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3a4d5c94 MT |
1 | /* Copyright (C) 2009 Red Hat, Inc. |
2 | * Copyright (C) 2006 Rusty Russell IBM Corporation | |
3 | * | |
4 | * Author: Michael S. Tsirkin <mst@redhat.com> | |
5 | * | |
6 | * Inspiration, some code, and most witty comments come from | |
61516587 | 7 | * Documentation/virtual/lguest/lguest.c, by Rusty Russell |
3a4d5c94 MT |
8 | * |
9 | * This work is licensed under the terms of the GNU GPL, version 2. | |
10 | * | |
11 | * Generic code for virtio server in host kernel. | |
12 | */ | |
13 | ||
14 | #include <linux/eventfd.h> | |
15 | #include <linux/vhost.h> | |
35596b27 | 16 | #include <linux/uio.h> |
3a4d5c94 | 17 | #include <linux/mm.h> |
64e1c807 | 18 | #include <linux/mmu_context.h> |
3a4d5c94 MT |
19 | #include <linux/miscdevice.h> |
20 | #include <linux/mutex.h> | |
3a4d5c94 MT |
21 | #include <linux/poll.h> |
22 | #include <linux/file.h> | |
23 | #include <linux/highmem.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
4de7255f | 25 | #include <linux/vmalloc.h> |
c23f3445 | 26 | #include <linux/kthread.h> |
9e3d1957 | 27 | #include <linux/cgroup.h> |
6ac1afbf | 28 | #include <linux/module.h> |
bcfeacab | 29 | #include <linux/sort.h> |
6e84f315 | 30 | #include <linux/sched/mm.h> |
174cd4b1 | 31 | #include <linux/sched/signal.h> |
a9709d68 | 32 | #include <linux/interval_tree_generic.h> |
3a4d5c94 | 33 | |
3a4d5c94 MT |
34 | #include "vhost.h" |
35 | ||
c9ce42f7 IM |
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)"); | |
6b1e6cc7 JW |
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)"); | |
c9ce42f7 | 44 | |
3a4d5c94 | 45 | enum { |
3a4d5c94 MT |
46 | VHOST_MEMORY_F_LOG = 0x1, |
47 | }; | |
48 | ||
3b1bbe89 MT |
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]) | |
8ea8cf89 | 51 | |
a9709d68 JW |
52 | INTERVAL_TREE_DEFINE(struct vhost_umem_node, |
53 | rb, __u64, __subtree_last, | |
2f952c01 | 54 | START, LAST, static inline, vhost_umem_interval_tree); |
a9709d68 | 55 | |
2751c988 | 56 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
c5072037 | 57 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
58 | { |
59 | vq->user_be = !virtio_legacy_is_little_endian(); | |
60 | } | |
61 | ||
c5072037 GK |
62 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
63 | { | |
64 | vq->user_be = true; | |
65 | } | |
66 | ||
67 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) | |
68 | { | |
69 | vq->user_be = false; | |
70 | } | |
71 | ||
2751c988 GK |
72 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
73 | { | |
74 | struct vhost_vring_state s; | |
75 | ||
76 | if (vq->private_data) | |
77 | return -EBUSY; | |
78 | ||
79 | if (copy_from_user(&s, argp, sizeof(s))) | |
80 | return -EFAULT; | |
81 | ||
82 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && | |
83 | s.num != VHOST_VRING_BIG_ENDIAN) | |
84 | return -EINVAL; | |
85 | ||
c5072037 GK |
86 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
87 | vhost_enable_cross_endian_big(vq); | |
88 | else | |
89 | vhost_enable_cross_endian_little(vq); | |
2751c988 GK |
90 | |
91 | return 0; | |
92 | } | |
93 | ||
94 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
95 | int __user *argp) | |
96 | { | |
97 | struct vhost_vring_state s = { | |
98 | .index = idx, | |
99 | .num = vq->user_be | |
100 | }; | |
101 | ||
102 | if (copy_to_user(argp, &s, sizeof(s))) | |
103 | return -EFAULT; | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
108 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
109 | { | |
110 | /* Note for legacy virtio: user_be is initialized at reset time | |
111 | * according to the host endianness. If userspace does not set an | |
112 | * explicit endianness, the default behavior is native endian, as | |
113 | * expected by legacy virtio. | |
114 | */ | |
115 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; | |
116 | } | |
117 | #else | |
c5072037 | 118 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
119 | { |
120 | } | |
121 | ||
122 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) | |
123 | { | |
124 | return -ENOIOCTLCMD; | |
125 | } | |
126 | ||
127 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
128 | int __user *argp) | |
129 | { | |
130 | return -ENOIOCTLCMD; | |
131 | } | |
132 | ||
133 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
134 | { | |
cda8bba0 HP |
135 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) |
136 | || virtio_legacy_is_little_endian(); | |
2751c988 GK |
137 | } |
138 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ | |
139 | ||
c5072037 GK |
140 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
141 | { | |
cda8bba0 | 142 | vhost_init_is_le(vq); |
c5072037 GK |
143 | } |
144 | ||
7235acdb JW |
145 | struct vhost_flush_struct { |
146 | struct vhost_work work; | |
147 | struct completion wait_event; | |
148 | }; | |
149 | ||
150 | static void vhost_flush_work(struct vhost_work *work) | |
151 | { | |
152 | struct vhost_flush_struct *s; | |
153 | ||
154 | s = container_of(work, struct vhost_flush_struct, work); | |
155 | complete(&s->wait_event); | |
156 | } | |
157 | ||
3a4d5c94 MT |
158 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
159 | poll_table *pt) | |
160 | { | |
161 | struct vhost_poll *poll; | |
3a4d5c94 | 162 | |
d47effe1 | 163 | poll = container_of(pt, struct vhost_poll, table); |
3a4d5c94 MT |
164 | poll->wqh = wqh; |
165 | add_wait_queue(wqh, &poll->wait); | |
166 | } | |
167 | ||
ac6424b9 | 168 | static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, |
3a4d5c94 MT |
169 | void *key) |
170 | { | |
c23f3445 TH |
171 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
172 | ||
3ad6f93e | 173 | if (!(key_to_poll(key) & poll->mask)) |
3a4d5c94 MT |
174 | return 0; |
175 | ||
c23f3445 | 176 | vhost_poll_queue(poll); |
3a4d5c94 MT |
177 | return 0; |
178 | } | |
179 | ||
163049ae | 180 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
87d6a412 | 181 | { |
04b96e55 | 182 | clear_bit(VHOST_WORK_QUEUED, &work->flags); |
87d6a412 MT |
183 | work->fn = fn; |
184 | init_waitqueue_head(&work->done); | |
87d6a412 | 185 | } |
6ac1afbf | 186 | EXPORT_SYMBOL_GPL(vhost_work_init); |
87d6a412 | 187 | |
3a4d5c94 | 188 | /* Init poll structure */ |
c23f3445 | 189 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
58e3b602 | 190 | __poll_t mask, struct vhost_dev *dev) |
3a4d5c94 | 191 | { |
3a4d5c94 MT |
192 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
193 | init_poll_funcptr(&poll->table, vhost_poll_func); | |
194 | poll->mask = mask; | |
c23f3445 | 195 | poll->dev = dev; |
2b8b328b | 196 | poll->wqh = NULL; |
c23f3445 | 197 | |
87d6a412 | 198 | vhost_work_init(&poll->work, fn); |
3a4d5c94 | 199 | } |
6ac1afbf | 200 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
3a4d5c94 MT |
201 | |
202 | /* Start polling a file. We add ourselves to file's wait queue. The caller must | |
203 | * keep a reference to a file until after vhost_poll_stop is called. */ | |
2b8b328b | 204 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
3a4d5c94 | 205 | { |
e6c8adca | 206 | __poll_t mask; |
2b8b328b | 207 | int ret = 0; |
d47effe1 | 208 | |
70181d51 JW |
209 | if (poll->wqh) |
210 | return 0; | |
211 | ||
3a4d5c94 MT |
212 | mask = file->f_op->poll(file, &poll->table); |
213 | if (mask) | |
3ad6f93e | 214 | vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); |
2b8b328b JW |
215 | if (mask & POLLERR) { |
216 | if (poll->wqh) | |
217 | remove_wait_queue(poll->wqh, &poll->wait); | |
218 | ret = -EINVAL; | |
219 | } | |
220 | ||
221 | return ret; | |
3a4d5c94 | 222 | } |
6ac1afbf | 223 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
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 | { | |
2b8b328b JW |
229 | if (poll->wqh) { |
230 | remove_wait_queue(poll->wqh, &poll->wait); | |
231 | poll->wqh = NULL; | |
232 | } | |
3a4d5c94 | 233 | } |
6ac1afbf | 234 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 235 | |
7235acdb | 236 | void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
0174b0c3 | 237 | { |
7235acdb | 238 | struct vhost_flush_struct flush; |
d47effe1 | 239 | |
7235acdb JW |
240 | if (dev->worker) { |
241 | init_completion(&flush.wait_event); | |
242 | vhost_work_init(&flush.work, vhost_flush_work); | |
0174b0c3 | 243 | |
7235acdb JW |
244 | vhost_work_queue(dev, &flush.work); |
245 | wait_for_completion(&flush.wait_event); | |
246 | } | |
3a4d5c94 | 247 | } |
6ac1afbf | 248 | EXPORT_SYMBOL_GPL(vhost_work_flush); |
3a4d5c94 | 249 | |
87d6a412 MT |
250 | /* Flush any work that has been scheduled. When calling this, don't hold any |
251 | * locks that are also used by the callback. */ | |
252 | void vhost_poll_flush(struct vhost_poll *poll) | |
253 | { | |
254 | vhost_work_flush(poll->dev, &poll->work); | |
255 | } | |
6ac1afbf | 256 | EXPORT_SYMBOL_GPL(vhost_poll_flush); |
87d6a412 | 257 | |
163049ae | 258 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 259 | { |
04b96e55 JW |
260 | if (!dev->worker) |
261 | return; | |
c23f3445 | 262 | |
04b96e55 JW |
263 | if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { |
264 | /* We can only add the work to the list after we're | |
265 | * sure it was not in the list. | |
635abf01 | 266 | * test_and_set_bit() implies a memory barrier. |
04b96e55 | 267 | */ |
04b96e55 | 268 | llist_add(&work->node, &dev->work_list); |
c23f3445 TH |
269 | wake_up_process(dev->worker); |
270 | } | |
3a4d5c94 | 271 | } |
6ac1afbf | 272 | EXPORT_SYMBOL_GPL(vhost_work_queue); |
3a4d5c94 | 273 | |
526d3e7f JW |
274 | /* A lockless hint for busy polling code to exit the loop */ |
275 | bool vhost_has_work(struct vhost_dev *dev) | |
276 | { | |
04b96e55 | 277 | return !llist_empty(&dev->work_list); |
526d3e7f JW |
278 | } |
279 | EXPORT_SYMBOL_GPL(vhost_has_work); | |
280 | ||
87d6a412 MT |
281 | void vhost_poll_queue(struct vhost_poll *poll) |
282 | { | |
283 | vhost_work_queue(poll->dev, &poll->work); | |
284 | } | |
6ac1afbf | 285 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 286 | |
f8894913 JW |
287 | static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq) |
288 | { | |
289 | int j; | |
290 | ||
291 | for (j = 0; j < VHOST_NUM_ADDRS; j++) | |
292 | vq->meta_iotlb[j] = NULL; | |
293 | } | |
294 | ||
295 | static void vhost_vq_meta_reset(struct vhost_dev *d) | |
296 | { | |
297 | int i; | |
298 | ||
299 | for (i = 0; i < d->nvqs; ++i) | |
300 | __vhost_vq_meta_reset(d->vqs[i]); | |
301 | } | |
302 | ||
3a4d5c94 MT |
303 | static void vhost_vq_reset(struct vhost_dev *dev, |
304 | struct vhost_virtqueue *vq) | |
305 | { | |
306 | vq->num = 1; | |
307 | vq->desc = NULL; | |
308 | vq->avail = NULL; | |
309 | vq->used = NULL; | |
310 | vq->last_avail_idx = 0; | |
311 | vq->avail_idx = 0; | |
312 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
313 | vq->signalled_used = 0; |
314 | vq->signalled_used_valid = false; | |
3a4d5c94 | 315 | vq->used_flags = 0; |
