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1 | /* |
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> | |
25 | #include <linux/module.h> | |
26 | #include <linux/mutex.h> | |
27 | #include <linux/sched.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/string.h> | |
30 | #include <linux/uaccess.h> | |
31 | #include <linux/vfio.h> | |
32 | #include <linux/wait.h> | |
33 | ||
34 | #define DRIVER_VERSION "0.3" | |
35 | #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" | |
36 | #define DRIVER_DESC "VFIO - User Level meta-driver" | |
37 | ||
38 | static struct vfio { | |
39 | struct class *class; | |
40 | struct list_head iommu_drivers_list; | |
41 | struct mutex iommu_drivers_lock; | |
42 | struct list_head group_list; | |
43 | struct idr group_idr; | |
44 | struct mutex group_lock; | |
45 | struct cdev group_cdev; | |
46 | struct device *dev; | |
47 | dev_t devt; | |
48 | struct cdev cdev; | |
49 | wait_queue_head_t release_q; | |
50 | } vfio; | |
51 | ||
52 | struct vfio_iommu_driver { | |
53 | const struct vfio_iommu_driver_ops *ops; | |
54 | struct list_head vfio_next; | |
55 | }; | |
56 | ||
57 | struct vfio_container { | |
58 | struct kref kref; | |
59 | struct list_head group_list; | |
60 | struct mutex group_lock; | |
61 | struct vfio_iommu_driver *iommu_driver; | |
62 | void *iommu_data; | |
63 | }; | |
64 | ||
65 | struct vfio_group { | |
66 | struct kref kref; | |
67 | int minor; | |
68 | atomic_t container_users; | |
69 | struct iommu_group *iommu_group; | |
70 | struct vfio_container *container; | |
71 | struct list_head device_list; | |
72 | struct mutex device_lock; | |
73 | struct device *dev; | |
74 | struct notifier_block nb; | |
75 | struct list_head vfio_next; | |
76 | struct list_head container_next; | |
77 | }; | |
78 | ||
79 | struct vfio_device { | |
80 | struct kref kref; | |
81 | struct device *dev; | |
82 | const struct vfio_device_ops *ops; | |
83 | struct vfio_group *group; | |
84 | struct list_head group_next; | |
85 | void *device_data; | |
86 | }; | |
87 | ||
88 | /** | |
89 | * IOMMU driver registration | |
90 | */ | |
91 | int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops) | |
92 | { | |
93 | struct vfio_iommu_driver *driver, *tmp; | |
94 | ||
95 | driver = kzalloc(sizeof(*driver), GFP_KERNEL); | |
96 | if (!driver) | |
97 | return -ENOMEM; | |
98 | ||
99 | driver->ops = ops; | |
100 | ||
101 | mutex_lock(&vfio.iommu_drivers_lock); | |
102 | ||
103 | /* Check for duplicates */ | |
104 | list_for_each_entry(tmp, &vfio.iommu_drivers_list, vfio_next) { | |
105 | if (tmp->ops == ops) { | |
106 | mutex_unlock(&vfio.iommu_drivers_lock); | |
107 | kfree(driver); | |
108 | return -EINVAL; | |
109 | } | |
110 | } | |
111 | ||
112 | list_add(&driver->vfio_next, &vfio.iommu_drivers_list); | |
113 | ||
114 | mutex_unlock(&vfio.iommu_drivers_lock); | |
115 | ||
116 | return 0; | |
117 | } | |
118 | EXPORT_SYMBOL_GPL(vfio_register_iommu_driver); | |
119 | ||
120 | void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops) | |
121 | { | |
122 | struct vfio_iommu_driver *driver; | |
123 | ||
124 | mutex_lock(&vfio.iommu_drivers_lock); | |
125 | list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) { | |
126 | if (driver->ops == ops) { | |
127 | list_del(&driver->vfio_next); | |
128 | mutex_unlock(&vfio.iommu_drivers_lock); | |
129 | kfree(driver); | |
130 | return; | |
131 | } | |
132 | } | |
133 | mutex_unlock(&vfio.iommu_drivers_lock); | |
134 | } | |
135 | EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver); | |
136 | ||
137 | /** | |
138 | * Group minor allocation/free - both called with vfio.group_lock held | |
139 | */ | |
140 | static int vfio_alloc_group_minor(struct vfio_group *group) | |
141 | { | |
142 | int ret, minor; | |
143 | ||
144 | again: | |
145 | if (unlikely(idr_pre_get(&vfio.group_idr, GFP_KERNEL) == 0)) | |
146 | return -ENOMEM; | |
147 | ||
148 | /* index 0 is used by /dev/vfio/vfio */ | |
149 | ret = idr_get_new_above(&vfio.group_idr, group, 1, &minor); | |
150 | if (ret == -EAGAIN) | |
151 | goto again; | |
152 | if (ret || minor > MINORMASK) { | |
153 | if (minor > MINORMASK) | |
154 | idr_remove(&vfio.group_idr, minor); | |
155 | return -ENOSPC; | |
156 | } | |
157 | ||
158 | return minor; | |
159 | } | |
160 | ||
161 | static void vfio_free_group_minor(int minor) | |
162 | { | |
163 | idr_remove(&vfio.group_idr, minor); | |
164 | } | |
165 | ||
166 | static int vfio_iommu_group_notifier(struct notifier_block *nb, | |
167 | unsigned long action, void *data); | |
168 | static void vfio_group_get(struct vfio_group *group); | |
169 | ||
170 | /** | |
171 | * Container objects - containers are created when /dev/vfio/vfio is | |
172 | * opened, but their lifecycle extends until the last user is done, so | |
173 | * it's freed via kref. Must support container/group/device being | |
174 | * closed in any order. | |
175 | */ | |
176 | static void vfio_container_get(struct vfio_container *container) | |
177 | { | |
178 | kref_get(&container->kref); | |
179 | } | |
180 | ||
181 | static void vfio_container_release(struct kref *kref) | |
182 | { | |
183 | struct vfio_container *container; | |
184 | container = container_of(kref, struct vfio_container, kref); | |
185 | ||
186 | kfree(container); | |
187 | } | |
188 | ||
189 | static void vfio_container_put(struct vfio_container *container) | |
190 | { | |
191 | kref_put(&container->kref, vfio_container_release); | |
192 | } | |
193 | ||
194 | /** | |
195 | * Group objects - create, release, get, put, search | |
196 | */ | |
197 | static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) | |
198 | { | |
199 | struct vfio_group *group, *tmp; | |
200 | struct device *dev; | |
201 | int ret, minor; | |
202 | ||
