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cba3345c AW |
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> | |
9587f44a | 27 | #include <linux/rwsem.h> |
cba3345c AW |
28 | #include <linux/sched.h> |
29 | #include <linux/slab.h> | |
664e9386 | 30 | #include <linux/stat.h> |
cba3345c AW |
31 | #include <linux/string.h> |
32 | #include <linux/uaccess.h> | |
33 | #include <linux/vfio.h> | |
34 | #include <linux/wait.h> | |
35 | ||
36 | #define DRIVER_VERSION "0.3" | |
37 | #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>" | |
38 | #define DRIVER_DESC "VFIO - User Level meta-driver" | |
39 | ||
40 | static struct vfio { | |
41 | struct class *class; | |
42 | struct list_head iommu_drivers_list; | |
43 | struct mutex iommu_drivers_lock; | |
44 | struct list_head group_list; | |
45 | struct idr group_idr; | |
46 | struct mutex group_lock; | |
47 | struct cdev group_cdev; | |
48 | struct device *dev; | |
49 | dev_t devt; | |
50 | struct cdev cdev; | |
51 | wait_queue_head_t release_q; | |
52 | } vfio; | |
53 | ||
54 | struct vfio_iommu_driver { | |
55 | const struct vfio_iommu_driver_ops *ops; | |
56 | struct list_head vfio_next; | |
57 | }; | |
58 | ||
59 | struct vfio_container { | |
60 | struct kref kref; | |
61 | struct list_head group_list; | |
9587f44a | 62 | struct rw_semaphore group_lock; |
cba3345c AW |
63 | struct vfio_iommu_driver *iommu_driver; |
64 | void *iommu_data; | |
65 | }; | |
66 | ||
67 | struct vfio_group { | |
68 | struct kref kref; | |
69 | int minor; | |
70 | atomic_t container_users; | |
71 | struct iommu_group *iommu_group; | |
72 | struct vfio_container *container; | |
73 | struct list_head device_list; | |
74 | struct mutex device_lock; | |
75 | struct device *dev; | |
76 | struct notifier_block nb; | |
77 | struct list_head vfio_next; | |
78 | struct list_head container_next; | |
79 | }; | |
80 | ||
81 | struct 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 | */ | |
93 | int 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 | } | |
120 | EXPORT_SYMBOL_GPL(vfio_register_iommu_driver); | |
121 | ||
122 | void 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 | } | |
137 | EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver); | |
138 | ||
139 | /** | |
140 | * Group minor allocation/free - both called with vfio.group_lock held | |
141 | */ | |
142 | static int vfio_alloc_group_minor(struct vfio_group *group) | |
143 | { | |
cba3345c | 144 | /* index 0 is used by /dev/vfio/vfio */ |
a1c36b16 | 145 | return idr_alloc(&vfio.group_idr, group, 1, MINORMASK + 1, GFP_KERNEL); |
cba3345c AW |
146 | } |
147 | ||
148 | static void vfio_free_group_minor(int minor) | |
149 | { | |
150 | idr_remove(&vfio.group_idr, minor); | |
151 | } | |
152 | ||
153 | static int vfio_iommu_group_notifier(struct notifier_block *nb, | |
154 | unsigned long action, void *data); | |
155 | static void vfio_group_get(struct vfio_group *group); | |
156 | ||
157 | /** | |
158 | * Container objects - containers are created when /dev/vfio/vfio is | |
159 | * opened, but their lifecycle extends until the last user is done, so | |
160 | * it's freed via kref. Must support container/group/device being | |
161 | * closed in any order. | |
162 | */ | |
163 | static void vfio_container_get(struct vfio_container *container) | |
164 | { | |
165 | kref_get(&container->kref); | |
166 | } | |
167 | ||
168 | static void vfio_container_release(struct kref *kref) | |
169 | { | |
170 | struct vfio_container *container; | |
171 | container = container_of(kref, struct vfio_container, kref); | |
172 | ||
173 | kfree(container); | |
174 | } | |
175 | ||
176 | static void vfio_container_put(struct vfio_container *container) | |
177 | { | |
178 | kref_put(&container->kref, vfio_container_release); | |
179 | } | |
180 | ||
9df7b25a JL |
181 | static void vfio_group_unlock_and_free(struct vfio_group *group) |
182 | { | |
183 | mutex_unlock(&vfio.group_lock); | |
184 | /* | |
185 | * Unregister outside of lock. A spurious callback is harmless now | |
186 | * that the group is no longer in vfio.group_list. | |
187 | */ | |
188 | iommu_group_unregister_notifier(group->iommu_group, &group->nb); | |
189 | kfree(group); | |
190 | } | |
191 | ||
cba3345c AW |
192 | /** |
193 | * Group objects - create, release, get, put, search | |
194 | */ | |
195 | static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group) | |
196 | { | |
197 | struct vfio_group *group, *tmp; | |
198 | struct device *dev; | |
199 | int ret, minor; | |
200 | ||
201 | group = kzalloc(sizeof(*group), GFP_KERNEL); | |
202 | if (!group) | |
203 | return ERR_PTR(-ENOMEM); | |
204 | ||
205 | kref_init(&group->kref); | |
206 | INIT_LIST_HEAD(&group->device_list); | |
207 | mutex_init(&group->device_lock); | |
208 | atomic_set(&group->container_users, 0); | |
209 | 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) { | |
9df7b25a | 230 | vfio_group_unlock_and_free(group); |
cba3345c AW |
231 | 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); | |
9df7b25a | 239 | vfio_group_unlock_and_free(group); |
cba3345c AW |
240 | return tmp; |
241 | } | |
242 | } | |
243 | ||
244 | dev = device_create(vfio.class, NULL, MKDEV(MAJOR(vfio.devt), minor), | |
245 | group, "%d", iommu_group_id(iommu_group)); | |
246 | if (IS_ERR(dev)) { | |
247 | vfio_free_group_minor(minor); | |
9df7b25a | 248 | vfio_group_unlock_and_free(group); |
cba3345c AW |
249 | return (struct vfio_group *)dev; /* ERR_PTR */ |
250 | } | |
251 | ||
252 | group->minor = minor; | |
253 | group->dev = dev; | |
254 | ||
255 | list_add(&group->vfio_next, &vfio.group_list); | |
256 | ||
257 | mutex_unlock(&vfio.group_lock); | |
258 | ||
259 | return group; | |
260 | } | |
261 | ||
6d2cd3ce | 262 | /* called with vfio.group_lock held */ |
