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Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux.git] / drivers / vfio / vfio_main.c
blob1fd261efc582d0d95067ef3034f3611cf3c40eea
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/cdev.h>
14 #include <linux/compat.h>
15 #include <linux/device.h>
16 #include <linux/fs.h>
17 #include <linux/idr.h>
18 #include <linux/iommu.h>
19 #if IS_ENABLED(CONFIG_KVM)
20 #include <linux/kvm_host.h>
21 #endif
22 #include <linux/list.h>
23 #include <linux/miscdevice.h>
24 #include <linux/module.h>
25 #include <linux/mount.h>
26 #include <linux/mutex.h>
27 #include <linux/pci.h>
28 #include <linux/pseudo_fs.h>
29 #include <linux/rwsem.h>
30 #include <linux/sched.h>
31 #include <linux/slab.h>
32 #include <linux/stat.h>
33 #include <linux/string.h>
34 #include <linux/uaccess.h>
35 #include <linux/vfio.h>
36 #include <linux/wait.h>
37 #include <linux/sched/signal.h>
38 #include <linux/pm_runtime.h>
39 #include <linux/interval_tree.h>
40 #include <linux/iova_bitmap.h>
41 #include <linux/iommufd.h>
42 #include "vfio.h"
43
44 #define DRIVER_VERSION "0.3"
45 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
46 #define DRIVER_DESC "VFIO - User Level meta-driver"
47
48 #define VFIO_MAGIC 0x5646494f /* "VFIO" */
49
50 static struct vfio {
51 struct class *device_class;
52 struct ida device_ida;
53 struct vfsmount *vfs_mount;
54 int fs_count;
55 } vfio;
56
57 #ifdef CONFIG_VFIO_NOIOMMU
58 bool vfio_noiommu __read_mostly;
59 module_param_named(enable_unsafe_noiommu_mode,
60 vfio_noiommu, bool, S_IRUGO | S_IWUSR);
61 MODULE_PARM_DESC(enable_unsafe_noiommu_mode, "Enable UNSAFE, no-IOMMU mode. This mode provides no device isolation, no DMA translation, no host kernel protection, cannot be used for device assignment to virtual machines, requires RAWIO permissions, and will taint the kernel. If you do not know what this is for, step away. (default: false)");
62 #endif
63
64 static DEFINE_XARRAY(vfio_device_set_xa);
65
66 int vfio_assign_device_set(struct vfio_device *device, void *set_id)
67 {
68 unsigned long idx = (unsigned long)set_id;
69 struct vfio_device_set *new_dev_set;
70 struct vfio_device_set *dev_set;
71
72 if (WARN_ON(!set_id))
73 return -EINVAL;
74
75 /*
76 * Atomically acquire a singleton object in the xarray for this set_id
77 */
78 xa_lock(&vfio_device_set_xa);
79 dev_set = xa_load(&vfio_device_set_xa, idx);
80 if (dev_set)
81 goto found_get_ref;
82 xa_unlock(&vfio_device_set_xa);
83
84 new_dev_set = kzalloc(sizeof(*new_dev_set), GFP_KERNEL);
85 if (!new_dev_set)
86 return -ENOMEM;
87 mutex_init(&new_dev_set->lock);
88 INIT_LIST_HEAD(&new_dev_set->device_list);
89 new_dev_set->set_id = set_id;
90
91 xa_lock(&vfio_device_set_xa);
92 dev_set = __xa_cmpxchg(&vfio_device_set_xa, idx, NULL, new_dev_set,
93 GFP_KERNEL);
94 if (!dev_set) {
95 dev_set = new_dev_set;
96 goto found_get_ref;
97 }
98
99 kfree(new_dev_set);
100 if (xa_is_err(dev_set)) {
101 xa_unlock(&vfio_device_set_xa);
102 return xa_err(dev_set);
103 }
104
105 found_get_ref:
106 dev_set->device_count++;
107 xa_unlock(&vfio_device_set_xa);
108 mutex_lock(&dev_set->lock);
109 device->dev_set = dev_set;
110 list_add_tail(&device->dev_set_list, &dev_set->device_list);
111 mutex_unlock(&dev_set->lock);
112 return 0;
113 }
114 EXPORT_SYMBOL_GPL(vfio_assign_device_set);
115
116 static void vfio_release_device_set(struct vfio_device *device)
117 {
118 struct vfio_device_set *dev_set = device->dev_set;
119
120 if (!dev_set)
121 return;
122
123 mutex_lock(&dev_set->lock);
124 list_del(&device->dev_set_list);
125 mutex_unlock(&dev_set->lock);
126
127 xa_lock(&vfio_device_set_xa);
128 if (!--dev_set->device_count) {
129 __xa_erase(&vfio_device_set_xa,
130 (unsigned long)dev_set->set_id);
131 mutex_destroy(&dev_set->lock);
132 kfree(dev_set);
133 }
134 xa_unlock(&vfio_device_set_xa);
135 }
136
137 unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
138 {
139 struct vfio_device *cur;
140 unsigned int open_count = 0;
141
142 lockdep_assert_held(&dev_set->lock);
143
144 list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
145 open_count += cur->open_count;
146 return open_count;
147 }
148 EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
149
150 struct vfio_device *
151 vfio_find_device_in_devset(struct vfio_device_set *dev_set,
152 struct device *dev)
153 {
154 struct vfio_device *cur;
155
156 lockdep_assert_held(&dev_set->lock);
157
158 list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
159 if (cur->dev == dev)
160 return cur;
161 return NULL;
162 }
163 EXPORT_SYMBOL_GPL(vfio_find_device_in_devset);
164
165 /*
166 * Device objects - create, release, get, put, search
167 */
168 /* Device reference always implies a group reference */
169 void vfio_device_put_registration(struct vfio_device *device)
170 {
171 if (refcount_dec_and_test(&device->refcount))
172 complete(&device->comp);
173 }
174
175 bool vfio_device_try_get_registration(struct vfio_device *device)
176 {
177 return refcount_inc_not_zero(&device->refcount);
178 }
179
180 /*
181 * VFIO driver API
182 */
183 /* Release helper called by vfio_put_device() */
184 static void vfio_device_release(struct device *dev)
185 {
186 struct vfio_device *device =
187 container_of(dev, struct vfio_device, device);
188
189 vfio_release_device_set(device);
190 ida_free(&vfio.device_ida, device->index);
191
192 if (device->ops->release)
193 device->ops->release(device);
194
195 iput(device->inode);
196 simple_release_fs(&vfio.vfs_mount, &vfio.fs_count);
197 kvfree(device);
198 }
199
200 static int vfio_init_device(struct vfio_device *device, struct device *dev,
201 const struct vfio_device_ops *ops);
202
203 /*
204 * Allocate and initialize vfio_device so it can be registered to vfio
205 * core.
206 *
207 * Drivers should use the wrapper vfio_alloc_device() for allocation.
208 * @size is the size of the structure to be allocated, including any
209 * private data used by the driver.
210 *
211 * Driver may provide an @init callback to cover device private data.