203 | group = kzalloc(sizeof(*group), GFP_KERNEL); | |
204 | if (!group) | |
205 | return ERR_PTR(-ENOMEM); | |
206 | ||
207 | kref_init(&group->kref); | |
208 | INIT_LIST_HEAD(&group->device_list); | |
209 | mutex_init(&group->device_lock); | |
210 | atomic_set(&group->container_users, 0); | |
211 | group->iommu_group = iommu_group; | |
212 | ||
213 | group->nb.notifier_call = vfio_iommu_group_notifier; | |
214 | ||
215 | /* | |
216 | * blocking notifiers acquire a rwsem around registering and hold | |
217 | * it around callback. Therefore, need to register outside of | |
218 | * vfio.group_lock to avoid A-B/B-A contention. Our callback won't | |
219 | * do anything unless it can find the group in vfio.group_list, so | |
220 | * no harm in registering early. | |
221 | */ | |
222 | ret = iommu_group_register_notifier(iommu_group, &group->nb); | |
223 | if (ret) { | |
224 | kfree(group); | |
225 | return ERR_PTR(ret); | |
226 | } | |
227 | ||
228 | mutex_lock(&vfio.group_lock); | |
229 | ||
230 | minor = vfio_alloc_group_minor(group); | |
231 | if (minor < 0) { | |
232 | mutex_unlock(&vfio.group_lock); | |
233 | kfree(group); | |
234 | return ERR_PTR(minor); | |
235 | } | |
236 | ||
237 | /* Did we race creating this group? */ | |
238 | list_for_each_entry(tmp, &vfio.group_list, vfio_next) { | |
239 | if (tmp->iommu_group == iommu_group) { | |
240 | vfio_group_get(tmp); | |
241 | vfio_free_group_minor(minor); | |
242 | mutex_unlock(&vfio.group_lock); | |
243 | kfree(group); | |
244 | return tmp; | |
245 | } | |
246 | } | |
247 | ||
248 | dev = device_create(vfio.class, NULL, MKDEV(MAJOR(vfio.devt), minor), | |
249 | group, "%d", iommu_group_id(iommu_group)); | |
250 | if (IS_ERR(dev)) { | |
251 | vfio_free_group_minor(minor); | |
252 | mutex_unlock(&vfio.group_lock); | |
253 | kfree(group); | |
254 | return (struct vfio_group *)dev; /* ERR_PTR */ | |
255 | } | |
256 | ||
257 | group->minor = minor; | |
258 | group->dev = dev; | |
259 | ||
260 | list_add(&group->vfio_next, &vfio.group_list); | |
261 | ||
262 | mutex_unlock(&vfio.group_lock); | |
263 | ||
264 | return group; | |
265 | } | |
266 | ||
267 | static void vfio_group_release(struct kref *kref) | |
268 | { | |
269 | struct vfio_group *group = container_of(kref, struct vfio_group, kref); | |
270 | ||
271 | WARN_ON(!list_empty(&group->device_list)); | |
272 | ||
273 | device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor)); | |
274 | list_del(&group->vfio_next); | |
275 | vfio_free_group_minor(group->minor); | |
276 | ||
277 | mutex_unlock(&vfio.group_lock); | |
278 | ||
279 | /* | |
280 | * Unregister outside of lock. A spurious callback is harmless now | |
281 | * that the group is no longer in vfio.group_list. | |
282 | */ | |
283 | iommu_group_unregister_notifier(group->iommu_group, &group->nb); | |
284 | ||
285 | kfree(group); | |
286 | } | |
287 | ||
288 | static void vfio_group_put(struct vfio_group *group) | |
289 | { | |
290 | mutex_lock(&vfio.group_lock); | |
291 | /* | |
292 | * Release needs to unlock to unregister the notifier, so only | |
293 | * unlock if not released. | |
294 | */ | |
295 | if (!kref_put(&group->kref, vfio_group_release)) | |
296 | mutex_unlock(&vfio.group_lock); | |
297 | } | |
298 | ||
299 | /* Assume group_lock or group reference is held */ | |
300 | static void vfio_group_get(struct vfio_group *group) | |
301 | { | |
302 | kref_get(&group->kref); | |
303 | } | |
304 | ||
305 | /* | |
306 | * Not really a try as we will sleep for mutex, but we need to make | |
307 | * sure the group pointer is valid under lock and get a reference. | |
308 | */ | |
309 | static struct vfio_group *vfio_group_try_get(struct vfio_group *group) | |
310 | { | |
311 | struct vfio_group *target = group; | |
312 | ||
313 | mutex_lock(&vfio.group_lock); | |
314 | list_for_each_entry(group, &vfio.group_list, vfio_next) { | |
315 | if (group == target) { | |
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 | ||
326 | static | |
327 | struct vfio_group *vfio_group_get_from_iommu(struct iommu_group *iommu_group) | |
328 | { | |
329 | struct vfio_group *group; | |
330 | ||
331 | mutex_lock(&vfio.group_lock); | |
332 | list_for_each_entry(group, &vfio.group_list, vfio_next) { | |
333 | if (group->iommu_group == iommu_group) { | |
334 | vfio_group_get(group); | |
335 | mutex_unlock(&vfio.group_lock); | |
336 | return group; | |
337 | } | |
338 | } | |
339 | mutex_unlock(&vfio.group_lock); | |
340 | ||
341 | return NULL; | |
342 | } | |
343 | ||
344 | static struct vfio_group *vfio_group_get_from_minor(int minor) | |
345 | { | |
346 | struct vfio_group *group; | |
347 | ||
348 | mutex_lock(&vfio.group_lock); | |
349 | group = idr_find(&vfio.group_idr, minor); | |
350 | if (!group) { | |
351 | mutex_unlock(&vfio.group_lock); | |
352 | return NULL; | |
353 | } | |
354 | vfio_group_get(group); | |
355 | mutex_unlock(&vfio.group_lock); | |
356 | ||
357 | return group; | |
358 | } | |
359 | ||
360 | /** | |
361 | * Device objects - create, release, get, put, search | |
362 | */ | |
363 | static | |
364 | struct vfio_device *vfio_group_create_device(struct vfio_group *group, | |
365 | struct device *dev, | |
366 | const struct vfio_device_ops *ops, | |
367 | void *device_data) | |
368 | { | |
369 | struct vfio_device *device; | |
370 | int ret; | |
371 | ||
372 | device = kzalloc(sizeof(*device), GFP_KERNEL); | |
373 | if (!device) | |
374 | return ERR_PTR(-ENOMEM); | |
375 | ||
376 | kref_init(&device->kref); | |
377 | device->dev = dev; | |
378 | device->group = group; | |
379 | device->ops = ops; | |
380 | device->device_data = device_data; | |
381 | ||
382 | ret = dev_set_drvdata(dev, device); | |
383 | if (ret) { | |
384 | kfree(device); | |
385 | return ERR_PTR(ret); | |
386 | } | |
