blob: f018d8d0f975360a091339699d12348c5c93a12b [file] [log] [blame]
Alex Williamsoncba33452012-07-31 08:16:22 -06001/*
2 * VFIO core
3 *
4 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
5 * Author: Alex Williamson <alex.williamson@redhat.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Derived from original vfio:
12 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
13 * Author: Tom Lyon, pugs@cisco.com
14 */
15
16#include <linux/cdev.h>
17#include <linux/compat.h>
18#include <linux/device.h>
19#include <linux/file.h>
20#include <linux/anon_inodes.h>
21#include <linux/fs.h>
22#include <linux/idr.h>
23#include <linux/iommu.h>
24#include <linux/list.h>
Alex Williamsond1099902013-12-19 10:17:13 -070025#include <linux/miscdevice.h>
Alex Williamsoncba33452012-07-31 08:16:22 -060026#include <linux/module.h>
27#include <linux/mutex.h>
Alex Williamson9587f442013-04-25 16:12:38 -060028#include <linux/rwsem.h>
Alex Williamsoncba33452012-07-31 08:16:22 -060029#include <linux/sched.h>
30#include <linux/slab.h>
Alex Williamson664e9382013-04-30 15:42:28 -060031#include <linux/stat.h>
Alex Williamsoncba33452012-07-31 08:16:22 -060032#include <linux/string.h>
33#include <linux/uaccess.h>
34#include <linux/vfio.h>
35#include <linux/wait.h>
36
37#define DRIVER_VERSION "0.3"
38#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
39#define DRIVER_DESC "VFIO - User Level meta-driver"
40
41static struct vfio {
42 struct class *class;
43 struct list_head iommu_drivers_list;
44 struct mutex iommu_drivers_lock;
45 struct list_head group_list;
46 struct idr group_idr;
47 struct mutex group_lock;
48 struct cdev group_cdev;
Alex Williamsond1099902013-12-19 10:17:13 -070049 dev_t group_devt;
Alex Williamsoncba33452012-07-31 08:16:22 -060050 wait_queue_head_t release_q;
51} vfio;
52
53struct vfio_iommu_driver {
54 const struct vfio_iommu_driver_ops *ops;
55 struct list_head vfio_next;
56};
57
58struct vfio_container {
59 struct kref kref;
60 struct list_head group_list;
Alex Williamson9587f442013-04-25 16:12:38 -060061 struct rw_semaphore group_lock;
Alex Williamsoncba33452012-07-31 08:16:22 -060062 struct vfio_iommu_driver *iommu_driver;
63 void *iommu_data;
64};
65
66struct vfio_group {
67 struct kref kref;
68 int minor;
69 atomic_t container_users;
70 struct iommu_group *iommu_group;
71 struct vfio_container *container;
72 struct list_head device_list;
73 struct mutex device_lock;
74 struct device *dev;
75 struct notifier_block nb;
76 struct list_head vfio_next;
77 struct list_head container_next;
Alex Williamson6d6768c2013-06-25 16:06:54 -060078 atomic_t opened;
Alex Williamsoncba33452012-07-31 08:16:22 -060079};
80
81struct vfio_device {
82 struct kref kref;
83 struct device *dev;
84 const struct vfio_device_ops *ops;
85 struct vfio_group *group;
86 struct list_head group_next;
87 void *device_data;
88};
89
90/**
91 * IOMMU driver registration
92 */
93int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops)
94{
95 struct vfio_iommu_driver *driver, *tmp;
96
97 driver = kzalloc(sizeof(*driver), GFP_KERNEL);
98 if (!driver)
99 return -ENOMEM;
100
101 driver->ops = ops;
102
103 mutex_lock(&vfio.iommu_drivers_lock);
104
105 /* Check for duplicates */
106 list_for_each_entry(tmp, &vfio.iommu_drivers_list, vfio_next) {
107 if (tmp->ops == ops) {
108 mutex_unlock(&vfio.iommu_drivers_lock);
109 kfree(driver);
110 return -EINVAL;
111 }
112 }
113
114 list_add(&driver->vfio_next, &vfio.iommu_drivers_list);
115
116 mutex_unlock(&vfio.iommu_drivers_lock);
117
118 return 0;
119}
120EXPORT_SYMBOL_GPL(vfio_register_iommu_driver);
121
122void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops)
123{
124 struct vfio_iommu_driver *driver;
125
126 mutex_lock(&vfio.iommu_drivers_lock);
127 list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) {
128 if (driver->ops == ops) {
129 list_del(&driver->vfio_next);
130 mutex_unlock(&vfio.iommu_drivers_lock);
131 kfree(driver);
132 return;
133 }
134 }
135 mutex_unlock(&vfio.iommu_drivers_lock);
136}
137EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver);
138
139/**
140 * Group minor allocation/free - both called with vfio.group_lock held
141 */
142static int vfio_alloc_group_minor(struct vfio_group *group)
143{
Alex Williamsond1099902013-12-19 10:17:13 -0700144 return idr_alloc(&vfio.group_idr, group, 0, MINORMASK + 1, GFP_KERNEL);
Alex Williamsoncba33452012-07-31 08:16:22 -0600145}
146
147static void vfio_free_group_minor(int minor)
148{
149 idr_remove(&vfio.group_idr, minor);
150}
151
152static int vfio_iommu_group_notifier(struct notifier_block *nb,
153 unsigned long action, void *data);
154static void vfio_group_get(struct vfio_group *group);
155
156/**
157 * Container objects - containers are created when /dev/vfio/vfio is
158 * opened, but their lifecycle extends until the last user is done, so
159 * it's freed via kref. Must support container/group/device being
160 * closed in any order.
161 */
162static void vfio_container_get(struct vfio_container *container)
163{
164 kref_get(&container->kref);
165}
166
167static void vfio_container_release(struct kref *kref)
168{
169 struct vfio_container *container;
170 container = container_of(kref, struct vfio_container, kref);
171
172 kfree(container);
173}
174
175static void vfio_container_put(struct vfio_container *container)
176{
177 kref_put(&container->kref, vfio_container_release);
178}
179
Jiang Liu9df7b252012-12-07 13:43:50 -0700180static void vfio_group_unlock_and_free(struct vfio_group *group)
181{
182 mutex_unlock(&vfio.group_lock);
183 /*
184 * Unregister outside of lock. A spurious callback is harmless now
185 * that the group is no longer in vfio.group_list.
186 */
187 iommu_group_unregister_notifier(group->iommu_group, &group->nb);
188 kfree(group);
189}
190
Alex Williamsoncba33452012-07-31 08:16:22 -0600191/**
192 * Group objects - create, release, get, put, search
193 */
194static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
195{
196 struct vfio_group *group, *tmp;
197 struct device *dev;
198 int ret, minor;
199
200 group = kzalloc(sizeof(*group), GFP_KERNEL);
201 if (!group)
202 return ERR_PTR(-ENOMEM);
203
204 kref_init(&group->kref);
205 INIT_LIST_HEAD(&group->device_list);
206 mutex_init(&group->device_lock);
207 atomic_set(&group->container_users, 0);
Alex Williamson6d6768c2013-06-25 16:06:54 -0600208 atomic_set(&group->opened, 0);
Alex Williamsoncba33452012-07-31 08:16:22 -0600209 group->iommu_group = iommu_group;
210
211 group->nb.notifier_call = vfio_iommu_group_notifier;
212
213 /*
214 * blocking notifiers acquire a rwsem around registering and hold
215 * it around callback. Therefore, need to register outside of
216 * vfio.group_lock to avoid A-B/B-A contention. Our callback won't
217 * do anything unless it can find the group in vfio.group_list, so
218 * no harm in registering early.