cba3345c AW |
263 | static void vfio_group_release(struct kref *kref) |
264 | { | |
265 | struct vfio_group *group = container_of(kref, struct vfio_group, kref); | |
266 | ||
267 | WARN_ON(!list_empty(&group->device_list)); | |
268 | ||
269 | device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor)); | |
270 | list_del(&group->vfio_next); | |
271 | vfio_free_group_minor(group->minor); | |
9df7b25a | 272 | vfio_group_unlock_and_free(group); |
cba3345c AW |
273 | } |
274 | ||
275 | static void vfio_group_put(struct vfio_group *group) | |
276 | { | |
6d2cd3ce | 277 | kref_put_mutex(&group->kref, vfio_group_release, &vfio.group_lock); |
cba3345c AW |
278 | } |
279 | ||
280 | /* Assume group_lock or group reference is held */ | |
281 | static void vfio_group_get(struct vfio_group *group) | |
282 | { | |
283 | kref_get(&group->kref); | |
284 | } | |
285 | ||
286 | /* | |
287 | * Not really a try as we will sleep for mutex, but we need to make | |
288 | * sure the group pointer is valid under lock and get a reference. | |
289 | */ | |
290 | static struct vfio_group *vfio_group_try_get(struct vfio_group *group) | |
291 | { | |
292 | struct vfio_group *target = group; | |
293 | ||
294 | mutex_lock(&vfio.group_lock); | |
295 | list_for_each_entry(group, &vfio.group_list, vfio_next) { | |
296 | if (group == target) { | |
297 | vfio_group_get(group); | |
298 | mutex_unlock(&vfio.group_lock); | |
299 | return group; | |
300 | } | |
301 | } | |
302 | mutex_unlock(&vfio.group_lock); | |
303 | ||
304 | return NULL; | |
305 | } | |
306 | ||
307 | static | |
308 | struct vfio_group *vfio_group_get_from_iommu(struct iommu_group *iommu_group) | |
309 | { | |
310 | struct vfio_group *group; | |
311 | ||
312 | mutex_lock(&vfio.group_lock); | |
313 | list_for_each_entry(group, &vfio.group_list, vfio_next) { | |
314 | if (group->iommu_group == iommu_group) { | |
315 | vfio_group_get(group); | |
316 | mutex_unlock(&vfio.group_lock); | |
317 | return group; | |
318 | } | |
319 | } | |
320 | mutex_unlock(&vfio.group_lock); | |
321 | ||
322 | return NULL; | |
323 | } | |
324 | ||
325 | static struct vfio_group *vfio_group_get_from_minor(int minor) | |
326 | { | |
327 | struct vfio_group *group; | |
328 | ||
329 | mutex_lock(&vfio.group_lock); | |
330 | group = idr_find(&vfio.group_idr, minor); | |
331 | if (!group) { | |
332 | mutex_unlock(&vfio.group_lock); | |
333 | return NULL; | |
334 | } | |
335 | vfio_group_get(group); | |
336 | mutex_unlock(&vfio.group_lock); | |
337 | ||
338 | return group; | |
339 | } | |
340 | ||
341 | /** | |
342 | * Device objects - create, release, get, put, search | |
343 | */ | |
344 | static | |
345 | struct vfio_device *vfio_group_create_device(struct vfio_group *group, | |
346 | struct device *dev, | |
347 | const struct vfio_device_ops *ops, | |
348 | void *device_data) | |
349 | { | |
350 | struct vfio_device *device; | |
351 | int ret; | |
352 | ||
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; | |
362 | ||
363 | ret = dev_set_drvdata(dev, device); | |
364 | if (ret) { | |
365 | kfree(device); | |
366 | return ERR_PTR(ret); | |
367 | } | |
368 | ||
369 | /* No need to get group_lock, caller has group reference */ | |
370 | vfio_group_get(group); | |
371 | ||
372 | mutex_lock(&group->device_lock); | |
373 | list_add(&device->group_next, &group->device_list); | |
374 | mutex_unlock(&group->device_lock); | |
375 | ||
376 | return device; | |
377 | } | |
378 | ||
379 | static void vfio_device_release(struct kref *kref) | |
380 | { | |
381 | struct vfio_device *device = container_of(kref, | |
382 | struct vfio_device, kref); | |
383 | struct vfio_group *group = device->group; | |
384 | ||
cba3345c AW |
385 | list_del(&device->group_next); |
386 | mutex_unlock(&group->device_lock); | |
387 | ||
388 | dev_set_drvdata(device->dev, NULL); | |
389 | ||
390 | kfree(device); | |
391 | ||
392 | /* vfio_del_group_dev may be waiting for this device */ | |
393 | wake_up(&vfio.release_q); | |
394 | } | |
395 | ||
396 | /* Device reference always implies a group reference */ | |
44f50716 | 397 | void vfio_device_put(struct vfio_device *device) |
cba3345c | 398 | { |
934ad4c2 | 399 | struct vfio_group *group = device->group; |
90b1253e | 400 | kref_put_mutex(&device->kref, vfio_device_release, &group->device_lock); |
934ad4c2 | 401 | vfio_group_put(group); |
cba3345c | 402 | } |
44f50716 | 403 | EXPORT_SYMBOL_GPL(vfio_device_put); |
cba3345c AW |
404 | |
405 | static void vfio_device_get(struct vfio_device *device) | |
406 | { | |
407 | vfio_group_get(device->group); | |
408 | kref_get(&device->kref); | |
409 | } | |
410 | ||
411 | static struct vfio_device *vfio_group_get_device(struct vfio_group *group, | |
412 | struct device *dev) | |
413 | { | |
414 | struct vfio_device *device; | |
415 | ||
416 | mutex_lock(&group->device_lock); | |
417 | list_for_each_entry(device, &group->device_list, group_next) { | |
418 | if (device->dev == dev) { | |
419 | vfio_device_get(device); | |
420 | mutex_unlock(&group->device_lock); | |
421 | return device; | |
422 | } | |
423 | } | |
424 | mutex_unlock(&group->device_lock); | |
425 | return NULL; | |
426 | } | |
427 | ||
428 | /* | |
429 | * Whitelist some drivers that we know are safe (no dma) or just sit on | |
430 | * a device. It's not always practical to leave a device within a group | |
431 | * driverless as it could get re-bound to something unsafe. | |
432 | */ | |
2b489a45 | 433 | static const char * const vfio_driver_whitelist[] = { "pci-stub", "pcieport" }; |
cba3345c AW |
434 | |
435 | static bool vfio_whitelisted_driver(struct device_driver *drv) | |
436 | { | |
437 | int i; | |
438 | ||
439 | for (i = 0; i < ARRAY_SIZE(vfio_driver_whitelist); i++) { | |
440 | if (!strcmp(drv->name, vfio_driver_whitelist[i])) | |