212 *
213 * Use vfio_put_device() to release the structure after success return.
214 */
215 struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
216 const struct vfio_device_ops *ops)
217 {
218 struct vfio_device *device;
219 int ret;
220
221 if (WARN_ON(size < sizeof(struct vfio_device)))
222 return ERR_PTR(-EINVAL);
223
224 device = kvzalloc(size, GFP_KERNEL);
225 if (!device)
226 return ERR_PTR(-ENOMEM);
227
228 ret = vfio_init_device(device, dev, ops);
229 if (ret)
230 goto out_free;
231 return device;
232
233 out_free:
234 kvfree(device);
235 return ERR_PTR(ret);
236 }
237 EXPORT_SYMBOL_GPL(_vfio_alloc_device);
238
239 static int vfio_fs_init_fs_context(struct fs_context *fc)
240 {
241 return init_pseudo(fc, VFIO_MAGIC) ? 0 : -ENOMEM;
242 }
243
244 static struct file_system_type vfio_fs_type = {
245 .name = "vfio",
246 .owner = THIS_MODULE,
247 .init_fs_context = vfio_fs_init_fs_context,
248 .kill_sb = kill_anon_super,
249 };
250
251 static struct inode *vfio_fs_inode_new(void)
252 {
253 struct inode *inode;
254 int ret;
255
256 ret = simple_pin_fs(&vfio_fs_type, &vfio.vfs_mount, &vfio.fs_count);
257 if (ret)
258 return ERR_PTR(ret);
259
260 inode = alloc_anon_inode(vfio.vfs_mount->mnt_sb);
261 if (IS_ERR(inode))
262 simple_release_fs(&vfio.vfs_mount, &vfio.fs_count);
263
264 return inode;
265 }
266
267 /*
268 * Initialize a vfio_device so it can be registered to vfio core.
269 */
270 static int vfio_init_device(struct vfio_device *device, struct device *dev,
271 const struct vfio_device_ops *ops)
272 {
273 int ret;
274
275 ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
276 if (ret < 0) {
277 dev_dbg(dev, "Error to alloc index\n");
278 return ret;
279 }
280
281 device->index = ret;
282 init_completion(&device->comp);
283 device->dev = dev;
284 device->ops = ops;
285 device->inode = vfio_fs_inode_new();
286 if (IS_ERR(device->inode)) {
287 ret = PTR_ERR(device->inode);
288 goto out_inode;
289 }
290
291 if (ops->init) {
292 ret = ops->init(device);
293 if (ret)
294 goto out_uninit;
295 }
296
297 device_initialize(&device->device);
298 device->device.release = vfio_device_release;
299 device->device.class = vfio.device_class;
300 device->device.parent = device->dev;
301 return 0;
302
303 out_uninit:
304 iput(device->inode);
305 simple_release_fs(&vfio.vfs_mount, &vfio.fs_count);
306 out_inode:
307 vfio_release_device_set(device);
308 ida_free(&vfio.device_ida, device->index);
309 return ret;
310 }
311
312 static int __vfio_register_dev(struct vfio_device *device,
313 enum vfio_group_type type)
314 {
315 int ret;
316
317 if (WARN_ON(IS_ENABLED(CONFIG_IOMMUFD) &&
318 (!device->ops->bind_iommufd ||
319 !device->ops->unbind_iommufd ||
320 !device->ops->attach_ioas ||
321 !device->ops->detach_ioas)))
322 return -EINVAL;
323
324 /*
325 * If the driver doesn't specify a set then the device is added to a
326 * singleton set just for itself.
327 */
328 if (!device->dev_set)
329 vfio_assign_device_set(device, device);
330
331 ret = dev_set_name(&device->device, "vfio%d", device->index);
332 if (ret)
333 return ret;
334
335 ret = vfio_device_set_group(device, type);
336 if (ret)
337 return ret;
338
339 /*
340 * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
341 * restore cache coherency. It has to be checked here because it is only
342 * valid for cases where we are using iommu groups.
343 */
344 if (type == VFIO_IOMMU && !vfio_device_is_noiommu(device) &&
345 !device_iommu_capable(device->dev, IOMMU_CAP_CACHE_COHERENCY)) {
346 ret = -EINVAL;
347 goto err_out;
348 }
349
350 ret = vfio_device_add(device);
351 if (ret)
352 goto err_out;
353
354 /* Refcounting can't start until the driver calls register */
355 refcount_set(&device->refcount, 1);
356
357 vfio_device_group_register(device);
358 vfio_device_debugfs_init(device);
359
360 return 0;
361 err_out:
362 vfio_device_remove_group(device);
363 return ret;
364 }
365
366 int vfio_register_group_dev(struct vfio_device *device)
367 {
368 return __vfio_register_dev(device, VFIO_IOMMU);
369 }
370 EXPORT_SYMBOL_GPL(vfio_register_group_dev);
371
372 /*
373 * Register a virtual device without IOMMU backing. The user of this
374 * device must not be able to directly trigger unmediated DMA.
375 */
376 int vfio_register_emulated_iommu_dev(struct vfio_device *device)
377 {
378 return __vfio_register_dev(device, VFIO_EMULATED_IOMMU);
379 }
380 EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
381
382 /*
383 * Decrement the device reference count and wait for the device to be
384 * removed. Open file descriptors for the device... */
385 void vfio_unregister_group_dev(struct vfio_device *device)
386 {
387 unsigned int i = 0;
388 bool interrupted = false;
389 long rc;
390
391 /*
392 * Prevent new device opened by userspace via the
393 * VFIO_GROUP_GET_DEVICE_FD in the group path.
394 */
395 vfio_device_group_unregister(device);
396
397 /*
398 * Balances vfio_device_add() in register path, also prevents
399 * new device opened by userspace in the cdev path.