3a4d5c94 MT |
316 | vq->log_used = false; |
317 | vq->log_addr = -1ull; | |
3a4d5c94 | 318 | vq->private_data = NULL; |
ea16c514 | 319 | vq->acked_features = 0; |
3a4d5c94 MT |
320 | vq->log_base = NULL; |
321 | vq->error_ctx = NULL; | |
322 | vq->error = NULL; | |
323 | vq->kick = NULL; | |
324 | vq->call_ctx = NULL; | |
325 | vq->call = NULL; | |
73a99f08 | 326 | vq->log_ctx = NULL; |
c5072037 GK |
327 | vhost_reset_is_le(vq); |
328 | vhost_disable_cross_endian(vq); | |
03088137 | 329 | vq->busyloop_timeout = 0; |
a9709d68 | 330 | vq->umem = NULL; |
6b1e6cc7 | 331 | vq->iotlb = NULL; |
f8894913 | 332 | __vhost_vq_meta_reset(vq); |
3a4d5c94 MT |
333 | } |
334 | ||
c23f3445 TH |
335 | static int vhost_worker(void *data) |
336 | { | |
337 | struct vhost_dev *dev = data; | |
04b96e55 JW |
338 | struct vhost_work *work, *work_next; |
339 | struct llist_node *node; | |
d7ffde35 | 340 | mm_segment_t oldfs = get_fs(); |
c23f3445 | 341 | |
d7ffde35 | 342 | set_fs(USER_DS); |
64e1c807 MT |
343 | use_mm(dev->mm); |
344 | ||
c23f3445 TH |
345 | for (;;) { |
346 | /* mb paired w/ kthread_stop */ | |
347 | set_current_state(TASK_INTERRUPTIBLE); | |
348 | ||
c23f3445 | 349 | if (kthread_should_stop()) { |
c23f3445 | 350 | __set_current_state(TASK_RUNNING); |
64e1c807 | 351 | break; |
c23f3445 | 352 | } |
04b96e55 JW |
353 | |
354 | node = llist_del_all(&dev->work_list); | |
355 | if (!node) | |
356 | schedule(); | |
357 | ||
358 | node = llist_reverse_order(node); | |
359 | /* make sure flag is seen after deletion */ | |
360 | smp_wmb(); | |
361 | llist_for_each_entry_safe(work, work_next, node, node) { | |
362 | clear_bit(VHOST_WORK_QUEUED, &work->flags); | |
c23f3445 TH |
363 | __set_current_state(TASK_RUNNING); |
364 | work->fn(work); | |
d550dda1 NHE |
365 | if (need_resched()) |
366 | schedule(); | |
04b96e55 | 367 | } |
c23f3445 | 368 | } |
64e1c807 | 369 | unuse_mm(dev->mm); |
d7ffde35 | 370 | set_fs(oldfs); |
64e1c807 | 371 | return 0; |
c23f3445 TH |
372 | } |
373 | ||
bab632d6 MT |
374 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
375 | { | |
376 | kfree(vq->indirect); | |
377 | vq->indirect = NULL; | |
378 | kfree(vq->log); | |
379 | vq->log = NULL; | |
380 | kfree(vq->heads); | |
381 | vq->heads = NULL; | |
bab632d6 MT |
382 | } |
383 | ||
e0e9b406 JW |
384 | /* Helper to allocate iovec buffers for all vqs. */ |
385 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
386 | { | |
6d5e6aa8 | 387 | struct vhost_virtqueue *vq; |
e0e9b406 | 388 | int i; |
d47effe1 | 389 | |
e0e9b406 | 390 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 AH |
391 | vq = dev->vqs[i]; |
392 | vq->indirect = kmalloc(sizeof *vq->indirect * UIO_MAXIOV, | |
393 | GFP_KERNEL); | |
394 | vq->log = kmalloc(sizeof *vq->log * UIO_MAXIOV, GFP_KERNEL); | |
395 | vq->heads = kmalloc(sizeof *vq->heads * UIO_MAXIOV, GFP_KERNEL); | |
396 | if (!vq->indirect || !vq->log || !vq->heads) | |
e0e9b406 JW |
397 | goto err_nomem; |
398 | } | |
399 | return 0; | |
d47effe1 | 400 | |
e0e9b406 | 401 | err_nomem: |
bab632d6 | 402 | for (; i >= 0; --i) |
3ab2e420 | 403 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
404 | return -ENOMEM; |
405 | } | |
406 | ||
407 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
408 | { | |
409 | int i; | |
d47effe1 | 410 | |
bab632d6 | 411 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 412 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
413 | } |
414 | ||
59566b6e | 415 | void vhost_dev_init(struct vhost_dev *dev, |
3ab2e420 | 416 | struct vhost_virtqueue **vqs, int nvqs) |
3a4d5c94 | 417 | { |
6d5e6aa8 | 418 | struct vhost_virtqueue *vq; |
3a4d5c94 | 419 | int i; |
c23f3445 | 420 | |
3a4d5c94 MT |
421 | dev->vqs = vqs; |
422 | dev->nvqs = nvqs; | |
423 | mutex_init(&dev->mutex); | |
424 | dev->log_ctx = NULL; | |
425 | dev->log_file = NULL; | |
a9709d68 | 426 | dev->umem = NULL; |
6b1e6cc7 | 427 | dev->iotlb = NULL; |
3a4d5c94 | 428 | dev->mm = NULL; |
c23f3445 | 429 | dev->worker = NULL; |
04b96e55 | 430 | init_llist_head(&dev->work_list); |
6b1e6cc7 JW |
431 | init_waitqueue_head(&dev->wait); |
432 | INIT_LIST_HEAD(&dev->read_list); | |
433 | INIT_LIST_HEAD(&dev->pending_list); | |
434 | spin_lock_init(&dev->iotlb_lock); | |
04b96e55 | 435 | |
3a4d5c94 MT |
436 | |
437 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
438 | vq = dev->vqs[i]; |
439 | vq->log = NULL; | |
440 | vq->indirect = NULL; | |
441 | vq->heads = NULL; | |
442 | vq->dev = dev; | |
443 | mutex_init(&vq->mutex); | |
444 | vhost_vq_reset(dev, vq); | |
445 | if (vq->handle_kick) | |
446 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
447 | POLLIN, dev); | |
3a4d5c94 | 448 | } |
3a4d5c94 | 449 | } |
6ac1afbf | 450 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
451 | |
452 | /* Caller should have device mutex */ | |
453 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
454 | { | |
455 | /* Are you the owner? If not, I don't think you mean to do that */ | |
456 | return dev->mm == current->mm ? 0 : -EPERM; | |
457 | } | |
6ac1afbf | 458 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 459 | |
87d6a412 | 460 | struct vhost_attach_cgroups_struct { |
d47effe1 KK |
461 | struct vhost_work work; |
462 | struct task_struct *owner; | |
463 | int ret; | |
87d6a412 MT |
464 | }; |
465 | ||
466 | static void vhost_attach_cgroups_work(struct vhost_work *work) | |
467 | { | |
d47effe1 KK |
468 | struct vhost_attach_cgroups_struct *s; |
469 | ||
470 | s = container_of(work, struct vhost_attach_cgroups_struct, work); | |
471 | s->ret = cgroup_attach_task_all(s->owner, current); | |
87d6a412 MT |
472 | } |
473 | ||
474 | static int vhost_attach_cgroups(struct vhost_dev *dev) | |
475 | { | |
d47effe1 KK |
476 | struct vhost_attach_cgroups_struct attach; |
477 | ||
478 | attach.owner = current; | |
479 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); | |
480 | vhost_work_queue(dev, &attach.work); | |
481 | vhost_work_flush(dev, &attach.work); | |
482 | return attach.ret; | |
87d6a412 MT |
483 | } |
484 | ||
05c05351 MT |
485 | /* Caller should have device mutex */ |
486 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
487 | { | |
488 | return dev->mm; | |
489 | } | |
6ac1afbf | 490 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 491 | |
3a4d5c94 | 492 | /* Caller should have device mutex */ |
54db63c2 | 493 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 494 | { |
c23f3445 TH |
495 | struct task_struct *worker; |
496 | int err; | |
d47effe1 | 497 | |
3a4d5c94 | 498 | /* Is there an owner already? */ |
05c05351 | 499 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
500 | err = -EBUSY; |
501 | goto err_mm; | |
502 | } | |
d47effe1 | 503 | |
3a4d5c94 MT |
504 | /* No owner, become one */ |
505 | dev->mm = get_task_mm(current); | |
c23f3445 TH |
506 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
507 | if (IS_ERR(worker)) { | |
508 | err = PTR_ERR(worker); | |
509 | goto err_worker; | |
510 | } | |
511 | ||
512 | dev->worker = worker; | |
87d6a412 MT |
513 | wake_up_process(worker); /* avoid contributing to loadavg */ |
514 | ||
515 | err = vhost_attach_cgroups(dev); | |
9e3d1957 MT |
516 | if (err) |
517 | goto err_cgroup; | |
c23f3445 | 518 | |
e0e9b406 JW |
519 | err = vhost_dev_alloc_iovecs(dev); |
520 | if (err) | |
521 | goto err_cgroup; | |
522 | ||
3a4d5c94 | 523 | return 0; |
9e3d1957 MT |
524 | err_cgroup: |
525 | kthread_stop(worker); | |
615cc221 | 526 | dev->worker = NULL; |
c23f3445 TH |
527 | err_worker: |
528 | if (dev->mm) | |
529 | mmput(dev->mm); | |
530 | dev->mm = NULL; | |
531 | err_mm: | |
532 | return err; | |
3a4d5c94 | 533 | } |
6ac1afbf | 534 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 535 | |
a9709d68 JW |
536 | struct vhost_umem *vhost_dev_reset_owner_prepare(void) |
537 | { | |
6c5ab651 | 538 | return kvzalloc(sizeof(struct vhost_umem), GFP_KERNEL); |
150b9e51 | 539 | } |
6ac1afbf | 540 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 541 | |
150b9e51 | 542 | /* Caller should have device mutex */ |
a9709d68 | 543 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_umem *umem) |
150b9e51 | 544 | { |
47283bef MT |
545 | int i; |
546 | ||
ea5d4046 | 547 | vhost_dev_cleanup(dev, true); |
3a4d5c94 | 548 | |
150b9e51 | 549 | /* Restore memory to default empty mapping. */ |
a9709d68 JW |
550 | INIT_LIST_HEAD(&umem->umem_list); |
551 | dev->umem = umem; | |
47283bef MT |
552 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
553 | * VQs aren't running. | |
554 | */ | |
555 | for (i = 0; i < dev->nvqs; ++i) | |
a9709d68 | 556 | dev->vqs[i]->umem = umem; |
3a4d5c94 | 557 | } |
6ac1afbf | 558 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 559 | |
b211616d | 560 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
561 | { |
562 | int i; | |
b211616d MT |
563 | |
564 | for (i = 0; i < dev->nvqs; ++i) { | |
3ab2e420 AH |
565 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) { |
566 | vhost_poll_stop(&dev->vqs[i]->poll); | |
567 | vhost_poll_flush(&dev->vqs[i]->poll); | |
b211616d | 568 | } |
bab632d6 | 569 | } |
bab632d6 | 570 | } |
6ac1afbf | 571 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 572 | |
6b1e6cc7 JW |
573 | static void vhost_umem_free(struct vhost_umem *umem, |
574 | struct vhost_umem_node *node) | |
575 | { | |
576 | vhost_umem_interval_tree_remove(node, &umem->umem_tree); | |
577 | list_del(&node->link); | |
578 | kfree(node); | |
579 | umem->numem--; | |
580 | } | |
581 | ||
a9709d68 JW |
582 | static void vhost_umem_clean(struct vhost_umem *umem) |
583 | { | |
584 | struct vhost_umem_node *node, *tmp; | |
585 | ||
586 | if (!umem) | |
587 | return; | |
588 | ||
6b1e6cc7 JW |
589 | list_for_each_entry_safe(node, tmp, &umem->umem_list, link) |
590 | vhost_umem_free(umem, node); | |
591 | ||
a9709d68 JW |
592 | kvfree(umem); |
593 | } | |
594 | ||
6b1e6cc7 JW |
595 | static void vhost_clear_msg(struct vhost_dev *dev) |
596 | { | |
597 | struct vhost_msg_node *node, *n; | |
598 | ||
599 | spin_lock(&dev->iotlb_lock); | |
600 | ||
601 | list_for_each_entry_safe(node, n, &dev->read_list, node) { | |
602 | list_del(&node->node); | |
603 | kfree(node); | |
604 | } | |
605 | ||
606 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { | |
607 | list_del(&node->node); | |
608 | kfree(node); | |
609 | } | |
610 | ||
611 | spin_unlock(&dev->iotlb_lock); | |
612 | } | |
613 | ||
ea5d4046 MT |
614 | /* Caller should have device mutex if and only if locked is set */ |
615 | void vhost_dev_cleanup(struct vhost_dev *dev, bool locked) | |
3a4d5c94 MT |
616 | { |
617 | int i; | |
d47effe1 | 618 | |
3a4d5c94 | 619 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
620 | if (dev->vqs[i]->error_ctx) |
621 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
622 | if (dev->vqs[i]->error) | |
623 | fput(dev->vqs[i]->error); | |
624 | if (dev->vqs[i]->kick) | |
