1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* Copyright (C) 2009 Red Hat, Inc. |
3 | * Copyright (C) 2006 Rusty Russell IBM Corporation |
4 | * |
5 | * Author: Michael S. Tsirkin <mst@redhat.com> |
6 | * |
7 | * Inspiration, some code, and most witty comments come from |
8 | * Documentation/virtual/lguest/lguest.c, by Rusty Russell |
9 | * |
10 | * Generic code for virtio server in host kernel. |
11 | */ |
12 | |
13 | #include <linux/eventfd.h> |
14 | #include <linux/vhost.h> |
15 | #include <linux/uio.h> |
16 | #include <linux/mm.h> |
17 | #include <linux/miscdevice.h> |
18 | #include <linux/mutex.h> |
19 | #include <linux/poll.h> |
20 | #include <linux/file.h> |
21 | #include <linux/highmem.h> |
22 | #include <linux/slab.h> |
23 | #include <linux/vmalloc.h> |
24 | #include <linux/kthread.h> |
25 | #include <linux/module.h> |
26 | #include <linux/sort.h> |
27 | #include <linux/sched/mm.h> |
28 | #include <linux/sched/signal.h> |
29 | #include <linux/sched/vhost_task.h> |
30 | #include <linux/interval_tree_generic.h> |
31 | #include <linux/nospec.h> |
32 | #include <linux/kcov.h> |
33 | |
34 | #include "vhost.h" |
35 | |
36 | static ushort max_mem_regions = 64; |
37 | module_param(max_mem_regions, ushort, 0444); |
38 | MODULE_PARM_DESC(max_mem_regions, |
39 | "Maximum number of memory regions in memory map. (default: 64)" ); |
40 | static int max_iotlb_entries = 2048; |
41 | module_param(max_iotlb_entries, int, 0444); |
42 | MODULE_PARM_DESC(max_iotlb_entries, |
43 | "Maximum number of iotlb entries. (default: 2048)" ); |
44 | |
45 | enum { |
46 | VHOST_MEMORY_F_LOG = 0x1, |
47 | }; |
48 | |
49 | #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) |
50 | #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) |
51 | |
52 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
53 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
54 | { |
55 | vq->user_be = !virtio_legacy_is_little_endian(); |
56 | } |
57 | |
58 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
59 | { |
60 | vq->user_be = true; |
61 | } |
62 | |
63 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) |
64 | { |
65 | vq->user_be = false; |
66 | } |
67 | |
68 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
69 | { |
70 | struct vhost_vring_state s; |
71 | |
72 | if (vq->private_data) |
73 | return -EBUSY; |
74 | |
75 | if (copy_from_user(to: &s, from: argp, n: sizeof(s))) |
76 | return -EFAULT; |
77 | |
78 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && |
79 | s.num != VHOST_VRING_BIG_ENDIAN) |
80 | return -EINVAL; |
81 | |
82 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
83 | vhost_enable_cross_endian_big(vq); |
84 | else |
85 | vhost_enable_cross_endian_little(vq); |
86 | |
87 | return 0; |
88 | } |
89 | |
90 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, |
91 | int __user *argp) |
92 | { |
93 | struct vhost_vring_state s = { |
94 | .index = idx, |
95 | .num = vq->user_be |
96 | }; |
97 | |
98 | if (copy_to_user(to: argp, from: &s, n: sizeof(s))) |
99 | return -EFAULT; |
100 | |
101 | return 0; |
102 | } |
103 | |
104 | static void vhost_init_is_le(struct vhost_virtqueue *vq) |
105 | { |
106 | /* Note for legacy virtio: user_be is initialized at reset time |
107 | * according to the host endianness. If userspace does not set an |
108 | * explicit endianness, the default behavior is native endian, as |
109 | * expected by legacy virtio. |
110 | */ |
111 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; |
112 | } |
113 | #else |
114 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
115 | { |
116 | } |
117 | |
118 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
119 | { |
120 | return -ENOIOCTLCMD; |
121 | } |
122 | |
123 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, |
124 | int __user *argp) |
125 | { |
126 | return -ENOIOCTLCMD; |
127 | } |
128 | |
129 | static void vhost_init_is_le(struct vhost_virtqueue *vq) |
130 | { |
131 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) |
132 | || virtio_legacy_is_little_endian(); |
133 | } |
134 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ |
135 | |
136 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
137 | { |
138 | vhost_init_is_le(vq); |
139 | } |
140 | |
141 | struct vhost_flush_struct { |
142 | struct vhost_work work; |
143 | struct completion wait_event; |
144 | }; |
145 | |
146 | static void vhost_flush_work(struct vhost_work *work) |
147 | { |
148 | struct vhost_flush_struct *s; |
149 | |
150 | s = container_of(work, struct vhost_flush_struct, work); |
151 | complete(&s->wait_event); |
152 | } |
153 | |
154 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
155 | poll_table *pt) |
156 | { |
157 | struct vhost_poll *poll; |
158 | |
159 | poll = container_of(pt, struct vhost_poll, table); |
160 | poll->wqh = wqh; |
161 | add_wait_queue(wq_head: wqh, wq_entry: &poll->wait); |
162 | } |
163 | |
164 | static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, |
165 | void *key) |
166 | { |
167 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
168 | struct vhost_work *work = &poll->work; |
169 | |
170 | if (!(key_to_poll(key) & poll->mask)) |
171 | return 0; |
172 | |
173 | if (!poll->dev->use_worker) |
174 | work->fn(work); |
175 | else |
176 | vhost_poll_queue(poll); |
177 | |
178 | return 0; |
179 | } |
180 | |
181 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
182 | { |
183 | clear_bit(VHOST_WORK_QUEUED, addr: &work->flags); |
184 | work->fn = fn; |
185 | } |
186 | EXPORT_SYMBOL_GPL(vhost_work_init); |
187 | |
188 | /* Init poll structure */ |
189 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
190 | __poll_t mask, struct vhost_dev *dev, |
191 | struct vhost_virtqueue *vq) |
192 | { |
193 | init_waitqueue_func_entry(wq_entry: &poll->wait, func: vhost_poll_wakeup); |
194 | init_poll_funcptr(pt: &poll->table, qproc: vhost_poll_func); |
195 | poll->mask = mask; |
196 | poll->dev = dev; |
197 | poll->wqh = NULL; |
198 | poll->vq = vq; |
199 | |
200 | vhost_work_init(&poll->work, fn); |
201 | } |
202 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
203 | |
204 | /* Start polling a file. We add ourselves to file's wait queue. The caller must |
205 | * keep a reference to a file until after vhost_poll_stop is called. */ |
206 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
207 | { |
208 | __poll_t mask; |
209 | |
210 | if (poll->wqh) |
211 | return 0; |
212 | |
213 | mask = vfs_poll(file, pt: &poll->table); |
214 | if (mask) |
215 | vhost_poll_wakeup(wait: &poll->wait, mode: 0, sync: 0, poll_to_key(mask)); |
216 | if (mask & EPOLLERR) { |
217 | vhost_poll_stop(poll); |
218 | return -EINVAL; |
219 | } |
220 | |
221 | return 0; |
222 | } |
223 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
224 | |
225 | /* Stop polling a file. After this function returns, it becomes safe to drop the |
226 | * file reference. You must also flush afterwards. */ |
227 | void vhost_poll_stop(struct vhost_poll *poll) |
228 | { |
229 | if (poll->wqh) { |
230 | remove_wait_queue(wq_head: poll->wqh, wq_entry: &poll->wait); |
231 | poll->wqh = NULL; |
232 | } |
233 | } |
234 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
235 | |
236 | static void vhost_worker_queue(struct vhost_worker *worker, |
237 | struct vhost_work *work) |
238 | { |
239 | if (!test_and_set_bit(VHOST_WORK_QUEUED, addr: &work->flags)) { |
240 | /* We can only add the work to the list after we're |
241 | * sure it was not in the list. |
242 | * test_and_set_bit() implies a memory barrier. |
243 | */ |
244 | llist_add(new: &work->node, head: &worker->work_list); |
245 | vhost_task_wake(vtsk: worker->vtsk); |
246 | } |
247 | } |
248 | |
249 | bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work) |
250 | { |
251 | struct vhost_worker *worker; |
252 | bool queued = false; |
253 | |
254 | rcu_read_lock(); |
255 | worker = rcu_dereference(vq->worker); |
256 | if (worker) { |
257 | queued = true; |
258 | vhost_worker_queue(worker, work); |
259 | } |
260 | rcu_read_unlock(); |
261 | |
262 | return queued; |
263 | } |
264 | EXPORT_SYMBOL_GPL(vhost_vq_work_queue); |
265 | |
266 | void vhost_vq_flush(struct vhost_virtqueue *vq) |
267 | { |
268 | struct vhost_flush_struct flush; |
269 | |
270 | init_completion(x: &flush.wait_event); |
271 | vhost_work_init(&flush.work, vhost_flush_work); |
272 | |
273 | if (vhost_vq_work_queue(vq, &flush.work)) |
274 | wait_for_completion(&flush.wait_event); |
275 | } |
276 | EXPORT_SYMBOL_GPL(vhost_vq_flush); |
277 | |
278 | /** |
279 | * vhost_worker_flush - flush a worker |
280 | * @worker: worker to flush |
281 | * |
282 | * This does not use RCU to protect the worker, so the device or worker |
283 | * mutex must be held. |
284 | */ |
285 | static void vhost_worker_flush(struct vhost_worker *worker) |
286 | { |
287 | struct vhost_flush_struct flush; |
288 | |
289 | init_completion(x: &flush.wait_event); |
290 | vhost_work_init(&flush.work, vhost_flush_work); |
291 | |
292 | vhost_worker_queue(worker, work: &flush.work); |
293 | wait_for_completion(&flush.wait_event); |
294 | } |
295 | |
296 | void vhost_dev_flush(struct vhost_dev *dev) |
297 | { |
298 | struct vhost_worker *worker; |
299 | unsigned long i; |
300 | |
301 | xa_for_each(&dev->worker_xa, i, worker) { |
302 | mutex_lock(&worker->mutex); |
303 | if (!worker->attachment_cnt) { |
304 | mutex_unlock(lock: &worker->mutex); |
305 | continue; |
306 | } |
307 | vhost_worker_flush(worker); |
308 | mutex_unlock(lock: &worker->mutex); |
309 | } |
310 | } |
311 | EXPORT_SYMBOL_GPL(vhost_dev_flush); |
312 | |
313 | /* A lockless hint for busy polling code to exit the loop */ |
314 | bool vhost_vq_has_work(struct vhost_virtqueue *vq) |
315 | { |
316 | struct vhost_worker *worker; |
317 | bool has_work = false; |
318 | |
319 | rcu_read_lock(); |
320 | worker = rcu_dereference(vq->worker); |
321 | if (worker && !llist_empty(head: &worker->work_list)) |
322 | has_work = true; |
323 | rcu_read_unlock(); |
324 | |
325 | return has_work; |
326 | } |
327 | EXPORT_SYMBOL_GPL(vhost_vq_has_work); |
328 | |
329 | void vhost_poll_queue(struct vhost_poll *poll) |
330 | { |
331 | vhost_vq_work_queue(poll->vq, &poll->work); |
332 | } |
333 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
334 | |
335 | static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq) |
336 | { |
337 | int j; |
338 | |
339 | for (j = 0; j < VHOST_NUM_ADDRS; j++) |
340 | vq->meta_iotlb[j] = NULL; |
341 | } |
342 | |
343 | static void vhost_vq_meta_reset(struct vhost_dev *d) |
344 | { |
345 | int i; |
346 | |
347 | for (i = 0; i < d->nvqs; ++i) |
348 | __vhost_vq_meta_reset(vq: d->vqs[i]); |
349 | } |
350 | |
351 | static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx) |
352 | { |
353 | call_ctx->ctx = NULL; |
354 | memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer)); |
355 | } |
356 | |
357 | bool vhost_vq_is_setup(struct vhost_virtqueue *vq) |
358 | { |
359 | return vq->avail && vq->desc && vq->used && vhost_vq_access_ok(vq); |
360 | } |
361 | EXPORT_SYMBOL_GPL(vhost_vq_is_setup); |
362 | |
363 | static void vhost_vq_reset(struct vhost_dev *dev, |
364 | struct vhost_virtqueue *vq) |
365 | { |
366 | vq->num = 1; |
367 | vq->desc = NULL; |
368 | vq->avail = NULL; |
369 | vq->used = NULL; |
370 | vq->last_avail_idx = 0; |
371 | vq->avail_idx = 0; |
372 | vq->last_used_idx = 0; |
373 | vq->signalled_used = 0; |
374 | vq->signalled_used_valid = false; |
375 | vq->used_flags = 0; |
376 | vq->log_used = false; |
377 | vq->log_addr = -1ull; |
378 | vq->private_data = NULL; |
379 | vq->acked_features = 0; |
380 | vq->acked_backend_features = 0; |
381 | vq->log_base = NULL; |
382 | vq->error_ctx = NULL; |
