge
904 * the gap until they're fully unbound.
906 unbound = kzalloc(sizeof(*unbound), GFP_KERNEL);
908 unbound->dev = device->dev;
909 mutex_lock(&group->unbound_lock);
910 list_add(&unbound->unbound_next, &group->unbound_list);
911 mutex_unlock(&group->unbound_lock);
915 vfio_device_put(device);
916 rc = try_wait_for_completion(&device->comp);
918 if (device->ops->request)
919 device->ops->request(device->device_data, i++);
922 rc = wait_for_completion_timeout(&device->comp,
925 rc = wait_for_completion_interruptible_timeout(
926 &device->comp, HZ * 10);
929 dev_warn(device->dev,
930 "Device is currently in use, task"
932 "blocked until device is released",
933 current->comm, task_pid_nr(current));
938 mutex_lock(&group->device_lock);
939 list_del(&device->group_next);
940 group->dev_counter--;
941 mutex_unlock(&group->device_lock);
944 * In order to support multiple devices per group, devices can be
945 * plucked from the group while other devices in the group are still
946 * in use. The container persists with this group and those remaining
947 * devices still attached. If the user creates an isolation violation
948 * by binding this device to another driver while the group is still in
949 * use, that's their fault. However, in the case of removing the last,
950 * or potentially the only, device in the group there can be no other
951 * in-use devices in the group. The user has done their due diligence
952 * and we should lay no claims to those devices. In order to do that,
953 * we need to make sure the group is detached from the container.
954 * Without this stall, we're potentially racing with a user process
955 * that may attempt to immediately bind this device to another driver.
957 if (list_empty(&group->device_list))
958 wait_event(group->container_q, !group->container);
960 /* Matches the get in vfio_register_group_dev() */
961 vfio_group_put(group);
963 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
965 void *vfio_del_group_dev(struct device *dev)
967 struct vfio_device *device = dev_get_drvdata(dev);
968 void *device_data = device->device_data;
970 vfio_unregister_group_dev(device);
971 dev_set_drvdata(dev, NULL);
975 EXPORT_SYMBOL_GPL(vfio_del_group_dev);
978 * VFIO base fd, /dev/vfio/vfio
980 static long vfio_ioctl_check_extension(struct vfio_container *container,
983 struct vfio_iommu_driver *driver;
986 down_read(&container->group_lock);
988 driver = container->iommu_driver;
991 /* No base extensions yet */
994 * If no driver is set, poll all registered drivers for
995 * extensions and return the first positive result. If
996 * a driver is already set, further queries will be passed
997 * only to that driver.
1000 mutex_lock(&vfio.iommu_drivers_lock);
1001 list_for_each_entry(driver, &vfio.iommu_drivers_list,
1004 #ifdef CONFIG_VFIO_NOIOMMU
1005 if (!list_empty(&container->group_list) &&
1006 (container->noiommu !=
1007 (driver->ops == &vfio_noiommu_ops)))
1011 if (!try_module_get(driver->ops->owner))
1014 ret = driver->ops->ioctl(NULL,
1015 VFIO_CHECK_EXTENSION,
1017 module_put(driver->ops->owner);
1021 mutex_unlock(&vfio.iommu_drivers_lock);
1023 ret = driver->ops->ioctl(container->iommu_data,
1024 VFIO_CHECK_EXTENSION, arg);
1027 up_read(&container->group_lock);
1032 /* hold write lock on container->group_lock */
1033 static int __vfio_container_attach_groups(struct vfio_container *container,
1034 struct vfio_iommu_driver *driver,
1037 struct vfio_group *group;
1040 list_for_each_entry(group, &container->group_list, container_next) {
1041 ret = driver->ops->attach_group(data, group->iommu_group);
1049 list_for_each_entry_continue_reverse(group, &container->group_list,
1051 driver->ops->detach_group(data, group->iommu_group);
1057 static long vfio_ioctl_set_iommu(struct vfio_container *container,
1060 struct vfio_iommu_driver *driver;
1063 down_write(&container->group_lock);
1066 * The container is designed to be an unprivileged interface while
1067 * the group can be assigned to specific users. Therefore, only by
1068 * adding a group to a container does the user get the privilege of
1069 * enabling the iommu, which may allocate finite resources. There
1070 * is no unset_iommu, but by removing all the groups from a container,
1071 * the container is deprivileged and returns to an unset state.
1073 if (list_empty(&container->group_list) || container->iommu_driver) {
1074 up_write(&container->group_lock);
1078 mutex_lock(&vfio.iommu_drivers_lock);
1079 list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) {
1082 #ifdef CONFIG_VFIO_NOIOMMU
1084 * Only noiommu containers can use vfio-noiommu and noiommu
1085 * containers can only use vfio-noiommu.
