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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * VFIO core
4 *
5 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
6 * Author: Alex Williamson <alex.williamson@redhat.com>
7 *
8 * Derived from original vfio:
9 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
10 * Author: Tom Lyon, pugs@cisco.com
11 */
12
13#include <linux/vfio.h>
14#include <linux/iommufd.h>
15#include <linux/anon_inodes.h>
16#include "vfio.h"
17
18static struct vfio {
19 struct class *class;
20 struct list_head group_list;
21 struct mutex group_lock; /* locks group_list */
22 struct ida group_ida;
23 dev_t group_devt;
24} vfio;
25
26static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
27 char *buf)
28{
29 struct vfio_device *it, *device = ERR_PTR(-ENODEV);
30
31 mutex_lock(&group->device_lock);
32 list_for_each_entry(it, &group->device_list, group_next) {
33 int ret;
34
35 if (it->ops->match) {
36 ret = it->ops->match(it, buf);
37 if (ret < 0) {
38 device = ERR_PTR(ret);
39 break;
40 }
41 } else {
42 ret = !strcmp(dev_name(it->dev), buf);
43 }
44
45 if (ret && vfio_device_try_get_registration(it)) {
46 device = it;
47 break;
48 }
49 }
50 mutex_unlock(&group->device_lock);
51
52 return device;
53}
54
55/*
56 * VFIO Group fd, /dev/vfio/$GROUP
57 */
58static bool vfio_group_has_iommu(struct vfio_group *group)
59{
60 lockdep_assert_held(&group->group_lock);
61 /*
62 * There can only be users if there is a container, and if there is a
63 * container there must be users.
64 */
65 WARN_ON(!group->container != !group->container_users);
66
67 return group->container || group->iommufd;
68}
69
70/*
71 * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
72 * if there was no container to unset. Since the ioctl is called on
73 * the group, we know that still exists, therefore the only valid
74 * transition here is 1->0.
75 */
76static int vfio_group_ioctl_unset_container(struct vfio_group *group)
77{
78 int ret = 0;
79
80 mutex_lock(&group->group_lock);
81 if (!vfio_group_has_iommu(group)) {
82 ret = -EINVAL;
83 goto out_unlock;
84 }
85 if (group->container) {
86 if (group->container_users != 1) {
87 ret = -EBUSY;
88 goto out_unlock;
89 }
90 vfio_group_detach_container(group);
91 }
92 if (group->iommufd) {
93 iommufd_ctx_put(group->iommufd);
94 group->iommufd = NULL;
95 }
96
97out_unlock:
98 mutex_unlock(&group->group_lock);
99 return ret;
100}
101
102static int vfio_group_ioctl_set_container(struct vfio_group *group,
103 int __user *arg)
104{
105 struct vfio_container *container;
106 struct iommufd_ctx *iommufd;
107 int ret;
108 int fd;
109
110 if (get_user(fd, arg))
111 return -EFAULT;
112
113 CLASS(fd, f)(fd);
114 if (fd_empty(f))
115 return -EBADF;
116
117 mutex_lock(&group->group_lock);
118 if (vfio_group_has_iommu(group)) {
119 ret = -EINVAL;
120 goto out_unlock;
121 }
122 if (!group->iommu_group) {
123 ret = -ENODEV;
124 goto out_unlock;
125 }
126
127 container = vfio_container_from_file(fd_file(f));
128 if (container) {
129 ret = vfio_container_attach_group(container, group);
130 goto out_unlock;
131 }
132
133 iommufd = iommufd_ctx_from_file(fd_file(f));
134 if (!IS_ERR(iommufd)) {
135 if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
136 group->type == VFIO_NO_IOMMU)
137 ret = iommufd_vfio_compat_set_no_iommu(iommufd);
138 else
139 ret = iommufd_vfio_compat_ioas_create(iommufd);
140
141 if (ret) {
142 iommufd_ctx_put(iommufd);
143 goto out_unlock;
144 }
145
146 group->iommufd = iommufd;
147 goto out_unlock;
148 }
149
150 /* The FD passed is not recognized. */
151 ret = -EBADFD;
152
153out_unlock:
154 mutex_unlock(&group->group_lock);
155 return ret;
156}
157
158static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
159{
160 spin_lock(&device->group->kvm_ref_lock);
161 vfio_device_get_kvm_safe(device, device->group->kvm);
162 spin_unlock(&device->group->kvm_ref_lock);
163}
164
165static int vfio_df_group_open(struct vfio_device_file *df)
166{
167 struct vfio_device *device = df->device;
168 int ret;
169
170 mutex_lock(&device->group->group_lock);
171 if (!vfio_group_has_iommu(device->group)) {
172 ret = -EINVAL;
173 goto out_unlock;
174 }
175
176 mutex_lock(&device->dev_set->lock);
177
178 /*
179 * Before the first device open, get the KVM pointer currently
180 * associated with the group (if there is one) and obtain a reference
181 * now that will be held until the open_count reaches 0 again. Save
182 * the pointer in the device for use by drivers.