219 */
220 ret = iommu_group_register_notifier(iommu_group, &group->nb);
221 if (ret) {
222 kfree(group);
223 return ERR_PTR(ret);
224 }
225
226 mutex_lock(&vfio.group_lock);
227
228 minor = vfio_alloc_group_minor(group);
229 if (minor < 0) {
Jiang Liu9df7b252012-12-07 13:43:50 -0700230 vfio_group_unlock_and_free(group);
Alex Williamsoncba33452012-07-31 08:16:22 -0600231 return ERR_PTR(minor);
232 }
233
234 /* Did we race creating this group? */
235 list_for_each_entry(tmp, &vfio.group_list, vfio_next) {
236 if (tmp->iommu_group == iommu_group) {
237 vfio_group_get(tmp);
238 vfio_free_group_minor(minor);
Jiang Liu9df7b252012-12-07 13:43:50 -0700239 vfio_group_unlock_and_free(group);
Alex Williamsoncba33452012-07-31 08:16:22 -0600240 return tmp;
241 }
242 }
243
Alex Williamsond1099902013-12-19 10:17:13 -0700244 dev = device_create(vfio.class, NULL,
245 MKDEV(MAJOR(vfio.group_devt), minor),
Alex Williamsoncba33452012-07-31 08:16:22 -0600246 group, "%d", iommu_group_id(iommu_group));
247 if (IS_ERR(dev)) {
248 vfio_free_group_minor(minor);
Jiang Liu9df7b252012-12-07 13:43:50 -0700249 vfio_group_unlock_and_free(group);
Alex Williamsoncba33452012-07-31 08:16:22 -0600250 return (struct vfio_group *)dev; /* ERR_PTR */
251 }
252
253 group->minor = minor;
254 group->dev = dev;
255
256 list_add(&group->vfio_next, &vfio.group_list);
257
258 mutex_unlock(&vfio.group_lock);
259
260 return group;
261}
262
Al Viro6d2cd3c2012-08-17 21:27:32 -0400263/* called with vfio.group_lock held */
Alex Williamsoncba33452012-07-31 08:16:22 -0600264static void vfio_group_release(struct kref *kref)
265{
266 struct vfio_group *group = container_of(kref, struct vfio_group, kref);
267
268 WARN_ON(!list_empty(&group->device_list));
269
Alex Williamsond1099902013-12-19 10:17:13 -0700270 device_destroy(vfio.class, MKDEV(MAJOR(vfio.group_devt), group->minor));
Alex Williamsoncba33452012-07-31 08:16:22 -0600271 list_del(&group->vfio_next);
272 vfio_free_group_minor(group->minor);
Jiang Liu9df7b252012-12-07 13:43:50 -0700273 vfio_group_unlock_and_free(group);
Alex Williamsoncba33452012-07-31 08:16:22 -0600274}
275
276static void vfio_group_put(struct vfio_group *group)
277{
Al Viro6d2cd3c2012-08-17 21:27:32 -0400278 kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600279}
280
281/* Assume group_lock or group reference is held */
282static void vfio_group_get(struct vfio_group *group)
283{
284 kref_get(&group->kref);
285}
286
287/*
288 * Not really a try as we will sleep for mutex, but we need to make
289 * sure the group pointer is valid under lock and get a reference.
290 */
291static struct vfio_group *vfio_group_try_get(struct vfio_group *group)
292{
293 struct vfio_group *target = group;
294
295 mutex_lock(&vfio.group_lock);
296 list_for_each_entry(group, &vfio.group_list, vfio_next) {
297 if (group == target) {
298 vfio_group_get(group);
299 mutex_unlock(&vfio.group_lock);
300 return group;
301 }
302 }
303 mutex_unlock(&vfio.group_lock);
304
305 return NULL;
306}
307
308static
309struct vfio_group *vfio_group_get_from_iommu(struct iommu_group *iommu_group)
310{
311 struct vfio_group *group;
312
313 mutex_lock(&vfio.group_lock);
314 list_for_each_entry(group, &vfio.group_list, vfio_next) {
315 if (group->iommu_group == iommu_group) {
316 vfio_group_get(group);
317 mutex_unlock(&vfio.group_lock);
318 return group;
319 }
320 }
321 mutex_unlock(&vfio.group_lock);
322
323 return NULL;
324}
325
326static struct vfio_group *vfio_group_get_from_minor(int minor)
327{
328 struct vfio_group *group;
329
330 mutex_lock(&vfio.group_lock);
331 group = idr_find(&vfio.group_idr, minor);
332 if (!group) {
333 mutex_unlock(&vfio.group_lock);
334 return NULL;
335 }
336 vfio_group_get(group);
337 mutex_unlock(&vfio.group_lock);
338
339 return group;
340}
341
342/**
343 * Device objects - create, release, get, put, search
344 */
345static
346struct vfio_device *vfio_group_create_device(struct vfio_group *group,
347 struct device *dev,
348 const struct vfio_device_ops *ops,
349 void *device_data)
350{
351 struct vfio_device *device;
Alex Williamsoncba33452012-07-31 08:16:22 -0600352
353 device = kzalloc(sizeof(*device), GFP_KERNEL);
354 if (!device)
355 return ERR_PTR(-ENOMEM);
356
357 kref_init(&device->kref);
358 device->dev = dev;
359 device->group = group;
360 device->ops = ops;
361 device->device_data = device_data;
Jean Delvare8283b492014-04-14 12:55:38 +0200362 dev_set_drvdata(dev, device);
Alex Williamsoncba33452012-07-31 08:16:22 -0600363
364 /* No need to get group_lock, caller has group reference */
365 vfio_group_get(group);
366
367 mutex_lock(&group->device_lock);
368 list_add(&device->group_next, &group->device_list);
369 mutex_unlock(&group->device_lock);
370
371 return device;
372}
373
374static void vfio_device_release(struct kref *kref)
375{
376 struct vfio_device *device = container_of(kref,
377 struct vfio_device, kref);
378 struct vfio_group *group = device->group;
379
Alex Williamsoncba33452012-07-31 08:16:22 -0600380 list_del(&device->group_next);
381 mutex_unlock(&group->device_lock);
382
383 dev_set_drvdata(device->dev, NULL);
384
385 kfree(device);
386
387 /* vfio_del_group_dev may be waiting for this device */
388 wake_up(&vfio.release_q);
389}
390
391/* Device reference always implies a group reference */
Vijay Mohan Pandarathil44f50712013-03-11 09:28:44 -0600392void vfio_device_put(struct vfio_device *device)
Alex Williamsoncba33452012-07-31 08:16:22 -0600393{
Al Viro934ad4c2012-08-17 19:49:09 -0400394 struct vfio_group *group = device->group;
Al Viro90b12532012-08-17 21:29:06 -0400395 kref_put_mutex(&device->kref, vfio_device_release, &group->device_lock);
Al Viro934ad4c2012-08-17 19:49:09 -0400396 vfio_group_put(group);
Alex Williamsoncba33452012-07-31 08:16:22 -0600397}
Vijay Mohan Pandarathil44f50712013-03-11 09:28:44 -0600398EXPORT_SYMBOL_GPL(vfio_device_put);
Alex Williamsoncba33452012-07-31 08:16:22 -0600399
400static void vfio_device_get(struct vfio_device *device)
401{
402 vfio_group_get(device->group);
403 kref_get(&device->kref);
404}
405
406static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
407 struct device *dev)
408{
409 struct vfio_device *device;
410
411 mutex_lock(&group->device_lock);
412 list_for_each_entry(device, &group->device_list, group_next) {
413 if (device->dev == dev) {
414 vfio_device_get(device);
415 mutex_unlock(&group->device_lock);
416 return device;
417 }
418 }
419 mutex_unlock(&group->device_lock);
420 return NULL;
421}
422
423/*
424 * Whitelist some drivers that we know are safe (no dma) or just sit on
425 * a device. It's not always practical to leave a device within a group
426 * driverless as it could get re-bound to something unsafe.