1087 if (container->noiommu != (driver->ops == &vfio_noiommu_ops))
1091 if (!try_module_get(driver->ops->owner))
1095 * The arg magic for SET_IOMMU is the same as CHECK_EXTENSION,
1096 * so test which iommu driver reported support for this
1097 * extension and call open on them. We also pass them the
1098 * magic, allowing a single driver to support multiple
1099 * interfaces if they'd like.
1101 if (driver->ops->ioctl(NULL, VFIO_CHECK_EXTENSION, arg) <= 0) {
1102 module_put(driver->ops->owner);
1106 data = driver->ops->open(arg);
1108 ret = PTR_ERR(data);
1109 module_put(driver->ops->owner);
1113 ret = __vfio_container_attach_groups(container, driver, data);
1115 driver->ops->release(data);
1116 module_put(driver->ops->owner);
1120 container->iommu_driver = driver;
1121 container->iommu_data = data;
1125 mutex_unlock(&vfio.iommu_drivers_lock);
1126 up_write(&container->group_lock);
1131 static long vfio_fops_unl_ioctl(struct file *filep,
1132 unsigned int cmd, unsigned long arg)
1134 struct vfio_container *container = filep->private_data;
1135 struct vfio_iommu_driver *driver;
1143 case VFIO_GET_API_VERSION:
1144 ret = VFIO_API_VERSION;
1146 case VFIO_CHECK_EXTENSION:
1147 ret = vfio_ioctl_check_extension(container, arg);
1149 case VFIO_SET_IOMMU:
1150 ret = vfio_ioctl_set_iommu(container, arg);
1153 driver = container->iommu_driver;
1154 data = container->iommu_data;
1156 if (driver) /* passthrough all unrecognized ioctls */
1157 ret = driver->ops->ioctl(data, cmd, arg);
1163 static int vfio_fops_open(struct inode *inode, struct file *filep)
1165 struct vfio_container *container;
1167 container = kzalloc(sizeof(*container), GFP_KERNEL);
1171 INIT_LIST_HEAD(&container->group_list);
1172 init_rwsem(&container->group_lock);
1173 kref_init(&container->kref);
1175 filep->private_data = container;
1180 static int vfio_fops_release(struct inode *inode, struct file *filep)
1182 struct vfio_container *container = filep->private_data;
1183 struct vfio_iommu_driver *driver = container->iommu_driver;
1185 if (driver && driver->ops->notify)
1186 driver->ops->notify(container->iommu_data,
1187 VFIO_IOMMU_CONTAINER_CLOSE);
1189 filep->private_data = NULL;
1191 vfio_container_put(container);
1197 * Once an iommu driver is set, we optionally pass read/write/mmap
1198 * on to the driver, allowing management interfaces beyond ioctl.
1200 static ssize_t vfio_fops_read(struct file *filep, char __user *buf,
1201 size_t count, loff_t *ppos)
1203 struct vfio_container *container = filep->private_data;
1204 struct vfio_iommu_driver *driver;
1205 ssize_t ret = -EINVAL;
1207 driver = container->iommu_driver;
1208 if (likely(driver && driver->ops->read))
1209 ret = driver->ops->read(container->iommu_data,
1215 static ssize_t vfio_fops_write(struct file *filep, const char __user *buf,
1216 size_t count, loff_t *ppos)
1218 struct vfio_container *container = filep->private_data;
1219 struct vfio_iommu_driver *driver;
1220 ssize_t ret = -EINVAL;
1222 driver = container->iommu_driver;
1223 if (likely(driver && driver->ops->write))
1224 ret = driver->ops->write(container->iommu_data,
1230 static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma)
1232 struct vfio_container *container = filep->private_data;
1233 struct vfio_iommu_driver *driver;
1236 driver = container->iommu_driver;
1237 if (likely(driver && driver->ops->mmap))
1238 ret = driver->ops->mmap(container->iommu_data, vma);
1243 static const struct file_operations vfio_fops = {
1244 .owner = THIS_MODULE,
1245 .open = vfio_fops_open,
1246 .release = vfio_fops_release,
1247 .read = vfio_fops_read,
1248 .write = vfio_fops_write,
1249 .unlocked_ioctl = vfio_fops_unl_ioctl,
1250 .compat_ioctl = compat_ptr_ioctl,
1251 .mmap = vfio_fops_mmap,
1255 * VFIO Group fd, /dev/vfio/$GROUP
1257 static void __vfio_group_unset_container(struct vfio_group *group)
1259 struct vfio_container *container = group->container;
1260 struct vfio_iommu_driver *driver;
1262 down_write(&container->group_lock);
1264 driver = container->iommu_driver;
1266 driver->ops->detach_group(container->iommu_data,
1267 group->iommu_group);
1269 group->container = NULL;
1270 wake_up(&group->container_q);
1271 list_del(&group->container_next);
1273 /* Detaching the last group deprivileges a container, remove iommu */
1274 if (driver && list_empty(&container->group_list)) {
1275 driver->ops->release(container->iommu_data);
1276 module_put(driver->ops->owner);
1277 container->iommu_driver = NULL;
1278 container->iommu_data = NULL;
1281 up_write(&container->group_lock);
1283 vfio_container_put(container);
1287 * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
1288 * if there was no container to unset. Since the ioctl is called on
1289 * the group, we know that still exists, therefore the only valid
1290 * transition here is 1->0.