183 */
184 if (device->open_count == 0)
185 vfio_device_group_get_kvm_safe(device);
186
187 df->iommufd = device->group->iommufd;
188 if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) {
189 /*
190 * Require no compat ioas to be assigned to proceed. The basic
191 * statement is that the user cannot have done something that
192 * implies they expected translation to exist
193 */
194 if (!capable(CAP_SYS_RAWIO) ||
195 vfio_iommufd_device_has_compat_ioas(device, df->iommufd))
196 ret = -EPERM;
197 else
198 ret = 0;
199 goto out_put_kvm;
200 }
201
202 ret = vfio_df_open(df);
203 if (ret)
204 goto out_put_kvm;
205
206 if (df->iommufd && device->open_count == 1) {
207 ret = vfio_iommufd_compat_attach_ioas(device, df->iommufd);
208 if (ret)
209 goto out_close_device;
210 }
211
212 /*
213 * Paired with smp_load_acquire() in vfio_device_fops::ioctl/
214 * read/write/mmap and vfio_file_has_device_access()
215 */
216 smp_store_release(&df->access_granted, true);
217
218 mutex_unlock(&device->dev_set->lock);
219 mutex_unlock(&device->group->group_lock);
220 return 0;
221
222out_close_device:
223 vfio_df_close(df);
224out_put_kvm:
225 df->iommufd = NULL;
226 if (device->open_count == 0)
227 vfio_device_put_kvm(device);
228 mutex_unlock(&device->dev_set->lock);
229out_unlock:
230 mutex_unlock(&device->group->group_lock);
231 return ret;
232}
233
234void vfio_df_group_close(struct vfio_device_file *df)
235{
236 struct vfio_device *device = df->device;
237
238 mutex_lock(&device->group->group_lock);
239 mutex_lock(&device->dev_set->lock);
240
241 vfio_df_close(df);
242 df->iommufd = NULL;
243
244 if (device->open_count == 0)
245 vfio_device_put_kvm(device);
246
247 mutex_unlock(&device->dev_set->lock);
248 mutex_unlock(&device->group->group_lock);
249}
250
251static struct file *vfio_device_open_file(struct vfio_device *device)
252{
253 struct vfio_device_file *df;
254 struct file *filep;
255 int ret;
256
257 df = vfio_allocate_device_file(device);
258 if (IS_ERR(df)) {
259 ret = PTR_ERR(df);
260 goto err_out;
261 }
262
263 df->group = device->group;
264
265 ret = vfio_df_group_open(df);
266 if (ret)
267 goto err_free;
268
269 /*
270 * We can't use anon_inode_getfd() because we need to modify
271 * the f_mode flags directly to allow more than just ioctls
272 */
273 filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
274 df, O_RDWR);
275 if (IS_ERR(filep)) {
276 ret = PTR_ERR(filep);
277 goto err_close_device;
278 }
279
280 /*
281 * TODO: add an anon_inode interface to do this.