441 | return true; | |
442 | } | |
443 | ||
444 | return false; | |
445 | } | |
446 | ||
447 | /* | |
448 | * A vfio group is viable for use by userspace if all devices are either | |
449 | * driver-less or bound to a vfio or whitelisted driver. We test the | |
450 | * latter by the existence of a struct vfio_device matching the dev. | |
451 | */ | |
452 | static int vfio_dev_viable(struct device *dev, void *data) | |
453 | { | |
454 | struct vfio_group *group = data; | |
455 | struct vfio_device *device; | |
de2b3eea | 456 | struct device_driver *drv = ACCESS_ONCE(dev->driver); |
cba3345c | 457 | |
de2b3eea | 458 | if (!drv || vfio_whitelisted_driver(drv)) |
cba3345c AW |
459 | return 0; |
460 | ||
461 | device = vfio_group_get_device(group, dev); | |
462 | if (device) { | |
463 | vfio_device_put(device); | |
464 | return 0; | |
465 | } | |
466 | ||
467 | return -EINVAL; | |
468 | } | |
469 | ||
470 | /** | |
471 | * Async device support | |
472 | */ | |
473 | static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev) | |
474 | { | |
475 | struct vfio_device *device; | |
476 | ||
477 | /* Do we already know about it? We shouldn't */ | |
478 | device = vfio_group_get_device(group, dev); | |
479 | if (WARN_ON_ONCE(device)) { | |
480 | vfio_device_put(device); | |
481 | return 0; | |
482 | } | |
483 | ||
484 | /* Nothing to do for idle groups */ | |
485 | if (!atomic_read(&group->container_users)) | |
486 | return 0; | |
487 | ||
488 | /* TODO Prevent device auto probing */ | |
489 | WARN("Device %s added to live group %d!\n", dev_name(dev), | |
490 | iommu_group_id(group->iommu_group)); | |
491 | ||
492 | return 0; | |
493 | } | |
494 | ||
495 | static int vfio_group_nb_del_dev(struct vfio_group *group, struct device *dev) | |
496 | { | |
497 | struct vfio_device *device; | |
498 | ||
499 | /* | |
500 | * Expect to fall out here. If a device was in use, it would | |
501 | * have been bound to a vfio sub-driver, which would have blocked | |
502 | * in .remove at vfio_del_group_dev. Sanity check that we no | |
503 | * longer track the device, so it's safe to remove. | |
504 | */ | |
505 | device = vfio_group_get_device(group, dev); | |
506 | if (likely(!device)) | |
507 | return 0; | |
508 | ||
509 | WARN("Device %s removed from live group %d!\n", dev_name(dev), | |
510 | iommu_group_id(group->iommu_group)); | |
511 | ||
512 | vfio_device_put(device); | |
513 | return 0; | |
514 | } | |
515 | ||
516 | static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev) | |
517 | { | |
518 | /* We don't care what happens when the group isn't in use */ | |
519 | if (!atomic_read(&group->container_users)) | |
520 | return 0; | |
521 | ||
522 | return vfio_dev_viable(dev, group); | |
523 | } | |
524 | ||
525 | static int vfio_iommu_group_notifier(struct notifier_block *nb, | |
526 | unsigned long action, void *data) | |
527 | { | |
528 | struct vfio_group *group = container_of(nb, struct vfio_group, nb); | |
529 | struct device *dev = data; | |
530 | ||
531 | /* | |
532 | * Need to go through a group_lock lookup to get a reference or | |
533 | * we risk racing a group being removed. Leave a WARN_ON for | |
534 | * debuging, but if the group no longer exists, a spurious notify | |
535 | * is harmless. | |
536 | */ | |
537 | group = vfio_group_try_get(group); | |
538 | if (WARN_ON(!group)) | |
539 | return NOTIFY_OK; | |
540 | ||
541 | switch (action) { | |
542 | case IOMMU_GROUP_NOTIFY_ADD_DEVICE: | |
543 | vfio_group_nb_add_dev(group, dev); | |
544 | break; | |
545 | case IOMMU_GROUP_NOTIFY_DEL_DEVICE: | |
546 | vfio_group_nb_del_dev(group, dev); | |
547 | break; | |
548 | case IOMMU_GROUP_NOTIFY_BIND_DRIVER: | |
549 | pr_debug("%s: Device %s, group %d binding to driver\n", | |
550 | __func__, dev_name(dev), | |
551 | iommu_group_id(group->iommu_group)); | |
552 | break; | |
553 | case IOMMU_GROUP_NOTIFY_BOUND_DRIVER: | |
554 | pr_debug("%s: Device %s, group %d bound to driver %s\n", | |
555 | __func__, dev_name(dev), | |
556 | iommu_group_id(group->iommu_group), dev->driver->name); | |
557 | BUG_ON(vfio_group_nb_verify(group, dev)); | |
558 | break; | |
559 | case IOMMU_GROUP_NOTIFY_UNBIND_DRIVER: | |
560 | pr_debug("%s: Device %s, group %d unbinding from driver %s\n", | |
561 | __func__, dev_name(dev), | |
562 | iommu_group_id(group->iommu_group), dev->driver->name); | |
563 | break; | |
564 | case IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER: | |
565 | pr_debug("%s: Device %s, group %d unbound from driver\n", | |
566 | __func__, dev_name(dev), | |
567 | iommu_group_id(group->iommu_group)); | |
568 | /* | |
569 | * XXX An unbound device in a live group is ok, but we'd | |
570 | * really like to avoid the above BUG_ON by preventing other | |
571 | * drivers from binding to it. Once that occurs, we have to | |
572 | * stop the system to maintain isolation. At a minimum, we'd | |
573 | * want a toggle to disable driver auto probe for this device. | |
574 | */ | |
575 | break; | |
576 | } | |
577 | ||
578 | vfio_group_put(group); | |
579 | return NOTIFY_OK; | |
580 | } | |
581 | ||
582 | /** | |
583 | * VFIO driver API | |
584 | */ | |
585 | int vfio_add_group_dev(struct device *dev, | |
586 | const struct vfio_device_ops *ops, void *device_data) | |
587 | { | |
588 | struct iommu_group *iommu_group; | |
589 | struct vfio_group *group; | |
590 | struct vfio_device *device; | |
591 | ||
592 | iommu_group = iommu_group_get(dev); | |
593 | if (!iommu_group) | |
594 | return -EINVAL; | |
595 | ||
596 | group = vfio_group_get_from_iommu(iommu_group); | |
597 | if (!group) { | |
598 | group = vfio_create_group(iommu_group); | |
599 | if (IS_ERR(group)) { | |
600 | iommu_group_put(iommu_group); | |
601 | return PTR_ERR(group); | |
602 | } | |
603 | } | |