1292 static int vfio_group_unset_container(struct vfio_group *group)
1294 int users = atomic_cmpxchg(&group->container_users, 1, 0);
1301 __vfio_group_unset_container(group);
1307 * When removing container users, anything that removes the last user
1308 * implicitly removes the group from the container. That is, if the
1309 * group file descriptor is closed, as well as any device file descriptors,
1310 * the group is free.
1312 static void vfio_group_try_dissolve_container(struct vfio_group *group)
1314 if (0 == atomic_dec_if_positive(&group->container_users))
1315 __vfio_group_unset_container(group);
1318 static int vfio_group_set_container(struct vfio_group *group, int container_fd)
1321 struct vfio_container *container;
1322 struct vfio_iommu_driver *driver;
1325 if (atomic_read(&group->container_users))
1328 if (group->noiommu && !capable(CAP_SYS_RAWIO))
1331 f = fdget(container_fd);
1335 /* Sanity check, is this really our fd? */
1336 if (f.file->f_op != &vfio_fops) {
1341 container = f.file->private_data;
1342 WARN_ON(!container); /* fget ensures we don't race vfio_release */
1344 down_write(&container->group_lock);
1346 /* Real groups and fake groups cannot mix */
1347 if (!list_empty(&container->group_list) &&
1348 container->noiommu != group->noiommu) {
1353 driver = container->iommu_driver;
1355 ret = driver->ops->attach_group(container->iommu_data,
1356 group->iommu_group);
1361 group->container = container;
1362 container->noiommu = group->noiommu;
1363 list_add(&group->container_next, &container->group_list);
1365 /* Get a reference on the container and mark a user within the group */
1366 vfio_container_get(container);
1367 atomic_inc(&group->container_users);
1370 up_write(&container->group_lock);
1375 static bool vfio_group_viable(struct vfio_group *group)
1377 return (iommu_group_for_each_dev(group->iommu_group,
1378 group, vfio_dev_viable) == 0);
1381 static int vfio_group_add_container_user(struct vfio_group *group)
1383 if (!atomic_inc_not_zero(&group->container_users))
1386 if (group->noiommu) {
1387 atomic_dec(&group->container_users);
1390 if (!group->container->iommu_driver || !vfio_group_viable(group)) {
1391 atomic_dec(&group->container_users);
1398 static const struct file_operations vfio_device_fops;
1400 static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
1402 struct vfio_device *device;
1406 if (0 == atomic_read(&group->container_users) ||
1407 !group->container->iommu_driver || !vfio_group_viable(group))
1410 if (group->noiommu && !capable(CAP_SYS_RAWIO))
1413 device = vfio_device_get_from_name(group, buf);
1415 return PTR_ERR(device);
1417 ret = device->ops->open(device->device_data);
1419 vfio_device_put(device);
1424 * We can't use anon_inode_getfd() because we need to modify
1425 * the f_mode flags directly to allow more than just ioctls
1427 ret = get_unused_fd_flags(O_CLOEXEC);
1429 device->ops->release(device->device_data);
1430 vfio_device_put(device);
1434 filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
1436 if (IS_ERR(filep)) {
1438 ret = PTR_ERR(filep);
1439 device->ops->release(device->device_data);
1440 vfio_device_put(device);
1445 * TODO: add an anon_inode interface to do this.
1446 * Appears to be missing by lack of need rather than
1447 * explicitly prevented. Now there's need.