400 */
401 vfio_device_del(device);
402
403 vfio_device_put_registration(device);
404 rc = try_wait_for_completion(&device->comp);
405 while (rc <= 0) {
406 if (device->ops->request)
407 device->ops->request(device, i++);
408
409 if (interrupted) {
410 rc = wait_for_completion_timeout(&device->comp,
411 HZ * 10);
412 } else {
413 rc = wait_for_completion_interruptible_timeout(
414 &device->comp, HZ * 10);
415 if (rc < 0) {
416 interrupted = true;
417 dev_warn(device->dev,
418 "Device is currently in use, task"
419 " \"%s\" (%d) "
420 "blocked until device is released",
421 current->comm, task_pid_nr(current));
422 }
423 }
424 }
425
426 vfio_device_debugfs_exit(device);
427 /* Balances vfio_device_set_group in register path */
428 vfio_device_remove_group(device);
429 }
430 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
431
432 #if IS_ENABLED(CONFIG_KVM)
433 void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
434 {
435 void (*pfn)(struct kvm *kvm);
436 bool (*fn)(struct kvm *kvm);
437 bool ret;
438
439 lockdep_assert_held(&device->dev_set->lock);
440
441 if (!kvm)
442 return;
443
444 pfn = symbol_get(kvm_put_kvm);
445 if (WARN_ON(!pfn))
446 return;
447
448 fn = symbol_get(kvm_get_kvm_safe);
449 if (WARN_ON(!fn)) {
450 symbol_put(kvm_put_kvm);
451 return;
452 }
453
454 ret = fn(kvm);
455 symbol_put(kvm_get_kvm_safe);
456 if (!ret) {
457 symbol_put(kvm_put_kvm);
458 return;
459 }
460
461 device->put_kvm = pfn;
462 device->kvm = kvm;
463 }
464
465 void vfio_device_put_kvm(struct vfio_device *device)
466 {
467 lockdep_assert_held(&device->dev_set->lock);
468
469 if (!device->kvm)
470 return;
471
472 if (WARN_ON(!device->put_kvm))
473 goto clear;
474
475 device->put_kvm(device->kvm);
476 device->put_kvm = NULL;
477 symbol_put(kvm_put_kvm);
478
479 clear:
480 device->kvm = NULL;
481 }
482 #endif
483
484 /* true if the vfio_device has open_device() called but not close_device() */
485 static bool vfio_assert_device_open(struct vfio_device *device)
486 {
487 return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
488 }
489
490 struct vfio_device_file *
491 vfio_allocate_device_file(struct vfio_device *device)
492 {
493 struct vfio_device_file *df;
494
495 df = kzalloc(sizeof(*df), GFP_KERNEL_ACCOUNT);
496 if (!df)
497 return ERR_PTR(-ENOMEM);
498
499 df->device = device;
500 spin_lock_init(&df->kvm_ref_lock);
501
502 return df;
503 }
504
505 static int vfio_df_device_first_open(struct vfio_device_file *df)
506 {
507 struct vfio_device *device = df->device;
508 struct iommufd_ctx *iommufd = df->iommufd;
509 int ret;
510
511 lockdep_assert_held(&device->dev_set->lock);
512
513 if (!try_module_get(device->dev->driver->owner))
514 return -ENODEV;
515
516 if (iommufd)
517 ret = vfio_df_iommufd_bind(df);
518 else
519 ret = vfio_device_group_use_iommu(device);
520 if (ret)
521 goto err_module_put;
522
523 if (device->ops->open_device) {
524 ret = device->ops->open_device(device);
525 if (ret)
526 goto err_unuse_iommu;
527 }
528 return 0;
529
530 err_unuse_iommu:
531 if (iommufd)
532 vfio_df_iommufd_unbind(df);
533 else
534 vfio_device_group_unuse_iommu(device);
535 err_module_put:
536 module_put(device->dev->driver->owner);
537 return ret;
538 }
539
540 static void vfio_df_device_last_close(struct vfio_device_file *df)
541 {
542 struct vfio_device *device = df->device;
543 struct iommufd_ctx *iommufd = df->iommufd;
544
545 lockdep_assert_held(&device->dev_set->lock);
546
547 if (device->ops->close_device)
548 device->ops->close_device(device);
549 if (iommufd)
550 vfio_df_iommufd_unbind(df);
551 else
552 vfio_device_group_unuse_iommu(device);
553 module_put(device->dev->driver->owner);
554 }
555
556 int vfio_df_open(struct vfio_device_file *df)
557 {
558 struct vfio_device *device = df->device;
559 int ret = 0;
560
561 lockdep_assert_held(&device->dev_set->lock);
562
563 /*
564 * Only the group path allows the device to be opened multiple
565 * times. The device cdev path doesn't have a secure way for it.
566 */
567 if (device->open_count != 0 && !df->group)
568 return -EINVAL;
569
570 device->open_count++;
571 if (device->open_count == 1) {
572 ret = vfio_df_device_first_open(df);
573 if (ret)
574 device->open_count--;
575 }
576
577 return ret;
578 }
579
580 void vfio_df_close(struct vfio_device_file *df)
581 {
582 struct vfio_device *device = df->device;
583
584 lockdep_assert_held(&device->dev_set->lock);
585
586 vfio_assert_device_open(device);
587 if (device->open_count == 1)
588 vfio_df_device_last_close(df);
589 device->open_count--;
590 }
591
592 /*
593 * Wrapper around pm_runtime_resume_and_get().
594 * Return error code on failure or 0 on success.
595 */
596 static inline int vfio_device_pm_runtime_get(struct vfio_device *device)
597 {
598 struct device *dev = device->dev;
599
600 if (dev->driver && dev->driver->pm) {
601 int ret;
602
603 ret = pm_runtime_resume_and_get(dev);
604 if (ret) {
605 dev_info_ratelimited(dev,
606 "vfio: runtime resume failed %d\n", ret);
607 return -EIO;
608 }
609 }
610
611 return 0;
612 }
613
614 /*
615 * Wrapper around pm_runtime_put().
616 */
617 static inline void vfio_device_pm_runtime_put(struct vfio_device *device)
618 {
619 struct device *dev = device->dev;
620
621 if (dev->driver && dev->driver->pm)
622 pm_runtime_put(dev);
623 }
624
625 /*
626 * VFIO Device fd
627 */
628 static int vfio_device_fops_release(struct inode *inode, struct file *filep)
629 {
630 struct vfio_device_file *df = filep->private_data;
631 struct vfio_device *device = df->device;
632
633 if (df->group)
634 vfio_df_group_close(df);
635 else
636 vfio_df_unbind_iommufd(df);
637
638 vfio_device_put_registration(device);
639
640 kfree(df);
641
642 return 0;
643 }
644
645 /*
646 * vfio_mig_get_next_state - Compute the next step in the FSM
647 * @cur_fsm - The current state the device is in
648 * @new_fsm - The target state to reach
649 * @next_fsm - Pointer to the next step to get to new_fsm
650 *
651 * Return 0 upon success, otherwise -errno
652 * Upon success the next step in the state progression between cur_fsm and
653 * new_fsm will be set in next_fsm.
654 *
655 * This breaks down requests for combination transitions into smaller steps and
656 * returns the next step to get to new_fsm. The function may need to be called
657 * multiple times before reaching new_fsm.