625 | fput(dev->vqs[i]->kick); | |
626 | if (dev->vqs[i]->call_ctx) | |
627 | eventfd_ctx_put(dev->vqs[i]->call_ctx); | |
628 | if (dev->vqs[i]->call) | |
629 | fput(dev->vqs[i]->call); | |
630 | vhost_vq_reset(dev, dev->vqs[i]); | |
3a4d5c94 | 631 | } |
e0e9b406 | 632 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
633 | if (dev->log_ctx) |
634 | eventfd_ctx_put(dev->log_ctx); | |
635 | dev->log_ctx = NULL; | |
636 | if (dev->log_file) | |
637 | fput(dev->log_file); | |
638 | dev->log_file = NULL; | |
639 | /* No one will access memory at this point */ | |
a9709d68 JW |
640 | vhost_umem_clean(dev->umem); |
641 | dev->umem = NULL; | |
6b1e6cc7 JW |
642 | vhost_umem_clean(dev->iotlb); |
643 | dev->iotlb = NULL; | |
644 | vhost_clear_msg(dev); | |
645 | wake_up_interruptible_poll(&dev->wait, POLLIN | POLLRDNORM); | |
04b96e55 | 646 | WARN_ON(!llist_empty(&dev->work_list)); |
78b620ce ED |
647 | if (dev->worker) { |
648 | kthread_stop(dev->worker); | |
649 | dev->worker = NULL; | |
650 | } | |
533a19b4 MT |
651 | if (dev->mm) |
652 | mmput(dev->mm); | |
653 | dev->mm = NULL; | |
3a4d5c94 | 654 | } |
6ac1afbf | 655 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 MT |
656 | |
657 | static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) | |
658 | { | |
659 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 660 | |
3a4d5c94 MT |
661 | /* Make sure 64 bit math will not overflow. */ |
662 | if (a > ULONG_MAX - (unsigned long)log_base || | |
663 | a + (unsigned long)log_base > ULONG_MAX) | |
6d97e55f | 664 | return 0; |
3a4d5c94 MT |
665 | |
666 | return access_ok(VERIFY_WRITE, log_base + a, | |
667 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); | |
668 | } | |
669 | ||
ec33d031 MT |
670 | static bool vhost_overflow(u64 uaddr, u64 size) |
671 | { | |
672 | /* Make sure 64 bit math will not overflow. */ | |
673 | return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size; | |
674 | } | |
675 | ||
3a4d5c94 | 676 | /* Caller should have vq mutex and device mutex. */ |
a9709d68 | 677 | static int vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, |
3a4d5c94 MT |
678 | int log_all) |
679 | { | |
a9709d68 | 680 | struct vhost_umem_node *node; |
179b284e | 681 | |
a9709d68 | 682 | if (!umem) |
f8322fbe | 683 | return 0; |
179b284e | 684 | |
a9709d68 JW |
685 | list_for_each_entry(node, &umem->umem_list, link) { |
686 | unsigned long a = node->userspace_addr; | |
687 | ||
ec33d031 | 688 | if (vhost_overflow(node->userspace_addr, node->size)) |
3a4d5c94 | 689 | return 0; |
ec33d031 MT |
690 | |
691 | ||
692 | if (!access_ok(VERIFY_WRITE, (void __user *)a, | |
a9709d68 | 693 | node->size)) |
3a4d5c94 MT |
694 | return 0; |
695 | else if (log_all && !log_access_ok(log_base, | |
a9709d68 JW |
696 | node->start, |
697 | node->size)) | |
3a4d5c94 MT |
698 | return 0; |
699 | } | |
700 | return 1; | |
701 | } | |
702 | ||
f8894913 JW |
703 | static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, |
704 | u64 addr, unsigned int size, | |
705 | int type) | |
706 | { | |
707 | const struct vhost_umem_node *node = vq->meta_iotlb[type]; | |
708 | ||
709 | if (!node) | |
710 | return NULL; | |
711 | ||
712 | return (void *)(uintptr_t)(node->userspace_addr + addr - node->start); | |
713 | } | |
714 | ||
3a4d5c94 MT |
715 | /* Can we switch to this memory table? */ |
716 | /* Caller should have device mutex but not vq mutex */ | |
a9709d68 | 717 | static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, |
3a4d5c94 MT |
718 | int log_all) |
719 | { | |
720 | int i; | |
d47effe1 | 721 | |
3a4d5c94 MT |
722 | for (i = 0; i < d->nvqs; ++i) { |
723 | int ok; | |
ea16c514 MT |
724 | bool log; |
725 | ||
3ab2e420 | 726 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 727 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 728 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 729 | if (d->vqs[i]->private_data) |
a9709d68 JW |
730 | ok = vq_memory_access_ok(d->vqs[i]->log_base, |
731 | umem, log); | |
3a4d5c94 MT |
732 | else |
733 | ok = 1; | |
3ab2e420 | 734 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 MT |
735 | if (!ok) |
736 | return 0; | |
737 | } | |
738 | return 1; | |
739 | } | |
740 | ||
6b1e6cc7 JW |
741 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
742 | struct iovec iov[], int iov_size, int access); | |
bfe2bc51 | 743 | |
72952cc0 | 744 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, |
bfe2bc51 JW |
745 | const void *from, unsigned size) |
746 | { | |
6b1e6cc7 | 747 | int ret; |
bfe2bc51 | 748 | |
6b1e6cc7 JW |
749 | if (!vq->iotlb) |
750 | return __copy_to_user(to, from, size); | |
751 | else { | |
752 | /* This function should be called after iotlb | |
753 | * prefetch, which means we're sure that all vq | |
754 | * could be access through iotlb. So -EAGAIN should | |
755 | * not happen in this case. | |
756 | */ | |
6b1e6cc7 | 757 | struct iov_iter t; |
f8894913 JW |
758 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
759 | (u64)(uintptr_t)to, size, | |
760 | VHOST_ADDR_DESC); | |
761 | ||
762 | if (uaddr) | |
763 | return __copy_to_user(uaddr, from, size); | |
764 | ||
6b1e6cc7 JW |
765 | ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, |
766 | ARRAY_SIZE(vq->iotlb_iov), | |
767 | VHOST_ACCESS_WO); | |
768 | if (ret < 0) | |
769 | goto out; | |
770 | iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size); | |
771 | ret = copy_to_iter(from, size, &t); | |
772 | if (ret == size) | |
773 | ret = 0; | |
774 | } | |
775 | out: | |
776 | return ret; | |
777 | } | |
bfe2bc51 JW |
778 | |
779 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, | |
72952cc0 | 780 | void __user *from, unsigned size) |
bfe2bc51 | 781 | { |
6b1e6cc7 JW |
782 | int ret; |
783 | ||
784 | if (!vq->iotlb) | |
785 | return __copy_from_user(to, from, size); | |
786 | else { | |
787 | /* This function should be called after iotlb | |
788 | * prefetch, which means we're sure that vq | |
789 | * could be access through iotlb. So -EAGAIN should | |
790 | * not happen in this case. | |
791 | */ | |
f8894913 JW |
792 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
793 | (u64)(uintptr_t)from, size, | |
794 | VHOST_ADDR_DESC); | |
6b1e6cc7 | 795 | struct iov_iter f; |
f8894913 JW |
796 | |
797 | if (uaddr) | |
798 | return __copy_from_user(to, uaddr, size); | |
799 | ||
6b1e6cc7 JW |
800 | ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, |
801 | ARRAY_SIZE(vq->iotlb_iov), | |
802 | VHOST_ACCESS_RO); | |
803 | if (ret < 0) { | |
804 | vq_err(vq, "IOTLB translation failure: uaddr " | |
805 | "%p size 0x%llx\n", from, | |
806 | (unsigned long long) size); | |
807 | goto out; | |
808 | } | |
809 | iov_iter_init(&f, READ, vq->iotlb_iov, ret, size); | |
810 | ret = copy_from_iter(to, size, &f); | |
811 | if (ret == size) | |
812 | ret = 0; | |
813 | } | |
814 | ||
815 | out: | |
816 | return ret; | |
817 | } | |
818 | ||
f8894913 JW |
819 | static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq, |
820 | void __user *addr, unsigned int size, | |
821 | int type) | |
6b1e6cc7 JW |
822 | { |
823 | int ret; | |
824 | ||
6b1e6cc7 JW |
825 | ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov, |
826 | ARRAY_SIZE(vq->iotlb_iov), | |
827 | VHOST_ACCESS_RO); | |
828 | if (ret < 0) { | |
829 | vq_err(vq, "IOTLB translation failure: uaddr " | |
830 | "%p size 0x%llx\n", addr, | |
831 | (unsigned long long) size); | |
832 | return NULL; | |
833 | } | |
834 | ||
835 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { | |
836 | vq_err(vq, "Non atomic userspace memory access: uaddr " | |
837 | "%p size 0x%llx\n", addr, | |
838 | (unsigned long long) size); | |
839 | return NULL; | |
840 | } | |
841 | ||
842 | return vq->iotlb_iov[0].iov_base; | |
843 | } | |
844 | ||
f8894913 JW |
845 | /* This function should be called after iotlb |
846 | * prefetch, which means we're sure that vq | |
847 | * could be access through iotlb. So -EAGAIN should | |
848 | * not happen in this case. | |
849 | */ | |
850 | static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, | |
851 | void *addr, unsigned int size, | |
852 | int type) | |
853 | { | |
854 | void __user *uaddr = vhost_vq_meta_fetch(vq, | |
855 | (u64)(uintptr_t)addr, size, type); | |
856 | if (uaddr) | |
857 | return uaddr; | |
858 | ||
859 | return __vhost_get_user_slow(vq, addr, size, type); | |
860 | } | |
861 | ||
862 | #define vhost_put_user(vq, x, ptr) \ | |
6b1e6cc7 JW |
863 | ({ \ |
864 | int ret = -EFAULT; \ | |
865 | if (!vq->iotlb) { \ | |
866 | ret = __put_user(x, ptr); \ | |
867 | } else { \ | |
868 | __typeof__(ptr) to = \ | |
f8894913 JW |
869 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
870 | sizeof(*ptr), VHOST_ADDR_USED); \ | |
6b1e6cc7 JW |
871 | if (to != NULL) \ |
872 | ret = __put_user(x, to); \ | |
873 | else \ | |
874 | ret = -EFAULT; \ | |
875 | } \ | |
876 | ret; \ | |
877 | }) | |
878 | ||
f8894913 | 879 | #define vhost_get_user(vq, x, ptr, type) \ |
6b1e6cc7 JW |
880 | ({ \ |
881 | int ret; \ | |
882 | if (!vq->iotlb) { \ | |
883 | ret = __get_user(x, ptr); \ | |
884 | } else { \ | |
885 | __typeof__(ptr) from = \ | |
f8894913 JW |
886 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
887 | sizeof(*ptr), \ | |
888 | type); \ | |
6b1e6cc7 JW |
889 | if (from != NULL) \ |
890 | ret = __get_user(x, from); \ | |
891 | else \ | |
892 | ret = -EFAULT; \ | |
893 | } \ | |
894 | ret; \ | |
895 | }) | |
896 | ||
f8894913 JW |
897 | #define vhost_get_avail(vq, x, ptr) \ |
898 | vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL) | |
899 | ||
900 | #define vhost_get_used(vq, x, ptr) \ | |
901 | vhost_get_user(vq, x, ptr, VHOST_ADDR_USED) | |
902 | ||
6b1e6cc7 JW |
903 | static void vhost_dev_lock_vqs(struct vhost_dev *d) |
904 | { | |
905 | int i = 0; | |
906 | for (i = 0; i < d->nvqs; ++i) | |
e9cb4239 | 907 | mutex_lock_nested(&d->vqs[i]->mutex, i); |
6b1e6cc7 JW |
908 | } |
909 | ||
910 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) | |
911 | { | |
912 | int i = 0; | |
913 | for (i = 0; i < d->nvqs; ++i) | |
914 | mutex_unlock(&d->vqs[i]->mutex); | |
915 | } | |
916 | ||
917 | static int vhost_new_umem_range(struct vhost_umem *umem, | |
918 | u64 start, u64 size, u64 end, | |
919 | u64 userspace_addr, int perm) | |
920 | { | |
921 | struct vhost_umem_node *tmp, *node = kmalloc(sizeof(*node), GFP_ATOMIC); | |
922 | ||
923 | if (!node) | |
924 | return -ENOMEM; | |
925 | ||
926 | if (umem->numem == max_iotlb_entries) { | |
927 | tmp = list_first_entry(&umem->umem_list, typeof(*tmp), link); | |
928 | vhost_umem_free(umem, tmp); | |
929 | } | |
930 | ||
931 | node->start = start; | |
932 | node->size = size; | |
933 | node->last = end; | |
934 | node->userspace_addr = userspace_addr; | |
935 | node->perm = perm; | |
936 | INIT_LIST_HEAD(&node->link); | |
937 | list_add_tail(&node->link, &umem->umem_list); | |
938 | vhost_umem_interval_tree_insert(node, &umem->umem_tree); | |