1449 filep->f_mode |= (FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1451 atomic_inc(&group->container_users);
1453 fd_install(ret, filep);
1456 dev_warn(device->dev, "vfio-noiommu device opened by user "
1457 "(%s:%d)\n", current->comm, task_pid_nr(current));
1462 static long vfio_group_fops_unl_ioctl(struct file *filep,
1463 unsigned int cmd, unsigned long arg)
1465 struct vfio_group *group = filep->private_data;
1469 case VFIO_GROUP_GET_STATUS:
1471 struct vfio_group_status status;
1472 unsigned long minsz;
1474 minsz = offsetofend(struct vfio_group_status, flags);
1476 if (copy_from_user(&status, (void __user *)arg, minsz))
1479 if (status.argsz < minsz)
1484 if (vfio_group_viable(group))
1485 status.flags |= VFIO_GROUP_FLAGS_VIABLE;
1487 if (group->container)
1488 status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET;
1490 if (copy_to_user((void __user *)arg, &status, minsz))
1496 case VFIO_GROUP_SET_CONTAINER:
1500 if (get_user(fd, (int __user *)arg))
1506 ret = vfio_group_set_container(group, fd);
1509 case VFIO_GROUP_UNSET_CONTAINER:
1510 ret = vfio_group_unset_container(group);
1512 case VFIO_GROUP_GET_DEVICE_FD:
1516 buf = strndup_user((const char __user *)arg, PAGE_SIZE);
1518 return PTR_ERR(buf);
1520 ret = vfio_group_get_device_fd(group, buf);
1529 static int vfio_group_fops_open(struct inode *inode, struct file *filep)
1531 struct vfio_group *group;
1534 group = vfio_group_get_from_minor(iminor(inode));
1538 if (group->noiommu && !capable(CAP_SYS_RAWIO)) {
1539 vfio_group_put(group);
1543 /* Do we need multiple instances of the group open? Seems not. */
1544 opened = atomic_cmpxchg(&group->opened, 0, 1);
1546 vfio_group_put(group);
1550 /* Is something still in use from a previous open? */
1551 if (group->container) {
1552 atomic_dec(&group->opened);
1553 vfio_group_put(group);
1557 /* Warn if previous user didn't cleanup and re-init to drop them */
1558 if (WARN_ON(group->notifier.head))
1559 BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
1561 filep->private_data = group;
1566 static int vfio_group_fops_release(struct inode *inode, struct file *filep)
1568 struct vfio_group *group = filep->private_data;
1570 filep->private_data = NULL;
1572 vfio_group_try_dissolve_container(group);
1574 atomic_dec(&group->opened);
1576 vfio_group_put(group);
1581 static const struct file_operations vfio_group_fops = {
1582 .owner = THIS_MODULE,
1583 .unlocked_ioctl = vfio_group_fops_unl_ioctl,
1584 .compat_ioctl = compat_ptr_ioctl,
1585 .open = vfio_group_fops_open,
1586 .release = vfio_group_fops_release,
1592 static int vfio_device_fops_release(struct inode *inode, struct file *filep)
1594 struct vfio_device *device = filep->private_data;
1596 device->ops->release(device->device_data);
1598 vfio_group_try_dissolve_container(device->group);
1600 vfio_device_put(device);
1605 static long vfio_device_fops_unl_ioctl(struct file *filep,
1606 unsigned int cmd, unsigned long arg)
1608 struct vfio_device *device = filep->private_data;
1610 if (unlikely(!device->ops->ioctl))
1613 return device->ops->ioctl(device->device_data, cmd, arg);
1616 static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
1617 size_t count, loff_t *ppos)
1619 struct vfio_device *device = filep->private_data;
1621 if (unlikely(!device->ops->read))
1624 return device->ops->read(device->device_data, buf, count, ppos);
1627 static ssize_t vfio_device_fops_write(struct file *filep,
1628 const char __user *buf,
1629 size_t count, loff_t *ppos)
1631 struct vfio_device *device = filep->private_data;
1633 if (unlikely(!device->ops->write))
1636 return device->ops->write(device->device_data, buf, count, ppos);
1639 static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
1641 struct vfio_device *device = filep->private_data;
1643 if (unlikely(!device->ops->mmap))
1646 return device->ops->mmap(device->device_data, vma);
1649 static const struct file_operations vfio_device_fops = {
1650 .owner = THIS_MODULE,
1651 .release = vfio_device_fops_release,
1652 .read = vfio_device_fops_read,
1653 .write = vfio_device_fops_write,
1654 .unlocked_ioctl = vfio_device_fops_unl_ioctl,
1655 .compat_ioctl = compat_ptr_ioctl,
1656 .mmap = vfio_device_fops_mmap,
1660 * External user API, exported by symbols to be linked dynamically.
1662 * The protocol includes:
1663 * 1. do normal VFIO init operation:
1664 * - opening a new container;
1665 * - attaching group(s) to it;
1666 * - setting an IOMMU driver for a container.
1667 * When IOMMU is set for a container, all groups in it are
1668 * considered ready to use by an external user.
1670 * 2. User space passes a group fd to an external user.
1671 * The external user calls vfio_group_get_external_user()
1673 * - the group is initialized;
1674 * - IOMMU is set for it.
1675 * If both checks passed, vfio_group_get_external_user()
1676 * increments the container user counter to prevent
1677 * the VFIO group from disposal before KVM exits.