383 | vq->kick = NULL; |
384 | vq->log_ctx = NULL; |
385 | vhost_disable_cross_endian(vq); |
386 | vhost_reset_is_le(vq); |
387 | vq->busyloop_timeout = 0; |
388 | vq->umem = NULL; |
389 | vq->iotlb = NULL; |
390 | rcu_assign_pointer(vq->worker, NULL); |
391 | vhost_vring_call_reset(call_ctx: &vq->call_ctx); |
392 | __vhost_vq_meta_reset(vq); |
393 | } |
394 | |
395 | static bool vhost_worker(void *data) |
396 | { |
397 | struct vhost_worker *worker = data; |
398 | struct vhost_work *work, *work_next; |
399 | struct llist_node *node; |
400 | |
401 | node = llist_del_all(head: &worker->work_list); |
402 | if (node) { |
403 | __set_current_state(TASK_RUNNING); |
404 | |
405 | node = llist_reverse_order(head: node); |
406 | /* make sure flag is seen after deletion */ |
407 | smp_wmb(); |
408 | llist_for_each_entry_safe(work, work_next, node, node) { |
409 | clear_bit(VHOST_WORK_QUEUED, addr: &work->flags); |
410 | kcov_remote_start_common(id: worker->kcov_handle); |
411 | work->fn(work); |
412 | kcov_remote_stop(); |
413 | cond_resched(); |
414 | } |
415 | } |
416 | |
417 | return !!node; |
418 | } |
419 | |
420 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
421 | { |
422 | kfree(objp: vq->indirect); |
423 | vq->indirect = NULL; |
424 | kfree(objp: vq->log); |
425 | vq->log = NULL; |
426 | kfree(objp: vq->heads); |
427 | vq->heads = NULL; |
428 | } |
429 | |
430 | /* Helper to allocate iovec buffers for all vqs. */ |
431 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) |
432 | { |
433 | struct vhost_virtqueue *vq; |
434 | int i; |
435 | |
436 | for (i = 0; i < dev->nvqs; ++i) { |
437 | vq = dev->vqs[i]; |
438 | vq->indirect = kmalloc_array(UIO_MAXIOV, |
439 | size: sizeof(*vq->indirect), |
440 | GFP_KERNEL); |
441 | vq->log = kmalloc_array(n: dev->iov_limit, size: sizeof(*vq->log), |
442 | GFP_KERNEL); |
443 | vq->heads = kmalloc_array(n: dev->iov_limit, size: sizeof(*vq->heads), |
444 | GFP_KERNEL); |
445 | if (!vq->indirect || !vq->log || !vq->heads) |
446 | goto err_nomem; |
447 | } |
448 | return 0; |
449 | |
450 | err_nomem: |
451 | for (; i >= 0; --i) |
452 | vhost_vq_free_iovecs(vq: dev->vqs[i]); |
453 | return -ENOMEM; |
454 | } |
455 | |
456 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) |
457 | { |
458 | int i; |
459 | |
460 | for (i = 0; i < dev->nvqs; ++i) |
461 | vhost_vq_free_iovecs(vq: dev->vqs[i]); |
462 | } |
463 | |
464 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, |
465 | int pkts, int total_len) |
466 | { |
467 | struct vhost_dev *dev = vq->dev; |
468 | |
469 | if ((dev->byte_weight && total_len >= dev->byte_weight) || |
470 | pkts >= dev->weight) { |
471 | vhost_poll_queue(&vq->poll); |
472 | return true; |
473 | } |
474 | |
475 | return false; |
476 | } |
477 | EXPORT_SYMBOL_GPL(vhost_exceeds_weight); |
478 | |
479 | static size_t vhost_get_avail_size(struct vhost_virtqueue *vq, |
480 | unsigned int num) |
481 | { |
482 | size_t event __maybe_unused = |
483 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
484 | |
485 | return size_add(struct_size(vq->avail, ring, num), addend2: event); |
486 | } |
487 | |
488 | static size_t vhost_get_used_size(struct vhost_virtqueue *vq, |
489 | unsigned int num) |
490 | { |
491 | size_t event __maybe_unused = |
492 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
493 | |
494 | return size_add(struct_size(vq->used, ring, num), addend2: event); |
495 | } |
496 | |
497 | static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, |
498 | unsigned int num) |
499 | { |
500 | return sizeof(*vq->desc) * num; |
501 | } |
502 | |
503 | void vhost_dev_init(struct vhost_dev *dev, |
504 | struct vhost_virtqueue **vqs, int nvqs, |
505 | int iov_limit, int weight, int byte_weight, |
506 | bool use_worker, |
507 | int (*msg_handler)(struct vhost_dev *dev, u32 asid, |
508 | struct vhost_iotlb_msg *msg)) |
509 | { |
510 | struct vhost_virtqueue *vq; |
511 | int i; |
512 | |
513 | dev->vqs = vqs; |
514 | dev->nvqs = nvqs; |
515 | mutex_init(&dev->mutex); |
516 | dev->log_ctx = NULL; |
517 | dev->umem = NULL; |
518 | dev->iotlb = NULL; |
519 | dev->mm = NULL; |
520 | dev->iov_limit = iov_limit; |
521 | dev->weight = weight; |
522 | dev->byte_weight = byte_weight; |
523 | dev->use_worker = use_worker; |
524 | dev->msg_handler = msg_handler; |
525 | init_waitqueue_head(&dev->wait); |
526 | INIT_LIST_HEAD(list: &dev->read_list); |
527 | INIT_LIST_HEAD(list: &dev->pending_list); |
528 | spin_lock_init(&dev->iotlb_lock); |
529 | xa_init_flags(xa: &dev->worker_xa, XA_FLAGS_ALLOC); |
530 | |
531 | for (i = 0; i < dev->nvqs; ++i) { |
532 | vq = dev->vqs[i]; |
533 | vq->log = NULL; |
534 | vq->indirect = NULL; |
535 | vq->heads = NULL; |
536 | vq->dev = dev; |
537 | mutex_init(&vq->mutex); |
538 | vhost_vq_reset(dev, vq); |
539 | if (vq->handle_kick) |
540 | vhost_poll_init(&vq->poll, vq->handle_kick, |
541 | EPOLLIN, dev, vq); |
542 | } |
543 | } |
544 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
545 | |
546 | /* Caller should have device mutex */ |
547 | long vhost_dev_check_owner(struct vhost_dev *dev) |
548 | { |
549 | /* Are you the owner? If not, I don't think you mean to do that */ |
550 | return dev->mm == current->mm ? 0 : -EPERM; |
551 | } |
552 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
553 | |
554 | /* Caller should have device mutex */ |
555 | bool vhost_dev_has_owner(struct vhost_dev *dev) |
556 | { |
557 | return dev->mm; |
558 | } |
559 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
560 | |
561 | static void vhost_attach_mm(struct vhost_dev *dev) |
562 | { |
563 | /* No owner, become one */ |
564 | if (dev->use_worker) { |
565 | dev->mm = get_task_mm(current); |
566 | } else { |
567 | /* vDPA device does not use worker thead, so there's |
568 | * no need to hold the address space for mm. This help |
569 | * to avoid deadlock in the case of mmap() which may |
570 | * held the refcnt of the file and depends on release |
571 | * method to remove vma. |
572 | */ |
573 | dev->mm = current->mm; |
574 | mmgrab(mm: dev->mm); |
575 | } |
576 | } |
577 | |
578 | static void vhost_detach_mm(struct vhost_dev *dev) |
579 | { |
580 | if (!dev->mm) |
581 | return; |
582 | |
583 | if (dev->use_worker) |
584 | mmput(dev->mm); |
585 | else |
586 | mmdrop(mm: dev->mm); |
587 | |
588 | dev->mm = NULL; |
589 | } |
590 | |
591 | static void vhost_worker_destroy(struct vhost_dev *dev, |
592 | struct vhost_worker *worker) |
593 | { |
594 | if (!worker) |
595 | return; |
596 | |
597 | WARN_ON(!llist_empty(&worker->work_list)); |
598 | xa_erase(&dev->worker_xa, index: worker->id); |
599 | vhost_task_stop(vtsk: worker->vtsk); |
600 | kfree(objp: worker); |
601 | } |
602 | |
603 | static void vhost_workers_free(struct vhost_dev *dev) |
604 | { |
605 | struct vhost_worker *worker; |
606 | unsigned long i; |
607 | |
608 | if (!dev->use_worker) |
609 | return; |
610 | |
611 | for (i = 0; i < dev->nvqs; i++) |
612 | rcu_assign_pointer(dev->vqs[i]->worker, NULL); |
613 | /* |
614 | * Free the default worker we created and cleanup workers userspace |
615 | * created but couldn't clean up (it forgot or crashed). |
616 | */ |
617 | xa_for_each(&dev->worker_xa, i, worker) |
618 | vhost_worker_destroy(dev, worker); |
619 | xa_destroy(&dev->worker_xa); |
620 | } |
621 | |
622 | static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev) |
623 | { |
624 | struct vhost_worker *worker; |
625 | struct vhost_task *vtsk; |
626 | char name[TASK_COMM_LEN]; |
627 | int ret; |
628 | u32 id; |
629 | |
630 | worker = kzalloc(size: sizeof(*worker), GFP_KERNEL_ACCOUNT); |
631 | if (!worker) |
632 | return NULL; |
633 | |
634 | snprintf(buf: name, size: sizeof(name), fmt: "vhost-%d" , current->pid); |
635 | |
636 | vtsk = vhost_task_create(fn: vhost_worker, arg: worker, name); |
637 | if (!vtsk) |
638 | goto free_worker; |
639 | |
640 | mutex_init(&worker->mutex); |
641 | init_llist_head(list: &worker->work_list); |
642 | worker->kcov_handle = kcov_common_handle(); |
643 | worker->vtsk = vtsk; |
644 | |
645 | vhost_task_start(vtsk); |
646 | |
647 | ret = xa_alloc(xa: &dev->worker_xa, id: &id, entry: worker, xa_limit_32b, GFP_KERNEL); |
648 | if (ret < 0) |
649 | goto stop_worker; |
650 | worker->id = id; |
651 | |
652 | return worker; |
653 | |
654 | stop_worker: |
655 | vhost_task_stop(vtsk); |
656 | free_worker: |
657 | kfree(objp: worker); |
658 | return NULL; |
659 | } |
660 | |
661 | /* Caller must have device mutex */ |
662 | static void __vhost_vq_attach_worker(struct vhost_virtqueue *vq, |
663 | struct vhost_worker *worker) |
664 | { |
665 | struct vhost_worker *old_worker; |
666 | |
667 | old_worker = rcu_dereference_check(vq->worker, |
668 | lockdep_is_held(&vq->dev->mutex)); |
669 | |
670 | mutex_lock(&worker->mutex); |
671 | worker->attachment_cnt++; |
672 | mutex_unlock(lock: &worker->mutex); |
673 | rcu_assign_pointer(vq->worker, worker); |
674 | |
675 | if (!old_worker) |
676 | return; |
677 | /* |
678 | * Take the worker mutex to make sure we see the work queued from |
679 | * device wide flushes which doesn't use RCU for execution. |
680 | */ |
681 | mutex_lock(&old_worker->mutex); |
682 | old_worker->attachment_cnt--; |
683 | /* |
684 | * We don't want to call synchronize_rcu for every vq during setup |
685 | * because it will slow down VM startup. If we haven't done |
686 | * VHOST_SET_VRING_KICK and not done the driver specific |
687 | * SET_ENDPOINT/RUNNUNG then we can skip the sync since there will |
688 | * not be any works queued for scsi and net. |
689 | */ |
690 | mutex_lock(&vq->mutex); |
691 | if (!vhost_vq_get_backend(vq) && !vq->kick) { |
692 | mutex_unlock(lock: &vq->mutex); |
693 | mutex_unlock(lock: &old_worker->mutex); |
694 | /* |
695 | * vsock can queue anytime after VHOST_VSOCK_SET_GUEST_CID. |
696 | * Warn if it adds support for multiple workers but forgets to |
697 | * handle the early queueing case. |
698 | */ |
699 | WARN_ON(!old_worker->attachment_cnt && |
700 | !llist_empty(&old_worker->work_list)); |
701 | return; |
702 | } |
703 | mutex_unlock(lock: &vq->mutex); |
704 | |
705 | /* Make sure new vq queue/flush/poll calls see the new worker */ |
706 | synchronize_rcu(); |
707 | /* Make sure whatever was queued gets run */ |
708 | vhost_worker_flush(worker: old_worker); |
709 | mutex_unlock(lock: &old_worker->mutex); |
710 | } |
711 | |
712 | /* Caller must have device mutex */ |
713 | static int vhost_vq_attach_worker(struct vhost_virtqueue *vq, |
714 | struct vhost_vring_worker *info) |
715 | { |
716 | unsigned long index = info->worker_id; |
717 | struct vhost_dev *dev = vq->dev; |
718 | struct vhost_worker *worker; |
719 | |
720 | if (!dev->use_worker) |
721 | return -EINVAL; |
722 | |
723 | worker = xa_find(xa: &dev->worker_xa, index: &index, UINT_MAX, XA_PRESENT); |
724 | if (!worker || worker->id != info->worker_id) |
725 | return -ENODEV; |
726 | |
727 | __vhost_vq_attach_worker(vq, worker); |
728 | return 0; |
729 | } |
730 | |
731 | /* Caller must have device mutex */ |
732 | static int vhost_new_worker(struct vhost_dev *dev, |
733 | struct vhost_worker_state *info) |
734 | { |
735 | struct vhost_worker *worker; |
736 | |
737 | worker = vhost_worker_create(dev); |
738 | if (!worker) |
739 | return -ENOMEM; |
740 | |
741 | info->worker_id = worker->id; |
742 | return 0; |
743 | } |
744 | |
745 | /* Caller must have device mutex */ |
746 | static int vhost_free_worker(struct vhost_dev *dev, |
747 | struct vhost_worker_state *info) |
748 | { |
749 | unsigned long index = info->worker_id; |
750 | struct vhost_worker *worker; |
751 | |
752 | worker = xa_find(xa: &dev->worker_xa, index: &index, UINT_MAX, XA_PRESENT); |