939 | umem->numem++; | |
940 | ||
941 | return 0; | |
942 | } | |
943 | ||
944 | static void vhost_del_umem_range(struct vhost_umem *umem, | |
945 | u64 start, u64 end) | |
946 | { | |
947 | struct vhost_umem_node *node; | |
948 | ||
949 | while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
950 | start, end))) | |
951 | vhost_umem_free(umem, node); | |
952 | } | |
953 | ||
954 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, | |
955 | struct vhost_iotlb_msg *msg) | |
956 | { | |
957 | struct vhost_msg_node *node, *n; | |
958 | ||
959 | spin_lock(&d->iotlb_lock); | |
960 | ||
961 | list_for_each_entry_safe(node, n, &d->pending_list, node) { | |
962 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; | |
963 | if (msg->iova <= vq_msg->iova && | |
964 | msg->iova + msg->size - 1 > vq_msg->iova && | |
965 | vq_msg->type == VHOST_IOTLB_MISS) { | |
966 | vhost_poll_queue(&node->vq->poll); | |
967 | list_del(&node->node); | |
968 | kfree(node); | |
969 | } | |
970 | } | |
971 | ||
972 | spin_unlock(&d->iotlb_lock); | |
973 | } | |
974 | ||
975 | static int umem_access_ok(u64 uaddr, u64 size, int access) | |
976 | { | |
977 | unsigned long a = uaddr; | |
978 | ||
ec33d031 MT |
979 | /* Make sure 64 bit math will not overflow. */ |
980 | if (vhost_overflow(uaddr, size)) | |
981 | return -EFAULT; | |
982 | ||
6b1e6cc7 JW |
983 | if ((access & VHOST_ACCESS_RO) && |
984 | !access_ok(VERIFY_READ, (void __user *)a, size)) | |
985 | return -EFAULT; | |
986 | if ((access & VHOST_ACCESS_WO) && | |
987 | !access_ok(VERIFY_WRITE, (void __user *)a, size)) | |
988 | return -EFAULT; | |
989 | return 0; | |
990 | } | |
991 | ||
72952cc0 MT |
992 | static int vhost_process_iotlb_msg(struct vhost_dev *dev, |
993 | struct vhost_iotlb_msg *msg) | |
6b1e6cc7 JW |
994 | { |
995 | int ret = 0; | |
996 | ||
997 | vhost_dev_lock_vqs(dev); | |
998 | switch (msg->type) { | |
999 | case VHOST_IOTLB_UPDATE: | |
1000 | if (!dev->iotlb) { | |
1001 | ret = -EFAULT; | |
1002 | break; | |
1003 | } | |
1004 | if (umem_access_ok(msg->uaddr, msg->size, msg->perm)) { | |
1005 | ret = -EFAULT; | |
1006 | break; | |
1007 | } | |
f8894913 | 1008 | vhost_vq_meta_reset(dev); |
6b1e6cc7 JW |
1009 | if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size, |
1010 | msg->iova + msg->size - 1, | |
1011 | msg->uaddr, msg->perm)) { | |
1012 | ret = -ENOMEM; | |
1013 | break; | |
1014 | } | |
1015 | vhost_iotlb_notify_vq(dev, msg); | |
1016 | break; | |
1017 | case VHOST_IOTLB_INVALIDATE: | |
6f3180af JW |
1018 | if (!dev->iotlb) { |
1019 | ret = -EFAULT; | |
1020 | break; | |
1021 | } | |
f8894913 | 1022 | vhost_vq_meta_reset(dev); |
6b1e6cc7 JW |
1023 | vhost_del_umem_range(dev->iotlb, msg->iova, |
1024 | msg->iova + msg->size - 1); | |
1025 | break; | |
1026 | default: | |
1027 | ret = -EINVAL; | |
1028 | break; | |
1029 | } | |
1030 | ||
1031 | vhost_dev_unlock_vqs(dev); | |
1032 | return ret; | |
1033 | } | |
1034 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, | |
1035 | struct iov_iter *from) | |
1036 | { | |
1037 | struct vhost_msg_node node; | |
1038 | unsigned size = sizeof(struct vhost_msg); | |
1039 | size_t ret; | |
1040 | int err; | |
1041 | ||
1042 | if (iov_iter_count(from) < size) | |
1043 | return 0; | |
1044 | ret = copy_from_iter(&node.msg, size, from); | |
1045 | if (ret != size) | |
1046 | goto done; | |
1047 | ||
1048 | switch (node.msg.type) { | |
1049 | case VHOST_IOTLB_MSG: | |
1050 | err = vhost_process_iotlb_msg(dev, &node.msg.iotlb); | |
1051 | if (err) | |
1052 | ret = err; | |
1053 | break; | |
1054 | default: | |
1055 | ret = -EINVAL; | |
1056 | break; | |
1057 | } | |
1058 | ||
1059 | done: | |
1060 | return ret; | |
1061 | } | |
1062 | EXPORT_SYMBOL(vhost_chr_write_iter); | |
1063 | ||
afc9a42b | 1064 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
6b1e6cc7 JW |
1065 | poll_table *wait) |
1066 | { | |
afc9a42b | 1067 | __poll_t mask = 0; |
6b1e6cc7 JW |
1068 | |
1069 | poll_wait(file, &dev->wait, wait); | |
1070 | ||
1071 | if (!list_empty(&dev->read_list)) | |
1072 | mask |= POLLIN | POLLRDNORM; | |
1073 | ||
1074 | return mask; | |
1075 | } | |
1076 | EXPORT_SYMBOL(vhost_chr_poll); | |
1077 | ||
1078 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, | |
1079 | int noblock) | |
1080 | { | |
1081 | DEFINE_WAIT(wait); | |
1082 | struct vhost_msg_node *node; | |
1083 | ssize_t ret = 0; | |
1084 | unsigned size = sizeof(struct vhost_msg); | |
1085 | ||
1086 | if (iov_iter_count(to) < size) | |
1087 | return 0; | |
1088 | ||
1089 | while (1) { | |
1090 | if (!noblock) | |
1091 | prepare_to_wait(&dev->wait, &wait, | |
1092 | TASK_INTERRUPTIBLE); | |
1093 | ||
1094 | node = vhost_dequeue_msg(dev, &dev->read_list); | |
1095 | if (node) | |
1096 | break; | |
1097 | if (noblock) { | |
1098 | ret = -EAGAIN; | |
1099 | break; | |
1100 | } | |
1101 | if (signal_pending(current)) { | |
1102 | ret = -ERESTARTSYS; | |
1103 | break; | |
1104 | } | |
1105 | if (!dev->iotlb) { | |
1106 | ret = -EBADFD; | |
1107 | break; | |
1108 | } | |
1109 | ||
1110 | schedule(); | |
1111 | } | |
1112 | ||
1113 | if (!noblock) | |
1114 | finish_wait(&dev->wait, &wait); | |
1115 | ||
1116 | if (node) { | |
1117 | ret = copy_to_iter(&node->msg, size, to); | |
1118 | ||
1119 | if (ret != size || node->msg.type != VHOST_IOTLB_MISS) { | |
1120 | kfree(node); | |
1121 | return ret; | |
1122 | } | |
1123 | ||
1124 | vhost_enqueue_msg(dev, &dev->pending_list, node); | |
1125 | } | |
1126 | ||
1127 | return ret; | |
1128 | } | |
1129 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); | |
1130 | ||
1131 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) | |
1132 | { | |
1133 | struct vhost_dev *dev = vq->dev; | |
1134 | struct vhost_msg_node *node; | |
1135 | struct vhost_iotlb_msg *msg; | |
1136 | ||
1137 | node = vhost_new_msg(vq, VHOST_IOTLB_MISS); | |
1138 | if (!node) | |
1139 | return -ENOMEM; | |
1140 | ||
1141 | msg = &node->msg.iotlb; | |
1142 | msg->type = VHOST_IOTLB_MISS; | |
1143 | msg->iova = iova; | |
1144 | msg->perm = access; | |
1145 | ||
1146 | vhost_enqueue_msg(dev, &dev->read_list, node); | |
1147 | ||
1148 | return 0; | |
bfe2bc51 JW |
1149 | } |
1150 | ||
ea16c514 | 1151 | static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
3a4d5c94 MT |
1152 | struct vring_desc __user *desc, |
1153 | struct vring_avail __user *avail, | |
1154 | struct vring_used __user *used) | |
6b1e6cc7 | 1155 | |
3a4d5c94 | 1156 | { |
ea16c514 | 1157 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
6b1e6cc7 | 1158 | |
3a4d5c94 MT |
1159 | return access_ok(VERIFY_READ, desc, num * sizeof *desc) && |
1160 | access_ok(VERIFY_READ, avail, | |
8ea8cf89 | 1161 | sizeof *avail + num * sizeof *avail->ring + s) && |
3a4d5c94 | 1162 | access_ok(VERIFY_WRITE, used, |
8ea8cf89 | 1163 | sizeof *used + num * sizeof *used->ring + s); |
3a4d5c94 MT |
1164 | } |
1165 | ||
f8894913 JW |
1166 | static void vhost_vq_meta_update(struct vhost_virtqueue *vq, |
1167 | const struct vhost_umem_node *node, | |
1168 | int type) | |
1169 | { | |
1170 | int access = (type == VHOST_ADDR_USED) ? | |
1171 | VHOST_ACCESS_WO : VHOST_ACCESS_RO; | |
1172 | ||
1173 | if (likely(node->perm & access)) | |
1174 | vq->meta_iotlb[type] = node; | |
1175 | } | |
1176 | ||
6b1e6cc7 | 1177 | static int iotlb_access_ok(struct vhost_virtqueue *vq, |
f8894913 | 1178 | int access, u64 addr, u64 len, int type) |
6b1e6cc7 JW |
1179 | { |
1180 | const struct vhost_umem_node *node; | |
1181 | struct vhost_umem *umem = vq->iotlb; | |
ca2c5b33 | 1182 | u64 s = 0, size, orig_addr = addr, last = addr + len - 1; |
f8894913 JW |
1183 | |
1184 | if (vhost_vq_meta_fetch(vq, addr, len, type)) | |
1185 | return true; | |
6b1e6cc7 JW |
1186 | |
1187 | while (len > s) { | |
1188 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
1189 | addr, | |
ca2c5b33 | 1190 | last); |
6b1e6cc7 JW |
1191 | if (node == NULL || node->start > addr) { |
1192 | vhost_iotlb_miss(vq, addr, access); | |
1193 | return false; | |
1194 | } else if (!(node->perm & access)) { | |
1195 | /* Report the possible access violation by | |
1196 | * request another translation from userspace. | |
1197 | */ | |
1198 | return false; | |
1199 | } | |
1200 | ||
1201 | size = node->size - addr + node->start; | |
f8894913 JW |
1202 | |
1203 | if (orig_addr == addr && size >= len) | |
1204 | vhost_vq_meta_update(vq, node, type); | |
1205 | ||
6b1e6cc7 JW |
1206 | s += size; |
1207 | addr += size; | |
1208 | } | |
1209 | ||
1210 | return true; | |
1211 | } | |
1212 | ||
1213 | int vq_iotlb_prefetch(struct vhost_virtqueue *vq) | |
1214 | { | |
1215 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
1216 | unsigned int num = vq->num; | |
1217 | ||
1218 | if (!vq->iotlb) | |
1219 | return 1; | |
1220 | ||
1221 | return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc, | |
f8894913 | 1222 | num * sizeof(*vq->desc), VHOST_ADDR_DESC) && |
6b1e6cc7 JW |
1223 | iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail, |
1224 | sizeof *vq->avail + | |
f8894913 JW |
1225 | num * sizeof(*vq->avail->ring) + s, |
1226 | VHOST_ADDR_AVAIL) && | |
6b1e6cc7 JW |
1227 | iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used, |
1228 | sizeof *vq->used + | |
f8894913 JW |
1229 | num * sizeof(*vq->used->ring) + s, |
1230 | VHOST_ADDR_USED); | |
6b1e6cc7 JW |
1231 | } |
1232 | EXPORT_SYMBOL_GPL(vq_iotlb_prefetch); | |
1233 | ||
3a4d5c94 MT |
1234 | /* Can we log writes? */ |
1235 | /* Caller should have device mutex but not vq mutex */ | |
1236 | int vhost_log_access_ok(struct vhost_dev *dev) | |
1237 | { | |
a9709d68 | 1238 | return memory_access_ok(dev, dev->umem, 1); |
3a4d5c94 | 1239 | } |
6ac1afbf | 1240 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 MT |
1241 | |
1242 | /* Verify access for write logging. */ | |
1243 | /* Caller should have vq mutex and device mutex */ | |
ea16c514 | 1244 | static int vq_log_access_ok(struct vhost_virtqueue *vq, |
8ea8cf89 | 1245 | void __user *log_base) |
3a4d5c94 | 1246 | { |
ea16c514 | 1247 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
28457ee6 | 1248 | |
a9709d68 | 1249 | return vq_memory_access_ok(log_base, vq->umem, |
ea16c514 | 1250 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
3a4d5c94 MT |
1251 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
1252 | sizeof *vq->used + | |
8ea8cf89 | 1253 | vq->num * sizeof *vq->used->ring + s)); |
3a4d5c94 MT |
1254 | } |
1255 | ||
1256 | /* Can we start vq? */ | |
1257 | /* Caller should have vq mutex and device mutex */ | |
1258 | int vhost_vq_access_ok(struct vhost_virtqueue *vq) | |
1259 | { | |
6b1e6cc7 JW |
1260 | if (vq->iotlb) { |
1261 | /* When device IOTLB was used, the access validation | |
1262 | * will be validated during prefetching. | |
1263 | */ | |
1264 | return 1; | |
1265 | } | |
ea16c514 MT |
1266 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) && |