1679 * 3. The external user calls vfio_external_user_iommu_id()
1680 * to know an IOMMU ID.
1682 * 4. When the external KVM finishes, it calls
1683 * vfio_group_put_external_user() to release the VFIO group.
1684 * This call decrements the container user counter.
1686 struct vfio_group *vfio_group_get_external_user(struct file *filep)
1688 struct vfio_group *group = filep->private_data;
1691 if (filep->f_op != &vfio_group_fops)
1692 return ERR_PTR(-EINVAL);
1694 ret = vfio_group_add_container_user(group);
1696 return ERR_PTR(ret);
1698 vfio_group_get(group);
1702 EXPORT_SYMBOL_GPL(vfio_group_get_external_user);
1705 * External user API, exported by symbols to be linked dynamically.
1706 * The external user passes in a device pointer
1708 * - A VFIO group is assiciated with the device;
1709 * - IOMMU is set for the group.
1710 * If both checks passed, vfio_group_get_external_user_from_dev()
1711 * increments the container user counter to prevent the VFIO group
1712 * from disposal before external user exits and returns the pointer
1713 * to the VFIO group.
1715 * When the external user finishes using the VFIO group, it calls
1716 * vfio_group_put_external_user() to release the VFIO group and
1717 * decrement the container user counter.
1719 * @dev [in] : device
1720 * Return error PTR or pointer to VFIO group.
1723 struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev)
1725 struct vfio_group *group;
1728 group = vfio_group_get_from_dev(dev);
1730 return ERR_PTR(-ENODEV);
1732 ret = vfio_group_add_container_user(group);
1734 vfio_group_put(group);
1735 return ERR_PTR(ret);
1740 EXPORT_SYMBOL_GPL(vfio_group_get_external_user_from_dev);
1742 void vfio_group_put_external_user(struct vfio_group *group)
1744 vfio_group_try_dissolve_container(group);
1745 vfio_group_put(group);
1747 EXPORT_SYMBOL_GPL(vfio_group_put_external_user);
1749 bool vfio_external_group_match_file(struct vfio_group *test_group,
1752 struct vfio_group *group = filep->private_data;
1754 return (filep->f_op == &vfio_group_fops) && (group == test_group);
1756 EXPORT_SYMBOL_GPL(vfio_external_group_match_file);
1758 int vfio_external_user_iommu_id(struct vfio_group *group)
1760 return iommu_group_id(group->iommu_group);
1762 EXPORT_SYMBOL_GPL(vfio_external_user_iommu_id);
1764 long vfio_external_check_extension(struct vfio_group *group, unsigned long arg)
1766 return vfio_ioctl_check_extension(group->container, arg);
1768 EXPORT_SYMBOL_GPL(vfio_external_check_extension);
1771 * Sub-module support
1774 * Helper for managing a buffer of info chain capabilities, allocate or
1775 * reallocate a buffer with additional @size, filling in @id and @version
1776 * of the capability. A pointer to the new capability is returned.
1778 * NB. The chain is based at the head of the buffer, so new entries are
1779 * added to the tail, vfio_info_cap_shift() should be called to fixup the
1780 * next offsets prior to copying to the user buffer.
1782 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
1783 size_t size, u16 id, u16 version)
1786 struct vfio_info_cap_header *header, *tmp;
1788 buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
1792 return ERR_PTR(-ENOMEM);
1796 header = buf + caps->size;
1798 /* Eventually copied to user buffer, zero */
1799 memset(header, 0, size);
1802 header->version = version;
1804 /* Add to the end of the capability chain */
1805 for (tmp = buf; tmp->next; tmp = buf + tmp->next)
1808 tmp->next = caps->size;
1813 EXPORT_SYMBOL_GPL(vfio_info_cap_add);
1815 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
1817 struct vfio_info_cap_header *tmp;
1818 void *buf = (void *)caps->buf;
1820 for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
1821 tmp->next += offset;
1823 EXPORT_SYMBOL(vfio_info_cap_shift);
1825 int vfio_info_add_capability(struct vfio_info_cap *caps,
1826 struct vfio_info_cap_header *cap, size_t size)
1828 struct vfio_info_cap_header *header;
1830 header = vfio_info_cap_add(caps, size, cap->id, cap->version);
1832 return PTR_ERR(header);
1834 memcpy(header + 1, cap + 1, size - sizeof(*header));
1838 EXPORT_SYMBOL(vfio_info_add_capability);
1840 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
1841 int max_irq_type, size_t *data_size)
1843 unsigned long minsz;
1846 minsz = offsetofend(struct vfio_irq_set, count);
1848 if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
1849 (hdr->count >= (U32_MAX - hdr->start)) ||
1850 (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
1851 VFIO_IRQ_SET_ACTION_TYPE_MASK)))
1857 if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
1860 switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
1861 case VFIO_IRQ_SET_DATA_NONE:
1864 case VFIO_IRQ_SET_DATA_BOOL:
1865 size = sizeof(uint8_t);
1867 case VFIO_IRQ_SET_DATA_EVENTFD:
1868 size = sizeof(int32_t);
1875 if (hdr->argsz - minsz < hdr->count * size)
1881 *data_size = hdr->count * size;
1886 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
1889 * Pin a set of guest PFNs and return their associated host PFNs for local
1891 * @dev [in] : device
1892 * @user_pfn [in]: array of user/guest PFNs to be pinned.