658 *
659 */
660 int vfio_mig_get_next_state(struct vfio_device *device,
661 enum vfio_device_mig_state cur_fsm,
662 enum vfio_device_mig_state new_fsm,
663 enum vfio_device_mig_state *next_fsm)
664 {
665 enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_PRE_COPY_P2P + 1 };
666 /*
667 * The coding in this table requires the driver to implement the
668 * following FSM arcs:
669 * RESUMING -> STOP
670 * STOP -> RESUMING
671 * STOP -> STOP_COPY
672 * STOP_COPY -> STOP
673 *
674 * If P2P is supported then the driver must also implement these FSM
675 * arcs:
676 * RUNNING -> RUNNING_P2P
677 * RUNNING_P2P -> RUNNING
678 * RUNNING_P2P -> STOP
679 * STOP -> RUNNING_P2P
680 *
681 * If precopy is supported then the driver must support these additional
682 * FSM arcs:
683 * RUNNING -> PRE_COPY
684 * PRE_COPY -> RUNNING
685 * PRE_COPY -> STOP_COPY
686 * However, if precopy and P2P are supported together then the driver
687 * must support these additional arcs beyond the P2P arcs above:
688 * PRE_COPY -> RUNNING
689 * PRE_COPY -> PRE_COPY_P2P
690 * PRE_COPY_P2P -> PRE_COPY
691 * PRE_COPY_P2P -> RUNNING_P2P
692 * PRE_COPY_P2P -> STOP_COPY
693 * RUNNING -> PRE_COPY
694 * RUNNING_P2P -> PRE_COPY_P2P
695 *
696 * Without P2P and precopy the driver must implement:
697 * RUNNING -> STOP
698 * STOP -> RUNNING
699 *
700 * The coding will step through multiple states for some combination
701 * transitions; if all optional features are supported, this means the
702 * following ones:
703 * PRE_COPY -> PRE_COPY_P2P -> STOP_COPY
704 * PRE_COPY -> RUNNING -> RUNNING_P2P
705 * PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP
706 * PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP -> RESUMING
707 * PRE_COPY_P2P -> RUNNING_P2P -> RUNNING
708 * PRE_COPY_P2P -> RUNNING_P2P -> STOP
709 * PRE_COPY_P2P -> RUNNING_P2P -> STOP -> RESUMING
710 * RESUMING -> STOP -> RUNNING_P2P
711 * RESUMING -> STOP -> RUNNING_P2P -> PRE_COPY_P2P
712 * RESUMING -> STOP -> RUNNING_P2P -> RUNNING
713 * RESUMING -> STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY
714 * RESUMING -> STOP -> STOP_COPY
715 * RUNNING -> RUNNING_P2P -> PRE_COPY_P2P
716 * RUNNING -> RUNNING_P2P -> STOP
717 * RUNNING -> RUNNING_P2P -> STOP -> RESUMING
718 * RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY
719 * RUNNING_P2P -> RUNNING -> PRE_COPY
720 * RUNNING_P2P -> STOP -> RESUMING
721 * RUNNING_P2P -> STOP -> STOP_COPY
722 * STOP -> RUNNING_P2P -> PRE_COPY_P2P
723 * STOP -> RUNNING_P2P -> RUNNING
724 * STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY
725 * STOP_COPY -> STOP -> RESUMING
726 * STOP_COPY -> STOP -> RUNNING_P2P
727 * STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING
728 *
729 * The following transitions are blocked:
730 * STOP_COPY -> PRE_COPY
731 * STOP_COPY -> PRE_COPY_P2P
732 */
733 static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = {
734 [VFIO_DEVICE_STATE_STOP] = {
735 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
736 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
737 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
738 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
739 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
740 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
741 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
742 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
743 },
744 [VFIO_DEVICE_STATE_RUNNING] = {
745 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
746 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
747 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
748 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
749 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
750 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
751 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
752 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
753 },
754 [VFIO_DEVICE_STATE_PRE_COPY] = {
755 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING,
756 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
757 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
758 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
759 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
760 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING,
761 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING,
762 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
763 },
764 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = {
765 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
766 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
767 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
768 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
769 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
770 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
771 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
772 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
773 },
774 [VFIO_DEVICE_STATE_STOP_COPY] = {
775 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
776 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
777 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_ERROR,
778 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_ERROR,
779 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
780 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
781 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
782 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
783 },
784 [VFIO_DEVICE_STATE_RESUMING] = {
785 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
786 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
787 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_STOP,
788 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_STOP,
789 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
790 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
791 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
792 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
793 },
794 [VFIO_DEVICE_STATE_RUNNING_P2P] = {
795 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
796 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
797 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING,
798 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
799 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
800 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
801 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
802 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
803 },
804 [VFIO_DEVICE_STATE_ERROR] = {
805 [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR,
806 [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR,
807 [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_ERROR,
808 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_ERROR,
809 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR,
810 [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR,
811 [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR,
812 [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
813 },
814 };
815
816 static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = {
817 [VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY,
818 [VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY,
819 [VFIO_DEVICE_STATE_PRE_COPY] =
820 VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_PRE_COPY,
821 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_MIGRATION_STOP_COPY |
822 VFIO_MIGRATION_P2P |
823 VFIO_MIGRATION_PRE_COPY,
824 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY,
825 [VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY,
826 [VFIO_DEVICE_STATE_RUNNING_P2P] =
827 VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P,
828 [VFIO_DEVICE_STATE_ERROR] = ~0U,
829 };
830
831 if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
832 (state_flags_table[cur_fsm] & device->migration_flags) !=
833 state_flags_table[cur_fsm]))
834 return -EINVAL;
835
836 if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
837 (state_flags_table[new_fsm] & device->migration_flags) !=
838 state_flags_table[new_fsm])
839 return -EINVAL;
840
841 /*
842 * Arcs touching optional and unsupported states are skipped over. The
843 * driver will instead see an arc from the original state to the next
844 * logical state, as per the above comment.