282 * Appears to be missing by lack of need rather than
283 * explicitly prevented. Now there's need.
284 */
285 filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
286
287 /*
288 * Use the pseudo fs inode on the device to link all mmaps
289 * to the same address space, allowing us to unmap all vmas
290 * associated to this device using unmap_mapping_range().
291 */
292 filep->f_mapping = device->inode->i_mapping;
293
294 if (device->group->type == VFIO_NO_IOMMU)
295 dev_warn(device->dev, "vfio-noiommu device opened by user "
296 "(%s:%d)\n", current->comm, task_pid_nr(current));
297 /*
298 * On success the ref of device is moved to the file and
299 * put in vfio_device_fops_release()
300 */
301 return filep;
302
303err_close_device:
304 vfio_df_group_close(df);
305err_free:
306 kfree(df);
307err_out:
308 return ERR_PTR(ret);
309}
310
311static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
312 char __user *arg)
313{
314 struct vfio_device *device;
315 struct file *filep;
316 char *buf;
317 int fdno;
318 int ret;
319
320 buf = strndup_user(arg, PAGE_SIZE);
321 if (IS_ERR(buf))
322 return PTR_ERR(buf);
323
324 device = vfio_device_get_from_name(group, buf);
325 kfree(buf);
326 if (IS_ERR(device))
327 return PTR_ERR(device);
328
329 fdno = get_unused_fd_flags(O_CLOEXEC);
330 if (fdno < 0) {
331 ret = fdno;
332 goto err_put_device;
333 }
334
335 filep = vfio_device_open_file(device);
336 if (IS_ERR(filep)) {
337 ret = PTR_ERR(filep);
338 goto err_put_fdno;
339 }
340
341 fd_install(fdno, filep);
342 return fdno;
343
344err_put_fdno:
345 put_unused_fd(fdno);
346err_put_device:
347 vfio_device_put_registration(device);
348 return ret;
349}
350
351static int vfio_group_ioctl_get_status(struct vfio_group *group,
352 struct vfio_group_status __user *arg)
353{
354 unsigned long minsz = offsetofend(struct vfio_group_status, flags);
355 struct vfio_group_status status;
356
357 if (copy_from_user(&status, arg, minsz))
358 return -EFAULT;
359
360 if (status.argsz < minsz)
361 return -EINVAL;
362
363 status.flags = 0;
364
365 mutex_lock(&group->group_lock);
366 if (!group->iommu_group) {
367 mutex_unlock(&group->group_lock);
368 return -ENODEV;
369 }
370
371 /*
372 * With the container FD the iommu_group_claim_dma_owner() is done
373 * during SET_CONTAINER but for IOMMFD this is done during
374 * VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd
375 * VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due
376 * to viability.
377 */
378 if (vfio_group_has_iommu(group))
379 status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
380 VFIO_GROUP_FLAGS_VIABLE;
381 else if (!iommu_group_dma_owner_claimed(group->iommu_group))
382 status.flags |= VFIO_GROUP_FLAGS_VIABLE;
383 mutex_unlock(&group->group_lock);
384
385 if (copy_to_user(arg, &status, minsz))
386 return -EFAULT;
387 return 0;
388}
389
390static long vfio_group_fops_unl_ioctl(struct file *filep,
391 unsigned int cmd, unsigned long arg)
392{
393 struct vfio_group *group = filep->private_data;
394 void __user *uarg = (void __user *)arg;
395
396 switch (cmd) {
397 case VFIO_GROUP_GET_DEVICE_FD:
398 return vfio_group_ioctl_get_device_fd(group, uarg);