1267 | vq_log_access_ok(vq, vq->log_base); | |
3a4d5c94 | 1268 | } |
6ac1afbf | 1269 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 | 1270 | |
6b1e6cc7 JW |
1271 | static struct vhost_umem *vhost_umem_alloc(void) |
1272 | { | |
6c5ab651 | 1273 | struct vhost_umem *umem = kvzalloc(sizeof(*umem), GFP_KERNEL); |
6b1e6cc7 JW |
1274 | |
1275 | if (!umem) | |
1276 | return NULL; | |
1277 | ||
f808c13f | 1278 | umem->umem_tree = RB_ROOT_CACHED; |
6b1e6cc7 JW |
1279 | umem->numem = 0; |
1280 | INIT_LIST_HEAD(&umem->umem_list); | |
1281 | ||
1282 | return umem; | |
1283 | } | |
1284 | ||
3a4d5c94 MT |
1285 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
1286 | { | |
a9709d68 JW |
1287 | struct vhost_memory mem, *newmem; |
1288 | struct vhost_memory_region *region; | |
a9709d68 | 1289 | struct vhost_umem *newumem, *oldumem; |
3a4d5c94 | 1290 | unsigned long size = offsetof(struct vhost_memory, regions); |
98f9ca0a | 1291 | int i; |
d47effe1 | 1292 | |
7ad9c9d2 TY |
1293 | if (copy_from_user(&mem, m, size)) |
1294 | return -EFAULT; | |
3a4d5c94 MT |
1295 | if (mem.padding) |
1296 | return -EOPNOTSUPP; | |
c9ce42f7 | 1297 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 1298 | return -E2BIG; |
6c5ab651 | 1299 | newmem = kvzalloc(size + mem.nregions * sizeof(*m->regions), GFP_KERNEL); |
3a4d5c94 MT |
1300 | if (!newmem) |
1301 | return -ENOMEM; | |
1302 | ||
1303 | memcpy(newmem, &mem, size); | |
7ad9c9d2 TY |
1304 | if (copy_from_user(newmem->regions, m->regions, |
1305 | mem.nregions * sizeof *m->regions)) { | |
bcfeacab | 1306 | kvfree(newmem); |
7ad9c9d2 | 1307 | return -EFAULT; |
3a4d5c94 MT |
1308 | } |
1309 | ||
6b1e6cc7 | 1310 | newumem = vhost_umem_alloc(); |
a9709d68 | 1311 | if (!newumem) { |
4de7255f | 1312 | kvfree(newmem); |
a9709d68 JW |
1313 | return -ENOMEM; |
1314 | } | |
1315 | ||
a9709d68 JW |
1316 | for (region = newmem->regions; |
1317 | region < newmem->regions + mem.nregions; | |
1318 | region++) { | |
6b1e6cc7 JW |
1319 | if (vhost_new_umem_range(newumem, |
1320 | region->guest_phys_addr, | |
1321 | region->memory_size, | |
1322 | region->guest_phys_addr + | |
1323 | region->memory_size - 1, | |
1324 | region->userspace_addr, | |
1325 | VHOST_ACCESS_RW)) | |
a9709d68 | 1326 | goto err; |
a02c3789 | 1327 | } |
a9709d68 JW |
1328 | |
1329 | if (!memory_access_ok(d, newumem, 0)) | |
1330 | goto err; | |
1331 | ||
1332 | oldumem = d->umem; | |
1333 | d->umem = newumem; | |
98f9ca0a | 1334 | |
47283bef | 1335 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
1336 | for (i = 0; i < d->nvqs; ++i) { |
1337 | mutex_lock(&d->vqs[i]->mutex); | |
a9709d68 | 1338 | d->vqs[i]->umem = newumem; |
98f9ca0a MT |
1339 | mutex_unlock(&d->vqs[i]->mutex); |
1340 | } | |
a9709d68 JW |
1341 | |
1342 | kvfree(newmem); | |
1343 | vhost_umem_clean(oldumem); | |
3a4d5c94 | 1344 | return 0; |
a9709d68 JW |
1345 | |
1346 | err: | |
1347 | vhost_umem_clean(newumem); | |
1348 | kvfree(newmem); | |
1349 | return -EFAULT; | |
3a4d5c94 MT |
1350 | } |
1351 | ||
935cdee7 | 1352 | long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) |
3a4d5c94 | 1353 | { |
cecb46f1 AV |
1354 | struct file *eventfp, *filep = NULL; |
1355 | bool pollstart = false, pollstop = false; | |
3a4d5c94 MT |
1356 | struct eventfd_ctx *ctx = NULL; |
1357 | u32 __user *idxp = argp; | |
1358 | struct vhost_virtqueue *vq; | |
1359 | struct vhost_vring_state s; | |
1360 | struct vhost_vring_file f; | |
1361 | struct vhost_vring_addr a; | |
1362 | u32 idx; | |
1363 | long r; | |
1364 | ||
1365 | r = get_user(idx, idxp); | |
1366 | if (r < 0) | |
1367 | return r; | |
0f3d9a17 | 1368 | if (idx >= d->nvqs) |
3a4d5c94 MT |
1369 | return -ENOBUFS; |
1370 | ||
3ab2e420 | 1371 | vq = d->vqs[idx]; |
3a4d5c94 MT |
1372 | |
1373 | mutex_lock(&vq->mutex); | |
1374 | ||
1375 | switch (ioctl) { | |
1376 | case VHOST_SET_VRING_NUM: | |
1377 | /* Resizing ring with an active backend? | |
1378 | * You don't want to do that. */ | |
1379 | if (vq->private_data) { | |
1380 | r = -EBUSY; | |
1381 | break; | |
1382 | } | |
7ad9c9d2 TY |
1383 | if (copy_from_user(&s, argp, sizeof s)) { |
1384 | r = -EFAULT; | |
3a4d5c94 | 1385 | break; |
7ad9c9d2 | 1386 | } |
3a4d5c94 MT |
1387 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) { |
1388 | r = -EINVAL; | |
1389 | break; | |
1390 | } | |
1391 | vq->num = s.num; | |
1392 | break; | |
1393 | case VHOST_SET_VRING_BASE: | |
1394 | /* Moving base with an active backend? | |
1395 | * You don't want to do that. */ | |
1396 | if (vq->private_data) { | |
1397 | r = -EBUSY; | |
1398 | break; | |
1399 | } | |
7ad9c9d2 TY |
1400 | if (copy_from_user(&s, argp, sizeof s)) { |
1401 | r = -EFAULT; | |
3a4d5c94 | 1402 | break; |
7ad9c9d2 | 1403 | } |
3a4d5c94 MT |
1404 | if (s.num > 0xffff) { |
1405 | r = -EINVAL; | |
1406 | break; | |
1407 | } | |
8d65843c | 1408 | vq->last_avail_idx = s.num; |
3a4d5c94 MT |
1409 | /* Forget the cached index value. */ |
1410 | vq->avail_idx = vq->last_avail_idx; | |
1411 | break; | |
1412 | case VHOST_GET_VRING_BASE: | |
1413 | s.index = idx; | |
1414 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
1415 | if (copy_to_user(argp, &s, sizeof s)) |
1416 | r = -EFAULT; | |
3a4d5c94 MT |
1417 | break; |
1418 | case VHOST_SET_VRING_ADDR: | |
7ad9c9d2 TY |
1419 | if (copy_from_user(&a, argp, sizeof a)) { |
1420 | r = -EFAULT; | |
3a4d5c94 | 1421 | break; |
7ad9c9d2 | 1422 | } |
3a4d5c94 MT |
1423 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) { |
1424 | r = -EOPNOTSUPP; | |
1425 | break; | |
1426 | } | |
1427 | /* For 32bit, verify that the top 32bits of the user | |
1428 | data are set to zero. */ | |
1429 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
1430 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
1431 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { | |
1432 | r = -EFAULT; | |
1433 | break; | |
1434 | } | |
5d9a07b0 MT |
1435 | |
1436 | /* Make sure it's safe to cast pointers to vring types. */ | |
1437 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
1438 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
1439 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
1440 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
d5424838 | 1441 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) { |
3a4d5c94 MT |
1442 | r = -EINVAL; |
1443 | break; | |
1444 | } | |
1445 | ||
1446 | /* We only verify access here if backend is configured. | |
1447 | * If it is not, we don't as size might not have been setup. | |
1448 | * We will verify when backend is configured. */ | |
1449 | if (vq->private_data) { | |
ea16c514 | 1450 | if (!vq_access_ok(vq, vq->num, |
3a4d5c94 MT |
1451 | (void __user *)(unsigned long)a.desc_user_addr, |
1452 | (void __user *)(unsigned long)a.avail_user_addr, | |
1453 | (void __user *)(unsigned long)a.used_user_addr)) { | |
1454 | r = -EINVAL; | |
1455 | break; | |
1456 | } | |
1457 | ||
1458 | /* Also validate log access for used ring if enabled. */ | |
1459 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && | |
1460 | !log_access_ok(vq->log_base, a.log_guest_addr, | |
1461 | sizeof *vq->used + | |
1462 | vq->num * sizeof *vq->used->ring)) { | |
1463 | r = -EINVAL; | |
1464 | break; | |
1465 | } | |
1466 | } | |
1467 | ||
3a4d5c94 MT |
1468 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); |
1469 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
1470 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
1471 | vq->log_addr = a.log_guest_addr; | |
1472 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
1473 | break; | |
1474 | case VHOST_SET_VRING_KICK: | |
7ad9c9d2 TY |
1475 | if (copy_from_user(&f, argp, sizeof f)) { |
1476 | r = -EFAULT; | |
3a4d5c94 | 1477 | break; |
7ad9c9d2 | 1478 | } |
3a4d5c94 | 1479 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1480 | if (IS_ERR(eventfp)) { |
1481 | r = PTR_ERR(eventfp); | |
1482 | break; | |
1483 | } | |
3a4d5c94 | 1484 | if (eventfp != vq->kick) { |
cecb46f1 AV |
1485 | pollstop = (filep = vq->kick) != NULL; |
1486 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
1487 | } else |
1488 | filep = eventfp; | |
1489 | break; | |
1490 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
1491 | if (copy_from_user(&f, argp, sizeof f)) { |
1492 | r = -EFAULT; | |
3a4d5c94 | 1493 | break; |
7ad9c9d2 | 1494 | } |
3a4d5c94 | 1495 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1496 | if (IS_ERR(eventfp)) { |
1497 | r = PTR_ERR(eventfp); | |
1498 | break; | |
1499 | } | |
3a4d5c94 MT |
1500 | if (eventfp != vq->call) { |
1501 | filep = vq->call; | |
1502 | ctx = vq->call_ctx; | |
1503 | vq->call = eventfp; | |
1504 | vq->call_ctx = eventfp ? | |
1505 | eventfd_ctx_fileget(eventfp) : NULL; | |
1506 | } else | |
1507 | filep = eventfp; | |
1508 | break; | |
1509 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
1510 | if (copy_from_user(&f, argp, sizeof f)) { |
1511 | r = -EFAULT; | |
3a4d5c94 | 1512 | break; |
7ad9c9d2 | 1513 | } |
3a4d5c94 | 1514 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1515 | if (IS_ERR(eventfp)) { |
1516 | r = PTR_ERR(eventfp); | |
1517 | break; | |
1518 | } | |
3a4d5c94 MT |
1519 | if (eventfp != vq->error) { |
1520 | filep = vq->error; | |
1521 | vq->error = eventfp; | |
1522 | ctx = vq->error_ctx; | |
1523 | vq->error_ctx = eventfp ? | |
1524 | eventfd_ctx_fileget(eventfp) : NULL; | |
1525 | } else | |
1526 | filep = eventfp; | |
1527 | break; | |
2751c988 GK |
1528 | case VHOST_SET_VRING_ENDIAN: |
1529 | r = vhost_set_vring_endian(vq, argp); | |
1530 | break; | |
1531 | case VHOST_GET_VRING_ENDIAN: | |
1532 | r = vhost_get_vring_endian(vq, idx, argp); | |
1533 | break; | |
03088137 JW |
1534 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1535 | if (copy_from_user(&s, argp, sizeof(s))) { | |
1536 | r = -EFAULT; | |
1537 | break; | |
1538 | } | |
1539 | vq->busyloop_timeout = s.num; | |
1540 | break; | |
1541 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
1542 | s.index = idx; | |
1543 | s.num = vq->busyloop_timeout; | |
1544 | if (copy_to_user(argp, &s, sizeof(s))) | |
1545 | r = -EFAULT; | |
1546 | break; | |
3a4d5c94 MT |
1547 | default: |
1548 | r = -ENOIOCTLCMD; | |
1549 | } | |
1550 | ||
1551 | if (pollstop && vq->handle_kick) | |
1552 | vhost_poll_stop(&vq->poll); | |
1553 | ||
1554 | if (ctx) | |
1555 | eventfd_ctx_put(ctx); | |
1556 | if (filep) | |
1557 | fput(filep); | |
1558 | ||
1559 | if (pollstart && vq->handle_kick) | |
2b8b328b | 1560 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
1561 | |
1562 | mutex_unlock(&vq->mutex); | |
1563 | ||
1564 | if (pollstop && vq->handle_kick) | |
1565 | vhost_poll_flush(&vq->poll); | |
1566 | return r; | |
1567 | } | |
6ac1afbf | 1568 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 | 1569 | |
6b1e6cc7 JW |
1570 | int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled) |
1571 | { | |
1572 | struct vhost_umem *niotlb, *oiotlb; | |