387 | ||
388 | /* No need to get group_lock, caller has group reference */ | |
389 | vfio_group_get(group); | |
390 | ||
391 | mutex_lock(&group->device_lock); | |
392 | list_add(&device->group_next, &group->device_list); | |
393 | mutex_unlock(&group->device_lock); | |
394 | ||
395 | return device; | |
396 | } | |
397 | ||
398 | static void vfio_device_release(struct kref *kref) | |
399 | { | |
400 | struct vfio_device *device = container_of(kref, | |
401 | struct vfio_device, kref); | |
402 | struct vfio_group *group = device->group; | |
403 | ||
404 | mutex_lock(&group->device_lock); | |
405 | list_del(&device->group_next); | |
406 | mutex_unlock(&group->device_lock); | |
407 | ||
408 | dev_set_drvdata(device->dev, NULL); | |
409 | ||
410 | kfree(device); | |
411 | ||
412 | /* vfio_del_group_dev may be waiting for this device */ | |
413 | wake_up(&vfio.release_q); | |
414 | } | |
415 | ||
416 | /* Device reference always implies a group reference */ | |
417 | static void vfio_device_put(struct vfio_device *device) | |
418 | { | |
419 | kref_put(&device->kref, vfio_device_release); | |
420 | vfio_group_put(device->group); | |
421 | } | |
422 | ||
423 | static void vfio_device_get(struct vfio_device *device) | |
424 | { | |
425 | vfio_group_get(device->group); | |
426 | kref_get(&device->kref); | |
427 | } | |
428 | ||
429 | static struct vfio_device *vfio_group_get_device(struct vfio_group *group, | |
430 | struct device *dev) | |
431 | { | |
432 | struct vfio_device *device; | |
433 | ||
434 | mutex_lock(&group->device_lock); | |
435 | list_for_each_entry(device, &group->device_list, group_next) { | |
436 | if (device->dev == dev) { | |
437 | vfio_device_get(device); | |
438 | mutex_unlock(&group->device_lock); | |
439 | return device; | |
440 | } | |
441 | } | |
442 | mutex_unlock(&group->device_lock); | |
443 | return NULL; | |
444 | } | |
445 | ||
446 | /* | |
447 | * Whitelist some drivers that we know are safe (no dma) or just sit on | |
448 | * a device. It's not always practical to leave a device within a group | |
449 | * driverless as it could get re-bound to something unsafe. | |
450 | */ | |
451 | static const char * const vfio_driver_whitelist[] = { "pci-stub" }; | |
452 | ||
453 | static bool vfio_whitelisted_driver(struct device_driver *drv) | |
454 | { | |
455 | int i; | |
456 | ||
457 | for (i = 0; i < ARRAY_SIZE(vfio_driver_whitelist); i++) { | |
458 | if (!strcmp(drv->name, vfio_driver_whitelist[i])) | |
459 | return true; | |
460 | } | |
461 | ||
462 | return false; | |
463 | } | |
464 | ||
465 | /* | |
466 | * A vfio group is viable for use by userspace if all devices are either | |
467 | * driver-less or bound to a vfio or whitelisted driver. We test the | |
468 | * latter by the existence of a struct vfio_device matching the dev. | |
469 | */ | |
470 | static int vfio_dev_viable(struct device *dev, void *data) | |
471 | { | |
472 | struct vfio_group *group = data; | |
473 | struct vfio_device *device; | |
474 | ||
475 | if (!dev->driver || vfio_whitelisted_driver(dev->driver)) | |
476 | return 0; | |
477 | ||
478 | device = vfio_group_get_device(group, dev); | |
479 | if (device) { | |
480 | vfio_device_put(device); | |
481 | return 0; | |
482 | } | |
483 | ||
484 | return -EINVAL; | |
485 | } | |
486 | ||
487 | /** | |
488 | * Async device support | |
489 | */ | |
490 | static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev) | |
491 | { | |
492 | struct vfio_device *device; | |
493 | ||
494 | /* Do we already know about it? We shouldn't */ | |
495 | device = vfio_group_get_device(group, dev); | |
496 | if (WARN_ON_ONCE(device)) { | |
497 | vfio_device_put(device); | |
498 | return 0; | |
499 | } | |
500 | ||
501 | /* Nothing to do for idle groups */ | |
502 | if (!atomic_read(&group->container_users)) | |
503 | return 0; | |
504 | ||
505 | /* TODO Prevent device auto probing */ | |
506 | WARN("Device %s added to live group %d!\n", dev_name(dev), | |
507 | iommu_group_id(group->iommu_group)); | |
508 | ||
509 | return 0; | |
510 | } | |
511 | ||
512 | static int vfio_group_nb_del_dev(struct vfio_group *group, struct device *dev) | |
513 | { | |
514 | struct vfio_device *device; | |
515 | ||
516 | /* | |
517 | * Expect to fall out here. If a device was in use, it would | |
518 | * have been bound to a vfio sub-driver, which would have blocked | |
519 | * in .remove at vfio_del_group_dev. Sanity check that we no | |
520 | * longer track the device, so it's safe to remove. | |
521 | */ | |
522 | device = vfio_group_get_device(group, dev); | |
523 | if (likely(!device)) | |
524 | return 0; | |
525 | ||
526 | WARN("Device %s removed from live group %d!\n", dev_name(dev), | |
527 | iommu_group_id(group->iommu_group)); | |
528 | ||
529 | vfio_device_put(device); | |
530 | return 0; | |
531 | } | |
532 | ||
533 | static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev) | |
534 | { | |
535 | /* We don't care what happens when the group isn't in use */ | |
536 | if (!atomic_read(&group->container_users)) | |
537 | return 0; | |
538 | ||
539 | return vfio_dev_viable(dev, group); | |
540 | } | |
541 | ||
542 | static int vfio_iommu_group_notifier(struct notifier_block *nb, | |
543 | unsigned long action, void *data) | |
544 | { | |
545 | struct vfio_group *group = container_of(nb, struct vfio_group, nb); | |
546 | struct device *dev = data; | |
547 | ||
548 | /* | |
549 | * Need to go through a group_lock lookup to get a reference or | |
550 | * we risk racing a group being removed. Leave a WARN_ON for | |
551 | * debuging, but if the group no longer exists, a spurious notify | |
552 | * is harmless. | |
553 | */ | |
554 | group = vfio_group_try_get(group); | |
555 | if (WARN_ON(!group)) | |
556 | return NOTIFY_OK; | |