399 case VFIO_GROUP_GET_STATUS:
400 return vfio_group_ioctl_get_status(group, uarg);
401 case VFIO_GROUP_SET_CONTAINER:
402 return vfio_group_ioctl_set_container(group, uarg);
403 case VFIO_GROUP_UNSET_CONTAINER:
404 return vfio_group_ioctl_unset_container(group);
405 default:
406 return -ENOTTY;
407 }
408}
409
410int vfio_device_block_group(struct vfio_device *device)
411{
412 struct vfio_group *group = device->group;
413 int ret = 0;
414
415 mutex_lock(&group->group_lock);
416 if (group->opened_file) {
417 ret = -EBUSY;
418 goto out_unlock;
419 }
420
421 group->cdev_device_open_cnt++;
422
423out_unlock:
424 mutex_unlock(&group->group_lock);
425 return ret;
426}
427
428void vfio_device_unblock_group(struct vfio_device *device)
429{
430 struct vfio_group *group = device->group;
431
432 mutex_lock(&group->group_lock);
433 group->cdev_device_open_cnt--;
434 mutex_unlock(&group->group_lock);
435}
436
437static int vfio_group_fops_open(struct inode *inode, struct file *filep)
438{
439 struct vfio_group *group =
440 container_of(inode->i_cdev, struct vfio_group, cdev);
441 int ret;
442
443 mutex_lock(&group->group_lock);
444
445 /*
446 * drivers can be zero if this races with vfio_device_remove_group(), it
447 * will be stable at 0 under the group rwsem
448 */
449 if (refcount_read(&group->drivers) == 0) {
450 ret = -ENODEV;
451 goto out_unlock;
452 }
453
454 if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
455 ret = -EPERM;
456 goto out_unlock;
457 }
458
459 if (group->cdev_device_open_cnt) {
460 ret = -EBUSY;
461 goto out_unlock;
462 }
463
464 /*
465 * Do we need multiple instances of the group open? Seems not.
466 */
467 if (group->opened_file) {
468 ret = -EBUSY;
469 goto out_unlock;
470 }
471 group->opened_file = filep;
472 filep->private_data = group;
473 ret = 0;
474out_unlock:
475 mutex_unlock(&group->group_lock);
476 return ret;
477}
478
479static int vfio_group_fops_release(struct inode *inode, struct file *filep)
480{
481 struct vfio_group *group = filep->private_data;
482
483 filep->private_data = NULL;
484
485 mutex_lock(&group->group_lock);
486 /*
487 * Device FDs hold a group file reference, therefore the group release
488 * is only called when there are no open devices.
489 */
490 WARN_ON(group->notifier.head);
491 if (group->container)
492 vfio_group_detach_container(group);
493 if (group->iommufd) {
494 iommufd_ctx_put(group->iommufd);
495 group->iommufd = NULL;
496 }
497 group->opened_file = NULL;
498 mutex_unlock(&group->group_lock);
499 return 0;
500}
501
502static const struct file_operations vfio_group_fops = {
503 .owner = THIS_MODULE,
504 .unlocked_ioctl = vfio_group_fops_unl_ioctl,
505 .compat_ioctl = compat_ptr_ioctl,
506 .open = vfio_group_fops_open,
507 .release = vfio_group_fops_release,
508};
509
510/*
511 * Group objects - create, release, get, put, search
512 */
513static struct vfio_group *
514vfio_group_find_from_iommu(struct iommu_group *iommu_group)
515{
516 struct vfio_group *group;
517
518 lockdep_assert_held(&vfio.group_lock);
519
520 /*
521 * group->iommu_group from the vfio.group_list cannot be NULL
522 * under the vfio.group_lock.