845 */
846 *next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm];
847 while ((state_flags_table[*next_fsm] & device->migration_flags) !=
848 state_flags_table[*next_fsm])
849 *next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm];
850
851 return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL;
852 }
853 EXPORT_SYMBOL_GPL(vfio_mig_get_next_state);
854
855 /*
856 * Convert the drivers's struct file into a FD number and return it to userspace
857 */
858 static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg,
859 struct vfio_device_feature_mig_state *mig)
860 {
861 int ret;
862 int fd;
863
864 fd = get_unused_fd_flags(O_CLOEXEC);
865 if (fd < 0) {
866 ret = fd;
867 goto out_fput;
868 }
869
870 mig->data_fd = fd;
871 if (copy_to_user(arg, mig, sizeof(*mig))) {
872 ret = -EFAULT;
873 goto out_put_unused;
874 }
875 fd_install(fd, filp);
876 return 0;
877
878 out_put_unused:
879 put_unused_fd(fd);
880 out_fput:
881 fput(filp);
882 return ret;
883 }
884
885 static int
886 vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device,
887 u32 flags, void __user *arg,
888 size_t argsz)
889 {
890 size_t minsz =
891 offsetofend(struct vfio_device_feature_mig_state, data_fd);
892 struct vfio_device_feature_mig_state mig;
893 struct file *filp = NULL;
894 int ret;
895
896 if (!device->mig_ops)
897 return -ENOTTY;
898
899 ret = vfio_check_feature(flags, argsz,
900 VFIO_DEVICE_FEATURE_SET |
901 VFIO_DEVICE_FEATURE_GET,
902 sizeof(mig));
903 if (ret != 1)
904 return ret;
905
906 if (copy_from_user(&mig, arg, minsz))
907 return -EFAULT;
908
909 if (flags & VFIO_DEVICE_FEATURE_GET) {
910 enum vfio_device_mig_state curr_state;
911
912 ret = device->mig_ops->migration_get_state(device,
913 &curr_state);
914 if (ret)
915 return ret;
916 mig.device_state = curr_state;
917 goto out_copy;
918 }
919
920 /* Handle the VFIO_DEVICE_FEATURE_SET */
921 filp = device->mig_ops->migration_set_state(device, mig.device_state);
922 if (IS_ERR(filp) || !filp)
923 goto out_copy;
924
925 return vfio_ioct_mig_return_fd(filp, arg, &mig);
926 out_copy:
927 mig.data_fd = -1;
928 if (copy_to_user(arg, &mig, sizeof(mig)))
929 return -EFAULT;
930 if (IS_ERR(filp))
931 return PTR_ERR(filp);
932 return 0;
933 }
934
935 static int
936 vfio_ioctl_device_feature_migration_data_size(struct vfio_device *device,
937 u32 flags, void __user *arg,
938 size_t argsz)
939 {
940 struct vfio_device_feature_mig_data_size data_size = {};
941 unsigned long stop_copy_length;
942 int ret;
943
944 if (!device->mig_ops)
945 return -ENOTTY;
946
947 ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
948 sizeof(data_size));
949 if (ret != 1)
950 return ret;
951
952 ret = device->mig_ops->migration_get_data_size(device, &stop_copy_length);
953 if (ret)
954 return ret;
955
956 data_size.stop_copy_length = stop_copy_length;
957 if (copy_to_user(arg, &data_size, sizeof(data_size)))
958 return -EFAULT;
959
960 return 0;
961 }
962
963 static int vfio_ioctl_device_feature_migration(struct vfio_device *device,
964 u32 flags, void __user *arg,
965 size_t argsz)
966 {
967 struct vfio_device_feature_migration mig = {
968 .flags = device->migration_flags,
969 };
970 int ret;
971
972 if (!device->mig_ops)
973 return -ENOTTY;
974
975 ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
976 sizeof(mig));
977 if (ret != 1)
978 return ret;
979 if (copy_to_user(arg, &mig, sizeof(mig)))
980 return -EFAULT;
981 return 0;
982 }
983
984 void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
985 u32 req_nodes)
986 {
987 struct interval_tree_node *prev, *curr, *comb_start, *comb_end;
988 unsigned long min_gap, curr_gap;
989
990 /* Special shortcut when a single range is required */
991 if (req_nodes == 1) {
992 unsigned long last;
993
994 comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);
995
996 /* Empty list */
997 if (WARN_ON_ONCE(!comb_start))
998 return;
999
1000 curr = comb_start;
1001 while (curr) {
1002 last = curr->last;
1003 prev = curr;
1004 curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
1005 if (prev != comb_start)
1006 interval_tree_remove(prev, root);
1007 }
1008 comb_start->last = last;
1009 return;
1010 }
1011
1012 /* Combine ranges which have the smallest gap */
1013 while (cur_nodes > req_nodes) {
1014 prev = NULL;
1015 min_gap = ULONG_MAX;
1016 curr = interval_tree_iter_first(root, 0, ULONG_MAX);
1017 while (curr) {
1018 if (prev) {
1019 curr_gap = curr->start - prev->last;
1020 if (curr_gap < min_gap) {
1021 min_gap = curr_gap;
1022 comb_start = prev;
1023 comb_end = curr;
1024 }
1025 }
1026 prev = curr;
1027 curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
1028 }
1029
1030 /* Empty list or no nodes to combine */
1031 if (WARN_ON_ONCE(min_gap == ULONG_MAX))
1032 break;
1033
1034 comb_start->last = comb_end->last;
1035 interval_tree_remove(comb_end, root);
1036 cur_nodes--;
1037 }
1038 }
1039 EXPORT_SYMBOL_GPL(vfio_combine_iova_ranges);
1040
1041 /* Ranges should fit into a single kernel page */
1042 #define LOG_MAX_RANGES \
1043 (PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range))
1044
1045 static int
1046 vfio_ioctl_device_feature_logging_start(struct vfio_device *device,
1047 u32 flags, void __user *arg,
1048 size_t argsz)
1049 {
1050 size_t minsz =
1051 offsetofend(struct vfio_device_feature_dma_logging_control,
1052 ranges);
1053 struct vfio_device_feature_dma_logging_range __user *ranges;
1054 struct vfio_device_feature_dma_logging_control control;
1055 struct vfio_device_feature_dma_logging_range range;
1056 struct rb_root_cached root = RB_ROOT_CACHED;
1057 struct interval_tree_node *nodes;
1058 u64 iova_end;
1059 u32 nnodes;
1060 int i, ret;
1061
1062 if (!device->log_ops)
1063 return -ENOTTY;
1064
1065 ret = vfio_check_feature(flags, argsz,
1066 VFIO_DEVICE_FEATURE_SET,
1067 sizeof(control));
1068 if (ret != 1)
1069 return ret;
1070
1071 if (copy_from_user(&control, arg, minsz))
1072 return -EFAULT;
1073
1074 nnodes = control.num_ranges;
1075 if (!nnodes)
1076 return -EINVAL;
1077
1078 if (nnodes > LOG_MAX_RANGES)
1079 return -E2BIG;
1080
1081 ranges = u64_to_user_ptr(control.ranges);
1082 nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
1083 GFP_KERNEL);
1084 if (!nodes)
1085 return -ENOMEM;
1086
1087 for (i = 0; i < nnodes; i++) {
1088 if (copy_from_user(&range, &ranges[i], sizeof(range))) {
1089 ret = -EFAULT;
1090 goto end;
1091 }
1092 if (!IS_ALIGNED(range.iova, control.page_size) ||
1093 !IS_ALIGNED(range.length, control.page_size)) {
1094 ret = -EINVAL;
1095 goto end;
1096 }
1097
1098 if (check_add_overflow(range.iova, range.length, &iova_end) ||
1099 iova_end > ULONG_MAX) {
1100 ret = -EOVERFLOW;
1101 goto end;
1102 }
1103
1104 nodes[i].start = range.iova;
1105 nodes[i].last = range.iova + range.length - 1;
1106 if (interval_tree_iter_first(&root, nodes[i].start,
1107 nodes[i].last)) {
1108 /* Range overlapping */
1109 ret = -EINVAL;
1110 goto end;
1111 }
1112 interval_tree_insert(nodes + i, &root);
1113 }
1114
1115 ret = device->log_ops->log_start(device, &root, nnodes,
1116 &control.page_size);
1117 if (ret)
1118 goto end;
1119
1120 if (copy_to_user(arg, &control, sizeof(control))) {
1121 ret = -EFAULT;
1122 device->log_ops->log_stop(device);
1123 }
1124
1125 end:
1126 kfree(nodes);
1127 return ret;
1128 }
1129
1130 static int
1131 vfio_ioctl_device_feature_logging_stop(struct vfio_device *device,
1132 u32 flags, void __user *arg,
1133 size_t argsz)
1134 {
1135 int ret;
1136
1137 if (!device->log_ops)
1138 return -ENOTTY;
1139
1140 ret = vfio_check_feature(flags, argsz,
1141 VFIO_DEVICE_FEATURE_SET, 0);
1142 if (ret != 1)
1143 return ret;
1144
1145 return device->log_ops->log_stop(device);
1146 }
1147