1893 * @npage [in] : count of elements in user_pfn array. This count should not
1894 * be greater VFIO_PIN_PAGES_MAX_ENTRIES.
1895 * @prot [in] : protection flags
1896 * @phys_pfn[out]: array of host PFNs
1897 * Return error or number of pages pinned.
1899 int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
1900 int prot, unsigned long *phys_pfn)
1902 struct vfio_container *container;
1903 struct vfio_group *group;
1904 struct vfio_iommu_driver *driver;
1907 if (!dev || !user_pfn || !phys_pfn || !npage)
1910 if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
1913 group = vfio_group_get_from_dev(dev);
1917 if (group->dev_counter > 1) {
1922 ret = vfio_group_add_container_user(group);
1926 container = group->container;
1927 driver = container->iommu_driver;
1928 if (likely(driver && driver->ops->pin_pages))
1929 ret = driver->ops->pin_pages(container->iommu_data,
1930 group->iommu_group, user_pfn,
1931 npage, prot, phys_pfn);
1935 vfio_group_try_dissolve_container(group);
1938 vfio_group_put(group);
1941 EXPORT_SYMBOL(vfio_pin_pages);
1944 * Unpin set of host PFNs for local domain only.
1945 * @dev [in] : device
1946 * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of user/guest
1947 * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
1948 * @npage [in] : count of elements in user_pfn array. This count should not
1949 * be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
1950 * Return error or number of pages unpinned.
1952 int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
1954 struct vfio_container *container;
1955 struct vfio_group *group;
1956 struct vfio_iommu_driver *driver;
1959 if (!dev || !user_pfn || !npage)
1962 if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
1965 group = vfio_group_get_from_dev(dev);
1969 ret = vfio_group_add_container_user(group);
1971 goto err_unpin_pages;
1973 container = group->container;
1974 driver = container->iommu_driver;
1975 if (likely(driver && driver->ops->unpin_pages))
1976 ret = driver->ops->unpin_pages(container->iommu_data, user_pfn,
1981 vfio_group_try_dissolve_container(group);
1984 vfio_group_put(group);
1987 EXPORT_SYMBOL(vfio_unpin_pages);
1990 * Pin a set of guest IOVA PFNs and return their associated host PFNs for a
1993 * The caller needs to call vfio_group_get_external_user() or
1994 * vfio_group_get_external_user_from_dev() prior to calling this interface,
1995 * so as to prevent the VFIO group from disposal in the middle of the call.
1996 * But it can keep the reference to the VFIO group for several calls into
1998 * After finishing using of the VFIO group, the caller needs to release the
1999 * VFIO group by calling vfio_group_put_external_user().
2001 * @group [in] : VFIO group
2002 * @user_iova_pfn [in] : array of user/guest IOVA PFNs to be pinned.
2003 * @npage [in] : count of elements in user_iova_pfn array.
2004 * This count should not be greater
2005 * VFIO_PIN_PAGES_MAX_ENTRIES.
2006 * @prot [in] : protection flags
2007 * @phys_pfn [out] : array of host PFNs
2008 * Return error or number of pages pinned.
2010 int vfio_group_pin_pages(struct vfio_group *group,
2011 unsigned long *user_iova_pfn, int npage,
2012 int prot, unsigned long *phys_pfn)
2014 struct vfio_container *container;
2015 struct vfio_iommu_driver *driver;
2018 if (!group || !user_iova_pfn || !phys_pfn || !npage)
2021 if (group->dev_counter > 1)
2024 if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
2027 container = group->container;
2028 driver = container->iommu_driver;
2029 if (likely(driver && driver->ops->pin_pages))
2030 ret = driver->ops->pin_pages(container->iommu_data,
2031 group->iommu_group, user_iova_pfn,
2032 npage, prot, phys_pfn);
2038 EXPORT_SYMBOL(vfio_group_pin_pages);
2041 * Unpin a set of guest IOVA PFNs for a VFIO group.
2043 * The caller needs to call vfio_group_get_external_user() or
2044 * vfio_group_get_external_user_from_dev() prior to calling this interface,
2045 * so as to prevent the VFIO group from disposal in the middle of the call.