753 | if (!worker || worker->id != info->worker_id) |
754 | return -ENODEV; |
755 | |
756 | mutex_lock(&worker->mutex); |
757 | if (worker->attachment_cnt) { |
758 | mutex_unlock(lock: &worker->mutex); |
759 | return -EBUSY; |
760 | } |
761 | mutex_unlock(lock: &worker->mutex); |
762 | |
763 | vhost_worker_destroy(dev, worker); |
764 | return 0; |
765 | } |
766 | |
767 | static int vhost_get_vq_from_user(struct vhost_dev *dev, void __user *argp, |
768 | struct vhost_virtqueue **vq, u32 *id) |
769 | { |
770 | u32 __user *idxp = argp; |
771 | u32 idx; |
772 | long r; |
773 | |
774 | r = get_user(idx, idxp); |
775 | if (r < 0) |
776 | return r; |
777 | |
778 | if (idx >= dev->nvqs) |
779 | return -ENOBUFS; |
780 | |
781 | idx = array_index_nospec(idx, dev->nvqs); |
782 | |
783 | *vq = dev->vqs[idx]; |
784 | *id = idx; |
785 | return 0; |
786 | } |
787 | |
788 | /* Caller must have device mutex */ |
789 | long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl, |
790 | void __user *argp) |
791 | { |
792 | struct vhost_vring_worker ring_worker; |
793 | struct vhost_worker_state state; |
794 | struct vhost_worker *worker; |
795 | struct vhost_virtqueue *vq; |
796 | long ret; |
797 | u32 idx; |
798 | |
799 | if (!dev->use_worker) |
800 | return -EINVAL; |
801 | |
802 | if (!vhost_dev_has_owner(dev)) |
803 | return -EINVAL; |
804 | |
805 | ret = vhost_dev_check_owner(dev); |
806 | if (ret) |
807 | return ret; |
808 | |
809 | switch (ioctl) { |
810 | /* dev worker ioctls */ |
811 | case VHOST_NEW_WORKER: |
812 | ret = vhost_new_worker(dev, info: &state); |
813 | if (!ret && copy_to_user(to: argp, from: &state, n: sizeof(state))) |
814 | ret = -EFAULT; |
815 | return ret; |
816 | case VHOST_FREE_WORKER: |
817 | if (copy_from_user(to: &state, from: argp, n: sizeof(state))) |
818 | return -EFAULT; |
819 | return vhost_free_worker(dev, info: &state); |
820 | /* vring worker ioctls */ |
821 | case VHOST_ATTACH_VRING_WORKER: |
822 | case VHOST_GET_VRING_WORKER: |
823 | break; |
824 | default: |
825 | return -ENOIOCTLCMD; |
826 | } |
827 | |
828 | ret = vhost_get_vq_from_user(dev, argp, vq: &vq, id: &idx); |
829 | if (ret) |
830 | return ret; |
831 | |
832 | switch (ioctl) { |
833 | case VHOST_ATTACH_VRING_WORKER: |
834 | if (copy_from_user(to: &ring_worker, from: argp, n: sizeof(ring_worker))) { |
835 | ret = -EFAULT; |
836 | break; |
837 | } |
838 | |
839 | ret = vhost_vq_attach_worker(vq, info: &ring_worker); |
840 | break; |
841 | case VHOST_GET_VRING_WORKER: |
842 | worker = rcu_dereference_check(vq->worker, |
843 | lockdep_is_held(&dev->mutex)); |
844 | if (!worker) { |
845 | ret = -EINVAL; |
846 | break; |
847 | } |
848 | |
849 | ring_worker.index = idx; |
850 | ring_worker.worker_id = worker->id; |
851 | |
852 | if (copy_to_user(to: argp, from: &ring_worker, n: sizeof(ring_worker))) |
853 | ret = -EFAULT; |
854 | break; |
855 | default: |
856 | ret = -ENOIOCTLCMD; |
857 | break; |
858 | } |
859 | |
860 | return ret; |
861 | } |
862 | EXPORT_SYMBOL_GPL(vhost_worker_ioctl); |
863 | |
864 | /* Caller should have device mutex */ |
865 | long vhost_dev_set_owner(struct vhost_dev *dev) |
866 | { |
867 | struct vhost_worker *worker; |
868 | int err, i; |
869 | |
870 | /* Is there an owner already? */ |
871 | if (vhost_dev_has_owner(dev)) { |
872 | err = -EBUSY; |
873 | goto err_mm; |
874 | } |
875 | |
876 | vhost_attach_mm(dev); |
877 | |
878 | err = vhost_dev_alloc_iovecs(dev); |
879 | if (err) |
880 | goto err_iovecs; |
881 | |
882 | if (dev->use_worker) { |
883 | /* |
884 | * This should be done last, because vsock can queue work |
885 | * before VHOST_SET_OWNER so it simplifies the failure path |
886 | * below since we don't have to worry about vsock queueing |
887 | * while we free the worker. |
888 | */ |
889 | worker = vhost_worker_create(dev); |
890 | if (!worker) { |
891 | err = -ENOMEM; |
892 | goto err_worker; |
893 | } |
894 | |
895 | for (i = 0; i < dev->nvqs; i++) |
896 | __vhost_vq_attach_worker(vq: dev->vqs[i], worker); |
897 | } |
898 | |
899 | return 0; |
900 | |
901 | err_worker: |
902 | vhost_dev_free_iovecs(dev); |
903 | err_iovecs: |
904 | vhost_detach_mm(dev); |
905 | err_mm: |
906 | return err; |
907 | } |
908 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
909 | |
910 | static struct vhost_iotlb *iotlb_alloc(void) |
911 | { |
912 | return vhost_iotlb_alloc(limit: max_iotlb_entries, |
913 | VHOST_IOTLB_FLAG_RETIRE); |
914 | } |
915 | |
916 | struct vhost_iotlb *vhost_dev_reset_owner_prepare(void) |
917 | { |
918 | return iotlb_alloc(); |
919 | } |
920 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
921 | |
922 | /* Caller should have device mutex */ |
923 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *umem) |
924 | { |
925 | int i; |
926 | |
927 | vhost_dev_cleanup(dev); |
928 | |
929 | dev->umem = umem; |
930 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
931 | * VQs aren't running. |
932 | */ |
933 | for (i = 0; i < dev->nvqs; ++i) |
934 | dev->vqs[i]->umem = umem; |
935 | } |
936 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
937 | |
938 | void vhost_dev_stop(struct vhost_dev *dev) |
939 | { |
940 | int i; |
941 | |
942 | for (i = 0; i < dev->nvqs; ++i) { |
943 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) |
944 | vhost_poll_stop(&dev->vqs[i]->poll); |
945 | } |
946 | |
947 | vhost_dev_flush(dev); |
948 | } |
949 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
950 | |
951 | void vhost_clear_msg(struct vhost_dev *dev) |
952 | { |
953 | struct vhost_msg_node *node, *n; |
954 | |
955 | spin_lock(lock: &dev->iotlb_lock); |
956 | |
957 | list_for_each_entry_safe(node, n, &dev->read_list, node) { |
958 | list_del(entry: &node->node); |
959 | kfree(objp: node); |
960 | } |
961 | |
962 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { |
963 | list_del(entry: &node->node); |
964 | kfree(objp: node); |
965 | } |
966 | |
967 | spin_unlock(lock: &dev->iotlb_lock); |
968 | } |
969 | EXPORT_SYMBOL_GPL(vhost_clear_msg); |
970 | |
971 | void vhost_dev_cleanup(struct vhost_dev *dev) |
972 | { |
973 | int i; |
974 | |
975 | for (i = 0; i < dev->nvqs; ++i) { |
976 | if (dev->vqs[i]->error_ctx) |
977 | eventfd_ctx_put(ctx: dev->vqs[i]->error_ctx); |
978 | if (dev->vqs[i]->kick) |
979 | fput(dev->vqs[i]->kick); |
980 | if (dev->vqs[i]->call_ctx.ctx) |
981 | eventfd_ctx_put(ctx: dev->vqs[i]->call_ctx.ctx); |
982 | vhost_vq_reset(dev, vq: dev->vqs[i]); |
983 | } |
984 | vhost_dev_free_iovecs(dev); |
985 | if (dev->log_ctx) |
986 | eventfd_ctx_put(ctx: dev->log_ctx); |
987 | dev->log_ctx = NULL; |
988 | /* No one will access memory at this point */ |
989 | vhost_iotlb_free(iotlb: dev->umem); |
990 | dev->umem = NULL; |
991 | vhost_iotlb_free(iotlb: dev->iotlb); |
992 | dev->iotlb = NULL; |
993 | vhost_clear_msg(dev); |
994 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
995 | vhost_workers_free(dev); |
996 | vhost_detach_mm(dev); |
997 | } |
998 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
999 | |
1000 | static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) |
1001 | { |
1002 | u64 a = addr / VHOST_PAGE_SIZE / 8; |
1003 | |
1004 | /* Make sure 64 bit math will not overflow. */ |
1005 | if (a > ULONG_MAX - (unsigned long)log_base || |
1006 | a + (unsigned long)log_base > ULONG_MAX) |
1007 | return false; |
1008 | |
1009 | return access_ok(log_base + a, |
1010 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); |
1011 | } |
1012 | |
1013 | /* Make sure 64 bit math will not overflow. */ |
1014 | static bool vhost_overflow(u64 uaddr, u64 size) |
1015 | { |
1016 | if (uaddr > ULONG_MAX || size > ULONG_MAX) |
1017 | return true; |
1018 | |
1019 | if (!size) |
1020 | return false; |
1021 | |
1022 | return uaddr > ULONG_MAX - size + 1; |
1023 | } |
1024 | |
1025 | /* Caller should have vq mutex and device mutex. */ |
1026 | static bool vq_memory_access_ok(void __user *log_base, struct vhost_iotlb *umem, |
1027 | int log_all) |
1028 | { |
1029 | struct vhost_iotlb_map *map; |
1030 | |
1031 | if (!umem) |
1032 | return false; |
1033 | |
1034 | list_for_each_entry(map, &umem->list, link) { |
1035 | unsigned long a = map->addr; |
1036 | |
1037 | if (vhost_overflow(uaddr: map->addr, size: map->size)) |
1038 | return false; |
1039 | |
1040 | |
1041 | if (!access_ok((void __user *)a, map->size)) |
1042 | return false; |
1043 | else if (log_all && !log_access_ok(log_base, |
1044 | addr: map->start, |
1045 | sz: map->size)) |
1046 | return false; |
1047 | } |
1048 | return true; |
1049 | } |
1050 | |
1051 | static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, |
1052 | u64 addr, unsigned int size, |
1053 | int type) |
1054 | { |
1055 | const struct vhost_iotlb_map *map = vq->meta_iotlb[type]; |
1056 | |
1057 | if (!map) |
1058 | return NULL; |
1059 | |
1060 | return (void __user *)(uintptr_t)(map->addr + addr - map->start); |
1061 | } |
1062 | |
1063 | /* Can we switch to this memory table? */ |
1064 | /* Caller should have device mutex but not vq mutex */ |
1065 | static bool memory_access_ok(struct vhost_dev *d, struct vhost_iotlb *umem, |
1066 | int log_all) |
1067 | { |
1068 | int i; |
1069 | |
1070 | for (i = 0; i < d->nvqs; ++i) { |
1071 | bool ok; |
1072 | bool log; |
1073 | |
1074 | mutex_lock(&d->vqs[i]->mutex); |
1075 | log = log_all || vhost_has_feature(vq: d->vqs[i], VHOST_F_LOG_ALL); |
1076 | /* If ring is inactive, will check when it's enabled. */ |
1077 | if (d->vqs[i]->private_data) |
1078 | ok = vq_memory_access_ok(log_base: d->vqs[i]->log_base, |
1079 | umem, log_all: log); |
1080 | else |
1081 | ok = true; |
1082 | mutex_unlock(lock: &d->vqs[i]->mutex); |
1083 | if (!ok) |
1084 | return false; |
1085 | } |
1086 | return true; |
1087 | } |
1088 | |
1089 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
1090 | struct iovec iov[], int iov_size, int access); |
1091 | |
1092 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, |
1093 | const void *from, unsigned size) |
1094 | { |
1095 | int ret; |
1096 | |
1097 | if (!vq->iotlb) |
1098 | return __copy_to_user(to, from, n: size); |
1099 | else { |
1100 | /* This function should be called after iotlb |
1101 | * prefetch, which means we're sure that all vq |
1102 | * could be access through iotlb. So -EAGAIN should |
1103 | * not happen in this case. |
1104 | */ |
1105 | struct iov_iter t; |
1106 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
1107 | addr: (u64)(uintptr_t)to, size, |
1108 | type: VHOST_ADDR_USED); |
1109 | |
1110 | if (uaddr) |
1111 | return __copy_to_user(to: uaddr, from, n: size); |
1112 | |
1113 | ret = translate_desc(vq, addr: (u64)(uintptr_t)to, len: size, iov: vq->iotlb_iov, |
1114 | ARRAY_SIZE(vq->iotlb_iov), |
1115 | VHOST_ACCESS_WO); |
1116 | if (ret < 0) |
1117 | goto out; |
1118 | iov_iter_init(i: &t, ITER_DEST, iov: vq->iotlb_iov, nr_segs: ret, count: size); |
1119 | ret = copy_to_iter(addr: from, bytes: size, i: &t); |
1120 | if (ret == size) |
1121 | ret = 0; |
1122 | } |
1123 | out: |
1124 | return ret; |
1125 | } |
1126 | |
1127 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, |
1128 | void __user *from, unsigned size) |
1129 | { |
1130 | int ret; |
1131 | |
1132 | if (!vq->iotlb) |
1133 | return __copy_from_user(to, from, n: size); |
1134 | else { |
1135 | /* This function should be called after iotlb |
1136 | * prefetch, which means we're sure that vq |
1137 | * could be access through iotlb. So -EAGAIN should |
1138 | * not happen in this case. |
1139 | */ |
1140 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
1141 | addr: (u64)(uintptr_t)from, size, |
1142 | type: VHOST_ADDR_DESC); |
1143 | struct iov_iter f; |
1144 | |
1145 | if (uaddr) |