1148 static int vfio_device_log_read_and_clear(struct iova_bitmap *iter,
1149 unsigned long iova, size_t length,
1150 void *opaque)
1151 {
1152 struct vfio_device *device = opaque;
1153
1154 return device->log_ops->log_read_and_clear(device, iova, length, iter);
1155 }
1156
1157 static int
1158 vfio_ioctl_device_feature_logging_report(struct vfio_device *device,
1159 u32 flags, void __user *arg,
1160 size_t argsz)
1161 {
1162 size_t minsz =
1163 offsetofend(struct vfio_device_feature_dma_logging_report,
1164 bitmap);
1165 struct vfio_device_feature_dma_logging_report report;
1166 struct iova_bitmap *iter;
1167 u64 iova_end;
1168 int ret;
1169
1170 if (!device->log_ops)
1171 return -ENOTTY;
1172
1173 ret = vfio_check_feature(flags, argsz,
1174 VFIO_DEVICE_FEATURE_GET,
1175 sizeof(report));
1176 if (ret != 1)
1177 return ret;
1178
1179 if (copy_from_user(&report, arg, minsz))
1180 return -EFAULT;
1181
1182 if (report.page_size < SZ_4K || !is_power_of_2(report.page_size))
1183 return -EINVAL;
1184
1185 if (check_add_overflow(report.iova, report.length, &iova_end) ||
1186 iova_end > ULONG_MAX)
1187 return -EOVERFLOW;
1188
1189 iter = iova_bitmap_alloc(report.iova, report.length,
1190 report.page_size,
1191 u64_to_user_ptr(report.bitmap));
1192 if (IS_ERR(iter))
1193 return PTR_ERR(iter);
1194
1195 ret = iova_bitmap_for_each(iter, device,
1196 vfio_device_log_read_and_clear);
1197
1198 iova_bitmap_free(iter);
1199 return ret;
1200 }
1201
1202 static int vfio_ioctl_device_feature(struct vfio_device *device,
1203 struct vfio_device_feature __user *arg)
1204 {
1205 size_t minsz = offsetofend(struct vfio_device_feature, flags);
1206 struct vfio_device_feature feature;
1207
1208 if (copy_from_user(&feature, arg, minsz))
1209 return -EFAULT;
1210
1211 if (feature.argsz < minsz)
1212 return -EINVAL;
1213
1214 /* Check unknown flags */
1215 if (feature.flags &
1216 ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET |
1217 VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE))
1218 return -EINVAL;
1219
1220 /* GET & SET are mutually exclusive except with PROBE */
1221 if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
1222 (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
1223 (feature.flags & VFIO_DEVICE_FEATURE_GET))
1224 return -EINVAL;
1225
1226 switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
1227 case VFIO_DEVICE_FEATURE_MIGRATION:
1228 return vfio_ioctl_device_feature_migration(
1229 device, feature.flags, arg->data,
1230 feature.argsz - minsz);
1231 case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE:
1232 return vfio_ioctl_device_feature_mig_device_state(
1233 device, feature.flags, arg->data,
1234 feature.argsz - minsz);
1235 case VFIO_DEVICE_FEATURE_DMA_LOGGING_START:
1236 return vfio_ioctl_device_feature_logging_start(
1237 device, feature.flags, arg->data,
1238 feature.argsz - minsz);
1239 case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP:
1240 return vfio_ioctl_device_feature_logging_stop(
1241 device, feature.flags, arg->data,
1242 feature.argsz - minsz);
1243 case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT:
1244 return vfio_ioctl_device_feature_logging_report(
1245 device, feature.flags, arg->data,
1246 feature.argsz - minsz);
1247 case VFIO_DEVICE_FEATURE_MIG_DATA_SIZE:
1248 return vfio_ioctl_device_feature_migration_data_size(
1249 device, feature.flags, arg->data,
1250 feature.argsz - minsz);
1251 default:
1252 if (unlikely(!device->ops->device_feature))
1253 return -EINVAL;
1254 return device->ops->device_feature(device, feature.flags,
1255 arg->data,
1256 feature.argsz - minsz);
1257 }
1258 }
1259
1260 static long vfio_device_fops_unl_ioctl(struct file *filep,
1261 unsigned int cmd, unsigned long arg)
1262 {
1263 struct vfio_device_file *df = filep->private_data;
1264 struct vfio_device *device = df->device;
1265 void __user *uptr = (void __user *)arg;
1266 int ret;
1267
1268 if (cmd == VFIO_DEVICE_BIND_IOMMUFD)
1269 return vfio_df_ioctl_bind_iommufd(df, uptr);
1270
1271 /* Paired with smp_store_release() following vfio_df_open() */
1272 if (!smp_load_acquire(&df->access_granted))
1273 return -EINVAL;
1274
1275 ret = vfio_device_pm_runtime_get(device);
1276 if (ret)
1277 return ret;
1278
1279 /* cdev only ioctls */
1280 if (IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV) && !df->group) {
1281 switch (cmd) {
1282 case VFIO_DEVICE_ATTACH_IOMMUFD_PT:
1283 ret = vfio_df_ioctl_attach_pt(df, uptr);
1284 goto out;
1285
1286 case VFIO_DEVICE_DETACH_IOMMUFD_PT:
1287 ret = vfio_df_ioctl_detach_pt(df, uptr);
1288 goto out;
1289 }
1290 }
1291
1292 switch (cmd) {
1293 case VFIO_DEVICE_FEATURE:
1294 ret = vfio_ioctl_device_feature(device, uptr);
1295 break;
1296
1297 default:
1298 if (unlikely(!device->ops->ioctl))
1299 ret = -EINVAL;
1300 else
1301 ret = device->ops->ioctl(device, cmd, arg);
1302 break;
1303 }
1304 out:
1305 vfio_device_pm_runtime_put(device);
1306 return ret;
1307 }
1308
1309 static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
1310 size_t count, loff_t *ppos)
1311 {
1312 struct vfio_device_file *df = filep->private_data;
1313 struct vfio_device *device = df->device;
1314
1315 /* Paired with smp_store_release() following vfio_df_open() */
1316 if (!smp_load_acquire(&df->access_granted))
1317 return -EINVAL;
1318
1319 if (unlikely(!device->ops->read))
1320 return -EINVAL;
1321
1322 return device->ops->read(device, buf, count, ppos);
1323 }
1324
1325 static ssize_t vfio_device_fops_write(struct file *filep,
1326 const char __user *buf,
1327 size_t count, loff_t *ppos)
1328 {
1329 struct vfio_device_file *df = filep->private_data;
1330 struct vfio_device *device = df->device;
1331
1332 /* Paired with smp_store_release() following vfio_df_open() */
1333 if (!smp_load_acquire(&df->access_granted))
1334 return -EINVAL;
1335
1336 if (unlikely(!device->ops->write))
1337 return -EINVAL;
1338
1339 return device->ops->write(device, buf, count, ppos);
1340 }
1341
1342 static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
1343 {
1344 struct vfio_device_file *df = filep->private_data;
1345 struct vfio_device *device = df->device;
1346
1347 /* Paired with smp_store_release() following vfio_df_open() */
1348 if (!smp_load_acquire(&df->access_granted))
1349 return -EINVAL;
1350
1351 if (unlikely(!device->ops->mmap))
1352 return -EINVAL;
1353
1354 return device->ops->mmap(device, vma);
1355 }
1356
1357 const struct file_operations vfio_device_fops = {
1358 .owner = THIS_MODULE,
1359 .open = vfio_device_fops_cdev_open,
1360 .release = vfio_device_fops_release,
1361 .read = vfio_device_fops_read,
1362 .write = vfio_device_fops_write,
1363 .unlocked_ioctl = vfio_device_fops_unl_ioctl,
1364 .compat_ioctl = compat_ptr_ioctl,
1365 .mmap = vfio_device_fops_mmap,
1366 };
1367
1368 static struct vfio_device *vfio_device_from_file(struct file *file)
1369 {
1370 struct vfio_device_file *df = file->private_data;
1371
1372 if (file->f_op != &vfio_device_fops)
1373 return NULL;
1374 return df->device;
1375 }
1376
1377 /**
1378 * vfio_file_is_valid - True if the file is valid vfio file
1379 * @file: VFIO group file or VFIO device file
1380 */
1381 bool vfio_file_is_valid(struct file *file)
1382 {
1383 return vfio_group_from_file(file) ||
1384 vfio_device_from_file(file);
1385 }
1386 EXPORT_SYMBOL_GPL(vfio_file_is_valid);
1387
1388 /**
1389 * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
1390 * is always CPU cache coherent
1391 * @file: VFIO group file or VFIO device file
1392 *
1393 * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
1394 * bit in DMA transactions. A return of false indicates that the user has
1395 * rights to access additional instructions such as wbinvd on x86.