523 */
524 list_for_each_entry(group, &vfio.group_list, vfio_next) {
525 if (group->iommu_group == iommu_group)
526 return group;
527 }
528 return NULL;
529}
530
531static void vfio_group_release(struct device *dev)
532{
533 struct vfio_group *group = container_of(dev, struct vfio_group, dev);
534
535 mutex_destroy(&group->device_lock);
536 mutex_destroy(&group->group_lock);
537 WARN_ON(group->iommu_group);
538 WARN_ON(group->cdev_device_open_cnt);
539 ida_free(&vfio.group_ida, MINOR(group->dev.devt));
540 kfree(group);
541}
542
543static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
544 enum vfio_group_type type)
545{
546 struct vfio_group *group;
547 int minor;
548
549 group = kzalloc(sizeof(*group), GFP_KERNEL);
550 if (!group)
551 return ERR_PTR(-ENOMEM);
552
553 minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
554 if (minor < 0) {
555 kfree(group);
556 return ERR_PTR(minor);
557 }
558
559 device_initialize(&group->dev);
560 group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
561 group->dev.class = vfio.class;
562 group->dev.release = vfio_group_release;
563 cdev_init(&group->cdev, &vfio_group_fops);
564 group->cdev.owner = THIS_MODULE;
565
566 refcount_set(&group->drivers, 1);
567 mutex_init(&group->group_lock);
568 spin_lock_init(&group->kvm_ref_lock);
569 INIT_LIST_HEAD(&group->device_list);
570 mutex_init(&group->device_lock);
571 group->iommu_group = iommu_group;
572 /* put in vfio_group_release() */
573 iommu_group_ref_get(iommu_group);
574 group->type = type;
575 BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
576
577 return group;
578}
579
580static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
581 enum vfio_group_type type)
582{
583 struct vfio_group *group;
584 struct vfio_group *ret;
585 int err;
586
587 lockdep_assert_held(&vfio.group_lock);
588
589 group = vfio_group_alloc(iommu_group, type);
590 if (IS_ERR(group))
591 return group;
592
593 err = dev_set_name(&group->dev, "%s%d",
594 group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
595 iommu_group_id(iommu_group));
596 if (err) {
597 ret = ERR_PTR(err);
598 goto err_put;
599 }
600
601 err = cdev_device_add(&group->cdev, &group->dev);
602 if (err) {
603 ret = ERR_PTR(err);
604 goto err_put;
605 }
606
607 list_add(&group->vfio_next, &vfio.group_list);
608
609 return group;
610
611err_put:
612 put_device(&group->dev);
613 return ret;
614}
615
616static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
617 enum vfio_group_type type)
618{
619 struct iommu_group *iommu_group;
620 struct vfio_group *group;
621 int ret;
622
623 iommu_group = iommu_group_alloc();
624 if (IS_ERR(iommu_group))
625 return ERR_CAST(iommu_group);
626
627 ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
628 if (ret)
629 goto out_put_group;
630 ret = iommu_group_add_device(iommu_group, dev);
631 if (ret)
632 goto out_put_group;
633
634 mutex_lock(&vfio.group_lock);
635 group = vfio_create_group(iommu_group, type);
636 mutex_unlock(&vfio.group_lock);
637 if (IS_ERR(group)) {
638 ret = PTR_ERR(group);
639 goto out_remove_device;
640 }
641 iommu_group_put(iommu_group);
642 return group;
643
644out_remove_device:
645 iommu_group_remove_device(dev);
646out_put_group:
647 iommu_group_put(iommu_group);
648 return ERR_PTR(ret);
649}
650
651static bool vfio_group_has_device(struct vfio_group *group, struct device *dev)
652{
653 struct vfio_device *device;
654
655 mutex_lock(&group->device_lock);
656 list_for_each_entry(device, &group->device_list, group_next) {
657 if (device->dev == dev) {
658 mutex_unlock(&group->device_lock);
659 return true;
660 }
661 }
662 mutex_unlock(&group->device_lock);
663 return false;
664}
665
666static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
667{
668 struct iommu_group *iommu_group;
669 struct vfio_group *group;
670
671 iommu_group = iommu_group_get(dev);
672 if (!iommu_group && vfio_noiommu) {
673 /*
674 * With noiommu enabled, create an IOMMU group for devices that
675 * don't already have one, implying no IOMMU hardware/driver
676 * exists. Taint the kernel because we're about to give a DMA
677 * capable device to a user without IOMMU protection.