427 */
Alex Williamson2b489a42013-02-14 14:02:13 -0700428static const char * const vfio_driver_whitelist[] = { "pci-stub", "pcieport" };
Alex Williamsoncba33452012-07-31 08:16:22 -0600429
430static bool vfio_whitelisted_driver(struct device_driver *drv)
431{
432 int i;
433
434 for (i = 0; i < ARRAY_SIZE(vfio_driver_whitelist); i++) {
435 if (!strcmp(drv->name, vfio_driver_whitelist[i]))
436 return true;
437 }
438
439 return false;
440}
441
442/*
443 * A vfio group is viable for use by userspace if all devices are either
444 * driver-less or bound to a vfio or whitelisted driver. We test the
445 * latter by the existence of a struct vfio_device matching the dev.
446 */
447static int vfio_dev_viable(struct device *dev, void *data)
448{
449 struct vfio_group *group = data;
450 struct vfio_device *device;
Jiang Liude2b3ee2012-12-07 13:43:50 -0700451 struct device_driver *drv = ACCESS_ONCE(dev->driver);
Alex Williamsoncba33452012-07-31 08:16:22 -0600452
Jiang Liude2b3ee2012-12-07 13:43:50 -0700453 if (!drv || vfio_whitelisted_driver(drv))
Alex Williamsoncba33452012-07-31 08:16:22 -0600454 return 0;
455
456 device = vfio_group_get_device(group, dev);
457 if (device) {
458 vfio_device_put(device);
459 return 0;
460 }
461
462 return -EINVAL;
463}
464
465/**
466 * Async device support
467 */
468static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev)
469{
470 struct vfio_device *device;
471
472 /* Do we already know about it? We shouldn't */
473 device = vfio_group_get_device(group, dev);
474 if (WARN_ON_ONCE(device)) {
475 vfio_device_put(device);
476 return 0;
477 }
478
479 /* Nothing to do for idle groups */
480 if (!atomic_read(&group->container_users))
481 return 0;
482
483 /* TODO Prevent device auto probing */
484 WARN("Device %s added to live group %d!\n", dev_name(dev),
485 iommu_group_id(group->iommu_group));
486
487 return 0;
488}
489
Alex Williamsoncba33452012-07-31 08:16:22 -0600490static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev)
491{
492 /* We don't care what happens when the group isn't in use */
493 if (!atomic_read(&group->container_users))
494 return 0;
495
496 return vfio_dev_viable(dev, group);
497}
498
499static int vfio_iommu_group_notifier(struct notifier_block *nb,
500 unsigned long action, void *data)
501{
502 struct vfio_group *group = container_of(nb, struct vfio_group, nb);
503 struct device *dev = data;
504
505 /*
Alex Williamsonc6401932013-06-10 16:40:56 -0600506 * Need to go through a group_lock lookup to get a reference or we
507 * risk racing a group being removed. Ignore spurious notifies.
Alex Williamsoncba33452012-07-31 08:16:22 -0600508 */
509 group = vfio_group_try_get(group);
Alex Williamsonc6401932013-06-10 16:40:56 -0600510 if (!group)
Alex Williamsoncba33452012-07-31 08:16:22 -0600511 return NOTIFY_OK;
512
513 switch (action) {
514 case IOMMU_GROUP_NOTIFY_ADD_DEVICE:
515 vfio_group_nb_add_dev(group, dev);
516 break;
517 case IOMMU_GROUP_NOTIFY_DEL_DEVICE:
Alex Williamsonde9c7602013-06-10 16:40:56 -0600518 /*
519 * Nothing to do here. If the device is in use, then the
520 * vfio sub-driver should block the remove callback until
521 * it is unused. If the device is unused or attached to a
522 * stub driver, then it should be released and we don't
523 * care that it will be going away.
524 */
Alex Williamsoncba33452012-07-31 08:16:22 -0600525 break;
526 case IOMMU_GROUP_NOTIFY_BIND_DRIVER:
527 pr_debug("%s: Device %s, group %d binding to driver\n",
528 __func__, dev_name(dev),
529 iommu_group_id(group->iommu_group));
530 break;
531 case IOMMU_GROUP_NOTIFY_BOUND_DRIVER:
532 pr_debug("%s: Device %s, group %d bound to driver %s\n",
533 __func__, dev_name(dev),
534 iommu_group_id(group->iommu_group), dev->driver->name);
535 BUG_ON(vfio_group_nb_verify(group, dev));
536 break;
537 case IOMMU_GROUP_NOTIFY_UNBIND_DRIVER:
538 pr_debug("%s: Device %s, group %d unbinding from driver %s\n",
539 __func__, dev_name(dev),
540 iommu_group_id(group->iommu_group), dev->driver->name);
541 break;
542 case IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER:
543 pr_debug("%s: Device %s, group %d unbound from driver\n",
544 __func__, dev_name(dev),
545 iommu_group_id(group->iommu_group));
546 /*
547 * XXX An unbound device in a live group is ok, but we'd
548 * really like to avoid the above BUG_ON by preventing other
549 * drivers from binding to it. Once that occurs, we have to
550 * stop the system to maintain isolation. At a minimum, we'd
551 * want a toggle to disable driver auto probe for this device.