604 | ||
605 | device = vfio_group_get_device(group, dev); | |
606 | if (device) { | |
607 | WARN(1, "Device %s already exists on group %d\n", | |
608 | dev_name(dev), iommu_group_id(iommu_group)); | |
609 | vfio_device_put(device); | |
610 | vfio_group_put(group); | |
611 | iommu_group_put(iommu_group); | |
612 | return -EBUSY; | |
613 | } | |
614 | ||
615 | device = vfio_group_create_device(group, dev, ops, device_data); | |
616 | if (IS_ERR(device)) { | |
617 | vfio_group_put(group); | |
618 | iommu_group_put(iommu_group); | |
619 | return PTR_ERR(device); | |
620 | } | |
621 | ||
622 | /* | |
623 | * Added device holds reference to iommu_group and vfio_device | |
624 | * (which in turn holds reference to vfio_group). Drop extra | |
625 | * group reference used while acquiring device. | |
626 | */ | |
627 | vfio_group_put(group); | |
628 | ||
629 | return 0; | |
630 | } | |
631 | EXPORT_SYMBOL_GPL(vfio_add_group_dev); | |
632 | ||
44f50716 VMP |
633 | /** |
634 | * Get a reference to the vfio_device for a device that is known to | |
635 | * be bound to a vfio driver. The driver implicitly holds a | |
636 | * vfio_device reference between vfio_add_group_dev and | |
637 | * vfio_del_group_dev. We can therefore use drvdata to increment | |
638 | * that reference from the struct device. This additional | |
639 | * reference must be released by calling vfio_device_put. | |
640 | */ | |
641 | struct vfio_device *vfio_device_get_from_dev(struct device *dev) | |
642 | { | |
643 | struct vfio_device *device = dev_get_drvdata(dev); | |
644 | ||
645 | vfio_device_get(device); | |
646 | ||
647 | return device; | |
648 | } | |
649 | EXPORT_SYMBOL_GPL(vfio_device_get_from_dev); | |
650 | ||
651 | /* | |
652 | * Caller must hold a reference to the vfio_device | |
653 | */ | |
654 | void *vfio_device_data(struct vfio_device *device) | |
655 | { | |
656 | return device->device_data; | |
657 | } | |
658 | EXPORT_SYMBOL_GPL(vfio_device_data); | |
659 | ||
e014e944 AW |
660 | /* Given a referenced group, check if it contains the device */ |
661 | static bool vfio_dev_present(struct vfio_group *group, struct device *dev) | |
cba3345c | 662 | { |
cba3345c AW |
663 | struct vfio_device *device; |
664 | ||
cba3345c | 665 | device = vfio_group_get_device(group, dev); |
e014e944 | 666 | if (!device) |
cba3345c | 667 | return false; |
cba3345c AW |
668 | |
669 | vfio_device_put(device); | |
cba3345c AW |
670 | return true; |
671 | } | |
672 | ||
673 | /* | |
674 | * Decrement the device reference count and wait for the device to be | |
675 | * removed. Open file descriptors for the device... */ | |
676 | void *vfio_del_group_dev(struct device *dev) | |
677 | { | |
678 | struct vfio_device *device = dev_get_drvdata(dev); | |
679 | struct vfio_group *group = device->group; | |
680 | struct iommu_group *iommu_group = group->iommu_group; | |
681 | void *device_data = device->device_data; | |
682 | ||
e014e944 AW |
683 | /* |
684 | * The group exists so long as we have a device reference. Get | |
685 | * a group reference and use it to scan for the device going away. | |
686 | */ | |
687 | vfio_group_get(group); | |
688 | ||
cba3345c AW |
689 | vfio_device_put(device); |
690 | ||
691 | /* TODO send a signal to encourage this to be released */ | |
e014e944 AW |
692 | wait_event(vfio.release_q, !vfio_dev_present(group, dev)); |
693 | ||
694 | vfio_group_put(group); | |
cba3345c AW |
695 | |
696 | iommu_group_put(iommu_group); | |
697 | ||
698 | return device_data; | |
699 | } | |
700 | EXPORT_SYMBOL_GPL(vfio_del_group_dev); | |
701 | ||
702 | /** | |
703 | * VFIO base fd, /dev/vfio/vfio | |
704 | */ | |
705 | static long vfio_ioctl_check_extension(struct vfio_container *container, | |
706 | unsigned long arg) | |
707 | { | |
0b43c082 | 708 | struct vfio_iommu_driver *driver; |
cba3345c AW |
709 | long ret = 0; |
710 | ||
0b43c082 AW |
711 | down_read(&container->group_lock); |
712 | ||
713 | driver = container->iommu_driver; | |
714 | ||
cba3345c AW |
715 | switch (arg) { |
716 | /* No base extensions yet */ | |
717 | default: | |
718 | /* | |
719 | * If no driver is set, poll all registered drivers for | |
720 | * extensions and return the first positive result. If | |
721 | * a driver is already set, further queries will be passed | |
722 | * only to that driver. | |
723 | */ | |
724 | if (!driver) { | |
725 | mutex_lock(&vfio.iommu_drivers_lock); | |
726 | list_for_each_entry(driver, &vfio.iommu_drivers_list, | |
727 | vfio_next) { | |
728 | if (!try_module_get(driver->ops->owner)) | |
729 | continue; | |
730 | ||
731 | ret = driver->ops->ioctl(NULL, | |
732 | VFIO_CHECK_EXTENSION, | |
733 | arg); | |
734 | module_put(driver->ops->owner); | |
735 | if (ret > 0) | |
736 | break; | |
737 | } | |
738 | mutex_unlock(&vfio.iommu_drivers_lock); | |
739 | } else | |
740 | ret = driver->ops->ioctl(container->iommu_data, | |
741 | VFIO_CHECK_EXTENSION, arg); | |
742 | } | |
743 | ||
0b43c082 AW |
744 | up_read(&container->group_lock); |
745 | ||
cba3345c AW |
746 | return ret; |
747 | } | |
748 | ||
9587f44a | 749 | /* hold write lock on container->group_lock */ |
cba3345c AW |
750 | static int __vfio_container_attach_groups(struct vfio_container *container, |
751 | struct vfio_iommu_driver *driver, | |
752 | void *data) | |
753 | { | |
754 | struct vfio_group *group; | |
755 | int ret = -ENODEV; | |
756 | ||
757 | list_for_each_entry(group, &container->group_list, container_next) { | |
758 | ret = driver->ops->attach_group(data, group->iommu_group); | |
759 | if (ret) | |
760 | goto unwind; | |
761 | } | |
762 | ||
763 | return ret; | |
764 | ||
765 | unwind: | |
766 | list_for_each_entry_continue_reverse(group, &container->group_list, | |
767 | container_next) { | |