2046 * But it can keep the reference to the VFIO group for several calls into
2048 * After finishing using of the VFIO group, the caller needs to release the
2049 * VFIO group by calling vfio_group_put_external_user().
2051 * @group [in] : vfio group
2052 * @user_iova_pfn [in] : array of user/guest IOVA PFNs to be unpinned.
2053 * @npage [in] : count of elements in user_iova_pfn array.
2054 * This count should not be greater than
2055 * VFIO_PIN_PAGES_MAX_ENTRIES.
2056 * Return error or number of pages unpinned.
2058 int vfio_group_unpin_pages(struct vfio_group *group,
2059 unsigned long *user_iova_pfn, int npage)
2061 struct vfio_container *container;
2062 struct vfio_iommu_driver *driver;
2065 if (!group || !user_iova_pfn || !npage)
2068 if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
2071 container = group->container;
2072 driver = container->iommu_driver;
2073 if (likely(driver && driver->ops->unpin_pages))
2074 ret = driver->ops->unpin_pages(container->iommu_data,
2075 user_iova_pfn, npage);
2081 EXPORT_SYMBOL(vfio_group_unpin_pages);
2085 * This interface allows the CPUs to perform some sort of virtual DMA on
2086 * behalf of the device.
2088 * CPUs read/write from/into a range of IOVAs pointing to user space memory
2089 * into/from a kernel buffer.
2091 * As the read/write of user space memory is conducted via the CPUs and is
2092 * not a real device DMA, it is not necessary to pin the user space memory.
2094 * The caller needs to call vfio_group_get_external_user() or
2095 * vfio_group_get_external_user_from_dev() prior to calling this interface,
2096 * so as to prevent the VFIO group from disposal in the middle of the call.
2097 * But it can keep the reference to the VFIO group for several calls into
2099 * After finishing using of the VFIO group, the caller needs to release the
2100 * VFIO group by calling vfio_group_put_external_user().
2102 * @group [in] : VFIO group
2103 * @user_iova [in] : base IOVA of a user space buffer
2104 * @data [in] : pointer to kernel buffer
2105 * @len [in] : kernel buffer length
2106 * @write : indicate read or write
2107 * Return error code on failure or 0 on success.
2109 int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova,
2110 void *data, size_t len, bool write)
2112 struct vfio_container *container;
2113 struct vfio_iommu_driver *driver;
2116 if (!group || !data || len <= 0)
2119 container = group->container;
2120 driver = container->iommu_driver;
2122 if (likely(driver && driver->ops->dma_rw))
2123 ret = driver->ops->dma_rw(container->iommu_data,
2124 user_iova, data, len, write);
2130 EXPORT_SYMBOL(vfio_dma_rw);
2132 static int vfio_register_iommu_notifier(struct vfio_group *group,
2133 unsigned long *events,
2134 struct notifier_block *nb)
2136 struct vfio_container *container;
2137 struct vfio_iommu_driver *driver;
2140 ret = vfio_group_add_container_user(group);
2144 container = group->container;
2145 driver = container->iommu_driver;
2146 if (likely(driver && driver->ops->register_notifier))
2147 ret = driver->ops->register_notifier(container->iommu_data,
2152 vfio_group_try_dissolve_container(group);
2157 static int vfio_unregister_iommu_notifier(struct vfio_group *group,
2158 struct notifier_block *nb)
2160 struct vfio_container *container;
2161 struct vfio_iommu_driver *driver;
2164 ret = vfio_group_add_container_user(group);
2168 container = group->container;
2169 driver = container->iommu_driver;
2170 if (likely(driver && driver->ops->unregister_notifier))
2171 ret = driver->ops->unregister_notifier(container->iommu_data,
2176 vfio_group_try_dissolve_container(group);
2181 void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
2184 blocking_notifier_call_chain(&group->notifier,
2185 VFIO_GROUP_NOTIFY_SET_KVM, kvm);
2187 EXPORT_SYMBOL_GPL(vfio_group_set_kvm);
2189 static int vfio_register_group_notifier(struct vfio_group *group,
2190 unsigned long *events,
2191 struct notifier_block *nb)
2194 bool set_kvm = false;
2196 if (*events & VFIO_GROUP_NOTIFY_SET_KVM)
2199 /* clear known events */
2200 *events &= ~VFIO_GROUP_NOTIFY_SET_KVM;
2202 /* refuse to continue if still events remaining */
2206 ret = vfio_group_add_container_user(group);
2210 ret = blocking_notifier_chain_register(&group->notifier, nb);
2213 * The attaching of kvm and vfio_group might already happen, so
2214 * here we replay once upon registration.