552 */
553 break;
554 }
555
556 vfio_group_put(group);
557 return NOTIFY_OK;
558}
559
560/**
561 * VFIO driver API
562 */
563int vfio_add_group_dev(struct device *dev,
564 const struct vfio_device_ops *ops, void *device_data)
565{
566 struct iommu_group *iommu_group;
567 struct vfio_group *group;
568 struct vfio_device *device;
569
570 iommu_group = iommu_group_get(dev);
571 if (!iommu_group)
572 return -EINVAL;
573
574 group = vfio_group_get_from_iommu(iommu_group);
575 if (!group) {
576 group = vfio_create_group(iommu_group);
577 if (IS_ERR(group)) {
578 iommu_group_put(iommu_group);
579 return PTR_ERR(group);
580 }
581 }
582
583 device = vfio_group_get_device(group, dev);
584 if (device) {
585 WARN(1, "Device %s already exists on group %d\n",
586 dev_name(dev), iommu_group_id(iommu_group));
587 vfio_device_put(device);
588 vfio_group_put(group);
589 iommu_group_put(iommu_group);
590 return -EBUSY;
591 }
592
593 device = vfio_group_create_device(group, dev, ops, device_data);
594 if (IS_ERR(device)) {
595 vfio_group_put(group);
596 iommu_group_put(iommu_group);
597 return PTR_ERR(device);
598 }
599
600 /*
601 * Added device holds reference to iommu_group and vfio_device
602 * (which in turn holds reference to vfio_group). Drop extra
603 * group reference used while acquiring device.
604 */
605 vfio_group_put(group);
606
607 return 0;
608}
609EXPORT_SYMBOL_GPL(vfio_add_group_dev);
610
Vijay Mohan Pandarathil44f50712013-03-11 09:28:44 -0600611/**
612 * Get a reference to the vfio_device for a device that is known to
613 * be bound to a vfio driver. The driver implicitly holds a
614 * vfio_device reference between vfio_add_group_dev and
615 * vfio_del_group_dev. We can therefore use drvdata to increment
616 * that reference from the struct device. This additional
617 * reference must be released by calling vfio_device_put.
618 */
619struct vfio_device *vfio_device_get_from_dev(struct device *dev)
620{
621 struct vfio_device *device = dev_get_drvdata(dev);
622
623 vfio_device_get(device);
624
625 return device;
626}
627EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
628
629/*
630 * Caller must hold a reference to the vfio_device
631 */
632void *vfio_device_data(struct vfio_device *device)
633{
634 return device->device_data;
635}
636EXPORT_SYMBOL_GPL(vfio_device_data);
637
Alex Williamsone014e942013-02-14 14:02:13 -0700638/* Given a referenced group, check if it contains the device */
639static bool vfio_dev_present(struct vfio_group *group, struct device *dev)
Alex Williamsoncba33452012-07-31 08:16:22 -0600640{
Alex Williamsoncba33452012-07-31 08:16:22 -0600641 struct vfio_device *device;
642
Alex Williamsoncba33452012-07-31 08:16:22 -0600643 device = vfio_group_get_device(group, dev);
Alex Williamsone014e942013-02-14 14:02:13 -0700644 if (!device)
Alex Williamsoncba33452012-07-31 08:16:22 -0600645 return false;
Alex Williamsoncba33452012-07-31 08:16:22 -0600646
647 vfio_device_put(device);
Alex Williamsoncba33452012-07-31 08:16:22 -0600648 return true;
649}
650
651/*
652 * Decrement the device reference count and wait for the device to be
653 * removed. Open file descriptors for the device... */
654void *vfio_del_group_dev(struct device *dev)
655{
656 struct vfio_device *device = dev_get_drvdata(dev);
657 struct vfio_group *group = device->group;
658 struct iommu_group *iommu_group = group->iommu_group;
659 void *device_data = device->device_data;
660
Alex Williamsone014e942013-02-14 14:02:13 -0700661 /*
662 * The group exists so long as we have a device reference. Get
663 * a group reference and use it to scan for the device going away.
664 */
665 vfio_group_get(group);
666
Alex Williamsoncba33452012-07-31 08:16:22 -0600667 vfio_device_put(device);
668
669 /* TODO send a signal to encourage this to be released */
Alex Williamsone014e942013-02-14 14:02:13 -0700670 wait_event(vfio.release_q, !vfio_dev_present(group, dev));
671
672 vfio_group_put(group);
Alex Williamsoncba33452012-07-31 08:16:22 -0600673
674 iommu_group_put(iommu_group);
675
676 return device_data;
677}
678EXPORT_SYMBOL_GPL(vfio_del_group_dev);
679
680/**
681 * VFIO base fd, /dev/vfio/vfio
682 */
683static long vfio_ioctl_check_extension(struct vfio_container *container,
684 unsigned long arg)
685{
Alex Williamson0b43c082013-04-29 08:41:36 -0600686 struct vfio_iommu_driver *driver;
Alex Williamsoncba33452012-07-31 08:16:22 -0600687 long ret = 0;
688
Alex Williamson0b43c082013-04-29 08:41:36 -0600689 down_read(&container->group_lock);
690
691 driver = container->iommu_driver;
692
Alex Williamsoncba33452012-07-31 08:16:22 -0600693 switch (arg) {
694 /* No base extensions yet */
695 default:
696 /*
697 * If no driver is set, poll all registered drivers for
698 * extensions and return the first positive result. If
699 * a driver is already set, further queries will be passed
700 * only to that driver.
701 */
702 if (!driver) {
703 mutex_lock(&vfio.iommu_drivers_lock);
704 list_for_each_entry(driver, &vfio.iommu_drivers_list,
705 vfio_next) {
706 if (!try_module_get(driver->ops->owner))
707 continue;
708
709 ret = driver->ops->ioctl(NULL,
710 VFIO_CHECK_EXTENSION,
711 arg);
712 module_put(driver->ops->owner);
713 if (ret > 0)
714 break;
715 }
716 mutex_unlock(&vfio.iommu_drivers_lock);
717 } else
718 ret = driver->ops->ioctl(container->iommu_data,
719 VFIO_CHECK_EXTENSION, arg);
720 }
721
Alex Williamson0b43c082013-04-29 08:41:36 -0600722 up_read(&container->group_lock);
723
Alex Williamsoncba33452012-07-31 08:16:22 -0600724 return ret;
725}
726
Alex Williamson9587f442013-04-25 16:12:38 -0600727/* hold write lock on container->group_lock */
Alex Williamsoncba33452012-07-31 08:16:22 -0600728static int __vfio_container_attach_groups(struct vfio_container *container,
729 struct vfio_iommu_driver *driver,
730 void *data)
731{
732 struct vfio_group *group;
733 int ret = -ENODEV;
734
735 list_for_each_entry(group, &container->group_list, container_next) {
736 ret = driver->ops->attach_group(data, group->iommu_group);
737 if (ret)
738 goto unwind;
739 }
740
741 return ret;
742
743unwind:
744 list_for_each_entry_continue_reverse(group, &container->group_list,
745 container_next) {
746 driver->ops->detach_group(data, group->iommu_group);
747 }
748
749 return ret;
750}
751
752static long vfio_ioctl_set_iommu(struct vfio_container *container,
753 unsigned long arg)
754{
755 struct vfio_iommu_driver *driver;
756 long ret = -ENODEV;
757
Alex Williamson9587f442013-04-25 16:12:38 -0600758 down_write(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600759
760 /*
761 * The container is designed to be an unprivileged interface while
762 * the group can be assigned to specific users. Therefore, only by
763 * adding a group to a container does the user get the privilege of
764 * enabling the iommu, which may allocate finite resources. There
765 * is no unset_iommu, but by removing all the groups from a container,
766 * the container is deprivileged and returns to an unset state.