557 | ||
558 | switch (action) { | |
559 | case IOMMU_GROUP_NOTIFY_ADD_DEVICE: | |
560 | vfio_group_nb_add_dev(group, dev); | |
561 | break; | |
562 | case IOMMU_GROUP_NOTIFY_DEL_DEVICE: | |
563 | vfio_group_nb_del_dev(group, dev); | |
564 | break; | |
565 | case IOMMU_GROUP_NOTIFY_BIND_DRIVER: | |
566 | pr_debug("%s: Device %s, group %d binding to driver\n", | |
567 | __func__, dev_name(dev), | |
568 | iommu_group_id(group->iommu_group)); | |
569 | break; | |
570 | case IOMMU_GROUP_NOTIFY_BOUND_DRIVER: | |
571 | pr_debug("%s: Device %s, group %d bound to driver %s\n", | |
572 | __func__, dev_name(dev), | |
573 | iommu_group_id(group->iommu_group), dev->driver->name); | |
574 | BUG_ON(vfio_group_nb_verify(group, dev)); | |
575 | break; | |
576 | case IOMMU_GROUP_NOTIFY_UNBIND_DRIVER: | |
577 | pr_debug("%s: Device %s, group %d unbinding from driver %s\n", | |
578 | __func__, dev_name(dev), | |
579 | iommu_group_id(group->iommu_group), dev->driver->name); | |
580 | break; | |
581 | case IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER: | |
582 | pr_debug("%s: Device %s, group %d unbound from driver\n", | |
583 | __func__, dev_name(dev), | |
584 | iommu_group_id(group->iommu_group)); | |
585 | /* | |
586 | * XXX An unbound device in a live group is ok, but we'd | |
587 | * really like to avoid the above BUG_ON by preventing other | |
588 | * drivers from binding to it. Once that occurs, we have to | |
589 | * stop the system to maintain isolation. At a minimum, we'd | |
590 | * want a toggle to disable driver auto probe for this device. | |
591 | */ | |
592 | break; | |
593 | } | |
594 | ||
595 | vfio_group_put(group); | |
596 | return NOTIFY_OK; | |
597 | } | |
598 | ||
599 | /** | |
600 | * VFIO driver API | |
601 | */ | |
602 | int vfio_add_group_dev(struct device *dev, | |
603 | const struct vfio_device_ops *ops, void *device_data) | |
604 | { | |
605 | struct iommu_group *iommu_group; | |
606 | struct vfio_group *group; | |
607 | struct vfio_device *device; | |
608 | ||
609 | iommu_group = iommu_group_get(dev); | |
610 | if (!iommu_group) | |
611 | return -EINVAL; | |
612 | ||
613 | group = vfio_group_get_from_iommu(iommu_group); | |
614 | if (!group) { | |
615 | group = vfio_create_group(iommu_group); | |
616 | if (IS_ERR(group)) { | |
617 | iommu_group_put(iommu_group); | |
618 | return PTR_ERR(group); | |
619 | } | |
620 | } | |
621 | ||
622 | device = vfio_group_get_device(group, dev); | |
623 | if (device) { | |
624 | WARN(1, "Device %s already exists on group %d\n", | |
625 | dev_name(dev), iommu_group_id(iommu_group)); | |
626 | vfio_device_put(device); | |
627 | vfio_group_put(group); | |
628 | iommu_group_put(iommu_group); | |
629 | return -EBUSY; | |
630 | } | |
631 | ||
632 | device = vfio_group_create_device(group, dev, ops, device_data); | |
633 | if (IS_ERR(device)) { | |
634 | vfio_group_put(group); | |
635 | iommu_group_put(iommu_group); | |
636 | return PTR_ERR(device); | |
637 | } | |
638 | ||
639 | /* | |
640 | * Added device holds reference to iommu_group and vfio_device | |
641 | * (which in turn holds reference to vfio_group). Drop extra | |
642 | * group reference used while acquiring device. | |
643 | */ | |
644 | vfio_group_put(group); | |
645 | ||
646 | return 0; | |
647 | } | |
648 | EXPORT_SYMBOL_GPL(vfio_add_group_dev); | |
649 | ||
650 | /* Test whether a struct device is present in our tracking */ | |
651 | static bool vfio_dev_present(struct device *dev) | |
652 | { | |
653 | struct iommu_group *iommu_group; | |
654 | struct vfio_group *group; | |
655 | struct vfio_device *device; | |
656 | ||
657 | iommu_group = iommu_group_get(dev); | |
658 | if (!iommu_group) | |
659 | return false; | |
660 | ||
661 | group = vfio_group_get_from_iommu(iommu_group); | |
662 | if (!group) { | |
663 | iommu_group_put(iommu_group); | |
664 | return false; | |
665 | } | |
666 | ||
667 | device = vfio_group_get_device(group, dev); | |
668 | if (!device) { | |
669 | vfio_group_put(group); | |
670 | iommu_group_put(iommu_group); | |
671 | return false; | |
672 | } | |
673 | ||
674 | vfio_device_put(device); | |
675 | vfio_group_put(group); | |
676 | iommu_group_put(iommu_group); | |
677 | return true; | |
678 | } | |
679 | ||
680 | /* | |
681 | * Decrement the device reference count and wait for the device to be | |
682 | * removed. Open file descriptors for the device... */ | |
683 | void *vfio_del_group_dev(struct device *dev) | |
684 | { | |
685 | struct vfio_device *device = dev_get_drvdata(dev); | |
686 | struct vfio_group *group = device->group; | |
687 | struct iommu_group *iommu_group = group->iommu_group; | |
688 | void *device_data = device->device_data; | |
689 | ||
690 | vfio_device_put(device); | |
691 | ||
692 | /* TODO send a signal to encourage this to be released */ | |
693 | wait_event(vfio.release_q, !vfio_dev_present(dev)); | |
694 | ||
695 | iommu_group_put(iommu_group); | |
696 | ||
697 | return device_data; | |
698 | } | |
699 | EXPORT_SYMBOL_GPL(vfio_del_group_dev); | |
700 | ||
701 | /** | |
702 | * VFIO base fd, /dev/vfio/vfio | |
703 | */ | |
704 | static long vfio_ioctl_check_extension(struct vfio_container *container, | |
705 | unsigned long arg) | |
706 | { | |
707 | struct vfio_iommu_driver *driver = container->iommu_driver; | |
708 | long ret = 0; | |
709 | ||
710 | switch (arg) { | |
711 | /* No base extensions yet */ | |
712 | default: | |
713 | /* | |
714 | * If no driver is set, poll all registered drivers for | |
715 | * extensions and return the first positive result. If | |
716 | * a driver is already set, further queries will be passed | |
717 | * only to that driver. | |
718 | */ | |
719 | if (!driver) { | |
720 | mutex_lock(&vfio.iommu_drivers_lock); | |