768 | driver->ops->detach_group(data, group->iommu_group); | |
769 | } | |
770 | ||
771 | return ret; | |
772 | } | |
773 | ||
774 | static long vfio_ioctl_set_iommu(struct vfio_container *container, | |
775 | unsigned long arg) | |
776 | { | |
777 | struct vfio_iommu_driver *driver; | |
778 | long ret = -ENODEV; | |
779 | ||
9587f44a | 780 | down_write(&container->group_lock); |
cba3345c AW |
781 | |
782 | /* | |
783 | * The container is designed to be an unprivileged interface while | |
784 | * the group can be assigned to specific users. Therefore, only by | |
785 | * adding a group to a container does the user get the privilege of | |
786 | * enabling the iommu, which may allocate finite resources. There | |
787 | * is no unset_iommu, but by removing all the groups from a container, | |
788 | * the container is deprivileged and returns to an unset state. | |
789 | */ | |
790 | if (list_empty(&container->group_list) || container->iommu_driver) { | |
9587f44a | 791 | up_write(&container->group_lock); |
cba3345c AW |
792 | return -EINVAL; |
793 | } | |
794 | ||
795 | mutex_lock(&vfio.iommu_drivers_lock); | |
796 | list_for_each_entry(driver, &vfio.iommu_drivers_list, vfio_next) { | |
797 | void *data; | |
798 | ||
799 | if (!try_module_get(driver->ops->owner)) | |
800 | continue; | |
801 | ||
802 | /* | |
803 | * The arg magic for SET_IOMMU is the same as CHECK_EXTENSION, | |
804 | * so test which iommu driver reported support for this | |
805 | * extension and call open on them. We also pass them the | |
806 | * magic, allowing a single driver to support multiple | |
807 | * interfaces if they'd like. | |
808 | */ | |
809 | if (driver->ops->ioctl(NULL, VFIO_CHECK_EXTENSION, arg) <= 0) { | |
810 | module_put(driver->ops->owner); | |
811 | continue; | |
812 | } | |
813 | ||
814 | /* module reference holds the driver we're working on */ | |
815 | mutex_unlock(&vfio.iommu_drivers_lock); | |
816 | ||
817 | data = driver->ops->open(arg); | |
818 | if (IS_ERR(data)) { | |
819 | ret = PTR_ERR(data); | |
820 | module_put(driver->ops->owner); | |
821 | goto skip_drivers_unlock; | |
822 | } | |
823 | ||
824 | ret = __vfio_container_attach_groups(container, driver, data); | |
825 | if (!ret) { | |
826 | container->iommu_driver = driver; | |
827 | container->iommu_data = data; | |
828 | } else { | |
829 | driver->ops->release(data); | |
830 | module_put(driver->ops->owner); | |
831 | } | |
832 | ||
833 | goto skip_drivers_unlock; | |
834 | } | |
835 | ||
836 | mutex_unlock(&vfio.iommu_drivers_lock); | |
837 | skip_drivers_unlock: | |
9587f44a | 838 | up_write(&container->group_lock); |
cba3345c AW |
839 | |
840 | return ret; | |
841 | } | |
842 | ||
843 | static long vfio_fops_unl_ioctl(struct file *filep, | |
844 | unsigned int cmd, unsigned long arg) | |
845 | { | |
846 | struct vfio_container *container = filep->private_data; | |
847 | struct vfio_iommu_driver *driver; | |
848 | void *data; | |
849 | long ret = -EINVAL; | |
850 | ||
851 | if (!container) | |
852 | return ret; | |
853 | ||
cba3345c AW |
854 | switch (cmd) { |
855 | case VFIO_GET_API_VERSION: | |
856 | ret = VFIO_API_VERSION; | |
857 | break; | |
858 | case VFIO_CHECK_EXTENSION: | |
859 | ret = vfio_ioctl_check_extension(container, arg); | |
860 | break; | |
861 | case VFIO_SET_IOMMU: | |
862 | ret = vfio_ioctl_set_iommu(container, arg); | |
863 | break; | |
864 | default: | |
0b43c082 AW |
865 | down_read(&container->group_lock); |
866 | ||
867 | driver = container->iommu_driver; | |
868 | data = container->iommu_data; | |
869 | ||
cba3345c AW |
870 | if (driver) /* passthrough all unrecognized ioctls */ |
871 | ret = driver->ops->ioctl(data, cmd, arg); | |
0b43c082 AW |
872 | |
873 | up_read(&container->group_lock); | |
cba3345c AW |
874 | } |
875 | ||
876 | return ret; | |
877 | } | |
878 | ||
879 | #ifdef CONFIG_COMPAT | |
880 | static long vfio_fops_compat_ioctl(struct file *filep, | |
881 | unsigned int cmd, unsigned long arg) | |
882 | { | |
883 | arg = (unsigned long)compat_ptr(arg); | |
884 | return vfio_fops_unl_ioctl(filep, cmd, arg); | |
885 | } | |
886 | #endif /* CONFIG_COMPAT */ | |
887 | ||
888 | static int vfio_fops_open(struct inode *inode, struct file *filep) | |
889 | { | |
890 | struct vfio_container *container; | |
891 | ||
892 | container = kzalloc(sizeof(*container), GFP_KERNEL); | |
893 | if (!container) | |
894 | return -ENOMEM; | |
895 | ||
896 | INIT_LIST_HEAD(&container->group_list); | |
9587f44a | 897 | init_rwsem(&container->group_lock); |
cba3345c AW |
898 | kref_init(&container->kref); |
899 | ||
900 | filep->private_data = container; | |
901 | ||
902 | return 0; | |
903 | } | |
904 | ||
905 | static int vfio_fops_release(struct inode *inode, struct file *filep) | |
906 | { | |
907 | struct vfio_container *container = filep->private_data; | |
908 | ||
909 | filep->private_data = NULL; | |
910 | ||
911 | vfio_container_put(container); | |
912 | ||
913 | return 0; | |
914 | } | |
915 | ||
916 | /* | |
917 | * Once an iommu driver is set, we optionally pass read/write/mmap | |
918 | * on to the driver, allowing management interfaces beyond ioctl. | |
919 | */ | |
920 | static ssize_t vfio_fops_read(struct file *filep, char __user *buf, | |
921 | size_t count, loff_t *ppos) | |
922 | { | |
923 | struct vfio_container *container = filep->private_data; | |
0b43c082 AW |
924 | struct vfio_iommu_driver *driver; |
925 | ssize_t ret = -EINVAL; | |
cba3345c | 926 | |
0b43c082 AW |
927 | down_read(&container->group_lock); |
928 | ||
929 | driver = container->iommu_driver; | |
930 | if (likely(driver && driver->ops->read)) | |
931 | ret = driver->ops->read(container->iommu_data, | |
932 | buf, count, ppos); | |
cba3345c | 933 | |
0b43c082 AW |
934 | up_read(&container->group_lock); |
935 | ||
936 | return ret; | |