1146 | return __copy_from_user(to, from: uaddr, n: size); |
1147 | |
1148 | ret = translate_desc(vq, addr: (u64)(uintptr_t)from, len: size, iov: vq->iotlb_iov, |
1149 | ARRAY_SIZE(vq->iotlb_iov), |
1150 | VHOST_ACCESS_RO); |
1151 | if (ret < 0) { |
1152 | vq_err(vq, "IOTLB translation failure: uaddr " |
1153 | "%p size 0x%llx\n" , from, |
1154 | (unsigned long long) size); |
1155 | goto out; |
1156 | } |
1157 | iov_iter_init(i: &f, ITER_SOURCE, iov: vq->iotlb_iov, nr_segs: ret, count: size); |
1158 | ret = copy_from_iter(addr: to, bytes: size, i: &f); |
1159 | if (ret == size) |
1160 | ret = 0; |
1161 | } |
1162 | |
1163 | out: |
1164 | return ret; |
1165 | } |
1166 | |
1167 | static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq, |
1168 | void __user *addr, unsigned int size, |
1169 | int type) |
1170 | { |
1171 | int ret; |
1172 | |
1173 | ret = translate_desc(vq, addr: (u64)(uintptr_t)addr, len: size, iov: vq->iotlb_iov, |
1174 | ARRAY_SIZE(vq->iotlb_iov), |
1175 | VHOST_ACCESS_RO); |
1176 | if (ret < 0) { |
1177 | vq_err(vq, "IOTLB translation failure: uaddr " |
1178 | "%p size 0x%llx\n" , addr, |
1179 | (unsigned long long) size); |
1180 | return NULL; |
1181 | } |
1182 | |
1183 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { |
1184 | vq_err(vq, "Non atomic userspace memory access: uaddr " |
1185 | "%p size 0x%llx\n" , addr, |
1186 | (unsigned long long) size); |
1187 | return NULL; |
1188 | } |
1189 | |
1190 | return vq->iotlb_iov[0].iov_base; |
1191 | } |
1192 | |
1193 | /* This function should be called after iotlb |
1194 | * prefetch, which means we're sure that vq |
1195 | * could be access through iotlb. So -EAGAIN should |
1196 | * not happen in this case. |
1197 | */ |
1198 | static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, |
1199 | void __user *addr, unsigned int size, |
1200 | int type) |
1201 | { |
1202 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
1203 | addr: (u64)(uintptr_t)addr, size, type); |
1204 | if (uaddr) |
1205 | return uaddr; |
1206 | |
1207 | return __vhost_get_user_slow(vq, addr, size, type); |
1208 | } |
1209 | |
1210 | #define vhost_put_user(vq, x, ptr) \ |
1211 | ({ \ |
1212 | int ret; \ |
1213 | if (!vq->iotlb) { \ |
1214 | ret = __put_user(x, ptr); \ |
1215 | } else { \ |
1216 | __typeof__(ptr) to = \ |
1217 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
1218 | sizeof(*ptr), VHOST_ADDR_USED); \ |
1219 | if (to != NULL) \ |
1220 | ret = __put_user(x, to); \ |
1221 | else \ |
1222 | ret = -EFAULT; \ |
1223 | } \ |
1224 | ret; \ |
1225 | }) |
1226 | |
1227 | static inline int vhost_put_avail_event(struct vhost_virtqueue *vq) |
1228 | { |
1229 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), |
1230 | vhost_avail_event(vq)); |
1231 | } |
1232 | |
1233 | static inline int vhost_put_used(struct vhost_virtqueue *vq, |
1234 | struct vring_used_elem *head, int idx, |
1235 | int count) |
1236 | { |
1237 | return vhost_copy_to_user(vq, to: vq->used->ring + idx, from: head, |
1238 | size: count * sizeof(*head)); |
1239 | } |
1240 | |
1241 | static inline int vhost_put_used_flags(struct vhost_virtqueue *vq) |
1242 | |
1243 | { |
1244 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), |
1245 | &vq->used->flags); |
1246 | } |
1247 | |
1248 | static inline int vhost_put_used_idx(struct vhost_virtqueue *vq) |
1249 | |
1250 | { |
1251 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), |
1252 | &vq->used->idx); |
1253 | } |
1254 | |
1255 | #define vhost_get_user(vq, x, ptr, type) \ |
1256 | ({ \ |
1257 | int ret; \ |
1258 | if (!vq->iotlb) { \ |
1259 | ret = __get_user(x, ptr); \ |
1260 | } else { \ |
1261 | __typeof__(ptr) from = \ |
1262 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
1263 | sizeof(*ptr), \ |
1264 | type); \ |
1265 | if (from != NULL) \ |
1266 | ret = __get_user(x, from); \ |
1267 | else \ |
1268 | ret = -EFAULT; \ |
1269 | } \ |
1270 | ret; \ |
1271 | }) |
1272 | |
1273 | #define vhost_get_avail(vq, x, ptr) \ |
1274 | vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL) |
1275 | |
1276 | #define vhost_get_used(vq, x, ptr) \ |
1277 | vhost_get_user(vq, x, ptr, VHOST_ADDR_USED) |
1278 | |
1279 | static void vhost_dev_lock_vqs(struct vhost_dev *d) |
1280 | { |
1281 | int i = 0; |
1282 | for (i = 0; i < d->nvqs; ++i) |
1283 | mutex_lock_nested(lock: &d->vqs[i]->mutex, subclass: i); |
1284 | } |
1285 | |
1286 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) |
1287 | { |
1288 | int i = 0; |
1289 | for (i = 0; i < d->nvqs; ++i) |
1290 | mutex_unlock(lock: &d->vqs[i]->mutex); |
1291 | } |
1292 | |
1293 | static inline int vhost_get_avail_idx(struct vhost_virtqueue *vq, |
1294 | __virtio16 *idx) |
1295 | { |
1296 | return vhost_get_avail(vq, *idx, &vq->avail->idx); |
1297 | } |
1298 | |
1299 | static inline int vhost_get_avail_head(struct vhost_virtqueue *vq, |
1300 | __virtio16 *head, int idx) |
1301 | { |
1302 | return vhost_get_avail(vq, *head, |
1303 | &vq->avail->ring[idx & (vq->num - 1)]); |
1304 | } |
1305 | |
1306 | static inline int vhost_get_avail_flags(struct vhost_virtqueue *vq, |
1307 | __virtio16 *flags) |
1308 | { |
1309 | return vhost_get_avail(vq, *flags, &vq->avail->flags); |
1310 | } |
1311 | |
1312 | static inline int vhost_get_used_event(struct vhost_virtqueue *vq, |
1313 | __virtio16 *event) |
1314 | { |
1315 | return vhost_get_avail(vq, *event, vhost_used_event(vq)); |
1316 | } |
1317 | |
1318 | static inline int vhost_get_used_idx(struct vhost_virtqueue *vq, |
1319 | __virtio16 *idx) |
1320 | { |
1321 | return vhost_get_used(vq, *idx, &vq->used->idx); |
1322 | } |
1323 | |
1324 | static inline int vhost_get_desc(struct vhost_virtqueue *vq, |
1325 | struct vring_desc *desc, int idx) |
1326 | { |
1327 | return vhost_copy_from_user(vq, to: desc, from: vq->desc + idx, size: sizeof(*desc)); |
1328 | } |
1329 | |
1330 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, |
1331 | struct vhost_iotlb_msg *msg) |
1332 | { |
1333 | struct vhost_msg_node *node, *n; |
1334 | |
1335 | spin_lock(lock: &d->iotlb_lock); |
1336 | |
1337 | list_for_each_entry_safe(node, n, &d->pending_list, node) { |
1338 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; |
1339 | if (msg->iova <= vq_msg->iova && |
1340 | msg->iova + msg->size - 1 >= vq_msg->iova && |
1341 | vq_msg->type == VHOST_IOTLB_MISS) { |
1342 | vhost_poll_queue(&node->vq->poll); |
1343 | list_del(entry: &node->node); |
1344 | kfree(objp: node); |
1345 | } |
1346 | } |
1347 | |
1348 | spin_unlock(lock: &d->iotlb_lock); |
1349 | } |
1350 | |
1351 | static bool umem_access_ok(u64 uaddr, u64 size, int access) |
1352 | { |
1353 | unsigned long a = uaddr; |
1354 | |
1355 | /* Make sure 64 bit math will not overflow. */ |
1356 | if (vhost_overflow(uaddr, size)) |
1357 | return false; |
1358 | |
1359 | if ((access & VHOST_ACCESS_RO) && |
1360 | !access_ok((void __user *)a, size)) |
1361 | return false; |
1362 | if ((access & VHOST_ACCESS_WO) && |
1363 | !access_ok((void __user *)a, size)) |
1364 | return false; |
1365 | return true; |
1366 | } |
1367 | |
1368 | static int vhost_process_iotlb_msg(struct vhost_dev *dev, u32 asid, |
1369 | struct vhost_iotlb_msg *msg) |
1370 | { |
1371 | int ret = 0; |
1372 | |
1373 | if (asid != 0) |
1374 | return -EINVAL; |
1375 | |
1376 | mutex_lock(&dev->mutex); |
1377 | vhost_dev_lock_vqs(d: dev); |
1378 | switch (msg->type) { |
1379 | case VHOST_IOTLB_UPDATE: |
1380 | if (!dev->iotlb) { |
1381 | ret = -EFAULT; |
1382 | break; |
1383 | } |
1384 | if (!umem_access_ok(uaddr: msg->uaddr, size: msg->size, access: msg->perm)) { |
1385 | ret = -EFAULT; |
1386 | break; |
1387 | } |
1388 | vhost_vq_meta_reset(d: dev); |
1389 | if (vhost_iotlb_add_range(iotlb: dev->iotlb, start: msg->iova, |
1390 | last: msg->iova + msg->size - 1, |
1391 | addr: msg->uaddr, perm: msg->perm)) { |
1392 | ret = -ENOMEM; |
1393 | break; |
1394 | } |
1395 | vhost_iotlb_notify_vq(d: dev, msg); |
1396 | break; |
1397 | case VHOST_IOTLB_INVALIDATE: |
1398 | if (!dev->iotlb) { |
1399 | ret = -EFAULT; |
1400 | break; |
1401 | } |
1402 | vhost_vq_meta_reset(d: dev); |
1403 | vhost_iotlb_del_range(iotlb: dev->iotlb, start: msg->iova, |
1404 | last: msg->iova + msg->size - 1); |
1405 | break; |
1406 | default: |
1407 | ret = -EINVAL; |
1408 | break; |
1409 | } |
1410 | |
1411 | vhost_dev_unlock_vqs(d: dev); |
1412 | mutex_unlock(lock: &dev->mutex); |
1413 | |
1414 | return ret; |
1415 | } |
1416 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, |
1417 | struct iov_iter *from) |
1418 | { |
1419 | struct vhost_iotlb_msg msg; |
1420 | size_t offset; |
1421 | int type, ret; |
1422 | u32 asid = 0; |
1423 | |
1424 | ret = copy_from_iter(addr: &type, bytes: sizeof(type), i: from); |
1425 | if (ret != sizeof(type)) { |
1426 | ret = -EINVAL; |
1427 | goto done; |
1428 | } |
1429 | |
1430 | switch (type) { |
1431 | case VHOST_IOTLB_MSG: |
1432 | /* There maybe a hole after type for V1 message type, |
1433 | * so skip it here. |
1434 | */ |
1435 | offset = offsetof(struct vhost_msg, iotlb) - sizeof(int); |
1436 | break; |
1437 | case VHOST_IOTLB_MSG_V2: |
1438 | if (vhost_backend_has_feature(vq: dev->vqs[0], |
1439 | VHOST_BACKEND_F_IOTLB_ASID)) { |
1440 | ret = copy_from_iter(addr: &asid, bytes: sizeof(asid), i: from); |
1441 | if (ret != sizeof(asid)) { |
1442 | ret = -EINVAL; |
1443 | goto done; |
1444 | } |
1445 | offset = 0; |
1446 | } else |
1447 | offset = sizeof(__u32); |
1448 | break; |
1449 | default: |
1450 | ret = -EINVAL; |
1451 | goto done; |
1452 | } |
1453 | |
1454 | iov_iter_advance(i: from, bytes: offset); |
1455 | ret = copy_from_iter(addr: &msg, bytes: sizeof(msg), i: from); |
1456 | if (ret != sizeof(msg)) { |
1457 | ret = -EINVAL; |
1458 | goto done; |
1459 | } |
1460 | |
1461 | if (msg.type == VHOST_IOTLB_UPDATE && msg.size == 0) { |
1462 | ret = -EINVAL; |
1463 | goto done; |
1464 | } |
1465 | |
1466 | if (dev->msg_handler) |
1467 | ret = dev->msg_handler(dev, asid, &msg); |
1468 | else |
1469 | ret = vhost_process_iotlb_msg(dev, asid, msg: &msg); |
1470 | if (ret) { |
1471 | ret = -EFAULT; |
1472 | goto done; |
1473 | } |
1474 | |
1475 | ret = (type == VHOST_IOTLB_MSG) ? sizeof(struct vhost_msg) : |
1476 | sizeof(struct vhost_msg_v2); |
1477 | done: |
1478 | return ret; |
1479 | } |
1480 | EXPORT_SYMBOL(vhost_chr_write_iter); |
1481 | |
1482 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
1483 | poll_table *wait) |
1484 | { |
1485 | __poll_t mask = 0; |
1486 | |
1487 | poll_wait(filp: file, wait_address: &dev->wait, p: wait); |
1488 | |
1489 | if (!list_empty(head: &dev->read_list)) |
1490 | mask |= EPOLLIN | EPOLLRDNORM; |
1491 | |
1492 | return mask; |
1493 | } |
1494 | EXPORT_SYMBOL(vhost_chr_poll); |
1495 | |
1496 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, |
1497 | int noblock) |
1498 | { |
1499 | DEFINE_WAIT(wait); |
1500 | struct vhost_msg_node *node; |
1501 | ssize_t ret = 0; |
1502 | unsigned size = sizeof(struct vhost_msg); |
1503 | |
1504 | if (iov_iter_count(i: to) < size) |
1505 | return 0; |
1506 | |
1507 | while (1) { |
1508 | if (!noblock) |
1509 | prepare_to_wait(wq_head: &dev->wait, wq_entry: &wait, |
1510 | TASK_INTERRUPTIBLE); |
1511 | |
1512 | node = vhost_dequeue_msg(dev, head: &dev->read_list); |
1513 | if (node) |
1514 | break; |
1515 | if (noblock) { |
1516 | ret = -EAGAIN; |
1517 | break; |
1518 | } |
1519 | if (signal_pending(current)) { |
1520 | ret = -ERESTARTSYS; |
1521 | break; |
1522 | } |
1523 | if (!dev->iotlb) { |
1524 | ret = -EBADFD; |
1525 | break; |
1526 | } |
1527 | |
1528 | schedule(); |
1529 | } |
1530 | |
1531 | if (!noblock) |
1532 | finish_wait(wq_head: &dev->wait, wq_entry: &wait); |
1533 | |