1573 | int i; | |
1574 | ||
1575 | niotlb = vhost_umem_alloc(); | |
1576 | if (!niotlb) | |
1577 | return -ENOMEM; | |
1578 | ||
1579 | oiotlb = d->iotlb; | |
1580 | d->iotlb = niotlb; | |
1581 | ||
1582 | for (i = 0; i < d->nvqs; ++i) { | |
1583 | mutex_lock(&d->vqs[i]->mutex); | |
1584 | d->vqs[i]->iotlb = niotlb; | |
1585 | mutex_unlock(&d->vqs[i]->mutex); | |
1586 | } | |
1587 | ||
1588 | vhost_umem_clean(oiotlb); | |
1589 | ||
1590 | return 0; | |
1591 | } | |
1592 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); | |
1593 | ||
3a4d5c94 | 1594 | /* Caller must have device mutex */ |
935cdee7 | 1595 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1596 | { |
3a4d5c94 MT |
1597 | struct file *eventfp, *filep = NULL; |
1598 | struct eventfd_ctx *ctx = NULL; | |
1599 | u64 p; | |
1600 | long r; | |
1601 | int i, fd; | |
1602 | ||
1603 | /* If you are not the owner, you can become one */ | |
1604 | if (ioctl == VHOST_SET_OWNER) { | |
1605 | r = vhost_dev_set_owner(d); | |
1606 | goto done; | |
1607 | } | |
1608 | ||
1609 | /* You must be the owner to do anything else */ | |
1610 | r = vhost_dev_check_owner(d); | |
1611 | if (r) | |
1612 | goto done; | |
1613 | ||
1614 | switch (ioctl) { | |
1615 | case VHOST_SET_MEM_TABLE: | |
1616 | r = vhost_set_memory(d, argp); | |
1617 | break; | |
1618 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
1619 | if (copy_from_user(&p, argp, sizeof p)) { |
1620 | r = -EFAULT; | |
3a4d5c94 | 1621 | break; |
7ad9c9d2 | 1622 | } |
3a4d5c94 MT |
1623 | if ((u64)(unsigned long)p != p) { |
1624 | r = -EFAULT; | |
1625 | break; | |
1626 | } | |
1627 | for (i = 0; i < d->nvqs; ++i) { | |
1628 | struct vhost_virtqueue *vq; | |
1629 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 1630 | vq = d->vqs[i]; |
3a4d5c94 MT |
1631 | mutex_lock(&vq->mutex); |
1632 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 1633 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
1634 | r = -EFAULT; |
1635 | else | |
1636 | vq->log_base = base; | |
1637 | mutex_unlock(&vq->mutex); | |
1638 | } | |
1639 | break; | |
1640 | case VHOST_SET_LOG_FD: | |
1641 | r = get_user(fd, (int __user *)argp); | |
1642 | if (r < 0) | |
1643 | break; | |
1644 | eventfp = fd == -1 ? NULL : eventfd_fget(fd); | |
1645 | if (IS_ERR(eventfp)) { | |
1646 | r = PTR_ERR(eventfp); | |
1647 | break; | |
1648 | } | |
1649 | if (eventfp != d->log_file) { | |
1650 | filep = d->log_file; | |
7932c0bd | 1651 | d->log_file = eventfp; |
3a4d5c94 MT |
1652 | ctx = d->log_ctx; |
1653 | d->log_ctx = eventfp ? | |
1654 | eventfd_ctx_fileget(eventfp) : NULL; | |
1655 | } else | |
1656 | filep = eventfp; | |
1657 | for (i = 0; i < d->nvqs; ++i) { | |
3ab2e420 AH |
1658 | mutex_lock(&d->vqs[i]->mutex); |
1659 | d->vqs[i]->log_ctx = d->log_ctx; | |
1660 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
1661 | } |
1662 | if (ctx) | |
1663 | eventfd_ctx_put(ctx); | |
1664 | if (filep) | |
1665 | fput(filep); | |
1666 | break; | |
1667 | default: | |
935cdee7 | 1668 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
1669 | break; |
1670 | } | |
1671 | done: | |
1672 | return r; | |
1673 | } | |
6ac1afbf | 1674 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 | 1675 | |
3a4d5c94 MT |
1676 | /* TODO: This is really inefficient. We need something like get_user() |
1677 | * (instruction directly accesses the data, with an exception table entry | |
1678 | * returning -EFAULT). See Documentation/x86/exception-tables.txt. | |
1679 | */ | |
1680 | static int set_bit_to_user(int nr, void __user *addr) | |
1681 | { | |
1682 | unsigned long log = (unsigned long)addr; | |
1683 | struct page *page; | |
1684 | void *base; | |
1685 | int bit = nr + (log % PAGE_SIZE) * 8; | |
1686 | int r; | |
d47effe1 | 1687 | |
3a4d5c94 | 1688 | r = get_user_pages_fast(log, 1, 1, &page); |
d6db3f5c | 1689 | if (r < 0) |
3a4d5c94 | 1690 | return r; |
d6db3f5c | 1691 | BUG_ON(r != 1); |
c6daa7ff | 1692 | base = kmap_atomic(page); |
3a4d5c94 | 1693 | set_bit(bit, base); |
c6daa7ff | 1694 | kunmap_atomic(base); |
3a4d5c94 MT |
1695 | set_page_dirty_lock(page); |
1696 | put_page(page); | |
1697 | return 0; | |
1698 | } | |
1699 | ||
1700 | static int log_write(void __user *log_base, | |
1701 | u64 write_address, u64 write_length) | |
1702 | { | |
28831ee6 | 1703 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 1704 | int r; |
d47effe1 | 1705 | |
3a4d5c94 MT |
1706 | if (!write_length) |
1707 | return 0; | |
3bf9be40 | 1708 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
1709 | for (;;) { |
1710 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
1711 | u64 log = base + write_page / 8; |
1712 | int bit = write_page % 8; | |
3a4d5c94 MT |
1713 | if ((u64)(unsigned long)log != log) |
1714 | return -EFAULT; | |
1715 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
1716 | if (r < 0) | |
1717 | return r; | |
1718 | if (write_length <= VHOST_PAGE_SIZE) | |
1719 | break; | |
1720 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 1721 | write_page += 1; |
3a4d5c94 MT |
1722 | } |
1723 | return r; | |
1724 | } | |
1725 | ||
1726 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
1727 | unsigned int log_num, u64 len) | |
1728 | { | |
1729 | int i, r; | |
1730 | ||
1731 | /* Make sure data written is seen before log. */ | |
5659338c | 1732 | smp_wmb(); |
3a4d5c94 MT |
1733 | for (i = 0; i < log_num; ++i) { |
1734 | u64 l = min(log[i].len, len); | |
1735 | r = log_write(vq->log_base, log[i].addr, l); | |
1736 | if (r < 0) | |
1737 | return r; | |
1738 | len -= l; | |
5786aee8 MT |
1739 | if (!len) { |
1740 | if (vq->log_ctx) | |
1741 | eventfd_signal(vq->log_ctx, 1); | |
3a4d5c94 | 1742 | return 0; |
5786aee8 | 1743 | } |
3a4d5c94 | 1744 | } |
3a4d5c94 MT |
1745 | /* Length written exceeds what we have stored. This is a bug. */ |
1746 | BUG(); | |
1747 | return 0; | |
1748 | } | |
6ac1afbf | 1749 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 1750 | |
2723feaa JW |
1751 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
1752 | { | |
1753 | void __user *used; | |
bfe2bc51 JW |
1754 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), |
1755 | &vq->used->flags) < 0) | |
2723feaa JW |
1756 | return -EFAULT; |
1757 | if (unlikely(vq->log_used)) { | |
1758 | /* Make sure the flag is seen before log. */ | |
1759 | smp_wmb(); | |
1760 | /* Log used flag write. */ | |
1761 | used = &vq->used->flags; | |
1762 | log_write(vq->log_base, vq->log_addr + | |
1763 | (used - (void __user *)vq->used), | |
1764 | sizeof vq->used->flags); | |
1765 | if (vq->log_ctx) | |
1766 | eventfd_signal(vq->log_ctx, 1); | |
1767 | } | |
1768 | return 0; | |
1769 | } | |
1770 | ||
1771 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) | |
1772 | { | |
bfe2bc51 JW |
1773 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), |
1774 | vhost_avail_event(vq))) | |
2723feaa JW |
1775 | return -EFAULT; |
1776 | if (unlikely(vq->log_used)) { | |
1777 | void __user *used; | |
1778 | /* Make sure the event is seen before log. */ | |
1779 | smp_wmb(); | |
1780 | /* Log avail event write */ | |
1781 | used = vhost_avail_event(vq); | |
1782 | log_write(vq->log_base, vq->log_addr + | |
1783 | (used - (void __user *)vq->used), | |
1784 | sizeof *vhost_avail_event(vq)); | |
1785 | if (vq->log_ctx) | |
1786 | eventfd_signal(vq->log_ctx, 1); | |
1787 | } | |
1788 | return 0; | |
1789 | } | |
1790 | ||
80f7d030 | 1791 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 1792 | { |
3b1bbe89 | 1793 | __virtio16 last_used_idx; |
2723feaa | 1794 | int r; |
e1f33be9 GK |
1795 | bool is_le = vq->is_le; |
1796 | ||
cda8bba0 | 1797 | if (!vq->private_data) |
2723feaa | 1798 | return 0; |
2751c988 GK |
1799 | |
1800 | vhost_init_is_le(vq); | |
2723feaa JW |
1801 | |
1802 | r = vhost_update_used_flags(vq); | |
1803 | if (r) | |
e1f33be9 | 1804 | goto err; |
2723feaa | 1805 | vq->signalled_used_valid = false; |
6b1e6cc7 JW |
1806 | if (!vq->iotlb && |
1807 | !access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) { | |
e1f33be9 GK |
1808 | r = -EFAULT; |
1809 | goto err; | |
1810 | } | |
f8894913 | 1811 | r = vhost_get_used(vq, last_used_idx, &vq->used->idx); |
6b1e6cc7 JW |
1812 | if (r) { |
1813 | vq_err(vq, "Can't access used idx at %p\n", | |
1814 | &vq->used->idx); | |
e1f33be9 | 1815 | goto err; |
6b1e6cc7 | 1816 | } |
3b1bbe89 | 1817 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 1818 | return 0; |
6b1e6cc7 | 1819 | |
e1f33be9 GK |
1820 | err: |
1821 | vq->is_le = is_le; | |
1822 | return r; | |
2723feaa | 1823 | } |
80f7d030 | 1824 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 1825 | |
47283bef | 1826 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
6b1e6cc7 | 1827 | struct iovec iov[], int iov_size, int access) |
3a4d5c94 | 1828 | { |
a9709d68 | 1829 | const struct vhost_umem_node *node; |
6b1e6cc7 JW |
1830 | struct vhost_dev *dev = vq->dev; |
1831 | struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem; | |
3a4d5c94 MT |
1832 | struct iovec *_iov; |
1833 | u64 s = 0; | |
1834 | int ret = 0; | |
1835 | ||
3a4d5c94 MT |
1836 | while ((u64)len > s) { |
1837 | u64 size; | |
7b3384fc | 1838 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
1839 | ret = -ENOBUFS; |
1840 | break; | |
1841 | } | |
6b1e6cc7 | 1842 | |
a9709d68 JW |
1843 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, |
1844 | addr, addr + len - 1); | |
1845 | if (node == NULL || node->start > addr) { | |
6b1e6cc7 JW |
1846 | if (umem != dev->iotlb) { |
1847 | ret = -EFAULT; | |
1848 | break; | |
1849 | } | |
1850 | ret = -EAGAIN; | |
1851 | break; | |
1852 | } else if (!(node->perm & access)) { | |
1853 | ret = -EPERM; | |
3a4d5c94 MT |
1854 | break; |
1855 | } | |
6b1e6cc7 | 1856 | |
3a4d5c94 | 1857 | _iov = iov + ret; |
a9709d68 | 1858 | size = node->size - addr + node->start; |
bd97120f | 1859 | _iov->iov_len = min((u64)len - s, size); |
a8d3782f | 1860 | _iov->iov_base = (void __user *)(unsigned long) |
a9709d68 | 1861 | (node->userspace_addr + addr - node->start); |
3a4d5c94 MT |
1862 | s += size; |
1863 | addr += size; | |
1864 | ++ret; | |
1865 | } | |
1866 | ||
6b1e6cc7 JW |
1867 | if (ret == -EAGAIN) |
1868 | vhost_iotlb_miss(vq, addr, access); | |
3a4d5c94 MT |
1869 | return ret; |
1870 | } | |
1871 | ||
1872 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
1873 | * function returns the next descriptor in the chain, | |
1874 | * or -1U if we're at the end. */ | |
3b1bbe89 | 1875 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
1876 | { |
1877 | unsigned int next; | |
1878 | ||
1879 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 1880 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
1881 | return -1U; |
1882 | ||
1883 | /* Check they're not leading us off end of descriptors. */ | |
3a5db0b1 | 1884 | next = vhost16_to_cpu(vq, READ_ONCE(desc->next)); |
3a4d5c94 MT |
1885 | return next; |