721 | list_for_each_entry(driver, &vfio.iommu_drivers_list, | |
722 | vfio_next) { | |
723 | if (!try_module_get(driver->ops->owner)) | |
724 | continue; | |
725 | ||
726 | ret = driver->ops->ioctl(NULL, | |
727 | VFIO_CHECK_EXTENSION, | |
728 | arg); | |
729 | module_put(driver->ops->owner); | |
730 | if (ret > 0) | |
731 | break; | |
732 | } | |
733 | mutex_unlock(&vfio.iommu_drivers_lock); | |
734 | } else | |
735 | ret = driver->ops->ioctl(container->iommu_data, | |
736 | VFIO_CHECK_EXTENSION, arg); | |
737 | } | |
738 | ||
739 | return ret; | |
740 | } | |
741 | ||
742 | /* hold container->group_lock */ | |
743 | static int __vfio_container_attach_groups(struct vfio_container *container, | |
744 | struct vfio_iommu_driver *driver, | |
745 | void *data) | |
746 | { | |
747 | struct vfio_group *group; | |
748 | int ret = -ENODEV; | |
749 | ||
750 | list_for_each_entry(group, &container->group_list, container_next) { | |
751 | ret = driver->ops->attach_group(data, group->iommu_group); | |
752 | if (ret) | |
753 | goto unwind; | |
754 | } | |
755 | ||
756 | return ret; | |
757 | ||
758 | unwind: | |
759 | list_for_each_entry_continue_reverse(group, &container->group_list, | |
760 | container_next) { | |
761 | driver->ops->detach_group(data, group->iommu_group); | |
762 | } | |
763 | ||
764 | return ret; | |
765 | } | |
766 | ||
767 | static long vfio_ioctl_set_iommu(struct vfio_container *container, | |
768 | unsigned long arg) | |
769 | { | |
770 | struct vfio_iommu_driver *driver; | |
771 | long ret = -ENODEV; | |
772 | ||
773 | mutex_lock(&container->group_lock); | |
774 | ||
775 | /* | |
776 | * The container is designed to be an unprivileged interface while | |
777 | * the group can be assigned to specific users. Therefore, only by | |
778 | * adding a group to a container does the user get the privilege of | |
779 | * enabling the iommu, which may allocate finite resources. There | |
780 | * is no unset_iommu, but by removing all the groups from a container, | |
781 | * the container is deprivileged and returns to an unset state. | |
782 | */ | |
783 | if (list_empty(&container->group_list) || container->iommu_driver) { | |
784 | mutex_unlock(&container->group_lock); | |
785 | return -EINVAL; | |
786 | } | |
787 | ||
788 | mutex_lock(&vfio.iommu_drivers_lock); | |
789 | list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) { | |
790 | void *data; | |
791 | ||
792 | if (!try_module_get(driver->ops->owner)) | |
793 | continue; | |
794 | ||
795 | /* | |
796 | * The arg magic for SET_IOMMU is the same as CHECK_EXTENSION, | |
797 | * so test which iommu driver reported support for this | |
798 | * extension and call open on them. We also pass them the | |
799 | * magic, allowing a single driver to support multiple | |
800 | * interfaces if they'd like. | |
801 | */ | |
802 | if (driver->ops->ioctl(NULL, VFIO_CHECK_EXTENSION, arg) <= 0) { | |
803 | module_put(driver->ops->owner); | |
804 | continue; | |
805 | } | |
806 | ||
807 | /* module reference holds the driver we're working on */ | |
808 | mutex_unlock(&vfio.iommu_drivers_lock); | |
809 | ||
810 | data = driver->ops->open(arg); | |
811 | if (IS_ERR(data)) { | |
812 | ret = PTR_ERR(data); | |
813 | module_put(driver->ops->owner); | |
814 | goto skip_drivers_unlock; | |
815 | } | |
816 | ||
817 | ret = __vfio_container_attach_groups(container, driver, data); | |
818 | if (!ret) { | |
819 | container->iommu_driver = driver; | |
820 | container->iommu_data = data; | |
821 | } else { | |
822 | driver->ops->release(data); | |
823 | module_put(driver->ops->owner); | |
824 | } | |
825 | ||
826 | goto skip_drivers_unlock; | |
827 | } | |
828 | ||
829 | mutex_unlock(&vfio.iommu_drivers_lock); | |
830 | skip_drivers_unlock: | |
831 | mutex_unlock(&container->group_lock); | |
832 | ||
833 | return ret; | |
834 | } | |
835 | ||
836 | static long vfio_fops_unl_ioctl(struct file *filep, | |
837 | unsigned int cmd, unsigned long arg) | |
838 | { | |
839 | struct vfio_container *container = filep->private_data; | |
840 | struct vfio_iommu_driver *driver; | |
841 | void *data; | |
842 | long ret = -EINVAL; | |
843 | ||
844 | if (!container) | |
845 | return ret; | |
846 | ||
847 | driver = container->iommu_driver; | |
848 | data = container->iommu_data; | |
849 | ||
850 | switch (cmd) { | |
851 | case VFIO_GET_API_VERSION: | |
852 | ret = VFIO_API_VERSION; | |
853 | break; | |
854 | case VFIO_CHECK_EXTENSION: | |
855 | ret = vfio_ioctl_check_extension(container, arg); | |
856 | break; | |
857 | case VFIO_SET_IOMMU: | |
858 | ret = vfio_ioctl_set_iommu(container, arg); | |
859 | break; | |
860 | default: | |
861 | if (driver) /* passthrough all unrecognized ioctls */ | |
862 | ret = driver->ops->ioctl(data, cmd, arg); | |
863 | } | |
864 | ||
865 | return ret; | |
866 | } | |
867 | ||
868 | #ifdef CONFIG_COMPAT | |
869 | static long vfio_fops_compat_ioctl(struct file *filep, | |
870 | unsigned int cmd, unsigned long arg) | |
871 | { | |
872 | arg = (unsigned long)compat_ptr(arg); | |
873 | return vfio_fops_unl_ioctl(filep, cmd, arg); | |
874 | } | |
875 | #endif /* CONFIG_COMPAT */ | |
876 | ||
877 | static int vfio_fops_open(struct inode *inode, struct file *filep) | |
878 | { | |
879 | struct vfio_container *container; | |
880 | ||
881 | container = kzalloc(sizeof(*container), GFP_KERNEL); | |
882 | if (!container) | |
883 | return -ENOMEM; | |
884 | ||
885 | INIT_LIST_HEAD(&container->group_list); | |
886 | mutex_init(&container->group_lock); | |
887 | kref_init(&container->kref); | |
888 | ||
889 | filep->private_data = container; | |
890 | ||
891 | return 0; | |
892 | } | |
893 | ||
894 | static int vfio_fops_release(struct inode *inode, struct file *filep) | |
895 | { | |
896 | struct vfio_container *container = filep->private_data; | |