678 */
679 group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
680 if (!IS_ERR(group)) {
681 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
682 dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
683 }
684 return group;
685 }
686
687 if (!iommu_group)
688 return ERR_PTR(-EINVAL);
689
690 mutex_lock(&vfio.group_lock);
691 group = vfio_group_find_from_iommu(iommu_group);
692 if (group) {
693 if (WARN_ON(vfio_group_has_device(group, dev)))
694 group = ERR_PTR(-EINVAL);
695 else
696 refcount_inc(&group->drivers);
697 } else {
698 group = vfio_create_group(iommu_group, VFIO_IOMMU);
699 }
700 mutex_unlock(&vfio.group_lock);
701
702 /* The vfio_group holds a reference to the iommu_group */
703 iommu_group_put(iommu_group);
704 return group;
705}
706
707int vfio_device_set_group(struct vfio_device *device,
708 enum vfio_group_type type)
709{
710 struct vfio_group *group;
711
712 if (type == VFIO_IOMMU)
713 group = vfio_group_find_or_alloc(device->dev);
714 else
715 group = vfio_noiommu_group_alloc(device->dev, type);
716
717 if (IS_ERR(group))
718 return PTR_ERR(group);
719
720 /* Our reference on group is moved to the device */
721 device->group = group;
722 return 0;
723}
724
725void vfio_device_remove_group(struct vfio_device *device)
726{
727 struct vfio_group *group = device->group;
728 struct iommu_group *iommu_group;
729
730 if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
731 iommu_group_remove_device(device->dev);
732
733 /* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
734 if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
735 return;
736 list_del(&group->vfio_next);
737
738 /*
739 * We could concurrently probe another driver in the group that might
740 * race vfio_device_remove_group() with vfio_get_group(), so we have to
741 * ensure that the sysfs is all cleaned up under lock otherwise the
742 * cdev_device_add() will fail due to the name aready existing.
743 */
744 cdev_device_del(&group->cdev, &group->dev);
745
746 mutex_lock(&group->group_lock);
747 /*
748 * These data structures all have paired operations that can only be
749 * undone when the caller holds a live reference on the device. Since
750 * all pairs must be undone these WARN_ON's indicate some caller did not
751 * properly hold the group reference.
752 */
753 WARN_ON(!list_empty(&group->device_list));
754 WARN_ON(group->notifier.head);
755
756 /*
757 * Revoke all users of group->iommu_group. At this point we know there
758 * are no devices active because we are unplugging the last one. Setting
759 * iommu_group to NULL blocks all new users.
760 */
761 if (group->container)
762 vfio_group_detach_container(group);
763 iommu_group = group->iommu_group;
764 group->iommu_group = NULL;
765 mutex_unlock(&group->group_lock);
766 mutex_unlock(&vfio.group_lock);
767
768 iommu_group_put(iommu_group);
769 put_device(&group->dev);
770}
771
772void vfio_device_group_register(struct vfio_device *device)
773{
774 mutex_lock(&device->group->device_lock);
775 list_add(&device->group_next, &device->group->device_list);
776 mutex_unlock(&device->group->device_lock);
777}
778
779void vfio_device_group_unregister(struct vfio_device *device)
780{
781 mutex_lock(&device->group->device_lock);
782 list_del(&device->group_next);
783 mutex_unlock(&device->group->device_lock);
784}
785
786int vfio_device_group_use_iommu(struct vfio_device *device)
787{
788 struct vfio_group *group = device->group;
789 int ret = 0;
790
791 lockdep_assert_held(&group->group_lock);
792
793 if (WARN_ON(!group->container))
794 return -EINVAL;
795
796 ret = vfio_group_use_container(group);
797 if (ret)
798 return ret;
799 vfio_device_container_register(device);
800 return 0;
801}
802
803void vfio_device_group_unuse_iommu(struct vfio_device *device)
804{
805 struct vfio_group *group = device->group;
806
807 lockdep_assert_held(&group->group_lock);
808
809 if (WARN_ON(!group->container))
810 return;
811
812 vfio_device_container_unregister(device);
813 vfio_group_unuse_container(group);
814}
815
816bool vfio_device_has_container(struct vfio_device *device)
817{
818 return device->group->container;
819}
820
821struct vfio_group *vfio_group_from_file(struct file *file)
822{
823 struct vfio_group *group = file->private_data;
824
825 if (file->f_op != &vfio_group_fops)
826 return NULL;
827 return group;
828}
829
830/**
831 * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
832 * @file: VFIO group file
833 *
834 * The returned iommu_group is valid as long as a ref is held on the file. This
835 * returns a reference on the group. This function is deprecated, only the SPAPR
836 * path in kvm should call it.