1534 | if (node) { |
1535 | struct vhost_iotlb_msg *msg; |
1536 | void *start = &node->msg; |
1537 | |
1538 | switch (node->msg.type) { |
1539 | case VHOST_IOTLB_MSG: |
1540 | size = sizeof(node->msg); |
1541 | msg = &node->msg.iotlb; |
1542 | break; |
1543 | case VHOST_IOTLB_MSG_V2: |
1544 | size = sizeof(node->msg_v2); |
1545 | msg = &node->msg_v2.iotlb; |
1546 | break; |
1547 | default: |
1548 | BUG(); |
1549 | break; |
1550 | } |
1551 | |
1552 | ret = copy_to_iter(addr: start, bytes: size, i: to); |
1553 | if (ret != size || msg->type != VHOST_IOTLB_MISS) { |
1554 | kfree(objp: node); |
1555 | return ret; |
1556 | } |
1557 | vhost_enqueue_msg(dev, head: &dev->pending_list, node); |
1558 | } |
1559 | |
1560 | return ret; |
1561 | } |
1562 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); |
1563 | |
1564 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) |
1565 | { |
1566 | struct vhost_dev *dev = vq->dev; |
1567 | struct vhost_msg_node *node; |
1568 | struct vhost_iotlb_msg *msg; |
1569 | bool v2 = vhost_backend_has_feature(vq, VHOST_BACKEND_F_IOTLB_MSG_V2); |
1570 | |
1571 | node = vhost_new_msg(vq, type: v2 ? VHOST_IOTLB_MSG_V2 : VHOST_IOTLB_MSG); |
1572 | if (!node) |
1573 | return -ENOMEM; |
1574 | |
1575 | if (v2) { |
1576 | node->msg_v2.type = VHOST_IOTLB_MSG_V2; |
1577 | msg = &node->msg_v2.iotlb; |
1578 | } else { |
1579 | msg = &node->msg.iotlb; |
1580 | } |
1581 | |
1582 | msg->type = VHOST_IOTLB_MISS; |
1583 | msg->iova = iova; |
1584 | msg->perm = access; |
1585 | |
1586 | vhost_enqueue_msg(dev, head: &dev->read_list, node); |
1587 | |
1588 | return 0; |
1589 | } |
1590 | |
1591 | static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
1592 | vring_desc_t __user *desc, |
1593 | vring_avail_t __user *avail, |
1594 | vring_used_t __user *used) |
1595 | |
1596 | { |
1597 | /* If an IOTLB device is present, the vring addresses are |
1598 | * GIOVAs. Access validation occurs at prefetch time. */ |
1599 | if (vq->iotlb) |
1600 | return true; |
1601 | |
1602 | return access_ok(desc, vhost_get_desc_size(vq, num)) && |
1603 | access_ok(avail, vhost_get_avail_size(vq, num)) && |
1604 | access_ok(used, vhost_get_used_size(vq, num)); |
1605 | } |
1606 | |
1607 | static void vhost_vq_meta_update(struct vhost_virtqueue *vq, |
1608 | const struct vhost_iotlb_map *map, |
1609 | int type) |
1610 | { |
1611 | int access = (type == VHOST_ADDR_USED) ? |
1612 | VHOST_ACCESS_WO : VHOST_ACCESS_RO; |
1613 | |
1614 | if (likely(map->perm & access)) |
1615 | vq->meta_iotlb[type] = map; |
1616 | } |
1617 | |
1618 | static bool iotlb_access_ok(struct vhost_virtqueue *vq, |
1619 | int access, u64 addr, u64 len, int type) |
1620 | { |
1621 | const struct vhost_iotlb_map *map; |
1622 | struct vhost_iotlb *umem = vq->iotlb; |
1623 | u64 s = 0, size, orig_addr = addr, last = addr + len - 1; |
1624 | |
1625 | if (vhost_vq_meta_fetch(vq, addr, size: len, type)) |
1626 | return true; |
1627 | |
1628 | while (len > s) { |
1629 | map = vhost_iotlb_itree_first(iotlb: umem, start: addr, last); |
1630 | if (map == NULL || map->start > addr) { |
1631 | vhost_iotlb_miss(vq, iova: addr, access); |
1632 | return false; |
1633 | } else if (!(map->perm & access)) { |
1634 | /* Report the possible access violation by |
1635 | * request another translation from userspace. |
1636 | */ |
1637 | return false; |
1638 | } |
1639 | |
1640 | size = map->size - addr + map->start; |
1641 | |
1642 | if (orig_addr == addr && size >= len) |
1643 | vhost_vq_meta_update(vq, map, type); |
1644 | |
1645 | s += size; |
1646 | addr += size; |
1647 | } |
1648 | |
1649 | return true; |
1650 | } |
1651 | |
1652 | int vq_meta_prefetch(struct vhost_virtqueue *vq) |
1653 | { |
1654 | unsigned int num = vq->num; |
1655 | |
1656 | if (!vq->iotlb) |
1657 | return 1; |
1658 | |
1659 | return iotlb_access_ok(vq, VHOST_MAP_RO, addr: (u64)(uintptr_t)vq->desc, |
1660 | len: vhost_get_desc_size(vq, num), type: VHOST_ADDR_DESC) && |
1661 | iotlb_access_ok(vq, VHOST_MAP_RO, addr: (u64)(uintptr_t)vq->avail, |
1662 | len: vhost_get_avail_size(vq, num), |
1663 | type: VHOST_ADDR_AVAIL) && |
1664 | iotlb_access_ok(vq, VHOST_MAP_WO, addr: (u64)(uintptr_t)vq->used, |
1665 | len: vhost_get_used_size(vq, num), type: VHOST_ADDR_USED); |
1666 | } |
1667 | EXPORT_SYMBOL_GPL(vq_meta_prefetch); |
1668 | |
1669 | /* Can we log writes? */ |
1670 | /* Caller should have device mutex but not vq mutex */ |
1671 | bool vhost_log_access_ok(struct vhost_dev *dev) |
1672 | { |
1673 | return memory_access_ok(d: dev, umem: dev->umem, log_all: 1); |
1674 | } |
1675 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
1676 | |
1677 | static bool vq_log_used_access_ok(struct vhost_virtqueue *vq, |
1678 | void __user *log_base, |
1679 | bool log_used, |
1680 | u64 log_addr) |
1681 | { |
1682 | /* If an IOTLB device is present, log_addr is a GIOVA that |
1683 | * will never be logged by log_used(). */ |
1684 | if (vq->iotlb) |
1685 | return true; |
1686 | |
1687 | return !log_used || log_access_ok(log_base, addr: log_addr, |
1688 | sz: vhost_get_used_size(vq, num: vq->num)); |
1689 | } |
1690 | |
1691 | /* Verify access for write logging. */ |
1692 | /* Caller should have vq mutex and device mutex */ |
1693 | static bool vq_log_access_ok(struct vhost_virtqueue *vq, |
1694 | void __user *log_base) |
1695 | { |
1696 | return vq_memory_access_ok(log_base, umem: vq->umem, |
1697 | log_all: vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
1698 | vq_log_used_access_ok(vq, log_base, log_used: vq->log_used, log_addr: vq->log_addr); |
1699 | } |
1700 | |
1701 | /* Can we start vq? */ |
1702 | /* Caller should have vq mutex and device mutex */ |
1703 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq) |
1704 | { |
1705 | if (!vq_log_access_ok(vq, log_base: vq->log_base)) |
1706 | return false; |
1707 | |
1708 | return vq_access_ok(vq, num: vq->num, desc: vq->desc, avail: vq->avail, used: vq->used); |
1709 | } |
1710 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
1711 | |
1712 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
1713 | { |
1714 | struct vhost_memory mem, *newmem; |
1715 | struct vhost_memory_region *region; |
1716 | struct vhost_iotlb *newumem, *oldumem; |
1717 | unsigned long size = offsetof(struct vhost_memory, regions); |
1718 | int i; |
1719 | |
1720 | if (copy_from_user(to: &mem, from: m, n: size)) |
1721 | return -EFAULT; |
1722 | if (mem.padding) |
1723 | return -EOPNOTSUPP; |
1724 | if (mem.nregions > max_mem_regions) |
1725 | return -E2BIG; |
1726 | newmem = kvzalloc(struct_size(newmem, regions, mem.nregions), |
1727 | GFP_KERNEL); |
1728 | if (!newmem) |
1729 | return -ENOMEM; |
1730 | |
1731 | memcpy(newmem, &mem, size); |
1732 | if (copy_from_user(to: newmem->regions, from: m->regions, |
1733 | flex_array_size(newmem, regions, mem.nregions))) { |
1734 | kvfree(addr: newmem); |
1735 | return -EFAULT; |
1736 | } |
1737 | |
1738 | newumem = iotlb_alloc(); |
1739 | if (!newumem) { |
1740 | kvfree(addr: newmem); |
1741 | return -ENOMEM; |
1742 | } |
1743 | |
1744 | for (region = newmem->regions; |
1745 | region < newmem->regions + mem.nregions; |
1746 | region++) { |
1747 | if (vhost_iotlb_add_range(iotlb: newumem, |
1748 | start: region->guest_phys_addr, |
1749 | last: region->guest_phys_addr + |
1750 | region->memory_size - 1, |
1751 | addr: region->userspace_addr, |
1752 | VHOST_MAP_RW)) |
1753 | goto err; |
1754 | } |
1755 | |
1756 | if (!memory_access_ok(d, umem: newumem, log_all: 0)) |
1757 | goto err; |
1758 | |
1759 | oldumem = d->umem; |
1760 | d->umem = newumem; |
1761 | |
1762 | /* All memory accesses are done under some VQ mutex. */ |
1763 | for (i = 0; i < d->nvqs; ++i) { |
1764 | mutex_lock(&d->vqs[i]->mutex); |
1765 | d->vqs[i]->umem = newumem; |
1766 | mutex_unlock(lock: &d->vqs[i]->mutex); |
1767 | } |
1768 | |
1769 | kvfree(addr: newmem); |
1770 | vhost_iotlb_free(iotlb: oldumem); |
1771 | return 0; |
1772 | |
1773 | err: |
1774 | vhost_iotlb_free(iotlb: newumem); |
1775 | kvfree(addr: newmem); |
1776 | return -EFAULT; |
1777 | } |
1778 | |
1779 | static long vhost_vring_set_num(struct vhost_dev *d, |
1780 | struct vhost_virtqueue *vq, |
1781 | void __user *argp) |
1782 | { |
1783 | struct vhost_vring_state s; |
1784 | |
1785 | /* Resizing ring with an active backend? |
1786 | * You don't want to do that. */ |
1787 | if (vq->private_data) |
1788 | return -EBUSY; |
1789 | |
1790 | if (copy_from_user(to: &s, from: argp, n: sizeof s)) |
1791 | return -EFAULT; |
1792 | |
1793 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) |
1794 | return -EINVAL; |
1795 | vq->num = s.num; |
1796 | |
1797 | return 0; |
1798 | } |
1799 | |
1800 | static long vhost_vring_set_addr(struct vhost_dev *d, |
1801 | struct vhost_virtqueue *vq, |
1802 | void __user *argp) |
1803 | { |
1804 | struct vhost_vring_addr a; |
1805 | |
1806 | if (copy_from_user(to: &a, from: argp, n: sizeof a)) |
1807 | return -EFAULT; |
1808 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) |
1809 | return -EOPNOTSUPP; |
1810 | |
1811 | /* For 32bit, verify that the top 32bits of the user |
1812 | data are set to zero. */ |
1813 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || |
1814 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || |
1815 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) |
1816 | return -EFAULT; |
1817 | |
1818 | /* Make sure it's safe to cast pointers to vring types. */ |
1819 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); |
1820 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); |
1821 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || |
1822 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || |
1823 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) |
1824 | return -EINVAL; |
1825 | |
1826 | /* We only verify access here if backend is configured. |
1827 | * If it is not, we don't as size might not have been setup. |
1828 | * We will verify when backend is configured. */ |
1829 | if (vq->private_data) { |
1830 | if (!vq_access_ok(vq, num: vq->num, |
1831 | desc: (void __user *)(unsigned long)a.desc_user_addr, |
1832 | avail: (void __user *)(unsigned long)a.avail_user_addr, |
1833 | used: (void __user *)(unsigned long)a.used_user_addr)) |
1834 | return -EINVAL; |
1835 | |
1836 | /* Also validate log access for used ring if enabled. */ |
1837 | if (!vq_log_used_access_ok(vq, log_base: vq->log_base, |
1838 | log_used: a.flags & (0x1 << VHOST_VRING_F_LOG), |
1839 | log_addr: a.log_guest_addr)) |
1840 | return -EINVAL; |
1841 | } |
1842 | |
1843 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); |
1844 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; |
1845 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; |
1846 | vq->log_addr = a.log_guest_addr; |
1847 | vq->used = (void __user *)(unsigned long)a.used_user_addr; |
1848 | |
1849 | return 0; |
1850 | } |
1851 | |
1852 | static long vhost_vring_set_num_addr(struct vhost_dev *d, |
1853 | struct vhost_virtqueue *vq, |
1854 | unsigned int ioctl, |
1855 | void __user *argp) |
1856 | { |
1857 | long r; |
1858 | |
1859 | mutex_lock(&vq->mutex); |
1860 | |
1861 | switch (ioctl) { |
1862 | case VHOST_SET_VRING_NUM: |
1863 | r = vhost_vring_set_num(d, vq, argp); |
1864 | break; |
1865 | case VHOST_SET_VRING_ADDR: |
1866 | r = vhost_vring_set_addr(d, vq, argp); |
1867 | break; |
1868 | default: |
1869 | BUG(); |
1870 | } |
1871 | |
1872 | mutex_unlock(lock: &vq->mutex); |
1873 | |
1874 | return r; |
1875 | } |
1876 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
1877 | { |
1878 | struct file *eventfp, *filep = NULL; |
1879 | bool pollstart = false, pollstop = false; |