cba3345c AW |
937 | } |
938 | ||
939 | static ssize_t vfio_fops_write(struct file *filep, const char __user *buf, | |
940 | size_t count, loff_t *ppos) | |
941 | { | |
942 | struct vfio_container *container = filep->private_data; | |
0b43c082 AW |
943 | struct vfio_iommu_driver *driver; |
944 | ssize_t ret = -EINVAL; | |
cba3345c | 945 | |
0b43c082 AW |
946 | down_read(&container->group_lock); |
947 | ||
948 | driver = container->iommu_driver; | |
949 | if (likely(driver && driver->ops->write)) | |
950 | ret = driver->ops->write(container->iommu_data, | |
951 | buf, count, ppos); | |
952 | ||
953 | up_read(&container->group_lock); | |
cba3345c | 954 | |
0b43c082 | 955 | return ret; |
cba3345c AW |
956 | } |
957 | ||
958 | static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma) | |
959 | { | |
960 | struct vfio_container *container = filep->private_data; | |
0b43c082 AW |
961 | struct vfio_iommu_driver *driver; |
962 | int ret = -EINVAL; | |
cba3345c | 963 | |
0b43c082 | 964 | down_read(&container->group_lock); |
cba3345c | 965 | |
0b43c082 AW |
966 | driver = container->iommu_driver; |
967 | if (likely(driver && driver->ops->mmap)) | |
968 | ret = driver->ops->mmap(container->iommu_data, vma); | |
969 | ||
970 | up_read(&container->group_lock); | |
971 | ||
972 | return ret; | |
cba3345c AW |
973 | } |
974 | ||
975 | static const struct file_operations vfio_fops = { | |
976 | .owner = THIS_MODULE, | |
977 | .open = vfio_fops_open, | |
978 | .release = vfio_fops_release, | |
979 | .read = vfio_fops_read, | |
980 | .write = vfio_fops_write, | |
981 | .unlocked_ioctl = vfio_fops_unl_ioctl, | |
982 | #ifdef CONFIG_COMPAT | |
983 | .compat_ioctl = vfio_fops_compat_ioctl, | |
984 | #endif | |
985 | .mmap = vfio_fops_mmap, | |
986 | }; | |
987 | ||
988 | /** | |
989 | * VFIO Group fd, /dev/vfio/$GROUP | |
990 | */ | |
991 | static void __vfio_group_unset_container(struct vfio_group *group) | |
992 | { | |
993 | struct vfio_container *container = group->container; | |
994 | struct vfio_iommu_driver *driver; | |
995 | ||
9587f44a | 996 | down_write(&container->group_lock); |
cba3345c AW |
997 | |
998 | driver = container->iommu_driver; | |
999 | if (driver) | |
1000 | driver->ops->detach_group(container->iommu_data, | |
1001 | group->iommu_group); | |
1002 | ||
1003 | group->container = NULL; | |
1004 | list_del(&group->container_next); | |
1005 | ||
1006 | /* Detaching the last group deprivileges a container, remove iommu */ | |
1007 | if (driver && list_empty(&container->group_list)) { | |
1008 | driver->ops->release(container->iommu_data); | |
1009 | module_put(driver->ops->owner); | |
1010 | container->iommu_driver = NULL; | |
1011 | container->iommu_data = NULL; | |
1012 | } | |
1013 | ||
9587f44a | 1014 | up_write(&container->group_lock); |
cba3345c AW |
1015 | |
1016 | vfio_container_put(container); | |
1017 | } | |
1018 | ||
1019 | /* | |
1020 | * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or | |
1021 | * if there was no container to unset. Since the ioctl is called on | |
1022 | * the group, we know that still exists, therefore the only valid | |
1023 | * transition here is 1->0. | |
1024 | */ | |
1025 | static int vfio_group_unset_container(struct vfio_group *group) | |
1026 | { | |
1027 | int users = atomic_cmpxchg(&group->container_users, 1, 0); | |
1028 | ||
1029 | if (!users) | |
1030 | return -EINVAL; | |
1031 | if (users != 1) | |
1032 | return -EBUSY; | |
1033 | ||
1034 | __vfio_group_unset_container(group); | |
1035 | ||
1036 | return 0; | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * When removing container users, anything that removes the last user | |
1041 | * implicitly removes the group from the container. That is, if the | |
1042 | * group file descriptor is closed, as well as any device file descriptors, | |
1043 | * the group is free. | |
1044 | */ | |
1045 | static void vfio_group_try_dissolve_container(struct vfio_group *group) | |
1046 | { | |
1047 | if (0 == atomic_dec_if_positive(&group->container_users)) | |
1048 | __vfio_group_unset_container(group); | |
1049 | } | |
1050 | ||
1051 | static int vfio_group_set_container(struct vfio_group *group, int container_fd) | |
1052 | { | |
2903ff01 | 1053 | struct fd f; |
cba3345c AW |
1054 | struct vfio_container *container; |
1055 | struct vfio_iommu_driver *driver; | |
2903ff01 | 1056 | int ret = 0; |
cba3345c AW |
1057 | |
1058 | if (atomic_read(&group->container_users)) | |
1059 | return -EINVAL; | |
1060 | ||
2903ff01 AV |
1061 | f = fdget(container_fd); |
1062 | if (!f.file) | |
cba3345c AW |
1063 | return -EBADF; |
1064 | ||
1065 | /* Sanity check, is this really our fd? */ | |
2903ff01 AV |
1066 | if (f.file->f_op != &vfio_fops) { |
1067 | fdput(f); | |
cba3345c AW |
1068 | return -EINVAL; |
1069 | } | |
1070 | ||
2903ff01 | 1071 | container = f.file->private_data; |
cba3345c AW |
1072 | WARN_ON(!container); /* fget ensures we don't race vfio_release */ |
1073 | ||
9587f44a | 1074 | down_write(&container->group_lock); |
cba3345c AW |
1075 | |
1076 | driver = container->iommu_driver; | |
1077 | if (driver) { | |
1078 | ret = driver->ops->attach_group(container->iommu_data, | |
1079 | group->iommu_group); | |
1080 | if (ret) | |
1081 | goto unlock_out; | |
1082 | } | |
1083 | ||
1084 | group->container = container; | |
1085 | list_add(&group->container_next, &container->group_list); | |
1086 | ||
1087 | /* Get a reference on the container and mark a user within the group */ | |
1088 | vfio_container_get(container); | |
1089 | atomic_inc(&group->container_users); | |
1090 | ||
1091 | unlock_out: | |
9587f44a | 1092 | up_write(&container->group_lock); |
2903ff01 | 1093 | fdput(f); |
cba3345c AW |
1094 | return ret; |
1095 | } | |
1096 | ||