767 */
768 if (list_empty(&container->group_list) || container->iommu_driver) {
Alex Williamson9587f442013-04-25 16:12:38 -0600769 up_write(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600770 return -EINVAL;
771 }
772
773 mutex_lock(&vfio.iommu_drivers_lock);
774 list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) {
775 void *data;
776
777 if (!try_module_get(driver->ops->owner))
778 continue;
779
780 /*
781 * The arg magic for SET_IOMMU is the same as CHECK_EXTENSION,
782 * so test which iommu driver reported support for this
783 * extension and call open on them. We also pass them the
784 * magic, allowing a single driver to support multiple
785 * interfaces if they'd like.
786 */
787 if (driver->ops->ioctl(NULL, VFIO_CHECK_EXTENSION, arg) <= 0) {
788 module_put(driver->ops->owner);
789 continue;
790 }
791
792 /* module reference holds the driver we're working on */
793 mutex_unlock(&vfio.iommu_drivers_lock);
794
795 data = driver->ops->open(arg);
796 if (IS_ERR(data)) {
797 ret = PTR_ERR(data);
798 module_put(driver->ops->owner);
799 goto skip_drivers_unlock;
800 }
801
802 ret = __vfio_container_attach_groups(container, driver, data);
803 if (!ret) {
804 container->iommu_driver = driver;
805 container->iommu_data = data;
806 } else {
807 driver->ops->release(data);
808 module_put(driver->ops->owner);
809 }
810
811 goto skip_drivers_unlock;
812 }
813
814 mutex_unlock(&vfio.iommu_drivers_lock);
815skip_drivers_unlock:
Alex Williamson9587f442013-04-25 16:12:38 -0600816 up_write(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600817
818 return ret;
819}
820
821static long vfio_fops_unl_ioctl(struct file *filep,
822 unsigned int cmd, unsigned long arg)
823{
824 struct vfio_container *container = filep->private_data;
825 struct vfio_iommu_driver *driver;
826 void *data;
827 long ret = -EINVAL;
828
829 if (!container)
830 return ret;
831
Alex Williamsoncba33452012-07-31 08:16:22 -0600832 switch (cmd) {
833 case VFIO_GET_API_VERSION:
834 ret = VFIO_API_VERSION;
835 break;
836 case VFIO_CHECK_EXTENSION:
837 ret = vfio_ioctl_check_extension(container, arg);
838 break;
839 case VFIO_SET_IOMMU:
840 ret = vfio_ioctl_set_iommu(container, arg);
841 break;
842 default:
Alex Williamson0b43c082013-04-29 08:41:36 -0600843 down_read(&container->group_lock);
844
845 driver = container->iommu_driver;
846 data = container->iommu_data;
847
Alex Williamsoncba33452012-07-31 08:16:22 -0600848 if (driver) /* passthrough all unrecognized ioctls */
849 ret = driver->ops->ioctl(data, cmd, arg);
Alex Williamson0b43c082013-04-29 08:41:36 -0600850
851 up_read(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600852 }
853
854 return ret;
855}
856
857#ifdef CONFIG_COMPAT
858static long vfio_fops_compat_ioctl(struct file *filep,
859 unsigned int cmd, unsigned long arg)
860{
861 arg = (unsigned long)compat_ptr(arg);
862 return vfio_fops_unl_ioctl(filep, cmd, arg);
863}
864#endif /* CONFIG_COMPAT */
865
866static int vfio_fops_open(struct inode *inode, struct file *filep)
867{
868 struct vfio_container *container;
869
870 container = kzalloc(sizeof(*container), GFP_KERNEL);
871 if (!container)
872 return -ENOMEM;
873
874 INIT_LIST_HEAD(&container->group_list);
Alex Williamson9587f442013-04-25 16:12:38 -0600875 init_rwsem(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600876 kref_init(&container->kref);
877
878 filep->private_data = container;
879
880 return 0;
881}
882
883static int vfio_fops_release(struct inode *inode, struct file *filep)
884{
885 struct vfio_container *container = filep->private_data;
886
887 filep->private_data = NULL;
888
889 vfio_container_put(container);
890
891 return 0;
892}
893
894/*
895 * Once an iommu driver is set, we optionally pass read/write/mmap
896 * on to the driver, allowing management interfaces beyond ioctl.
897 */
898static ssize_t vfio_fops_read(struct file *filep, char __user *buf,
899 size_t count, loff_t *ppos)
900{
901 struct vfio_container *container = filep->private_data;
Alex Williamson0b43c082013-04-29 08:41:36 -0600902 struct vfio_iommu_driver *driver;
903 ssize_t ret = -EINVAL;
Alex Williamsoncba33452012-07-31 08:16:22 -0600904
Alex Williamson0b43c082013-04-29 08:41:36 -0600905 down_read(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600906
Alex Williamson0b43c082013-04-29 08:41:36 -0600907 driver = container->iommu_driver;
908 if (likely(driver && driver->ops->read))
909 ret = driver->ops->read(container->iommu_data,
910 buf, count, ppos);
911
912 up_read(&container->group_lock);
913
914 return ret;
Alex Williamsoncba33452012-07-31 08:16:22 -0600915}
916
917static ssize_t vfio_fops_write(struct file *filep, const char __user *buf,
918 size_t count, loff_t *ppos)
919{
920 struct vfio_container *container = filep->private_data;
Alex Williamson0b43c082013-04-29 08:41:36 -0600921 struct vfio_iommu_driver *driver;
922 ssize_t ret = -EINVAL;
Alex Williamsoncba33452012-07-31 08:16:22 -0600923
Alex Williamson0b43c082013-04-29 08:41:36 -0600924 down_read(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600925
Alex Williamson0b43c082013-04-29 08:41:36 -0600926 driver = container->iommu_driver;
927 if (likely(driver && driver->ops->write))
928 ret = driver->ops->write(container->iommu_data,
929 buf, count, ppos);
930
931 up_read(&container->group_lock);
932
933 return ret;
Alex Williamsoncba33452012-07-31 08:16:22 -0600934}
935
936static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma)
937{
938 struct vfio_container *container = filep->private_data;
Alex Williamson0b43c082013-04-29 08:41:36 -0600939 struct vfio_iommu_driver *driver;
940 int ret = -EINVAL;
Alex Williamsoncba33452012-07-31 08:16:22 -0600941
Alex Williamson0b43c082013-04-29 08:41:36 -0600942 down_read(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600943
Alex Williamson0b43c082013-04-29 08:41:36 -0600944 driver = container->iommu_driver;
945 if (likely(driver && driver->ops->mmap))
946 ret = driver->ops->mmap(container->iommu_data, vma);
947
948 up_read(&container->group_lock);
949
950 return ret;
Alex Williamsoncba33452012-07-31 08:16:22 -0600951}
952
953static const struct file_operations vfio_fops = {
954 .owner = THIS_MODULE,
955 .open = vfio_fops_open,
956 .release = vfio_fops_release,
957 .read = vfio_fops_read,
958 .write = vfio_fops_write,
959 .unlocked_ioctl = vfio_fops_unl_ioctl,
960#ifdef CONFIG_COMPAT
961 .compat_ioctl = vfio_fops_compat_ioctl,
962#endif
963 .mmap = vfio_fops_mmap,
964};
965
966/**
967 * VFIO Group fd, /dev/vfio/$GROUP
968 */
969static void __vfio_group_unset_container(struct vfio_group *group)
970{
971 struct vfio_container *container = group->container;
972 struct vfio_iommu_driver *driver;
973
Alex Williamson9587f442013-04-25 16:12:38 -0600974 down_write(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600975
976 driver = container->iommu_driver;
977 if (driver)
978 driver->ops->detach_group(container->iommu_data,
979 group->iommu_group);
980
981 group->container = NULL;
982 list_del(&group->container_next);
983
984 /* Detaching the last group deprivileges a container, remove iommu */
985 if (driver && list_empty(&container->group_list)) {
986 driver->ops->release(container->iommu_data);
987 module_put(driver->ops->owner);
988 container->iommu_driver = NULL;
989 container->iommu_data = NULL;
990 }
991
Alex Williamson9587f442013-04-25 16:12:38 -0600992 up_write(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -0600993
994 vfio_container_put(container);
995}
996
997/*
998 * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
999 * if there was no container to unset. Since the ioctl is called on
1000 * the group, we know that still exists, therefore the only valid
1001 * transition here is 1->0.