1880 | struct eventfd_ctx *ctx = NULL; |
1881 | struct vhost_virtqueue *vq; |
1882 | struct vhost_vring_state s; |
1883 | struct vhost_vring_file f; |
1884 | u32 idx; |
1885 | long r; |
1886 | |
1887 | r = vhost_get_vq_from_user(dev: d, argp, vq: &vq, id: &idx); |
1888 | if (r < 0) |
1889 | return r; |
1890 | |
1891 | if (ioctl == VHOST_SET_VRING_NUM || |
1892 | ioctl == VHOST_SET_VRING_ADDR) { |
1893 | return vhost_vring_set_num_addr(d, vq, ioctl, argp); |
1894 | } |
1895 | |
1896 | mutex_lock(&vq->mutex); |
1897 | |
1898 | switch (ioctl) { |
1899 | case VHOST_SET_VRING_BASE: |
1900 | /* Moving base with an active backend? |
1901 | * You don't want to do that. */ |
1902 | if (vq->private_data) { |
1903 | r = -EBUSY; |
1904 | break; |
1905 | } |
1906 | if (copy_from_user(to: &s, from: argp, n: sizeof s)) { |
1907 | r = -EFAULT; |
1908 | break; |
1909 | } |
1910 | if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { |
1911 | vq->last_avail_idx = s.num & 0xffff; |
1912 | vq->last_used_idx = (s.num >> 16) & 0xffff; |
1913 | } else { |
1914 | if (s.num > 0xffff) { |
1915 | r = -EINVAL; |
1916 | break; |
1917 | } |
1918 | vq->last_avail_idx = s.num; |
1919 | } |
1920 | /* Forget the cached index value. */ |
1921 | vq->avail_idx = vq->last_avail_idx; |
1922 | break; |
1923 | case VHOST_GET_VRING_BASE: |
1924 | s.index = idx; |
1925 | if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) |
1926 | s.num = (u32)vq->last_avail_idx | ((u32)vq->last_used_idx << 16); |
1927 | else |
1928 | s.num = vq->last_avail_idx; |
1929 | if (copy_to_user(to: argp, from: &s, n: sizeof s)) |
1930 | r = -EFAULT; |
1931 | break; |
1932 | case VHOST_SET_VRING_KICK: |
1933 | if (copy_from_user(to: &f, from: argp, n: sizeof f)) { |
1934 | r = -EFAULT; |
1935 | break; |
1936 | } |
1937 | eventfp = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_fget(fd: f.fd); |
1938 | if (IS_ERR(ptr: eventfp)) { |
1939 | r = PTR_ERR(ptr: eventfp); |
1940 | break; |
1941 | } |
1942 | if (eventfp != vq->kick) { |
1943 | pollstop = (filep = vq->kick) != NULL; |
1944 | pollstart = (vq->kick = eventfp) != NULL; |
1945 | } else |
1946 | filep = eventfp; |
1947 | break; |
1948 | case VHOST_SET_VRING_CALL: |
1949 | if (copy_from_user(to: &f, from: argp, n: sizeof f)) { |
1950 | r = -EFAULT; |
1951 | break; |
1952 | } |
1953 | ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd: f.fd); |
1954 | if (IS_ERR(ptr: ctx)) { |
1955 | r = PTR_ERR(ptr: ctx); |
1956 | break; |
1957 | } |
1958 | |
1959 | swap(ctx, vq->call_ctx.ctx); |
1960 | break; |
1961 | case VHOST_SET_VRING_ERR: |
1962 | if (copy_from_user(to: &f, from: argp, n: sizeof f)) { |
1963 | r = -EFAULT; |
1964 | break; |
1965 | } |
1966 | ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd: f.fd); |
1967 | if (IS_ERR(ptr: ctx)) { |
1968 | r = PTR_ERR(ptr: ctx); |
1969 | break; |
1970 | } |
1971 | swap(ctx, vq->error_ctx); |
1972 | break; |
1973 | case VHOST_SET_VRING_ENDIAN: |
1974 | r = vhost_set_vring_endian(vq, argp); |
1975 | break; |
1976 | case VHOST_GET_VRING_ENDIAN: |
1977 | r = vhost_get_vring_endian(vq, idx, argp); |
1978 | break; |
1979 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1980 | if (copy_from_user(to: &s, from: argp, n: sizeof(s))) { |
1981 | r = -EFAULT; |
1982 | break; |
1983 | } |
1984 | vq->busyloop_timeout = s.num; |
1985 | break; |
1986 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: |
1987 | s.index = idx; |
1988 | s.num = vq->busyloop_timeout; |
1989 | if (copy_to_user(to: argp, from: &s, n: sizeof(s))) |
1990 | r = -EFAULT; |
1991 | break; |
1992 | default: |
1993 | r = -ENOIOCTLCMD; |
1994 | } |
1995 | |
1996 | if (pollstop && vq->handle_kick) |
1997 | vhost_poll_stop(&vq->poll); |
1998 | |
1999 | if (!IS_ERR_OR_NULL(ptr: ctx)) |
2000 | eventfd_ctx_put(ctx); |
2001 | if (filep) |
2002 | fput(filep); |
2003 | |
2004 | if (pollstart && vq->handle_kick) |
2005 | r = vhost_poll_start(&vq->poll, vq->kick); |
2006 | |
2007 | mutex_unlock(lock: &vq->mutex); |
2008 | |
2009 | if (pollstop && vq->handle_kick) |
2010 | vhost_dev_flush(vq->poll.dev); |
2011 | return r; |
2012 | } |
2013 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
2014 | |
2015 | int vhost_init_device_iotlb(struct vhost_dev *d) |
2016 | { |
2017 | struct vhost_iotlb *niotlb, *oiotlb; |
2018 | int i; |
2019 | |
2020 | niotlb = iotlb_alloc(); |
2021 | if (!niotlb) |
2022 | return -ENOMEM; |
2023 | |
2024 | oiotlb = d->iotlb; |
2025 | d->iotlb = niotlb; |
2026 | |
2027 | for (i = 0; i < d->nvqs; ++i) { |
2028 | struct vhost_virtqueue *vq = d->vqs[i]; |
2029 | |
2030 | mutex_lock(&vq->mutex); |
2031 | vq->iotlb = niotlb; |
2032 | __vhost_vq_meta_reset(vq); |
2033 | mutex_unlock(lock: &vq->mutex); |
2034 | } |
2035 | |
2036 | vhost_iotlb_free(iotlb: oiotlb); |
2037 | |
2038 | return 0; |
2039 | } |
2040 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); |
2041 | |
2042 | /* Caller must have device mutex */ |
2043 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
2044 | { |
2045 | struct eventfd_ctx *ctx; |
2046 | u64 p; |
2047 | long r; |
2048 | int i, fd; |
2049 | |
2050 | /* If you are not the owner, you can become one */ |
2051 | if (ioctl == VHOST_SET_OWNER) { |
2052 | r = vhost_dev_set_owner(d); |
2053 | goto done; |
2054 | } |
2055 | |
2056 | /* You must be the owner to do anything else */ |
2057 | r = vhost_dev_check_owner(d); |
2058 | if (r) |
2059 | goto done; |
2060 | |
2061 | switch (ioctl) { |
2062 | case VHOST_SET_MEM_TABLE: |
2063 | r = vhost_set_memory(d, m: argp); |
2064 | break; |
2065 | case VHOST_SET_LOG_BASE: |
2066 | if (copy_from_user(to: &p, from: argp, n: sizeof p)) { |
2067 | r = -EFAULT; |
2068 | break; |
2069 | } |
2070 | if ((u64)(unsigned long)p != p) { |
2071 | r = -EFAULT; |
2072 | break; |
2073 | } |
2074 | for (i = 0; i < d->nvqs; ++i) { |
2075 | struct vhost_virtqueue *vq; |
2076 | void __user *base = (void __user *)(unsigned long)p; |
2077 | vq = d->vqs[i]; |
2078 | mutex_lock(&vq->mutex); |
2079 | /* If ring is inactive, will check when it's enabled. */ |
2080 | if (vq->private_data && !vq_log_access_ok(vq, log_base: base)) |
2081 | r = -EFAULT; |
2082 | else |
2083 | vq->log_base = base; |
2084 | mutex_unlock(lock: &vq->mutex); |
2085 | } |
2086 | break; |
2087 | case VHOST_SET_LOG_FD: |
2088 | r = get_user(fd, (int __user *)argp); |
2089 | if (r < 0) |
2090 | break; |
2091 | ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd); |
2092 | if (IS_ERR(ptr: ctx)) { |
2093 | r = PTR_ERR(ptr: ctx); |
2094 | break; |
2095 | } |
2096 | swap(ctx, d->log_ctx); |
2097 | for (i = 0; i < d->nvqs; ++i) { |
2098 | mutex_lock(&d->vqs[i]->mutex); |
2099 | d->vqs[i]->log_ctx = d->log_ctx; |
2100 | mutex_unlock(lock: &d->vqs[i]->mutex); |
2101 | } |
2102 | if (ctx) |
2103 | eventfd_ctx_put(ctx); |
2104 | break; |
2105 | default: |
2106 | r = -ENOIOCTLCMD; |
2107 | break; |
2108 | } |
2109 | done: |
2110 | return r; |
2111 | } |
2112 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
2113 | |
2114 | /* TODO: This is really inefficient. We need something like get_user() |
2115 | * (instruction directly accesses the data, with an exception table entry |
2116 | * returning -EFAULT). See Documentation/arch/x86/exception-tables.rst. |
2117 | */ |
2118 | static int set_bit_to_user(int nr, void __user *addr) |
2119 | { |
2120 | unsigned long log = (unsigned long)addr; |
2121 | struct page *page; |
2122 | void *base; |
2123 | int bit = nr + (log % PAGE_SIZE) * 8; |
2124 | int r; |
2125 | |
2126 | r = pin_user_pages_fast(start: log, nr_pages: 1, gup_flags: FOLL_WRITE, pages: &page); |
2127 | if (r < 0) |
2128 | return r; |
2129 | BUG_ON(r != 1); |
2130 | base = kmap_atomic(page); |
2131 | set_bit(nr: bit, addr: base); |
2132 | kunmap_atomic(base); |
2133 | unpin_user_pages_dirty_lock(pages: &page, npages: 1, make_dirty: true); |
2134 | return 0; |
2135 | } |
2136 | |
2137 | static int log_write(void __user *log_base, |
2138 | u64 write_address, u64 write_length) |
2139 | { |
2140 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
2141 | int r; |
2142 | |
2143 | if (!write_length) |
2144 | return 0; |
2145 | write_length += write_address % VHOST_PAGE_SIZE; |
2146 | for (;;) { |
2147 | u64 base = (u64)(unsigned long)log_base; |
2148 | u64 log = base + write_page / 8; |
2149 | int bit = write_page % 8; |
2150 | if ((u64)(unsigned long)log != log) |
2151 | return -EFAULT; |
2152 | r = set_bit_to_user(nr: bit, addr: (void __user *)(unsigned long)log); |
2153 | if (r < 0) |
2154 | return r; |
2155 | if (write_length <= VHOST_PAGE_SIZE) |
2156 | break; |
2157 | write_length -= VHOST_PAGE_SIZE; |
2158 | write_page += 1; |
2159 | } |
2160 | return r; |
2161 | } |
2162 | |
2163 | static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len) |
2164 | { |
2165 | struct vhost_iotlb *umem = vq->umem; |
2166 | struct vhost_iotlb_map *u; |
2167 | u64 start, end, l, min; |
2168 | int r; |
2169 | bool hit = false; |
2170 | |
2171 | while (len) { |
2172 | min = len; |
2173 | /* More than one GPAs can be mapped into a single HVA. So |
2174 | * iterate all possible umems here to be safe. |
2175 | */ |
2176 | list_for_each_entry(u, &umem->list, link) { |
2177 | if (u->addr > hva - 1 + len || |
2178 | u->addr - 1 + u->size < hva) |
2179 | continue; |
2180 | start = max(u->addr, hva); |
2181 | end = min(u->addr - 1 + u->size, hva - 1 + len); |
2182 | l = end - start + 1; |
2183 | r = log_write(log_base: vq->log_base, |
2184 | write_address: u->start + start - u->addr, |
2185 | write_length: l); |
2186 | if (r < 0) |
2187 | return r; |
2188 | hit = true; |
2189 | min = min(l, min); |
2190 | } |
2191 | |
2192 | if (!hit) |
2193 | return -EFAULT; |
2194 | |
2195 | len -= min; |
2196 | hva += min; |
2197 | } |
2198 | |
2199 | return 0; |
2200 | } |
2201 | |
2202 | static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) |
2203 | { |
2204 | struct iovec *iov = vq->log_iov; |
2205 | int i, ret; |
2206 | |
2207 | if (!vq->iotlb) |
2208 | return log_write(log_base: vq->log_base, write_address: vq->log_addr + used_offset, write_length: len); |
2209 | |
2210 | ret = translate_desc(vq, addr: (uintptr_t)vq->used + used_offset, |
2211 | len, iov, iov_size: 64, VHOST_ACCESS_WO); |
2212 | if (ret < 0) |
2213 | return ret; |
2214 | |
2215 | for (i = 0; i < ret; i++) { |
2216 | ret = log_write_hva(vq, hva: (uintptr_t)iov[i].iov_base, |
2217 | len: iov[i].iov_len); |
2218 | if (ret) |
2219 | return ret; |
2220 | } |
2221 | |
2222 | return 0; |
2223 | } |
2224 | |
2225 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
2226 | unsigned int log_num, u64 len, struct iovec *iov, int count) |
2227 | { |
2228 | int i, r; |
2229 | |
2230 | /* Make sure data written is seen before log. */ |
2231 | smp_wmb(); |
2232 | |
2233 | if (vq->iotlb) { |
2234 | for (i = 0; i < count; i++) { |
2235 | r = log_write_hva(vq, hva: (uintptr_t)iov[i].iov_base, |
2236 | len: iov[i].iov_len); |
2237 | if (r < 0) |
2238 | return r; |
2239 | } |
2240 | return 0; |
2241 | } |
2242 | |
2243 | for (i = 0; i < log_num; ++i) { |
2244 | u64 l = min(log[i].len, len); |
2245 | r = log_write(log_base: vq->log_base, write_address: log[i].addr, write_length: l); |
2246 | if (r < 0) |
2247 | return r; |
2248 | len -= l; |
2249 | if (!len) { |
2250 | if (vq->log_ctx) |
2251 | eventfd_signal(ctx: vq->log_ctx, n: 1); |
2252 | return 0; |
2253 | } |
2254 | } |
2255 | /* Length written exceeds what we have stored. This is a bug. */ |
2256 | BUG(); |
2257 | return 0; |
2258 | } |
2259 | EXPORT_SYMBOL_GPL(vhost_log_write); |
2260 | |
2261 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
2262 | { |
2263 | void __user *used; |
2264 | if (vhost_put_used_flags(vq)) |