1097 | static bool vfio_group_viable(struct vfio_group *group) | |
1098 | { | |
1099 | return (iommu_group_for_each_dev(group->iommu_group, | |
1100 | group, vfio_dev_viable) == 0); | |
1101 | } | |
1102 | ||
1103 | static const struct file_operations vfio_device_fops; | |
1104 | ||
1105 | static int vfio_group_get_device_fd(struct vfio_group *group, char *buf) | |
1106 | { | |
1107 | struct vfio_device *device; | |
1108 | struct file *filep; | |
1109 | int ret = -ENODEV; | |
1110 | ||
1111 | if (0 == atomic_read(&group->container_users) || | |
1112 | !group->container->iommu_driver || !vfio_group_viable(group)) | |
1113 | return -EINVAL; | |
1114 | ||
1115 | mutex_lock(&group->device_lock); | |
1116 | list_for_each_entry(device, &group->device_list, group_next) { | |
1117 | if (strcmp(dev_name(device->dev), buf)) | |
1118 | continue; | |
1119 | ||
1120 | ret = device->ops->open(device->device_data); | |
1121 | if (ret) | |
1122 | break; | |
1123 | /* | |
1124 | * We can't use anon_inode_getfd() because we need to modify | |
1125 | * the f_mode flags directly to allow more than just ioctls | |
1126 | */ | |
1127 | ret = get_unused_fd(); | |
1128 | if (ret < 0) { | |
1129 | device->ops->release(device->device_data); | |
1130 | break; | |
1131 | } | |
1132 | ||
1133 | filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, | |
1134 | device, O_RDWR); | |
1135 | if (IS_ERR(filep)) { | |
1136 | put_unused_fd(ret); | |
1137 | ret = PTR_ERR(filep); | |
1138 | device->ops->release(device->device_data); | |
1139 | break; | |
1140 | } | |
1141 | ||
1142 | /* | |
1143 | * TODO: add an anon_inode interface to do this. | |
1144 | * Appears to be missing by lack of need rather than | |
1145 | * explicitly prevented. Now there's need. | |
1146 | */ | |
1147 | filep->f_mode |= (FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1148 | ||
cba3345c AW |
1149 | vfio_device_get(device); |
1150 | atomic_inc(&group->container_users); | |
31605deb AV |
1151 | |
1152 | fd_install(ret, filep); | |
cba3345c AW |
1153 | break; |
1154 | } | |
1155 | mutex_unlock(&group->device_lock); | |
1156 | ||
1157 | return ret; | |
1158 | } | |
1159 | ||
1160 | static long vfio_group_fops_unl_ioctl(struct file *filep, | |
1161 | unsigned int cmd, unsigned long arg) | |
1162 | { | |
1163 | struct vfio_group *group = filep->private_data; | |
1164 | long ret = -ENOTTY; | |
1165 | ||
1166 | switch (cmd) { | |
1167 | case VFIO_GROUP_GET_STATUS: | |
1168 | { | |
1169 | struct vfio_group_status status; | |
1170 | unsigned long minsz; | |
1171 | ||
1172 | minsz = offsetofend(struct vfio_group_status, flags); | |
1173 | ||
1174 | if (copy_from_user(&status, (void __user *)arg, minsz)) | |
1175 | return -EFAULT; | |
1176 | ||
1177 | if (status.argsz < minsz) | |
1178 | return -EINVAL; | |
1179 | ||
1180 | status.flags = 0; | |
1181 | ||
1182 | if (vfio_group_viable(group)) | |
1183 | status.flags |= VFIO_GROUP_FLAGS_VIABLE; | |
1184 | ||
1185 | if (group->container) | |
1186 | status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET; | |
1187 | ||
1188 | if (copy_to_user((void __user *)arg, &status, minsz)) | |
1189 | return -EFAULT; | |
1190 | ||
1191 | ret = 0; | |
1192 | break; | |
1193 | } | |
1194 | case VFIO_GROUP_SET_CONTAINER: | |
1195 | { | |
1196 | int fd; | |
1197 | ||
1198 | if (get_user(fd, (int __user *)arg)) | |
1199 | return -EFAULT; | |
1200 | ||
1201 | if (fd < 0) | |
1202 | return -EINVAL; | |
1203 | ||
1204 | ret = vfio_group_set_container(group, fd); | |
1205 | break; | |
1206 | } | |
1207 | case VFIO_GROUP_UNSET_CONTAINER: | |
1208 | ret = vfio_group_unset_container(group); | |
1209 | break; | |
1210 | case VFIO_GROUP_GET_DEVICE_FD: | |
1211 | { | |
1212 | char *buf; | |
1213 | ||
1214 | buf = strndup_user((const char __user *)arg, PAGE_SIZE); | |
1215 | if (IS_ERR(buf)) | |
1216 | return PTR_ERR(buf); | |
1217 | ||
1218 | ret = vfio_group_get_device_fd(group, buf); | |
1219 | kfree(buf); | |
1220 | break; | |
1221 | } | |
1222 | } | |
1223 | ||
1224 | return ret; | |
1225 | } | |
1226 | ||
1227 | #ifdef CONFIG_COMPAT | |
1228 | static long vfio_group_fops_compat_ioctl(struct file *filep, | |
1229 | unsigned int cmd, unsigned long arg) | |
1230 | { | |
1231 | arg = (unsigned long)compat_ptr(arg); | |
1232 | return vfio_group_fops_unl_ioctl(filep, cmd, arg); | |
1233 | } | |
1234 | #endif /* CONFIG_COMPAT */ | |
1235 | ||
1236 | static int vfio_group_fops_open(struct inode *inode, struct file *filep) | |
1237 | { | |
1238 | struct vfio_group *group; | |
1239 | ||
1240 | group = vfio_group_get_from_minor(iminor(inode)); | |
1241 | if (!group) | |
1242 | return -ENODEV; | |
1243 | ||
1244 | if (group->container) { | |
1245 | vfio_group_put(group); | |
1246 | return -EBUSY; | |
1247 | } | |
1248 | ||
1249 | filep->private_data = group; | |
1250 | ||
1251 | return 0; | |
1252 | } | |
1253 | ||
1254 | static int vfio_group_fops_release(struct inode *inode, struct file *filep) | |
1255 | { | |
1256 | struct vfio_group *group = filep->private_data; | |
1257 | ||
1258 | filep->private_data = NULL; | |
1259 | ||
1260 | vfio_group_try_dissolve_container(group); | |
1261 | ||
1262 | vfio_group_put(group); | |
1263 | ||
1264 | return 0; | |
1265 | } | |
1266 | ||
1267 | static const struct file_operations vfio_group_fops = { | |
1268 | .owner = THIS_MODULE, | |
1269 | .unlocked_ioctl = vfio_group_fops_unl_ioctl, | |
1270 | #ifdef CONFIG_COMPAT | |
1271 | .compat_ioctl = vfio_group_fops_compat_ioctl, | |
1272 | #endif | |
1273 | .open = vfio_group_fops_open, | |
1274 | .release = vfio_group_fops_release, | |
1275 | }; | |
1276 | ||
1277 | /** | |
1278 | * VFIO Device fd | |
1279 | */ | |
1280 | static int vfio_device_fops_release(struct inode *inode, struct file *filep) | |
1281 | { | |