1886 | } | |
1887 | ||
47283bef | 1888 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc MT |
1889 | struct iovec iov[], unsigned int iov_size, |
1890 | unsigned int *out_num, unsigned int *in_num, | |
1891 | struct vhost_log *log, unsigned int *log_num, | |
1892 | struct vring_desc *indirect) | |
3a4d5c94 MT |
1893 | { |
1894 | struct vring_desc desc; | |
1895 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 1896 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 1897 | struct iov_iter from; |
6b1e6cc7 | 1898 | int ret, access; |
3a4d5c94 MT |
1899 | |
1900 | /* Sanity check */ | |
3b1bbe89 | 1901 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
1902 | vq_err(vq, "Invalid length in indirect descriptor: " |
1903 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 1904 | (unsigned long long)len, |
3a4d5c94 MT |
1905 | sizeof desc); |
1906 | return -EINVAL; | |
1907 | } | |
1908 | ||
3b1bbe89 | 1909 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
6b1e6cc7 | 1910 | UIO_MAXIOV, VHOST_ACCESS_RO); |
7b3384fc | 1911 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
1912 | if (ret != -EAGAIN) |
1913 | vq_err(vq, "Translation failure %d in indirect.\n", ret); | |
3a4d5c94 MT |
1914 | return ret; |
1915 | } | |
aad9a1ce | 1916 | iov_iter_init(&from, READ, vq->indirect, ret, len); |
3a4d5c94 MT |
1917 | |
1918 | /* We will use the result as an address to read from, so most | |
1919 | * architectures only need a compiler barrier here. */ | |
1920 | read_barrier_depends(); | |
1921 | ||
3b1bbe89 | 1922 | count = len / sizeof desc; |
3a4d5c94 MT |
1923 | /* Buffers are chained via a 16 bit next field, so |
1924 | * we can have at most 2^16 of these. */ | |
7b3384fc | 1925 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
1926 | vq_err(vq, "Indirect buffer length too big: %d\n", |
1927 | indirect->len); | |
1928 | return -E2BIG; | |
1929 | } | |
1930 | ||
1931 | do { | |
1932 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 1933 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
1934 | vq_err(vq, "Loop detected: last one at %u " |
1935 | "indirect size %u\n", | |
1936 | i, count); | |
1937 | return -EINVAL; | |
1938 | } | |
cbbd26b8 | 1939 | if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) { |
3a4d5c94 | 1940 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 1941 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
1942 | return -EINVAL; |
1943 | } | |
3b1bbe89 | 1944 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 1945 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 1946 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
1947 | return -EINVAL; |
1948 | } | |
1949 | ||
6b1e6cc7 JW |
1950 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
1951 | access = VHOST_ACCESS_WO; | |
1952 | else | |
1953 | access = VHOST_ACCESS_RO; | |
1954 | ||
3b1bbe89 MT |
1955 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
1956 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 1957 | iov_size - iov_count, access); |
7b3384fc | 1958 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
1959 | if (ret != -EAGAIN) |
1960 | vq_err(vq, "Translation failure %d indirect idx %d\n", | |
1961 | ret, i); | |
3a4d5c94 MT |
1962 | return ret; |
1963 | } | |
1964 | /* If this is an input descriptor, increment that count. */ | |
6b1e6cc7 | 1965 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
1966 | *in_num += ret; |
1967 | if (unlikely(log)) { | |
3b1bbe89 MT |
1968 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
1969 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
1970 | ++*log_num; |
1971 | } | |
1972 | } else { | |
1973 | /* If it's an output descriptor, they're all supposed | |
1974 | * to come before any input descriptors. */ | |
7b3384fc | 1975 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
1976 | vq_err(vq, "Indirect descriptor " |
1977 | "has out after in: idx %d\n", i); | |
1978 | return -EINVAL; | |
1979 | } | |
1980 | *out_num += ret; | |
1981 | } | |
3b1bbe89 | 1982 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
1983 | return 0; |
1984 | } | |
1985 | ||
1986 | /* This looks in the virtqueue and for the first available buffer, and converts | |
1987 | * it to an iovec for convenient access. Since descriptors consist of some | |
1988 | * number of output then some number of input descriptors, it's actually two | |
1989 | * iovecs, but we pack them into one and note how many of each there were. | |
1990 | * | |
d5675bd2 MT |
1991 | * This function returns the descriptor number found, or vq->num (which is |
1992 | * never a valid descriptor number) if none was found. A negative code is | |
1993 | * returned on error. */ | |
47283bef | 1994 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
1995 | struct iovec iov[], unsigned int iov_size, |
1996 | unsigned int *out_num, unsigned int *in_num, | |
1997 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
1998 | { |
1999 | struct vring_desc desc; | |
2000 | unsigned int i, head, found = 0; | |
2001 | u16 last_avail_idx; | |
3b1bbe89 MT |
2002 | __virtio16 avail_idx; |
2003 | __virtio16 ring_head; | |
6b1e6cc7 | 2004 | int ret, access; |
3a4d5c94 MT |
2005 | |
2006 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
2007 | last_avail_idx = vq->last_avail_idx; | |
3a4d5c94 | 2008 | |
e3b56cdd | 2009 | if (vq->avail_idx == vq->last_avail_idx) { |
f8894913 | 2010 | if (unlikely(vhost_get_avail(vq, avail_idx, &vq->avail->idx))) { |
e3b56cdd JW |
2011 | vq_err(vq, "Failed to access avail idx at %p\n", |
2012 | &vq->avail->idx); | |
2013 | return -EFAULT; | |
2014 | } | |
2015 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); | |
3a4d5c94 | 2016 | |
e3b56cdd JW |
2017 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
2018 | vq_err(vq, "Guest moved used index from %u to %u", | |
2019 | last_avail_idx, vq->avail_idx); | |
2020 | return -EFAULT; | |
2021 | } | |
2022 | ||
2023 | /* If there's nothing new since last we looked, return | |
2024 | * invalid. | |
2025 | */ | |
2026 | if (vq->avail_idx == last_avail_idx) | |
2027 | return vq->num; | |
3a4d5c94 | 2028 | |
e3b56cdd JW |
2029 | /* Only get avail ring entries after they have been |
2030 | * exposed by guest. | |
2031 | */ | |
2032 | smp_rmb(); | |
2033 | } | |
3a4d5c94 MT |
2034 | |
2035 | /* Grab the next descriptor number they're advertising, and increment | |
2036 | * the index we've seen. */ | |
f8894913 | 2037 | if (unlikely(vhost_get_avail(vq, ring_head, |
bfe2bc51 | 2038 | &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) { |
3a4d5c94 MT |
2039 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
2040 | last_avail_idx, | |
2041 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 2042 | return -EFAULT; |
3a4d5c94 MT |
2043 | } |
2044 | ||
3b1bbe89 MT |
2045 | head = vhost16_to_cpu(vq, ring_head); |
2046 | ||
3a4d5c94 | 2047 | /* If their number is silly, that's an error. */ |
7b3384fc | 2048 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
2049 | vq_err(vq, "Guest says index %u > %u is available", |
2050 | head, vq->num); | |
d5675bd2 | 2051 | return -EINVAL; |
3a4d5c94 MT |
2052 | } |
2053 | ||
2054 | /* When we start there are none of either input nor output. */ | |
2055 | *out_num = *in_num = 0; | |
2056 | if (unlikely(log)) | |
2057 | *log_num = 0; | |
2058 | ||
2059 | i = head; | |
2060 | do { | |
2061 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2062 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
2063 | vq_err(vq, "Desc index is %u > %u, head = %u", |
2064 | i, vq->num, head); | |
d5675bd2 | 2065 | return -EINVAL; |
3a4d5c94 | 2066 | } |
7b3384fc | 2067 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
2068 | vq_err(vq, "Loop detected: last one at %u " |
2069 | "vq size %u head %u\n", | |
2070 | i, vq->num, head); | |
d5675bd2 | 2071 | return -EINVAL; |
3a4d5c94 | 2072 | } |
bfe2bc51 JW |
2073 | ret = vhost_copy_from_user(vq, &desc, vq->desc + i, |
2074 | sizeof desc); | |
7b3384fc | 2075 | if (unlikely(ret)) { |
3a4d5c94 MT |
2076 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
2077 | i, vq->desc + i); | |
d5675bd2 | 2078 | return -EFAULT; |
3a4d5c94 | 2079 | } |
3b1bbe89 | 2080 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 2081 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
2082 | out_num, in_num, |
2083 | log, log_num, &desc); | |
7b3384fc | 2084 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2085 | if (ret != -EAGAIN) |
2086 | vq_err(vq, "Failure detected " | |
2087 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 2088 | return ret; |
3a4d5c94 MT |
2089 | } |
2090 | continue; | |
2091 | } | |
2092 | ||
6b1e6cc7 JW |
2093 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2094 | access = VHOST_ACCESS_WO; | |
2095 | else | |
2096 | access = VHOST_ACCESS_RO; | |
3b1bbe89 MT |
2097 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2098 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2099 | iov_size - iov_count, access); |
7b3384fc | 2100 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2101 | if (ret != -EAGAIN) |
2102 | vq_err(vq, "Translation failure %d descriptor idx %d\n", | |
2103 | ret, i); | |
d5675bd2 | 2104 | return ret; |
3a4d5c94 | 2105 | } |
6b1e6cc7 | 2106 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2107 | /* If this is an input descriptor, |
2108 | * increment that count. */ | |
2109 | *in_num += ret; | |
2110 | if (unlikely(log)) { | |
3b1bbe89 MT |
2111 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2112 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2113 | ++*log_num; |
2114 | } | |
2115 | } else { | |
2116 | /* If it's an output descriptor, they're all supposed | |
2117 | * to come before any input descriptors. */ | |
7b3384fc | 2118 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2119 | vq_err(vq, "Descriptor has out after in: " |
2120 | "idx %d\n", i); | |
d5675bd2 | 2121 | return -EINVAL; |
3a4d5c94 MT |
2122 | } |
2123 | *out_num += ret; | |
2124 | } | |
3b1bbe89 | 2125 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2126 | |
2127 | /* On success, increment avail index. */ | |
2128 | vq->last_avail_idx++; | |
8ea8cf89 MT |
2129 | |
2130 | /* Assume notifications from guest are disabled at this point, | |
2131 | * if they aren't we would need to update avail_event index. */ | |
2132 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
2133 | return head; |
2134 | } | |
6ac1afbf | 2135 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
2136 | |
2137 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 2138 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 2139 | { |
8dd014ad | 2140 | vq->last_avail_idx -= n; |
3a4d5c94 | 2141 | } |
6ac1afbf | 2142 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
2143 | |
2144 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2145 | * want to notify the guest, using eventfd. */ | |