2216 if (!ret && set_kvm && group->kvm)
2217 blocking_notifier_call_chain(&group->notifier,
2218 VFIO_GROUP_NOTIFY_SET_KVM, group->kvm);
2220 vfio_group_try_dissolve_container(group);
2225 static int vfio_unregister_group_notifier(struct vfio_group *group,
2226 struct notifier_block *nb)
2230 ret = vfio_group_add_container_user(group);
2234 ret = blocking_notifier_chain_unregister(&group->notifier, nb);
2236 vfio_group_try_dissolve_container(group);
2241 int vfio_register_notifier(struct device *dev, enum vfio_notify_type type,
2242 unsigned long *events, struct notifier_block *nb)
2244 struct vfio_group *group;
2247 if (!dev || !nb || !events || (*events == 0))
2250 group = vfio_group_get_from_dev(dev);
2255 case VFIO_IOMMU_NOTIFY:
2256 ret = vfio_register_iommu_notifier(group, events, nb);
2258 case VFIO_GROUP_NOTIFY:
2259 ret = vfio_register_group_notifier(group, events, nb);
2265 vfio_group_put(group);
2268 EXPORT_SYMBOL(vfio_register_notifier);
2270 int vfio_unregister_notifier(struct device *dev, enum vfio_notify_type type,
2271 struct notifier_block *nb)
2273 struct vfio_group *group;
2279 group = vfio_group_get_from_dev(dev);
2284 case VFIO_IOMMU_NOTIFY:
2285 ret = vfio_unregister_iommu_notifier(group, nb);
2287 case VFIO_GROUP_NOTIFY:
2288 ret = vfio_unregister_group_notifier(group, nb);
2294 vfio_group_put(group);
2297 EXPORT_SYMBOL(vfio_unregister_notifier);
2299 struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group)
2301 struct vfio_container *container;
2302 struct vfio_iommu_driver *driver;
2305 return ERR_PTR(-EINVAL);
2307 container = group->container;
2308 driver = container->iommu_driver;
2309 if (likely(driver && driver->ops->group_iommu_domain))
2310 return driver->ops->group_iommu_domain(container->iommu_data,
2311 group->iommu_group);
2313 return ERR_PTR(-ENOTTY);
2315 EXPORT_SYMBOL_GPL(vfio_group_iommu_domain);
2318 * Module/class support
2320 static char *vfio_devnode(struct device *dev, umode_t *mode)
2322 return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
2325 static struct miscdevice vfio_dev = {
2326 .minor = VFIO_MINOR,
2329 .nodename = "vfio/vfio",
2330 .mode = S_IRUGO | S_IWUGO,
2333 static int __init vfio_init(void)
2337 idr_init(&vfio.group_idr);
2338 mutex_init(&vfio.group_lock);
2339 mutex_init(&vfio.iommu_drivers_lock);
2340 INIT_LIST_HEAD(&vfio.group_list);
2341 INIT_LIST_HEAD(&vfio.iommu_drivers_list);
2343 ret = misc_register(&vfio_dev);
2345 pr_err("vfio: misc device register failed\n");
2349 /* /dev/vfio/$GROUP */
2350 vfio.class = class_create(THIS_MODULE, "vfio");
2351 if (IS_ERR(vfio.class)) {
2352 ret = PTR_ERR(vfio.class);
2356 vfio.class->devnode = vfio_devnode;
2358 ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
2360 goto err_alloc_chrdev;
2362 cdev_init(&vfio.group_cdev, &vfio_group_fops);
2363 ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK + 1);
2367 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
2369 #ifdef CONFIG_VFIO_NOIOMMU
2370 vfio_register_iommu_driver(&vfio_noiommu_ops);
2375 unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
2377 class_destroy(vfio.class);
2380 misc_deregister(&vfio_dev);
2384 static void __exit vfio_cleanup(void)
2386 WARN_ON(!list_empty(&vfio.group_list));
2388 #ifdef CONFIG_VFIO_NOIOMMU
2389 vfio_unregister_iommu_driver(&vfio_noiommu_ops);
2391 idr_destroy(&vfio.group_idr);
2392 cdev_del(&vfio.group_cdev);
2393 unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
2394 class_destroy(vfio.class);
2396 misc_deregister(&vfio_dev);
2399 module_init(vfio_init);
2400 module_exit(vfio_cleanup);
2402 MODULE_VERSION(DRIVER_VERSION);
2403 MODULE_LICENSE("GPL v2");
2404 MODULE_AUTHOR(DRIVER_AUTHOR);
2405 MODULE_DESCRIPTION(DRIVER_DESC);
2406 MODULE_ALIAS_MISCDEV(VFIO_MINOR);
2407 MODULE_ALIAS("devname:vfio/vfio");
2408 MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");