1282 | struct vfio_device *device = filep->private_data; | |
1283 | ||
1284 | device->ops->release(device->device_data); | |
1285 | ||
1286 | vfio_group_try_dissolve_container(device->group); | |
1287 | ||
1288 | vfio_device_put(device); | |
1289 | ||
1290 | return 0; | |
1291 | } | |
1292 | ||
1293 | static long vfio_device_fops_unl_ioctl(struct file *filep, | |
1294 | unsigned int cmd, unsigned long arg) | |
1295 | { | |
1296 | struct vfio_device *device = filep->private_data; | |
1297 | ||
1298 | if (unlikely(!device->ops->ioctl)) | |
1299 | return -EINVAL; | |
1300 | ||
1301 | return device->ops->ioctl(device->device_data, cmd, arg); | |
1302 | } | |
1303 | ||
1304 | static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf, | |
1305 | size_t count, loff_t *ppos) | |
1306 | { | |
1307 | struct vfio_device *device = filep->private_data; | |
1308 | ||
1309 | if (unlikely(!device->ops->read)) | |
1310 | return -EINVAL; | |
1311 | ||
1312 | return device->ops->read(device->device_data, buf, count, ppos); | |
1313 | } | |
1314 | ||
1315 | static ssize_t vfio_device_fops_write(struct file *filep, | |
1316 | const char __user *buf, | |
1317 | size_t count, loff_t *ppos) | |
1318 | { | |
1319 | struct vfio_device *device = filep->private_data; | |
1320 | ||
1321 | if (unlikely(!device->ops->write)) | |
1322 | return -EINVAL; | |
1323 | ||
1324 | return device->ops->write(device->device_data, buf, count, ppos); | |
1325 | } | |
1326 | ||
1327 | static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) | |
1328 | { | |
1329 | struct vfio_device *device = filep->private_data; | |
1330 | ||
1331 | if (unlikely(!device->ops->mmap)) | |
1332 | return -EINVAL; | |
1333 | ||
1334 | return device->ops->mmap(device->device_data, vma); | |
1335 | } | |
1336 | ||
1337 | #ifdef CONFIG_COMPAT | |
1338 | static long vfio_device_fops_compat_ioctl(struct file *filep, | |
1339 | unsigned int cmd, unsigned long arg) | |
1340 | { | |
1341 | arg = (unsigned long)compat_ptr(arg); | |
1342 | return vfio_device_fops_unl_ioctl(filep, cmd, arg); | |
1343 | } | |
1344 | #endif /* CONFIG_COMPAT */ | |
1345 | ||
1346 | static const struct file_operations vfio_device_fops = { | |
1347 | .owner = THIS_MODULE, | |
1348 | .release = vfio_device_fops_release, | |
1349 | .read = vfio_device_fops_read, | |
1350 | .write = vfio_device_fops_write, | |
1351 | .unlocked_ioctl = vfio_device_fops_unl_ioctl, | |
1352 | #ifdef CONFIG_COMPAT | |
1353 | .compat_ioctl = vfio_device_fops_compat_ioctl, | |
1354 | #endif | |
1355 | .mmap = vfio_device_fops_mmap, | |
1356 | }; | |
1357 | ||
1358 | /** | |
1359 | * Module/class support | |
1360 | */ | |
1361 | static char *vfio_devnode(struct device *dev, umode_t *mode) | |
1362 | { | |
9a6aa279 | 1363 | if (mode && (MINOR(dev->devt) == 0)) |
664e9386 AW |
1364 | *mode = S_IRUGO | S_IWUGO; |
1365 | ||
cba3345c AW |
1366 | return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); |
1367 | } | |
1368 | ||
1369 | static int __init vfio_init(void) | |
1370 | { | |
1371 | int ret; | |
1372 | ||
1373 | idr_init(&vfio.group_idr); | |
1374 | mutex_init(&vfio.group_lock); | |
1375 | mutex_init(&vfio.iommu_drivers_lock); | |
1376 | INIT_LIST_HEAD(&vfio.group_list); | |
1377 | INIT_LIST_HEAD(&vfio.iommu_drivers_list); | |
1378 | init_waitqueue_head(&vfio.release_q); | |
1379 | ||
1380 | vfio.class = class_create(THIS_MODULE, "vfio"); | |
1381 | if (IS_ERR(vfio.class)) { | |
1382 | ret = PTR_ERR(vfio.class); | |
1383 | goto err_class; | |
1384 | } | |
1385 | ||
1386 | vfio.class->devnode = vfio_devnode; | |
1387 | ||
1388 | ret = alloc_chrdev_region(&vfio.devt, 0, MINORMASK, "vfio"); | |
1389 | if (ret) | |
1390 | goto err_base_chrdev; | |
1391 | ||
1392 | cdev_init(&vfio.cdev, &vfio_fops); | |
1393 | ret = cdev_add(&vfio.cdev, vfio.devt, 1); | |
1394 | if (ret) | |
1395 | goto err_base_cdev; | |
1396 | ||
1397 | vfio.dev = device_create(vfio.class, NULL, vfio.devt, NULL, "vfio"); | |
1398 | if (IS_ERR(vfio.dev)) { | |
1399 | ret = PTR_ERR(vfio.dev); | |
1400 | goto err_base_dev; | |
1401 | } | |
1402 | ||
1403 | /* /dev/vfio/$GROUP */ | |
1404 | cdev_init(&vfio.group_cdev, &vfio_group_fops); | |
1405 | ret = cdev_add(&vfio.group_cdev, | |
1406 | MKDEV(MAJOR(vfio.devt), 1), MINORMASK - 1); | |
1407 | if (ret) | |
1408 | goto err_groups_cdev; | |
1409 | ||
1410 | pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); | |
1411 | ||
73fa0d10 AW |
1412 | /* |
1413 | * Attempt to load known iommu-drivers. This gives us a working | |
1414 | * environment without the user needing to explicitly load iommu | |
1415 | * drivers. | |
1416 | */ | |
1417 | request_module_nowait("vfio_iommu_type1"); | |
1418 | ||
cba3345c AW |
1419 | return 0; |
1420 | ||
1421 | err_groups_cdev: | |
1422 | device_destroy(vfio.class, vfio.devt); | |
1423 | err_base_dev: | |
1424 | cdev_del(&vfio.cdev); | |
1425 | err_base_cdev: | |
1426 | unregister_chrdev_region(vfio.devt, MINORMASK); | |
1427 | err_base_chrdev: | |
1428 | class_destroy(vfio.class); | |
1429 | vfio.class = NULL; | |
1430 | err_class: | |
1431 | return ret; | |
1432 | } | |
1433 | ||
1434 | static void __exit vfio_cleanup(void) | |
1435 | { | |
1436 | WARN_ON(!list_empty(&vfio.group_list)); | |
1437 | ||
1438 | idr_destroy(&vfio.group_idr); | |
1439 | cdev_del(&vfio.group_cdev); | |
1440 | device_destroy(vfio.class, vfio.devt); | |
1441 | cdev_del(&vfio.cdev); | |
1442 | unregister_chrdev_region(vfio.devt, MINORMASK); | |
1443 | class_destroy(vfio.class); | |
1444 | vfio.class = NULL; | |
1445 | } | |
1446 | ||
1447 | module_init(vfio_init); | |
1448 | module_exit(vfio_cleanup); | |
1449 | ||
1450 | MODULE_VERSION(DRIVER_VERSION); | |
1451 | MODULE_LICENSE("GPL v2"); | |
1452 | MODULE_AUTHOR(DRIVER_AUTHOR); | |
1453 | MODULE_DESCRIPTION(DRIVER_DESC); |