897 | ||
898 | filep->private_data = NULL; | |
899 | ||
900 | vfio_container_put(container); | |
901 | ||
902 | return 0; | |
903 | } | |
904 | ||
905 | /* | |
906 | * Once an iommu driver is set, we optionally pass read/write/mmap | |
907 | * on to the driver, allowing management interfaces beyond ioctl. | |
908 | */ | |
909 | static ssize_t vfio_fops_read(struct file *filep, char __user *buf, | |
910 | size_t count, loff_t *ppos) | |
911 | { | |
912 | struct vfio_container *container = filep->private_data; | |
913 | struct vfio_iommu_driver *driver = container->iommu_driver; | |
914 | ||
915 | if (unlikely(!driver || !driver->ops->read)) | |
916 | return -EINVAL; | |
917 | ||
918 | return driver->ops->read(container->iommu_data, buf, count, ppos); | |
919 | } | |
920 | ||
921 | static ssize_t vfio_fops_write(struct file *filep, const char __user *buf, | |
922 | size_t count, loff_t *ppos) | |
923 | { | |
924 | struct vfio_container *container = filep->private_data; | |
925 | struct vfio_iommu_driver *driver = container->iommu_driver; | |
926 | ||
927 | if (unlikely(!driver || !driver->ops->write)) | |
928 | return -EINVAL; | |
929 | ||
930 | return driver->ops->write(container->iommu_data, buf, count, ppos); | |
931 | } | |
932 | ||
933 | static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma) | |
934 | { | |
935 | struct vfio_container *container = filep->private_data; | |
936 | struct vfio_iommu_driver *driver = container->iommu_driver; | |
937 | ||
938 | if (unlikely(!driver || !driver->ops->mmap)) | |
939 | return -EINVAL; | |
940 | ||
941 | return driver->ops->mmap(container->iommu_data, vma); | |
942 | } | |
943 | ||
944 | static const struct file_operations vfio_fops = { | |
945 | .owner = THIS_MODULE, | |
946 | .open = vfio_fops_open, | |
947 | .release = vfio_fops_release, | |
948 | .read = vfio_fops_read, | |
949 | .write = vfio_fops_write, | |
950 | .unlocked_ioctl = vfio_fops_unl_ioctl, | |
951 | #ifdef CONFIG_COMPAT | |
952 | .compat_ioctl = vfio_fops_compat_ioctl, | |
953 | #endif | |
954 | .mmap = vfio_fops_mmap, | |
955 | }; | |
956 | ||
957 | /** | |
958 | * VFIO Group fd, /dev/vfio/$GROUP | |
959 | */ | |
960 | static void __vfio_group_unset_container(struct vfio_group *group) | |
961 | { | |
962 | struct vfio_container *container = group->container; | |
963 | struct vfio_iommu_driver *driver; | |
964 | ||
965 | mutex_lock(&container->group_lock); | |
966 | ||
967 | driver = container->iommu_driver; | |
968 | if (driver) | |
969 | driver->ops->detach_group(container->iommu_data, | |
970 | group->iommu_group); | |
971 | ||
972 | group->container = NULL; | |
973 | list_del(&group->container_next); | |
974 | ||
975 | /* Detaching the last group deprivileges a container, remove iommu */ | |
976 | if (driver && list_empty(&container->group_list)) { | |
977 | driver->ops->release(container->iommu_data); | |
978 | module_put(driver->ops->owner); | |
979 | container->iommu_driver = NULL; | |
980 | container->iommu_data = NULL; | |
981 | } | |
982 | ||
983 | mutex_unlock(&container->group_lock); | |
984 | ||
985 | vfio_container_put(container); | |
986 | } | |
987 | ||
988 | /* | |
989 | * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or | |
990 | * if there was no container to unset. Since the ioctl is called on | |
991 | * the group, we know that still exists, therefore the only valid | |
992 | * transition here is 1->0. | |
993 | */ | |
994 | static int vfio_group_unset_container(struct vfio_group *group) | |
995 | { | |
996 | int users = atomic_cmpxchg(&group->container_users, 1, 0); | |
997 | ||
998 | if (!users) | |
999 | return -EINVAL; | |
1000 | if (users != 1) | |
1001 | return -EBUSY; | |
1002 | ||
1003 | __vfio_group_unset_container(group); | |
1004 | ||
1005 | return 0; | |
1006 | } | |
1007 | ||
1008 | /* | |
1009 | * When removing container users, anything that removes the last user | |
1010 | * implicitly removes the group from the container. That is, if the | |
1011 | * group file descriptor is closed, as well as any device file descriptors, | |
1012 | * the group is free. | |
1013 | */ | |
1014 | static void vfio_group_try_dissolve_container(struct vfio_group *group) | |
1015 | { | |
1016 | if (0 == atomic_dec_if_positive(&group->container_users)) | |
1017 | __vfio_group_unset_container(group); | |
1018 | } | |
1019 | ||
1020 | static int vfio_group_set_container(struct vfio_group *group, int container_fd) | |
1021 | { | |
1022 | struct file *filep; | |
1023 | struct vfio_container *container; | |
1024 | struct vfio_iommu_driver *driver; | |
1025 | int ret = 0; | |
1026 | ||
1027 | if (atomic_read(&group->container_users)) | |
1028 | return -EINVAL; | |
1029 | ||
1030 | filep = fget(container_fd); | |
1031 | if (!filep) | |
1032 | return -EBADF; | |
1033 | ||
1034 | /* Sanity check, is this really our fd? */ | |
1035 | if (filep->f_op != &vfio_fops) { | |
1036 | fput(filep); | |
1037 | return -EINVAL; | |
1038 | } | |
1039 | ||
1040 | container = filep->private_data; | |
1041 | WARN_ON(!container); /* fget ensures we don't race vfio_release */ | |
1042 | ||
1043 | mutex_lock(&container->group_lock); | |
1044 | ||
1045 | driver = container->iommu_driver; | |
1046 | if (driver) { | |
1047 | ret = driver->ops->attach_group(container->iommu_data, | |
1048 | group->iommu_group); | |
1049 | if (ret) | |
1050 | goto unlock_out; | |
1051 | } | |
1052 | ||
1053 | group->container = container; | |
1054 | list_add(&group->container_next, &container->group_list); | |
1055 | ||
1056 | /* Get a reference on the container and mark a user within the group */ | |
1057 | vfio_container_get(container); | |
1058 | atomic_inc(&group->container_users); | |
1059 | ||
1060 | unlock_out: | |