2265 | return -EFAULT; |
2266 | if (unlikely(vq->log_used)) { |
2267 | /* Make sure the flag is seen before log. */ |
2268 | smp_wmb(); |
2269 | /* Log used flag write. */ |
2270 | used = &vq->used->flags; |
2271 | log_used(vq, used_offset: (used - (void __user *)vq->used), |
2272 | len: sizeof vq->used->flags); |
2273 | if (vq->log_ctx) |
2274 | eventfd_signal(ctx: vq->log_ctx, n: 1); |
2275 | } |
2276 | return 0; |
2277 | } |
2278 | |
2279 | static int vhost_update_avail_event(struct vhost_virtqueue *vq) |
2280 | { |
2281 | if (vhost_put_avail_event(vq)) |
2282 | return -EFAULT; |
2283 | if (unlikely(vq->log_used)) { |
2284 | void __user *used; |
2285 | /* Make sure the event is seen before log. */ |
2286 | smp_wmb(); |
2287 | /* Log avail event write */ |
2288 | used = vhost_avail_event(vq); |
2289 | log_used(vq, used_offset: (used - (void __user *)vq->used), |
2290 | len: sizeof *vhost_avail_event(vq)); |
2291 | if (vq->log_ctx) |
2292 | eventfd_signal(ctx: vq->log_ctx, n: 1); |
2293 | } |
2294 | return 0; |
2295 | } |
2296 | |
2297 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2298 | { |
2299 | __virtio16 last_used_idx; |
2300 | int r; |
2301 | bool is_le = vq->is_le; |
2302 | |
2303 | if (!vq->private_data) |
2304 | return 0; |
2305 | |
2306 | vhost_init_is_le(vq); |
2307 | |
2308 | r = vhost_update_used_flags(vq); |
2309 | if (r) |
2310 | goto err; |
2311 | vq->signalled_used_valid = false; |
2312 | if (!vq->iotlb && |
2313 | !access_ok(&vq->used->idx, sizeof vq->used->idx)) { |
2314 | r = -EFAULT; |
2315 | goto err; |
2316 | } |
2317 | r = vhost_get_used_idx(vq, idx: &last_used_idx); |
2318 | if (r) { |
2319 | vq_err(vq, "Can't access used idx at %p\n" , |
2320 | &vq->used->idx); |
2321 | goto err; |
2322 | } |
2323 | vq->last_used_idx = vhost16_to_cpu(vq, val: last_used_idx); |
2324 | return 0; |
2325 | |
2326 | err: |
2327 | vq->is_le = is_le; |
2328 | return r; |
2329 | } |
2330 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2331 | |
2332 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
2333 | struct iovec iov[], int iov_size, int access) |
2334 | { |
2335 | const struct vhost_iotlb_map *map; |
2336 | struct vhost_dev *dev = vq->dev; |
2337 | struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem; |
2338 | struct iovec *_iov; |
2339 | u64 s = 0, last = addr + len - 1; |
2340 | int ret = 0; |
2341 | |
2342 | while ((u64)len > s) { |
2343 | u64 size; |
2344 | if (unlikely(ret >= iov_size)) { |
2345 | ret = -ENOBUFS; |
2346 | break; |
2347 | } |
2348 | |
2349 | map = vhost_iotlb_itree_first(iotlb: umem, start: addr, last); |
2350 | if (map == NULL || map->start > addr) { |
2351 | if (umem != dev->iotlb) { |
2352 | ret = -EFAULT; |
2353 | break; |
2354 | } |
2355 | ret = -EAGAIN; |
2356 | break; |
2357 | } else if (!(map->perm & access)) { |
2358 | ret = -EPERM; |
2359 | break; |
2360 | } |
2361 | |
2362 | _iov = iov + ret; |
2363 | size = map->size - addr + map->start; |
2364 | _iov->iov_len = min((u64)len - s, size); |
2365 | _iov->iov_base = (void __user *)(unsigned long) |
2366 | (map->addr + addr - map->start); |
2367 | s += size; |
2368 | addr += size; |
2369 | ++ret; |
2370 | } |
2371 | |
2372 | if (ret == -EAGAIN) |
2373 | vhost_iotlb_miss(vq, iova: addr, access); |
2374 | return ret; |
2375 | } |
2376 | |
2377 | /* Each buffer in the virtqueues is actually a chain of descriptors. This |
2378 | * function returns the next descriptor in the chain, |
2379 | * or -1U if we're at the end. */ |
2380 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
2381 | { |
2382 | unsigned int next; |
2383 | |
2384 | /* If this descriptor says it doesn't chain, we're done. */ |
2385 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
2386 | return -1U; |
2387 | |
2388 | /* Check they're not leading us off end of descriptors. */ |
2389 | next = vhost16_to_cpu(vq, READ_ONCE(desc->next)); |
2390 | return next; |
2391 | } |
2392 | |
2393 | static int get_indirect(struct vhost_virtqueue *vq, |
2394 | struct iovec iov[], unsigned int iov_size, |
2395 | unsigned int *out_num, unsigned int *in_num, |
2396 | struct vhost_log *log, unsigned int *log_num, |
2397 | struct vring_desc *indirect) |
2398 | { |
2399 | struct vring_desc desc; |
2400 | unsigned int i = 0, count, found = 0; |
2401 | u32 len = vhost32_to_cpu(vq, val: indirect->len); |
2402 | struct iov_iter from; |
2403 | int ret, access; |
2404 | |
2405 | /* Sanity check */ |
2406 | if (unlikely(len % sizeof desc)) { |
2407 | vq_err(vq, "Invalid length in indirect descriptor: " |
2408 | "len 0x%llx not multiple of 0x%zx\n" , |
2409 | (unsigned long long)len, |
2410 | sizeof desc); |
2411 | return -EINVAL; |
2412 | } |
2413 | |
2414 | ret = translate_desc(vq, addr: vhost64_to_cpu(vq, val: indirect->addr), len, iov: vq->indirect, |
2415 | UIO_MAXIOV, VHOST_ACCESS_RO); |
2416 | if (unlikely(ret < 0)) { |
2417 | if (ret != -EAGAIN) |
2418 | vq_err(vq, "Translation failure %d in indirect.\n" , ret); |
2419 | return ret; |
2420 | } |
2421 | iov_iter_init(i: &from, ITER_SOURCE, iov: vq->indirect, nr_segs: ret, count: len); |
2422 | count = len / sizeof desc; |
2423 | /* Buffers are chained via a 16 bit next field, so |
2424 | * we can have at most 2^16 of these. */ |
2425 | if (unlikely(count > USHRT_MAX + 1)) { |
2426 | vq_err(vq, "Indirect buffer length too big: %d\n" , |
2427 | indirect->len); |
2428 | return -E2BIG; |
2429 | } |
2430 | |
2431 | do { |
2432 | unsigned iov_count = *in_num + *out_num; |
2433 | if (unlikely(++found > count)) { |
2434 | vq_err(vq, "Loop detected: last one at %u " |
2435 | "indirect size %u\n" , |
2436 | i, count); |
2437 | return -EINVAL; |
2438 | } |
2439 | if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) { |
2440 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n" , |
2441 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
2442 | return -EINVAL; |
2443 | } |
2444 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
2445 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n" , |
2446 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
2447 | return -EINVAL; |
2448 | } |
2449 | |
2450 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2451 | access = VHOST_ACCESS_WO; |
2452 | else |
2453 | access = VHOST_ACCESS_RO; |
2454 | |
2455 | ret = translate_desc(vq, addr: vhost64_to_cpu(vq, val: desc.addr), |
2456 | len: vhost32_to_cpu(vq, val: desc.len), iov: iov + iov_count, |
2457 | iov_size: iov_size - iov_count, access); |
2458 | if (unlikely(ret < 0)) { |
2459 | if (ret != -EAGAIN) |
2460 | vq_err(vq, "Translation failure %d indirect idx %d\n" , |
2461 | ret, i); |
2462 | return ret; |
2463 | } |
2464 | /* If this is an input descriptor, increment that count. */ |
2465 | if (access == VHOST_ACCESS_WO) { |
2466 | *in_num += ret; |
2467 | if (unlikely(log && ret)) { |
2468 | log[*log_num].addr = vhost64_to_cpu(vq, val: desc.addr); |
2469 | log[*log_num].len = vhost32_to_cpu(vq, val: desc.len); |
2470 | ++*log_num; |
2471 | } |
2472 | } else { |
2473 | /* If it's an output descriptor, they're all supposed |
2474 | * to come before any input descriptors. */ |
2475 | if (unlikely(*in_num)) { |
2476 | vq_err(vq, "Indirect descriptor " |
2477 | "has out after in: idx %d\n" , i); |
2478 | return -EINVAL; |
2479 | } |
2480 | *out_num += ret; |
2481 | } |
2482 | } while ((i = next_desc(vq, desc: &desc)) != -1); |
2483 | return 0; |
2484 | } |
2485 | |
2486 | /* This looks in the virtqueue and for the first available buffer, and converts |
2487 | * it to an iovec for convenient access. Since descriptors consist of some |
2488 | * number of output then some number of input descriptors, it's actually two |
2489 | * iovecs, but we pack them into one and note how many of each there were. |
2490 | * |
2491 | * This function returns the descriptor number found, or vq->num (which is |
2492 | * never a valid descriptor number) if none was found. A negative code is |
2493 | * returned on error. */ |
2494 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
2495 | struct iovec iov[], unsigned int iov_size, |
2496 | unsigned int *out_num, unsigned int *in_num, |
2497 | struct vhost_log *log, unsigned int *log_num) |
2498 | { |
2499 | struct vring_desc desc; |
2500 | unsigned int i, head, found = 0; |
2501 | u16 last_avail_idx; |
2502 | __virtio16 avail_idx; |
2503 | __virtio16 ring_head; |
2504 | int ret, access; |
2505 | |
2506 | /* Check it isn't doing very strange things with descriptor numbers. */ |
2507 | last_avail_idx = vq->last_avail_idx; |
2508 | |
2509 | if (vq->avail_idx == vq->last_avail_idx) { |
2510 | if (unlikely(vhost_get_avail_idx(vq, &avail_idx))) { |
2511 | vq_err(vq, "Failed to access avail idx at %p\n" , |
2512 | &vq->avail->idx); |
2513 | return -EFAULT; |
2514 | } |
2515 | vq->avail_idx = vhost16_to_cpu(vq, val: avail_idx); |
2516 | |
2517 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
2518 | vq_err(vq, "Guest moved used index from %u to %u" , |
2519 | last_avail_idx, vq->avail_idx); |
2520 | return -EFAULT; |
2521 | } |
2522 | |
2523 | /* If there's nothing new since last we looked, return |
2524 | * invalid. |
2525 | */ |
2526 | if (vq->avail_idx == last_avail_idx) |
2527 | return vq->num; |
2528 | |
2529 | /* Only get avail ring entries after they have been |
2530 | * exposed by guest. |
2531 | */ |
2532 | smp_rmb(); |
2533 | } |
2534 | |
2535 | /* Grab the next descriptor number they're advertising, and increment |
2536 | * the index we've seen. */ |
2537 | if (unlikely(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) { |
2538 | vq_err(vq, "Failed to read head: idx %d address %p\n" , |
2539 | last_avail_idx, |
2540 | &vq->avail->ring[last_avail_idx % vq->num]); |
2541 | return -EFAULT; |
2542 | } |
2543 | |
2544 | head = vhost16_to_cpu(vq, val: ring_head); |
2545 | |
2546 | /* If their number is silly, that's an error. */ |
2547 | if (unlikely(head >= vq->num)) { |
2548 | vq_err(vq, "Guest says index %u > %u is available" , |
2549 | head, vq->num); |
2550 | return -EINVAL; |
2551 | } |
2552 | |
2553 | /* When we start there are none of either input nor output. */ |
2554 | *out_num = *in_num = 0; |
2555 | if (unlikely(log)) |
2556 | *log_num = 0; |
2557 | |
2558 | i = head; |
2559 | do { |
2560 | unsigned iov_count = *in_num + *out_num; |
2561 | if (unlikely(i >= vq->num)) { |
2562 | vq_err(vq, "Desc index is %u > %u, head = %u" , |
2563 | i, vq->num, head); |
2564 | return -EINVAL; |
2565 | } |
2566 | if (unlikely(++found > vq->num)) { |
2567 | vq_err(vq, "Loop detected: last one at %u " |
2568 | "vq size %u head %u\n" , |
2569 | i, vq->num, head); |
2570 | return -EINVAL; |
2571 | } |
2572 | ret = vhost_get_desc(vq, desc: &desc, idx: i); |
2573 | if (unlikely(ret)) { |
2574 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n" , |
2575 | i, vq->desc + i); |
2576 | return -EFAULT; |
2577 | } |
2578 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
2579 | ret = get_indirect(vq, iov, iov_size, |
2580 | out_num, in_num, |
2581 | log, log_num, indirect: &desc); |
2582 | if (unlikely(ret < 0)) { |
2583 | if (ret != -EAGAIN) |
2584 | vq_err(vq, "Failure detected " |
2585 | "in indirect descriptor at idx %d\n" , i); |
2586 | return ret; |
2587 | } |
2588 | continue; |
2589 | } |
2590 | |
2591 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2592 | access = VHOST_ACCESS_WO; |
2593 | else |
2594 | access = VHOST_ACCESS_RO; |
2595 | ret = translate_desc(vq, addr: vhost64_to_cpu(vq, val: desc.addr), |
2596 | len: vhost32_to_cpu(vq, val: desc.len), iov: iov + iov_count, |
2597 | iov_size: iov_size - iov_count, access); |
2598 | if (unlikely(ret < 0)) { |
2599 | if (ret != -EAGAIN) |