1002 */
1003static int vfio_group_unset_container(struct vfio_group *group)
1004{
1005 int users = atomic_cmpxchg(&group->container_users, 1, 0);
1006
1007 if (!users)
1008 return -EINVAL;
1009 if (users != 1)
1010 return -EBUSY;
1011
1012 __vfio_group_unset_container(group);
1013
1014 return 0;
1015}
1016
1017/*
1018 * When removing container users, anything that removes the last user
1019 * implicitly removes the group from the container. That is, if the
1020 * group file descriptor is closed, as well as any device file descriptors,
1021 * the group is free.
1022 */
1023static void vfio_group_try_dissolve_container(struct vfio_group *group)
1024{
1025 if (0 == atomic_dec_if_positive(&group->container_users))
1026 __vfio_group_unset_container(group);
1027}
1028
1029static int vfio_group_set_container(struct vfio_group *group, int container_fd)
1030{
Al Viro2903ff02012-08-28 12:52:22 -04001031 struct fd f;
Alex Williamsoncba33452012-07-31 08:16:22 -06001032 struct vfio_container *container;
1033 struct vfio_iommu_driver *driver;
Al Viro2903ff02012-08-28 12:52:22 -04001034 int ret = 0;
Alex Williamsoncba33452012-07-31 08:16:22 -06001035
1036 if (atomic_read(&group->container_users))
1037 return -EINVAL;
1038
Al Viro2903ff02012-08-28 12:52:22 -04001039 f = fdget(container_fd);
1040 if (!f.file)
Alex Williamsoncba33452012-07-31 08:16:22 -06001041 return -EBADF;
1042
1043 /* Sanity check, is this really our fd? */
Al Viro2903ff02012-08-28 12:52:22 -04001044 if (f.file->f_op != &vfio_fops) {
1045 fdput(f);
Alex Williamsoncba33452012-07-31 08:16:22 -06001046 return -EINVAL;
1047 }
1048
Al Viro2903ff02012-08-28 12:52:22 -04001049 container = f.file->private_data;
Alex Williamsoncba33452012-07-31 08:16:22 -06001050 WARN_ON(!container); /* fget ensures we don't race vfio_release */
1051
Alex Williamson9587f442013-04-25 16:12:38 -06001052 down_write(&container->group_lock);
Alex Williamsoncba33452012-07-31 08:16:22 -06001053
1054 driver = container->iommu_driver;
1055 if (driver) {
1056 ret = driver->ops->attach_group(container->iommu_data,
1057 group->iommu_group);
1058 if (ret)
1059 goto unlock_out;
1060 }
1061
1062 group->container = container;
1063 list_add(&group->container_next, &container->group_list);
1064
1065 /* Get a reference on the container and mark a user within the group */
1066 vfio_container_get(container);
1067 atomic_inc(&group->container_users);
1068
1069unlock_out:
Alex Williamson9587f442013-04-25 16:12:38 -06001070 up_write(&container->group_lock);
Al Viro2903ff02012-08-28 12:52:22 -04001071 fdput(f);
Alex Williamsoncba33452012-07-31 08:16:22 -06001072 return ret;
1073}
1074
1075static bool vfio_group_viable(struct vfio_group *group)
1076{
1077 return (iommu_group_for_each_dev(group->iommu_group,
1078 group, vfio_dev_viable) == 0);
1079}
1080
1081static const struct file_operations vfio_device_fops;
1082
1083static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
1084{
1085 struct vfio_device *device;
1086 struct file *filep;
1087 int ret = -ENODEV;
1088
1089 if (0 == atomic_read(&group->container_users) ||
1090 !group->container->iommu_driver || !vfio_group_viable(group))
1091 return -EINVAL;
1092
1093 mutex_lock(&group->device_lock);
1094 list_for_each_entry(device, &group->device_list, group_next) {
1095 if (strcmp(dev_name(device->dev), buf))
1096 continue;
1097
1098 ret = device->ops->open(device->device_data);
1099 if (ret)
1100 break;
1101 /*
1102 * We can't use anon_inode_getfd() because we need to modify
1103 * the f_mode flags directly to allow more than just ioctls
1104 */
Alex Williamson5d042fb2013-08-22 10:33:41 -06001105 ret = get_unused_fd_flags(O_CLOEXEC);
Alex Williamsoncba33452012-07-31 08:16:22 -06001106 if (ret < 0) {
1107 device->ops->release(device->device_data);
1108 break;
1109 }
1110
1111 filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
1112 device, O_RDWR);
1113 if (IS_ERR(filep)) {
1114 put_unused_fd(ret);
1115 ret = PTR_ERR(filep);
1116 device->ops->release(device->device_data);
1117 break;
1118 }
1119
1120 /*
1121 * TODO: add an anon_inode interface to do this.
1122 * Appears to be missing by lack of need rather than
1123 * explicitly prevented. Now there's need.