2146 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
2147 | { | |
3b1bbe89 MT |
2148 | struct vring_used_elem heads = { |
2149 | cpu_to_vhost32(vq, head), | |
2150 | cpu_to_vhost32(vq, len) | |
2151 | }; | |
3a4d5c94 | 2152 | |
c49e4e57 | 2153 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 2154 | } |
6ac1afbf | 2155 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 2156 | |
8dd014ad DS |
2157 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2158 | struct vring_used_elem *heads, | |
2159 | unsigned count) | |
2160 | { | |
2161 | struct vring_used_elem __user *used; | |
8ea8cf89 | 2162 | u16 old, new; |
8dd014ad DS |
2163 | int start; |
2164 | ||
5fba13b5 | 2165 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 2166 | used = vq->used->ring + start; |
c49e4e57 | 2167 | if (count == 1) { |
bfe2bc51 | 2168 | if (vhost_put_user(vq, heads[0].id, &used->id)) { |
c49e4e57 JW |
2169 | vq_err(vq, "Failed to write used id"); |
2170 | return -EFAULT; | |
2171 | } | |
bfe2bc51 | 2172 | if (vhost_put_user(vq, heads[0].len, &used->len)) { |
c49e4e57 JW |
2173 | vq_err(vq, "Failed to write used len"); |
2174 | return -EFAULT; | |
2175 | } | |
bfe2bc51 | 2176 | } else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) { |
8dd014ad DS |
2177 | vq_err(vq, "Failed to write used"); |
2178 | return -EFAULT; | |
2179 | } | |
2180 | if (unlikely(vq->log_used)) { | |
2181 | /* Make sure data is seen before log. */ | |
2182 | smp_wmb(); | |
2183 | /* Log used ring entry write. */ | |
2184 | log_write(vq->log_base, | |
2185 | vq->log_addr + | |
2186 | ((void __user *)used - (void __user *)vq->used), | |
2187 | count * sizeof *used); | |
2188 | } | |
8ea8cf89 MT |
2189 | old = vq->last_used_idx; |
2190 | new = (vq->last_used_idx += count); | |
2191 | /* If the driver never bothers to signal in a very long while, | |
2192 | * used index might wrap around. If that happens, invalidate | |
2193 | * signalled_used index we stored. TODO: make sure driver | |
2194 | * signals at least once in 2^16 and remove this. */ | |
2195 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
2196 | vq->signalled_used_valid = false; | |
8dd014ad DS |
2197 | return 0; |
2198 | } | |
2199 | ||
2200 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2201 | * want to notify the guest, using eventfd. */ | |
2202 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
2203 | unsigned count) | |
2204 | { | |
2205 | int start, n, r; | |
2206 | ||
5fba13b5 | 2207 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
2208 | n = vq->num - start; |
2209 | if (n < count) { | |
2210 | r = __vhost_add_used_n(vq, heads, n); | |
2211 | if (r < 0) | |
2212 | return r; | |
2213 | heads += n; | |
2214 | count -= n; | |
2215 | } | |
2216 | r = __vhost_add_used_n(vq, heads, count); | |
2217 | ||
2218 | /* Make sure buffer is written before we update index. */ | |
2219 | smp_wmb(); | |
bfe2bc51 JW |
2220 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), |
2221 | &vq->used->idx)) { | |
8dd014ad DS |
2222 | vq_err(vq, "Failed to increment used idx"); |
2223 | return -EFAULT; | |
2224 | } | |
2225 | if (unlikely(vq->log_used)) { | |
2226 | /* Log used index update. */ | |
2227 | log_write(vq->log_base, | |
2228 | vq->log_addr + offsetof(struct vring_used, idx), | |
2229 | sizeof vq->used->idx); | |
2230 | if (vq->log_ctx) | |
2231 | eventfd_signal(vq->log_ctx, 1); | |
2232 | } | |
2233 | return r; | |
2234 | } | |
6ac1afbf | 2235 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 2236 | |
8ea8cf89 | 2237 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2238 | { |
3b1bbe89 MT |
2239 | __u16 old, new; |
2240 | __virtio16 event; | |
8ea8cf89 | 2241 | bool v; |
8d65843c JW |
2242 | /* Flush out used index updates. This is paired |
2243 | * with the barrier that the Guest executes when enabling | |
2244 | * interrupts. */ | |
2245 | smp_mb(); | |
0d499356 | 2246 | |
ea16c514 | 2247 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
2248 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2249 | return true; | |
2250 | ||
ea16c514 | 2251 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 2252 | __virtio16 flags; |
f8894913 | 2253 | if (vhost_get_avail(vq, flags, &vq->avail->flags)) { |
8ea8cf89 MT |
2254 | vq_err(vq, "Failed to get flags"); |
2255 | return true; | |
2256 | } | |
3b1bbe89 | 2257 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 2258 | } |
8ea8cf89 MT |
2259 | old = vq->signalled_used; |
2260 | v = vq->signalled_used_valid; | |
2261 | new = vq->signalled_used = vq->last_used_idx; | |
2262 | vq->signalled_used_valid = true; | |
3a4d5c94 | 2263 | |
8ea8cf89 MT |
2264 | if (unlikely(!v)) |
2265 | return true; | |
3a4d5c94 | 2266 | |
f8894913 | 2267 | if (vhost_get_avail(vq, event, vhost_used_event(vq))) { |
8ea8cf89 MT |
2268 | vq_err(vq, "Failed to get used event idx"); |
2269 | return true; | |
2270 | } | |
8d65843c | 2271 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
2272 | } |
2273 | ||
2274 | /* This actually signals the guest, using eventfd. */ | |
2275 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2276 | { | |
3a4d5c94 | 2277 | /* Signal the Guest tell them we used something up. */ |
8ea8cf89 | 2278 | if (vq->call_ctx && vhost_notify(dev, vq)) |
3a4d5c94 MT |
2279 | eventfd_signal(vq->call_ctx, 1); |
2280 | } | |
6ac1afbf | 2281 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
2282 | |
2283 | /* And here's the combo meal deal. Supersize me! */ | |
2284 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
2285 | struct vhost_virtqueue *vq, | |
2286 | unsigned int head, int len) | |
2287 | { | |
2288 | vhost_add_used(vq, head, len); | |
2289 | vhost_signal(dev, vq); | |
2290 | } | |
6ac1afbf | 2291 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 2292 | |
8dd014ad DS |
2293 | /* multi-buffer version of vhost_add_used_and_signal */ |
2294 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
2295 | struct vhost_virtqueue *vq, | |
2296 | struct vring_used_elem *heads, unsigned count) | |
2297 | { | |
2298 | vhost_add_used_n(vq, heads, count); | |
2299 | vhost_signal(dev, vq); | |
2300 | } | |
6ac1afbf | 2301 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 2302 | |
d4a60603 JW |
2303 | /* return true if we're sure that avaiable ring is empty */ |
2304 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2305 | { | |
2306 | __virtio16 avail_idx; | |
2307 | int r; | |
2308 | ||
275bf960 JW |
2309 | if (vq->avail_idx != vq->last_avail_idx) |
2310 | return false; | |
2311 | ||
f8894913 | 2312 | r = vhost_get_avail(vq, avail_idx, &vq->avail->idx); |
275bf960 | 2313 | if (unlikely(r)) |
d4a60603 | 2314 | return false; |
275bf960 | 2315 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
d4a60603 | 2316 | |
275bf960 | 2317 | return vq->avail_idx == vq->last_avail_idx; |
d4a60603 JW |
2318 | } |
2319 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
2320 | ||
3a4d5c94 | 2321 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 2322 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2323 | { |
3b1bbe89 | 2324 | __virtio16 avail_idx; |
3a4d5c94 | 2325 | int r; |
d47effe1 | 2326 | |
3a4d5c94 MT |
2327 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2328 | return false; | |
2329 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2330 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2331 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2332 | if (r) { |
2333 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2334 | &vq->used->flags, r); | |
2335 | return false; | |
2336 | } | |
2337 | } else { | |
2723feaa | 2338 | r = vhost_update_avail_event(vq, vq->avail_idx); |
8ea8cf89 MT |
2339 | if (r) { |
2340 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
2341 | vhost_avail_event(vq), r); | |
2342 | return false; | |
2343 | } | |
2344 | } | |
3a4d5c94 MT |
2345 | /* They could have slipped one in as we were doing that: make |
2346 | * sure it's written, then check again. */ | |
5659338c | 2347 | smp_mb(); |
f8894913 | 2348 | r = vhost_get_avail(vq, avail_idx, &vq->avail->idx); |
3a4d5c94 MT |
2349 | if (r) { |
2350 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
2351 | &vq->avail->idx, r); | |
2352 | return false; | |
2353 | } | |
2354 | ||
3b1bbe89 | 2355 | return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx; |
3a4d5c94 | 2356 | } |
6ac1afbf | 2357 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
2358 | |
2359 | /* We don't need to be notified again. */ | |
8ea8cf89 | 2360 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
2361 | { |
2362 | int r; | |
d47effe1 | 2363 | |
3a4d5c94 MT |
2364 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2365 | return; | |
2366 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2367 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2368 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2369 | if (r) |
2370 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2371 | &vq->used->flags, r); | |
2372 | } | |
3a4d5c94 | 2373 | } |
6ac1afbf AH |
2374 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2375 | ||
6b1e6cc7 JW |
2376 | /* Create a new message. */ |
2377 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) | |
2378 | { | |
2379 | struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL); | |
2380 | if (!node) | |
2381 | return NULL; | |
2382 | node->vq = vq; | |
2383 | node->msg.type = type; | |
2384 | return node; | |
2385 | } | |
2386 | EXPORT_SYMBOL_GPL(vhost_new_msg); | |
2387 | ||
2388 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, | |
2389 | struct vhost_msg_node *node) | |
2390 | { | |
2391 | spin_lock(&dev->iotlb_lock); | |
2392 | list_add_tail(&node->node, head); | |
2393 | spin_unlock(&dev->iotlb_lock); | |
2394 | ||
2395 | wake_up_interruptible_poll(&dev->wait, POLLIN | POLLRDNORM); | |
2396 | } | |
2397 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); | |
2398 | ||
2399 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, | |
2400 | struct list_head *head) | |
2401 | { | |
2402 | struct vhost_msg_node *node = NULL; | |
2403 | ||
2404 | spin_lock(&dev->iotlb_lock); | |
2405 | if (!list_empty(head)) { | |
2406 | node = list_first_entry(head, struct vhost_msg_node, | |
2407 | node); | |
2408 | list_del(&node->node); | |
2409 | } | |
2410 | spin_unlock(&dev->iotlb_lock); | |
2411 | ||
2412 | return node; | |
2413 | } | |
2414 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); | |
2415 | ||
2416 | ||
6ac1afbf AH |
2417 | static int __init vhost_init(void) |
2418 | { | |
2419 | return 0; | |
2420 | } | |
2421 | ||
2422 | static void __exit vhost_exit(void) | |
2423 | { | |
2424 | } | |
2425 | ||
2426 | module_init(vhost_init); | |
2427 | module_exit(vhost_exit); | |
2428 | ||
2429 | MODULE_VERSION("0.0.1"); | |
2430 | MODULE_LICENSE("GPL v2"); | |
2431 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
2432 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |