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