1124 */
1125 filep->f_mode |= (FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1126
Alex Williamsoncba33452012-07-31 08:16:22 -06001127 vfio_device_get(device);
1128 atomic_inc(&group->container_users);
Al Viro31605de2012-08-17 21:32:56 -04001129
1130 fd_install(ret, filep);
Alex Williamsoncba33452012-07-31 08:16:22 -06001131 break;
1132 }
1133 mutex_unlock(&group->device_lock);
1134
1135 return ret;
1136}
1137
1138static long vfio_group_fops_unl_ioctl(struct file *filep,
1139 unsigned int cmd, unsigned long arg)
1140{
1141 struct vfio_group *group = filep->private_data;
1142 long ret = -ENOTTY;
1143
1144 switch (cmd) {
1145 case VFIO_GROUP_GET_STATUS:
1146 {
1147 struct vfio_group_status status;
1148 unsigned long minsz;
1149
1150 minsz = offsetofend(struct vfio_group_status, flags);
1151
1152 if (copy_from_user(&status, (void __user *)arg, minsz))
1153 return -EFAULT;
1154
1155 if (status.argsz < minsz)
1156 return -EINVAL;
1157
1158 status.flags = 0;
1159
1160 if (vfio_group_viable(group))
1161 status.flags |= VFIO_GROUP_FLAGS_VIABLE;
1162
1163 if (group->container)
1164 status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET;
1165
1166 if (copy_to_user((void __user *)arg, &status, minsz))
1167 return -EFAULT;
1168
1169 ret = 0;
1170 break;
1171 }
1172 case VFIO_GROUP_SET_CONTAINER:
1173 {
1174 int fd;
1175
1176 if (get_user(fd, (int __user *)arg))
1177 return -EFAULT;
1178
1179 if (fd < 0)
1180 return -EINVAL;
1181
1182 ret = vfio_group_set_container(group, fd);
1183 break;
1184 }
1185 case VFIO_GROUP_UNSET_CONTAINER:
1186 ret = vfio_group_unset_container(group);
1187 break;
1188 case VFIO_GROUP_GET_DEVICE_FD:
1189 {
1190 char *buf;
1191
1192 buf = strndup_user((const char __user *)arg, PAGE_SIZE);
1193 if (IS_ERR(buf))
1194 return PTR_ERR(buf);
1195
1196 ret = vfio_group_get_device_fd(group, buf);
1197 kfree(buf);
1198 break;
1199 }
1200 }
1201
1202 return ret;
1203}
1204
1205#ifdef CONFIG_COMPAT
1206static long vfio_group_fops_compat_ioctl(struct file *filep,
1207 unsigned int cmd, unsigned long arg)
1208{
1209 arg = (unsigned long)compat_ptr(arg);
1210 return vfio_group_fops_unl_ioctl(filep, cmd, arg);
1211}
1212#endif /* CONFIG_COMPAT */
1213
1214static int vfio_group_fops_open(struct inode *inode, struct file *filep)
1215{
1216 struct vfio_group *group;
Alex Williamson6d6768c2013-06-25 16:06:54 -06001217 int opened;
Alex Williamsoncba33452012-07-31 08:16:22 -06001218
1219 group = vfio_group_get_from_minor(iminor(inode));
1220 if (!group)
1221 return -ENODEV;
1222
Alex Williamson6d6768c2013-06-25 16:06:54 -06001223 /* Do we need multiple instances of the group open? Seems not. */
1224 opened = atomic_cmpxchg(&group->opened, 0, 1);
1225 if (opened) {
1226 vfio_group_put(group);
1227 return -EBUSY;
1228 }
1229
1230 /* Is something still in use from a previous open? */
Alex Williamsoncba33452012-07-31 08:16:22 -06001231 if (group->container) {
Alex Williamson6d6768c2013-06-25 16:06:54 -06001232 atomic_dec(&group->opened);
Alex Williamsoncba33452012-07-31 08:16:22 -06001233 vfio_group_put(group);
1234 return -EBUSY;
1235 }
1236
1237 filep->private_data = group;
1238
1239 return 0;
1240}
1241
1242static int vfio_group_fops_release(struct inode *inode, struct file *filep)
1243{
1244 struct vfio_group *group = filep->private_data;
1245
1246 filep->private_data = NULL;
1247
1248 vfio_group_try_dissolve_container(group);
1249
Alex Williamson6d6768c2013-06-25 16:06:54 -06001250 atomic_dec(&group->opened);
1251
Alex Williamsoncba33452012-07-31 08:16:22 -06001252 vfio_group_put(group);
1253
1254 return 0;
1255}
1256
1257static const struct file_operations vfio_group_fops = {
1258 .owner = THIS_MODULE,
1259 .unlocked_ioctl = vfio_group_fops_unl_ioctl,
1260#ifdef CONFIG_COMPAT
1261 .compat_ioctl = vfio_group_fops_compat_ioctl,
1262#endif
1263 .open = vfio_group_fops_open,
1264 .release = vfio_group_fops_release,
1265};
1266
1267/**
1268 * VFIO Device fd
1269 */
1270static int vfio_device_fops_release(struct inode *inode, struct file *filep)
1271{
1272 struct vfio_device *device = filep->private_data;
1273
1274 device->ops->release(device->device_data);
1275
1276 vfio_group_try_dissolve_container(device->group);
1277
1278 vfio_device_put(device);
1279
1280 return 0;
1281}
1282
1283static long vfio_device_fops_unl_ioctl(struct file *filep,
1284 unsigned int cmd, unsigned long arg)
1285{
1286 struct vfio_device *device = filep->private_data;
1287
1288 if (unlikely(!device->ops->ioctl))
1289 return -EINVAL;
1290
1291 return device->ops->ioctl(device->device_data, cmd, arg);
1292}
1293
1294static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
1295 size_t count, loff_t *ppos)
1296{
1297 struct vfio_device *device = filep->private_data;
1298
1299 if (unlikely(!device->ops->read))
1300 return -EINVAL;
1301
1302 return device->ops->read(device->device_data, buf, count, ppos);
1303}
1304
1305static ssize_t vfio_device_fops_write(struct file *filep,
1306 const char __user *buf,
1307 size_t count, loff_t *ppos)
1308{
1309 struct vfio_device *device = filep->private_data;
1310
1311 if (unlikely(!device->ops->write))
1312 return -EINVAL;
1313
1314 return device->ops->write(device->device_data, buf, count, ppos);
1315}
1316
1317static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
1318{
1319 struct vfio_device *device = filep->private_data;
1320
1321 if (unlikely(!device->ops->mmap))
1322 return -EINVAL;
1323
1324 return device->ops->mmap(device->device_data, vma);
1325}
1326
1327#ifdef CONFIG_COMPAT
1328static long vfio_device_fops_compat_ioctl(struct file *filep,
1329 unsigned int cmd, unsigned long arg)
1330{
1331 arg = (unsigned long)compat_ptr(arg);
1332 return vfio_device_fops_unl_ioctl(filep, cmd, arg);
1333}
1334#endif /* CONFIG_COMPAT */
1335
1336static const struct file_operations vfio_device_fops = {
1337 .owner = THIS_MODULE,
1338 .release = vfio_device_fops_release,
1339 .read = vfio_device_fops_read,
1340 .write = vfio_device_fops_write,
1341 .unlocked_ioctl = vfio_device_fops_unl_ioctl,
1342#ifdef CONFIG_COMPAT
1343 .compat_ioctl = vfio_device_fops_compat_ioctl,
1344#endif
1345 .mmap = vfio_device_fops_mmap,
1346};
1347
1348/**
Alexey Kardashevskiy6cdd9782013-08-05 10:52:36 -06001349 * External user API, exported by symbols to be linked dynamically.
1350 *
1351 * The protocol includes:
1352 * 1. do normal VFIO init operation:
1353 * - opening a new container;
1354 * - attaching group(s) to it;
1355 * - setting an IOMMU driver for a container.
1356 * When IOMMU is set for a container, all groups in it are
1357 * considered ready to use by an external user.
1358 *
1359 * 2. User space passes a group fd to an external user.