2600 | vq_err(vq, "Translation failure %d descriptor idx %d\n" , |
2601 | ret, i); |
2602 | return ret; |
2603 | } |
2604 | if (access == VHOST_ACCESS_WO) { |
2605 | /* If this is an input descriptor, |
2606 | * increment that count. */ |
2607 | *in_num += ret; |
2608 | if (unlikely(log && ret)) { |
2609 | log[*log_num].addr = vhost64_to_cpu(vq, val: desc.addr); |
2610 | log[*log_num].len = vhost32_to_cpu(vq, val: desc.len); |
2611 | ++*log_num; |
2612 | } |
2613 | } else { |
2614 | /* If it's an output descriptor, they're all supposed |
2615 | * to come before any input descriptors. */ |
2616 | if (unlikely(*in_num)) { |
2617 | vq_err(vq, "Descriptor has out after in: " |
2618 | "idx %d\n" , i); |
2619 | return -EINVAL; |
2620 | } |
2621 | *out_num += ret; |
2622 | } |
2623 | } while ((i = next_desc(vq, desc: &desc)) != -1); |
2624 | |
2625 | /* On success, increment avail index. */ |
2626 | vq->last_avail_idx++; |
2627 | |
2628 | /* Assume notifications from guest are disabled at this point, |
2629 | * if they aren't we would need to update avail_event index. */ |
2630 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); |
2631 | return head; |
2632 | } |
2633 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
2634 | |
2635 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ |
2636 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
2637 | { |
2638 | vq->last_avail_idx -= n; |
2639 | } |
2640 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
2641 | |
2642 | /* After we've used one of their buffers, we tell them about it. We'll then |
2643 | * want to notify the guest, using eventfd. */ |
2644 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) |
2645 | { |
2646 | struct vring_used_elem heads = { |
2647 | cpu_to_vhost32(vq, val: head), |
2648 | cpu_to_vhost32(vq, val: len) |
2649 | }; |
2650 | |
2651 | return vhost_add_used_n(vq, heads: &heads, count: 1); |
2652 | } |
2653 | EXPORT_SYMBOL_GPL(vhost_add_used); |
2654 | |
2655 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2656 | struct vring_used_elem *heads, |
2657 | unsigned count) |
2658 | { |
2659 | vring_used_elem_t __user *used; |
2660 | u16 old, new; |
2661 | int start; |
2662 | |
2663 | start = vq->last_used_idx & (vq->num - 1); |
2664 | used = vq->used->ring + start; |
2665 | if (vhost_put_used(vq, head: heads, idx: start, count)) { |
2666 | vq_err(vq, "Failed to write used" ); |
2667 | return -EFAULT; |
2668 | } |
2669 | if (unlikely(vq->log_used)) { |
2670 | /* Make sure data is seen before log. */ |
2671 | smp_wmb(); |
2672 | /* Log used ring entry write. */ |
2673 | log_used(vq, used_offset: ((void __user *)used - (void __user *)vq->used), |
2674 | len: count * sizeof *used); |
2675 | } |
2676 | old = vq->last_used_idx; |
2677 | new = (vq->last_used_idx += count); |
2678 | /* If the driver never bothers to signal in a very long while, |
2679 | * used index might wrap around. If that happens, invalidate |
2680 | * signalled_used index we stored. TODO: make sure driver |
2681 | * signals at least once in 2^16 and remove this. */ |
2682 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) |
2683 | vq->signalled_used_valid = false; |
2684 | return 0; |
2685 | } |
2686 | |
2687 | /* After we've used one of their buffers, we tell them about it. We'll then |
2688 | * want to notify the guest, using eventfd. */ |
2689 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, |
2690 | unsigned count) |
2691 | { |
2692 | int start, n, r; |
2693 | |
2694 | start = vq->last_used_idx & (vq->num - 1); |
2695 | n = vq->num - start; |
2696 | if (n < count) { |
2697 | r = __vhost_add_used_n(vq, heads, count: n); |
2698 | if (r < 0) |
2699 | return r; |
2700 | heads += n; |
2701 | count -= n; |
2702 | } |
2703 | r = __vhost_add_used_n(vq, heads, count); |
2704 | |
2705 | /* Make sure buffer is written before we update index. */ |
2706 | smp_wmb(); |
2707 | if (vhost_put_used_idx(vq)) { |
2708 | vq_err(vq, "Failed to increment used idx" ); |
2709 | return -EFAULT; |
2710 | } |
2711 | if (unlikely(vq->log_used)) { |
2712 | /* Make sure used idx is seen before log. */ |
2713 | smp_wmb(); |
2714 | /* Log used index update. */ |
2715 | log_used(vq, offsetof(struct vring_used, idx), |
2716 | len: sizeof vq->used->idx); |
2717 | if (vq->log_ctx) |
2718 | eventfd_signal(ctx: vq->log_ctx, n: 1); |
2719 | } |
2720 | return r; |
2721 | } |
2722 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
2723 | |
2724 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
2725 | { |
2726 | __u16 old, new; |
2727 | __virtio16 event; |
2728 | bool v; |
2729 | /* Flush out used index updates. This is paired |
2730 | * with the barrier that the Guest executes when enabling |
2731 | * interrupts. */ |
2732 | smp_mb(); |
2733 | |
2734 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
2735 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2736 | return true; |
2737 | |
2738 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2739 | __virtio16 flags; |
2740 | if (vhost_get_avail_flags(vq, flags: &flags)) { |
2741 | vq_err(vq, "Failed to get flags" ); |
2742 | return true; |
2743 | } |
2744 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
2745 | } |
2746 | old = vq->signalled_used; |
2747 | v = vq->signalled_used_valid; |
2748 | new = vq->signalled_used = vq->last_used_idx; |
2749 | vq->signalled_used_valid = true; |
2750 | |
2751 | if (unlikely(!v)) |
2752 | return true; |
2753 | |
2754 | if (vhost_get_used_event(vq, event: &event)) { |
2755 | vq_err(vq, "Failed to get used event idx" ); |
2756 | return true; |
2757 | } |
2758 | return vring_need_event(event_idx: vhost16_to_cpu(vq, val: event), new_idx: new, old); |
2759 | } |
2760 | |
2761 | /* This actually signals the guest, using eventfd. */ |
2762 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
2763 | { |
2764 | /* Signal the Guest tell them we used something up. */ |
2765 | if (vq->call_ctx.ctx && vhost_notify(dev, vq)) |
2766 | eventfd_signal(ctx: vq->call_ctx.ctx, n: 1); |
2767 | } |
2768 | EXPORT_SYMBOL_GPL(vhost_signal); |
2769 | |
2770 | /* And here's the combo meal deal. Supersize me! */ |
2771 | void vhost_add_used_and_signal(struct vhost_dev *dev, |
2772 | struct vhost_virtqueue *vq, |
2773 | unsigned int head, int len) |
2774 | { |
2775 | vhost_add_used(vq, head, len); |
2776 | vhost_signal(dev, vq); |
2777 | } |
2778 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
2779 | |
2780 | /* multi-buffer version of vhost_add_used_and_signal */ |
2781 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, |
2782 | struct vhost_virtqueue *vq, |
2783 | struct vring_used_elem *heads, unsigned count) |
2784 | { |
2785 | vhost_add_used_n(vq, heads, count); |
2786 | vhost_signal(dev, vq); |
2787 | } |
2788 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
2789 | |
2790 | /* return true if we're sure that avaiable ring is empty */ |
2791 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
2792 | { |
2793 | __virtio16 avail_idx; |
2794 | int r; |
2795 | |
2796 | if (vq->avail_idx != vq->last_avail_idx) |
2797 | return false; |
2798 | |
2799 | r = vhost_get_avail_idx(vq, idx: &avail_idx); |
2800 | if (unlikely(r)) |
2801 | return false; |
2802 | vq->avail_idx = vhost16_to_cpu(vq, val: avail_idx); |
2803 | |
2804 | return vq->avail_idx == vq->last_avail_idx; |
2805 | } |
2806 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); |
2807 | |
2808 | /* OK, now we need to know about added descriptors. */ |
2809 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
2810 | { |
2811 | __virtio16 avail_idx; |
2812 | int r; |
2813 | |
2814 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2815 | return false; |
2816 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; |
2817 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2818 | r = vhost_update_used_flags(vq); |
2819 | if (r) { |
2820 | vq_err(vq, "Failed to enable notification at %p: %d\n" , |
2821 | &vq->used->flags, r); |
2822 | return false; |
2823 | } |
2824 | } else { |
2825 | r = vhost_update_avail_event(vq); |
2826 | if (r) { |
2827 | vq_err(vq, "Failed to update avail event index at %p: %d\n" , |
2828 | vhost_avail_event(vq), r); |
2829 | return false; |
2830 | } |
2831 | } |
2832 | /* They could have slipped one in as we were doing that: make |
2833 | * sure it's written, then check again. */ |
2834 | smp_mb(); |
2835 | r = vhost_get_avail_idx(vq, idx: &avail_idx); |
2836 | if (r) { |
2837 | vq_err(vq, "Failed to check avail idx at %p: %d\n" , |
2838 | &vq->avail->idx, r); |
2839 | return false; |
2840 | } |
2841 | vq->avail_idx = vhost16_to_cpu(vq, val: avail_idx); |
2842 | |
2843 | return vq->avail_idx != vq->last_avail_idx; |
2844 | } |
2845 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
2846 | |
2847 | /* We don't need to be notified again. */ |
2848 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
2849 | { |
2850 | int r; |
2851 | |
2852 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2853 | return; |
2854 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; |
2855 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2856 | r = vhost_update_used_flags(vq); |
2857 | if (r) |
2858 | vq_err(vq, "Failed to disable notification at %p: %d\n" , |
2859 | &vq->used->flags, r); |
2860 | } |
2861 | } |
2862 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2863 | |
2864 | /* Create a new message. */ |
2865 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) |
2866 | { |
2867 | /* Make sure all padding within the structure is initialized. */ |
2868 | struct vhost_msg_node *node = kzalloc(size: sizeof(*node), GFP_KERNEL); |
2869 | if (!node) |
2870 | return NULL; |
2871 | |
2872 | node->vq = vq; |
2873 | node->msg.type = type; |
2874 | return node; |
2875 | } |
2876 | EXPORT_SYMBOL_GPL(vhost_new_msg); |
2877 | |
2878 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, |
2879 | struct vhost_msg_node *node) |
2880 | { |
2881 | spin_lock(lock: &dev->iotlb_lock); |
2882 | list_add_tail(new: &node->node, head); |
2883 | spin_unlock(lock: &dev->iotlb_lock); |
2884 | |
2885 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
2886 | } |
2887 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); |
2888 | |
2889 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, |
2890 | struct list_head *head) |
2891 | { |
2892 | struct vhost_msg_node *node = NULL; |
2893 | |
2894 | spin_lock(lock: &dev->iotlb_lock); |
2895 | if (!list_empty(head)) { |
2896 | node = list_first_entry(head, struct vhost_msg_node, |
2897 | node); |
2898 | list_del(entry: &node->node); |
2899 | } |
2900 | spin_unlock(lock: &dev->iotlb_lock); |
2901 | |
2902 | return node; |
2903 | } |
2904 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); |
2905 | |
2906 | void vhost_set_backend_features(struct vhost_dev *dev, u64 features) |
2907 | { |
2908 | struct vhost_virtqueue *vq; |
2909 | int i; |
2910 | |
2911 | mutex_lock(&dev->mutex); |
2912 | for (i = 0; i < dev->nvqs; ++i) { |
2913 | vq = dev->vqs[i]; |
2914 | mutex_lock(&vq->mutex); |
2915 | vq->acked_backend_features = features; |
2916 | mutex_unlock(lock: &vq->mutex); |
2917 | } |
2918 | mutex_unlock(lock: &dev->mutex); |
2919 | } |
2920 | EXPORT_SYMBOL_GPL(vhost_set_backend_features); |
2921 | |
2922 | static int __init vhost_init(void) |
2923 | { |
2924 | return 0; |
2925 | } |
2926 | |
2927 | static void __exit vhost_exit(void) |
2928 | { |
2929 | } |
2930 | |
2931 | module_init(vhost_init); |
2932 | module_exit(vhost_exit); |
2933 | |
2934 | MODULE_VERSION("0.0.1" ); |
2935 | MODULE_LICENSE("GPL v2" ); |
2936 | MODULE_AUTHOR("Michael S. Tsirkin" ); |
2937 | MODULE_DESCRIPTION("Host kernel accelerator for virtio" ); |
2938 | |