1396 */
1397 bool vfio_file_enforced_coherent(struct file *file)
1398 {
1399 struct vfio_device *device;
1400 struct vfio_group *group;
1401
1402 group = vfio_group_from_file(file);
1403 if (group)
1404 return vfio_group_enforced_coherent(group);
1405
1406 device = vfio_device_from_file(file);
1407 if (device)
1408 return device_iommu_capable(device->dev,
1409 IOMMU_CAP_ENFORCE_CACHE_COHERENCY);
1410
1411 return true;
1412 }
1413 EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
1414
1415 static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
1416 {
1417 struct vfio_device_file *df = file->private_data;
1418
1419 /*
1420 * The kvm is first recorded in the vfio_device_file, and will
1421 * be propagated to vfio_device::kvm when the file is bound to
1422 * iommufd successfully in the vfio device cdev path.
1423 */
1424 spin_lock(&df->kvm_ref_lock);
1425 df->kvm = kvm;
1426 spin_unlock(&df->kvm_ref_lock);
1427 }
1428
1429 /**
1430 * vfio_file_set_kvm - Link a kvm with VFIO drivers
1431 * @file: VFIO group file or VFIO device file
1432 * @kvm: KVM to link
1433 *
1434 * When a VFIO device is first opened the KVM will be available in
1435 * device->kvm if one was associated with the file.
1436 */
1437 void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
1438 {
1439 struct vfio_group *group;
1440
1441 group = vfio_group_from_file(file);
1442 if (group)
1443 vfio_group_set_kvm(group, kvm);
1444
1445 if (vfio_device_from_file(file))
1446 vfio_device_file_set_kvm(file, kvm);
1447 }
1448 EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
1449
1450 /*
1451 * Sub-module support
1452 */
1453 /*
1454 * Helper for managing a buffer of info chain capabilities, allocate or
1455 * reallocate a buffer with additional @size, filling in @id and @version
1456 * of the capability. A pointer to the new capability is returned.
1457 *
1458 * NB. The chain is based at the head of the buffer, so new entries are
1459 * added to the tail, vfio_info_cap_shift() should be called to fixup the
1460 * next offsets prior to copying to the user buffer.
1461 */
1462 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
1463 size_t size, u16 id, u16 version)
1464 {
1465 void *buf;
1466 struct vfio_info_cap_header *header, *tmp;
1467
1468 /* Ensure that the next capability struct will be aligned */
1469 size = ALIGN(size, sizeof(u64));
1470
1471 buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
1472 if (!buf) {
1473 kfree(caps->buf);
1474 caps->buf = NULL;
1475 caps->size = 0;
1476 return ERR_PTR(-ENOMEM);
1477 }
1478
1479 caps->buf = buf;
1480 header = buf + caps->size;
1481
1482 /* Eventually copied to user buffer, zero */
1483 memset(header, 0, size);
1484
1485 header->id = id;
1486 header->version = version;
1487
1488 /* Add to the end of the capability chain */
1489 for (tmp = buf; tmp->next; tmp = buf + tmp->next)
1490 ; /* nothing */
1491
1492 tmp->next = caps->size;
1493 caps->size += size;
1494
1495 return header;
1496 }
1497 EXPORT_SYMBOL_GPL(vfio_info_cap_add);
1498
1499 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
1500 {
1501 struct vfio_info_cap_header *tmp;
1502 void *buf = (void *)caps->buf;
1503
1504 /* Capability structs should start with proper alignment */
1505 WARN_ON(!IS_ALIGNED(offset, sizeof(u64)));
1506
1507 for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
1508 tmp->next += offset;
1509 }
1510 EXPORT_SYMBOL(vfio_info_cap_shift);
1511
1512 int vfio_info_add_capability(struct vfio_info_cap *caps,
1513 struct vfio_info_cap_header *cap, size_t size)
1514 {
1515 struct vfio_info_cap_header *header;
1516
1517 header = vfio_info_cap_add(caps, size, cap->id, cap->version);
1518 if (IS_ERR(header))
1519 return PTR_ERR(header);
1520
1521 memcpy(header + 1, cap + 1, size - sizeof(*header));
1522
1523 return 0;
1524 }
1525 EXPORT_SYMBOL(vfio_info_add_capability);
1526
1527 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
1528 int max_irq_type, size_t *data_size)
1529 {
1530 unsigned long minsz;
1531 size_t size;
1532
1533 minsz = offsetofend(struct vfio_irq_set, count);
1534
1535 if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
1536 (hdr->count >= (U32_MAX - hdr->start)) ||
1537 (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
1538 VFIO_IRQ_SET_ACTION_TYPE_MASK)))
1539 return -EINVAL;
1540
1541 if (data_size)
1542 *data_size = 0;
1543
1544 if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
1545 return -EINVAL;
1546
1547 switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
1548 case VFIO_IRQ_SET_DATA_NONE:
1549 size = 0;
1550 break;
1551 case VFIO_IRQ_SET_DATA_BOOL:
1552 size = sizeof(uint8_t);
1553 break;
1554 case VFIO_IRQ_SET_DATA_EVENTFD:
1555 size = sizeof(int32_t);
1556 break;
1557 default:
1558 return -EINVAL;
1559 }
1560
1561 if (size) {
1562 if (hdr->argsz - minsz < hdr->count * size)
1563 return -EINVAL;
1564
1565 if (!data_size)
1566 return -EINVAL;
1567
1568 *data_size = hdr->count * size;
1569 }
1570
1571 return 0;
1572 }
1573 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
1574
1575 /*
1576 * Pin contiguous user pages and return their associated host pages for local
1577 * domain only.