1360 * The external user calls vfio_group_get_external_user()
1361 * to verify that:
1362 * - the group is initialized;
1363 * - IOMMU is set for it.
1364 * If both checks passed, vfio_group_get_external_user()
1365 * increments the container user counter to prevent
1366 * the VFIO group from disposal before KVM exits.
1367 *
1368 * 3. The external user calls vfio_external_user_iommu_id()
1369 * to know an IOMMU ID.
1370 *
1371 * 4. When the external KVM finishes, it calls
1372 * vfio_group_put_external_user() to release the VFIO group.
1373 * This call decrements the container user counter.
1374 */
1375struct vfio_group *vfio_group_get_external_user(struct file *filep)
1376{
1377 struct vfio_group *group = filep->private_data;
1378
1379 if (filep->f_op != &vfio_group_fops)
1380 return ERR_PTR(-EINVAL);
1381
1382 if (!atomic_inc_not_zero(&group->container_users))
1383 return ERR_PTR(-EINVAL);
1384
1385 if (!group->container->iommu_driver ||
1386 !vfio_group_viable(group)) {
1387 atomic_dec(&group->container_users);
1388 return ERR_PTR(-EINVAL);
1389 }
1390
1391 vfio_group_get(group);
1392
1393 return group;
1394}
1395EXPORT_SYMBOL_GPL(vfio_group_get_external_user);
1396
1397void vfio_group_put_external_user(struct vfio_group *group)
1398{
1399 vfio_group_put(group);
1400 vfio_group_try_dissolve_container(group);
1401}
1402EXPORT_SYMBOL_GPL(vfio_group_put_external_user);
1403
1404int vfio_external_user_iommu_id(struct vfio_group *group)
1405{
1406 return iommu_group_id(group->iommu_group);
1407}
1408EXPORT_SYMBOL_GPL(vfio_external_user_iommu_id);
1409
Alex Williamson88d7ab82014-02-26 11:38:39 -07001410long vfio_external_check_extension(struct vfio_group *group, unsigned long arg)
1411{
1412 return vfio_ioctl_check_extension(group->container, arg);
1413}
1414EXPORT_SYMBOL_GPL(vfio_external_check_extension);
1415
Alexey Kardashevskiy6cdd9782013-08-05 10:52:36 -06001416/**
Alex Williamsoncba33452012-07-31 08:16:22 -06001417 * Module/class support
1418 */
1419static char *vfio_devnode(struct device *dev, umode_t *mode)
1420{
1421 return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
1422}
1423
Alex Williamsond1099902013-12-19 10:17:13 -07001424static struct miscdevice vfio_dev = {
1425 .minor = VFIO_MINOR,
1426 .name = "vfio",
1427 .fops = &vfio_fops,
1428 .nodename = "vfio/vfio",
1429 .mode = S_IRUGO | S_IWUGO,
1430};
1431
Alex Williamsoncba33452012-07-31 08:16:22 -06001432static int __init vfio_init(void)
1433{
1434 int ret;
1435
1436 idr_init(&vfio.group_idr);
1437 mutex_init(&vfio.group_lock);
1438 mutex_init(&vfio.iommu_drivers_lock);
1439 INIT_LIST_HEAD(&vfio.group_list);
1440 INIT_LIST_HEAD(&vfio.iommu_drivers_list);
1441 init_waitqueue_head(&vfio.release_q);
1442
Alex Williamsond1099902013-12-19 10:17:13 -07001443 ret = misc_register(&vfio_dev);
1444 if (ret) {
1445 pr_err("vfio: misc device register failed\n");
1446 return ret;
1447 }
1448
1449 /* /dev/vfio/$GROUP */
Alex Williamsoncba33452012-07-31 08:16:22 -06001450 vfio.class = class_create(THIS_MODULE, "vfio");
1451 if (IS_ERR(vfio.class)) {
1452 ret = PTR_ERR(vfio.class);
1453 goto err_class;
1454 }
1455
1456 vfio.class->devnode = vfio_devnode;
1457
Alex Williamsond1099902013-12-19 10:17:13 -07001458 ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK, "vfio");
Alex Williamsoncba33452012-07-31 08:16:22 -06001459 if (ret)
Alex Williamsond1099902013-12-19 10:17:13 -07001460 goto err_alloc_chrdev;
Alex Williamsoncba33452012-07-31 08:16:22 -06001461
Alex Williamsoncba33452012-07-31 08:16:22 -06001462 cdev_init(&vfio.group_cdev, &vfio_group_fops);
Alex Williamsond1099902013-12-19 10:17:13 -07001463 ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK);
Alex Williamsoncba33452012-07-31 08:16:22 -06001464 if (ret)
Alex Williamsond1099902013-12-19 10:17:13 -07001465 goto err_cdev_add;
Alex Williamsoncba33452012-07-31 08:16:22 -06001466
1467 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
1468
Alex Williamson73fa0d12012-07-31 08:16:23 -06001469 /*
1470 * Attempt to load known iommu-drivers. This gives us a working
1471 * environment without the user needing to explicitly load iommu
1472 * drivers.
1473 */
1474 request_module_nowait("vfio_iommu_type1");
Alexey Kardashevskiy5ffd2292013-05-21 13:33:10 +10001475 request_module_nowait("vfio_iommu_spapr_tce");
Alex Williamson73fa0d12012-07-31 08:16:23 -06001476
Alex Williamsoncba33452012-07-31 08:16:22 -06001477 return 0;
1478
Alex Williamsond1099902013-12-19 10:17:13 -07001479err_cdev_add:
1480 unregister_chrdev_region(vfio.group_devt, MINORMASK);
1481err_alloc_chrdev:
Alex Williamsoncba33452012-07-31 08:16:22 -06001482 class_destroy(vfio.class);
1483 vfio.class = NULL;
1484err_class:
Alex Williamsond1099902013-12-19 10:17:13 -07001485 misc_deregister(&vfio_dev);
Alex Williamsoncba33452012-07-31 08:16:22 -06001486 return ret;
1487}
1488
1489static void __exit vfio_cleanup(void)
1490{
1491 WARN_ON(!list_empty(&vfio.group_list));
1492
1493 idr_destroy(&vfio.group_idr);
1494 cdev_del(&vfio.group_cdev);
Alex Williamsond1099902013-12-19 10:17:13 -07001495 unregister_chrdev_region(vfio.group_devt, MINORMASK);
Alex Williamsoncba33452012-07-31 08:16:22 -06001496 class_destroy(vfio.class);
1497 vfio.class = NULL;
Alex Williamsond1099902013-12-19 10:17:13 -07001498 misc_deregister(&vfio_dev);
Alex Williamsoncba33452012-07-31 08:16:22 -06001499}
1500
1501module_init(vfio_init);
1502module_exit(vfio_cleanup);
1503
1504MODULE_VERSION(DRIVER_VERSION);
1505MODULE_LICENSE("GPL v2");
1506MODULE_AUTHOR(DRIVER_AUTHOR);
1507MODULE_DESCRIPTION(DRIVER_DESC);
Alex Williamsond1099902013-12-19 10:17:13 -07001508MODULE_ALIAS_MISCDEV(VFIO_MINOR);
1509MODULE_ALIAS("devname:vfio/vfio");