837 */
838struct iommu_group *vfio_file_iommu_group(struct file *file)
839{
840 struct vfio_group *group = vfio_group_from_file(file);
841 struct iommu_group *iommu_group = NULL;
842
843 if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
844 return NULL;
845
846 if (!group)
847 return NULL;
848
849 mutex_lock(&group->group_lock);
850 if (group->iommu_group) {
851 iommu_group = group->iommu_group;
852 iommu_group_ref_get(iommu_group);
853 }
854 mutex_unlock(&group->group_lock);
855 return iommu_group;
856}
857EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
858
859/**
860 * vfio_file_is_group - True if the file is a vfio group file
861 * @file: VFIO group file
862 */
863bool vfio_file_is_group(struct file *file)
864{
865 return vfio_group_from_file(file);
866}
867EXPORT_SYMBOL_GPL(vfio_file_is_group);
868
869bool vfio_group_enforced_coherent(struct vfio_group *group)
870{
871 struct vfio_device *device;
872 bool ret = true;
873
874 /*
875 * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
876 * any domain later attached to it will also not support it. If the cap
877 * is set then the iommu_domain eventually attached to the device/group
878 * must use a domain with enforce_cache_coherency().
879 */
880 mutex_lock(&group->device_lock);
881 list_for_each_entry(device, &group->device_list, group_next) {
882 if (!device_iommu_capable(device->dev,
883 IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) {
884 ret = false;
885 break;
886 }
887 }
888 mutex_unlock(&group->device_lock);
889 return ret;
890}
891
892void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
893{
894 spin_lock(&group->kvm_ref_lock);
895 group->kvm = kvm;
896 spin_unlock(&group->kvm_ref_lock);
897}
898
899/**
900 * vfio_file_has_dev - True if the VFIO file is a handle for device
901 * @file: VFIO file to check
902 * @device: Device that must be part of the file
903 *
904 * Returns true if given file has permission to manipulate the given device.
905 */
906bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
907{
908 struct vfio_group *group = vfio_group_from_file(file);
909
910 if (!group)
911 return false;
912
913 return group == device->group;
914}
915EXPORT_SYMBOL_GPL(vfio_file_has_dev);
916
917static char *vfio_devnode(const struct device *dev, umode_t *mode)
918{
919 return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
920}
921
922int __init vfio_group_init(void)
923{
924 int ret;
925
926 ida_init(&vfio.group_ida);
927 mutex_init(&vfio.group_lock);
928 INIT_LIST_HEAD(&vfio.group_list);
929
930 ret = vfio_container_init();
931 if (ret)
932 return ret;
933
934 /* /dev/vfio/$GROUP */
935 vfio.class = class_create("vfio");
936 if (IS_ERR(vfio.class)) {
937 ret = PTR_ERR(vfio.class);
938 goto err_group_class;
939 }
940
941 vfio.class->devnode = vfio_devnode;
942
943 ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
944 if (ret)
945 goto err_alloc_chrdev;
946 return 0;
947
948err_alloc_chrdev:
949 class_destroy(vfio.class);
950 vfio.class = NULL;
951err_group_class:
952 vfio_container_cleanup();
953 return ret;
954}
955
956void vfio_group_cleanup(void)
957{
958 WARN_ON(!list_empty(&vfio.group_list));
959 ida_destroy(&vfio.group_ida);
960 unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
961 class_destroy(vfio.class);
962 vfio.class = NULL;
963 vfio_container_cleanup();
964}