1578 * @device [in] : device
1579 * @iova [in] : starting IOVA of user pages to be pinned.
1580 * @npage [in] : count of pages to be pinned. This count should not
1581 * be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
1582 * @prot [in] : protection flags
1583 * @pages[out] : array of host pages
1584 * Return error or number of pages pinned.
1585 *
1586 * A driver may only call this function if the vfio_device was created
1587 * by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages().
1588 */
1589 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
1590 int npage, int prot, struct page **pages)
1591 {
1592 /* group->container cannot change while a vfio device is open */
1593 if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device)))
1594 return -EINVAL;
1595 if (!device->ops->dma_unmap)
1596 return -EINVAL;
1597 if (vfio_device_has_container(device))
1598 return vfio_device_container_pin_pages(device, iova,
1599 npage, prot, pages);
1600 if (device->iommufd_access) {
1601 int ret;
1602
1603 if (iova > ULONG_MAX)
1604 return -EINVAL;
1605 /*
1606 * VFIO ignores the sub page offset, npages is from the start of
1607 * a PAGE_SIZE chunk of IOVA. The caller is expected to recover
1608 * the sub page offset by doing:
1609 * pages[0] + (iova % PAGE_SIZE)
1610 */
1611 ret = iommufd_access_pin_pages(
1612 device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE),
1613 npage * PAGE_SIZE, pages,
1614 (prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0);
1615 if (ret)
1616 return ret;
1617 return npage;
1618 }
1619 return -EINVAL;
1620 }
1621 EXPORT_SYMBOL(vfio_pin_pages);
1622
1623 /*
1624 * Unpin contiguous host pages for local domain only.
1625 * @device [in] : device
1626 * @iova [in] : starting address of user pages to be unpinned.
1627 * @npage [in] : count of pages to be unpinned. This count should not
1628 * be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
1629 */
1630 void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
1631 {
1632 if (WARN_ON(!vfio_assert_device_open(device)))
1633 return;
1634 if (WARN_ON(!device->ops->dma_unmap))
1635 return;
1636
1637 if (vfio_device_has_container(device)) {
1638 vfio_device_container_unpin_pages(device, iova, npage);
1639 return;
1640 }
1641 if (device->iommufd_access) {
1642 if (WARN_ON(iova > ULONG_MAX))
1643 return;
1644 iommufd_access_unpin_pages(device->iommufd_access,
1645 ALIGN_DOWN(iova, PAGE_SIZE),
1646 npage * PAGE_SIZE);
1647 return;
1648 }
1649 }
1650 EXPORT_SYMBOL(vfio_unpin_pages);
1651
1652 /*
1653 * This interface allows the CPUs to perform some sort of virtual DMA on
1654 * behalf of the device.
1655 *
1656 * CPUs read/write from/into a range of IOVAs pointing to user space memory
1657 * into/from a kernel buffer.
1658 *
1659 * As the read/write of user space memory is conducted via the CPUs and is
1660 * not a real device DMA, it is not necessary to pin the user space memory.
1661 *
1662 * @device [in] : VFIO device
1663 * @iova [in] : base IOVA of a user space buffer
1664 * @data [in] : pointer to kernel buffer
1665 * @len [in] : kernel buffer length
1666 * @write : indicate read or write
1667 * Return error code on failure or 0 on success.
1668 */
1669 int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
1670 size_t len, bool write)
1671 {
1672 if (!data || len <= 0 || !vfio_assert_device_open(device))
1673 return -EINVAL;
1674
1675 if (vfio_device_has_container(device))
1676 return vfio_device_container_dma_rw(device, iova,
1677 data, len, write);
1678
1679 if (device->iommufd_access) {
1680 unsigned int flags = 0;
1681
1682 if (iova > ULONG_MAX)
1683 return -EINVAL;
1684
1685 /* VFIO historically tries to auto-detect a kthread */
1686 if (!current->mm)
1687 flags |= IOMMUFD_ACCESS_RW_KTHREAD;
1688 if (write)
1689 flags |= IOMMUFD_ACCESS_RW_WRITE;
1690 return iommufd_access_rw(device->iommufd_access, iova, data,
1691 len, flags);
1692 }
1693 return -EINVAL;
1694 }
1695 EXPORT_SYMBOL(vfio_dma_rw);
1696
1697 /*
1698 * Module/class support
1699 */
1700 static int __init vfio_init(void)
1701 {
1702 int ret;
1703
1704 ida_init(&vfio.device_ida);
1705
1706 ret = vfio_group_init();
1707 if (ret)
1708 return ret;
1709
1710 ret = vfio_virqfd_init();
1711 if (ret)
1712 goto err_virqfd;
1713
1714 /* /sys/class/vfio-dev/vfioX */
1715 vfio.device_class = class_create("vfio-dev");
1716 if (IS_ERR(vfio.device_class)) {
1717 ret = PTR_ERR(vfio.device_class);
1718 goto err_dev_class;
1719 }
1720
1721 ret = vfio_cdev_init(vfio.device_class);
1722 if (ret)
1723 goto err_alloc_dev_chrdev;
1724
1725 vfio_debugfs_create_root();
1726 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
1727 return 0;
1728
1729 err_alloc_dev_chrdev:
1730 class_destroy(vfio.device_class);
1731 vfio.device_class = NULL;
1732 err_dev_class:
1733 vfio_virqfd_exit();
1734 err_virqfd:
1735 vfio_group_cleanup();
1736 return ret;
1737 }
1738
1739 static void __exit vfio_cleanup(void)
1740 {
1741 vfio_debugfs_remove_root();
1742 ida_destroy(&vfio.device_ida);
1743 vfio_cdev_cleanup();
1744 class_destroy(vfio.device_class);
1745 vfio.device_class = NULL;
1746 vfio_virqfd_exit();
1747 vfio_group_cleanup();
1748 xa_destroy(&vfio_device_set_xa);
1749 }
1750
1751 module_init(vfio_init);
1752 module_exit(vfio_cleanup);
1753
1754 MODULE_IMPORT_NS("IOMMUFD");
1755 MODULE_VERSION(DRIVER_VERSION);
1756 MODULE_LICENSE("GPL v2");
1757 MODULE_AUTHOR(DRIVER_AUTHOR);
1758 MODULE_DESCRIPTION(DRIVER_DESC);
1759 MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");
Linux Kernel