1061 | mutex_unlock(&container->group_lock); | |
1062 | fput(filep); | |
1063 | ||
1064 | return ret; | |
1065 | } | |
1066 | ||
1067 | static bool vfio_group_viable(struct vfio_group *group) | |
1068 | { | |
1069 | return (iommu_group_for_each_dev(group->iommu_group, | |
1070 | group, vfio_dev_viable) == 0); | |
1071 | } | |
1072 | ||
1073 | static const struct file_operations vfio_device_fops; | |
1074 | ||
1075 | static int vfio_group_get_device_fd(struct vfio_group *group, char *buf) | |
1076 | { | |
1077 | struct vfio_device *device; | |
1078 | struct file *filep; | |
1079 | int ret = -ENODEV; | |
1080 | ||
1081 | if (0 == atomic_read(&group->container_users) || | |
1082 | !group->container->iommu_driver || !vfio_group_viable(group)) | |
1083 | return -EINVAL; | |
1084 | ||
1085 | mutex_lock(&group->device_lock); | |
1086 | list_for_each_entry(device, &group->device_list, group_next) { | |
1087 | if (strcmp(dev_name(device->dev), buf)) | |
1088 | continue; | |
1089 | ||
1090 | ret = device->ops->open(device->device_data); | |
1091 | if (ret) | |
1092 | break; | |
1093 | /* | |
1094 | * We can't use anon_inode_getfd() because we need to modify | |
1095 | * the f_mode flags directly to allow more than just ioctls | |
1096 | */ | |
1097 | ret = get_unused_fd(); | |
1098 | if (ret < 0) { | |
1099 | device->ops->release(device->device_data); | |
1100 | break; | |
1101 | } | |
1102 | ||
1103 | filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, | |
1104 | device, O_RDWR); | |
1105 | if (IS_ERR(filep)) { | |
1106 | put_unused_fd(ret); | |
1107 | ret = PTR_ERR(filep); | |
1108 | device->ops->release(device->device_data); | |
1109 | break; | |
1110 | } | |
1111 | ||
1112 | /* | |
1113 | * TODO: add an anon_inode interface to do this. | |
1114 | * Appears to be missing by lack of need rather than | |
1115 | * explicitly prevented. Now there's need. | |
1116 | */ | |
1117 | filep->f_mode |= (FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1118 | ||
1119 | fd_install(ret, filep); | |
1120 | ||
1121 | vfio_device_get(device); | |
1122 | atomic_inc(&group->container_users); | |
1123 | break; | |
1124 | } | |
1125 | mutex_unlock(&group->device_lock); | |
1126 | ||
1127 | return ret; | |
1128 | } | |
1129 | ||
1130 | static long vfio_group_fops_unl_ioctl(struct file *filep, | |
1131 | unsigned int cmd, unsigned long arg) | |
1132 | { | |
1133 | struct vfio_group *group = filep->private_data; | |
1134 | long ret = -ENOTTY; | |
1135 | ||
1136 | switch (cmd) { | |
1137 | case VFIO_GROUP_GET_STATUS: | |
1138 | { | |
1139 | struct vfio_group_status status; | |
1140 | unsigned long minsz; | |
1141 | ||
1142 | minsz = offsetofend(struct vfio_group_status, flags); | |
1143 | ||
1144 | if (copy_from_user(&status, (void __user *)arg, minsz)) | |
1145 | return -EFAULT; | |
1146 | ||
1147 | if (status.argsz < minsz) | |
1148 | return -EINVAL; | |
1149 | ||
1150 | status.flags = 0; | |
1151 | ||
1152 | if (vfio_group_viable(group)) | |
1153 | status.flags |= VFIO_GROUP_FLAGS_VIABLE; | |
1154 | ||
1155 | if (group->container) | |
1156 | status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET; | |
1157 | ||
1158 | if (copy_to_user((void __user *)arg, &status, minsz)) | |
1159 | return -EFAULT; | |
1160 | ||
1161 | ret = 0; | |
1162 | break; | |
1163 | } | |
1164 | case VFIO_GROUP_SET_CONTAINER: | |
1165 | { | |
1166 | int fd; | |
1167 | ||
1168 | if (get_user(fd, (int __user *)arg)) | |
1169 | return -EFAULT; | |
1170 | ||
1171 | if (fd < 0) | |
1172 | return -EINVAL; | |
1173 | ||
1174 | ret = vfio_group_set_container(group, fd); | |
1175 | break; | |
1176 | } | |
1177 | case VFIO_GROUP_UNSET_CONTAINER: | |
1178 | ret = vfio_group_unset_container(group); | |
1179 | break; | |
1180 | case VFIO_GROUP_GET_DEVICE_FD: | |
1181 | { | |
1182 | char *buf; | |
1183 | ||
1184 | buf = strndup_user((const char __user *)arg, PAGE_SIZE); | |
1185 | if (IS_ERR(buf)) | |
1186 | return PTR_ERR(buf); | |
1187 | ||
1188 | ret = vfio_group_get_device_fd(group, buf); | |
1189 | kfree(buf); | |
1190 | break; | |
1191 | } | |
1192 | } | |
1193 | ||
1194 | return ret; | |
1195 | } | |
1196 | ||
1197 | #ifdef CONFIG_COMPAT | |
1198 | static long vfio_group_fops_compat_ioctl(struct file *filep, | |
1199 | unsigned int cmd, unsigned long arg) | |
1200 | { | |
1201 | arg = (unsigned long)compat_ptr(arg); | |
1202 | return vfio_group_fops_unl_ioctl(filep, cmd, arg); | |
1203 | } | |
1204 | #endif /* CONFIG_COMPAT */ | |
1205 | ||
1206 | static int vfio_group_fops_open(struct inode *inode, struct file *filep) | |
1207 | { | |
1208 | struct vfio_group *group; | |
1209 | ||
1210 | group = vfio_group_get_from_minor(iminor(inode)); | |
1211 | if (!group) | |
1212 | return -ENODEV; | |
1213 | ||
1214 | if (group->container) { | |
1215 | vfio_group_put(group); | |
1216 | return -EBUSY; | |
1217 | } | |
1218 | ||
1219 | filep->private_data = group; | |
1220 | ||
1221 | return 0; | |
1222 | } | |
1223 | ||
1224 | static int vfio_group_fops_release(struct inode *inode, struct file *filep) | |
1225 | { | |
1226 | struct vfio_group *group = filep->private_data; | |
1227 | ||
1228 | filep->private_data = NULL; | |
1229 | ||
1230 | vfio_group_try_dissolve_container(group); | |
1231 | ||
1232 | vfio_group_put(group); | |
1233 | ||
1234 | return 0; | |
1235 | } | |
1236 | ||
1237 | static const struct file_operations vfio_group_fops = { | |
1238 | .owner = THIS_MODULE, | |
1239 | .unlocked_ioctl = vfio_group_fops_unl_ioctl, | |
1240 | #ifdef CONFIG_COMPAT | |
1241 | .compat_ioctl = vfio_group_fops_compat_ioctl, | |
1242 | #endif | |
1243 | .open = vfio_group_fops_open, | |
1244 | .release = vfio_group_fops_release, | |
1245 | }; | |
1246 | ||
1247 | /** | |
1248 | * VFIO Device fd | |
1249 | */ | |
1250 | static int vfio_device_fops_release(struct inode *inode, struct file *filep) | |
1251 | { | |
1252 | struct vfio_device *device = filep->private_data; | |
1253 | ||
1254 | device->ops->release(device->device_data); | |
1255 | ||
1256 | vfio_group_try_dissolve_container(device->group); | |
1257 | ||
1258 | vfio_device_put(device); | |
1259 | ||
1260 | return 0; | |
1261 | } | |
1262 | ||
1263 | static long vfio_device_fops_unl_ioctl(struct file *filep, | |
1264 | unsigned int cmd, unsigned long arg) | |
1265 | { | |
1266 | struct vfio_device *device = filep->private_data; | |
1267 | ||
1268 | if (unlikely(!device->ops->ioctl)) | |
1269 | return -EINVAL; | |
1270 | ||
1271 | return device->ops->ioctl(device->device_data, cmd, arg); | |
1272 | } | |
1273 | ||
1274 | static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf, | |
1275 | size_t count, loff_t *ppos) | |
1276 | { | |
1277 | struct vfio_device *device = filep->private_data; | |
1278 | ||
1279 | if (unlikely(!device->ops->read)) | |
1280 | return -EINVAL; | |
1281 | ||
1282 | return device->ops->read(device->device_data, buf, count, ppos); | |
1283 | } | |
1284 | ||
1285 | static ssize_t vfio_device_fops_write(struct file *filep, | |
1286 | const char __user *buf, | |
1287 | size_t count, loff_t *ppos) | |
1288 | { | |
1289 | struct vfio_device *device = filep->private_data; | |
1290 | ||
1291 | if (unlikely(!device->ops->write)) | |
1292 | return -EINVAL; | |
1293 | ||
1294 | return device->ops->write(device->device_data, buf, count, ppos); | |
1295 | } | |
1296 | ||
1297 | static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) | |
1298 | { | |
1299 | struct vfio_device *device = filep->private_data; | |
1300 | ||
1301 | if (unlikely(!device->ops->mmap)) | |
1302 | return -EINVAL; | |
1303 | ||
1304 | return device->ops->mmap(device->device_data, vma); | |
1305 | } | |
1306 | ||
1307 | #ifdef CONFIG_COMPAT | |
1308 | static long vfio_device_fops_compat_ioctl(struct file *filep, | |
1309 | unsigned int cmd, unsigned long arg) | |
1310 | { | |
1311 | arg = (unsigned long)compat_ptr(arg); | |
1312 | return vfio_device_fops_unl_ioctl(filep, cmd, arg); | |
1313 | } | |
1314 | #endif /* CONFIG_COMPAT */ | |
1315 | ||
1316 | static const struct file_operations vfio_device_fops = { | |
1317 | .owner = THIS_MODULE, | |
1318 | .release = vfio_device_fops_release, | |
1319 | .read = vfio_device_fops_read, | |
1320 | .write = vfio_device_fops_write, | |
1321 | .unlocked_ioctl = vfio_device_fops_unl_ioctl, | |
1322 | #ifdef CONFIG_COMPAT | |
1323 | .compat_ioctl = vfio_device_fops_compat_ioctl, | |
1324 | #endif | |
1325 | .mmap = vfio_device_fops_mmap, | |
1326 | }; | |
1327 | ||
1328 | /** | |
1329 | * Module/class support | |
1330 | */ | |
1331 | static char *vfio_devnode(struct device *dev, umode_t *mode) | |
1332 | { | |
1333 | return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); | |
1334 | } | |
1335 | ||
1336 | static int __init vfio_init(void) | |
1337 | { | |
1338 | int ret; | |
1339 | ||
1340 | idr_init(&vfio.group_idr); | |
1341 | mutex_init(&vfio.group_lock); | |
1342 | mutex_init(&vfio.iommu_drivers_lock); | |
1343 | INIT_LIST_HEAD(&vfio.group_list); | |
1344 | INIT_LIST_HEAD(&vfio.iommu_drivers_list); | |
1345 | init_waitqueue_head(&vfio.release_q); | |
1346 | ||
1347 | vfio.class = class_create(THIS_MODULE, "vfio"); | |
1348 | if (IS_ERR(vfio.class)) { | |
1349 | ret = PTR_ERR(vfio.class); | |
1350 | goto err_class; | |
1351 | } | |
1352 | ||
1353 | vfio.class->devnode = vfio_devnode; | |
1354 | ||
1355 | ret = alloc_chrdev_region(&vfio.devt, 0, MINORMASK, "vfio"); | |
1356 | if (ret) | |
1357 | goto err_base_chrdev; | |
1358 | ||
1359 | cdev_init(&vfio.cdev, &vfio_fops); | |
1360 | ret = cdev_add(&vfio.cdev, vfio.devt, 1); | |
1361 | if (ret) | |
1362 | goto err_base_cdev; | |
1363 | ||
1364 | vfio.dev = device_create(vfio.class, NULL, vfio.devt, NULL, "vfio"); | |
1365 | if (IS_ERR(vfio.dev)) { | |
1366 | ret = PTR_ERR(vfio.dev); | |
1367 | goto err_base_dev; | |
1368 | } | |
1369 | ||
1370 | /* /dev/vfio/$GROUP */ | |
1371 | cdev_init(&vfio.group_cdev, &vfio_group_fops); | |
1372 | ret = cdev_add(&vfio.group_cdev, | |
1373 | MKDEV(MAJOR(vfio.devt), 1), MINORMASK - 1); | |
1374 | if (ret) | |
1375 | goto err_groups_cdev; | |
1376 | ||
1377 | pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); | |
1378 | ||
73fa0d10 AW |
1379 | /* |
1380 | * Attempt to load known iommu-drivers. This gives us a working | |
1381 | * environment without the user needing to explicitly load iommu | |
1382 | * drivers. | |
1383 | */ | |
1384 | request_module_nowait("vfio_iommu_type1"); | |
1385 | ||
cba3345c AW |
1386 | return 0; |
1387 | ||
1388 | err_groups_cdev: | |
1389 | device_destroy(vfio.class, vfio.devt); | |
1390 | err_base_dev: | |
1391 | cdev_del(&vfio.cdev); | |
1392 | err_base_cdev: | |
1393 | unregister_chrdev_region(vfio.devt, MINORMASK); | |
1394 | err_base_chrdev: | |
1395 | class_destroy(vfio.class); | |
1396 | vfio.class = NULL; | |
1397 | err_class: | |
1398 | return ret; | |
1399 | } | |
1400 | ||
1401 | static void __exit vfio_cleanup(void) | |
1402 | { | |
1403 | WARN_ON(!list_empty(&vfio.group_list)); | |
1404 | ||
1405 | idr_destroy(&vfio.group_idr); | |
1406 | cdev_del(&vfio.group_cdev); | |
1407 | device_destroy(vfio.class, vfio.devt); | |
1408 | cdev_del(&vfio.cdev); | |
1409 | unregister_chrdev_region(vfio.devt, MINORMASK); | |
1410 | class_destroy(vfio.class); | |
1411 | vfio.class = NULL; | |
1412 | } | |
1413 | ||
1414 | module_init(vfio_init); | |
1415 | module_exit(vfio_cleanup); | |
1416 | ||
1417 | MODULE_VERSION(DRIVER_VERSION); | |
1418 | MODULE_LICENSE("GPL v2"); | |
1419 | MODULE_AUTHOR(DRIVER_AUTHOR); | |
1420 | MODULE_DESCRIPTION(DRIVER_DESC); |