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7a338472 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3a4d5c94 MT |
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 | |
61516587 | 8 | * Documentation/virtual/lguest/lguest.c, by Rusty Russell |
3a4d5c94 | 9 | * |
3a4d5c94 MT |
10 | * Generic code for virtio server in host kernel. |
11 | */ | |
12 | ||
13 | #include <linux/eventfd.h> | |
14 | #include <linux/vhost.h> | |
35596b27 | 15 | #include <linux/uio.h> |
3a4d5c94 | 16 | #include <linux/mm.h> |
64e1c807 | 17 | #include <linux/mmu_context.h> |
3a4d5c94 MT |
18 | #include <linux/miscdevice.h> |
19 | #include <linux/mutex.h> | |
3a4d5c94 MT |
20 | #include <linux/poll.h> |
21 | #include <linux/file.h> | |
22 | #include <linux/highmem.h> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
4de7255f | 24 | #include <linux/vmalloc.h> |
c23f3445 | 25 | #include <linux/kthread.h> |
9e3d1957 | 26 | #include <linux/cgroup.h> |
6ac1afbf | 27 | #include <linux/module.h> |
bcfeacab | 28 | #include <linux/sort.h> |
6e84f315 | 29 | #include <linux/sched/mm.h> |
174cd4b1 | 30 | #include <linux/sched/signal.h> |
a9709d68 | 31 | #include <linux/interval_tree_generic.h> |
ff002269 | 32 | #include <linux/nospec.h> |
8f6a7f96 | 33 | #include <linux/kcov.h> |
3a4d5c94 | 34 | |
3a4d5c94 MT |
35 | #include "vhost.h" |
36 | ||
c9ce42f7 IM |
37 | static ushort max_mem_regions = 64; |
38 | module_param(max_mem_regions, ushort, 0444); | |
39 | MODULE_PARM_DESC(max_mem_regions, | |
40 | "Maximum number of memory regions in memory map. (default: 64)"); | |
6b1e6cc7 JW |
41 | static int max_iotlb_entries = 2048; |
42 | module_param(max_iotlb_entries, int, 0444); | |
43 | MODULE_PARM_DESC(max_iotlb_entries, | |
44 | "Maximum number of iotlb entries. (default: 2048)"); | |
c9ce42f7 | 45 | |
3a4d5c94 | 46 | enum { |
3a4d5c94 MT |
47 | VHOST_MEMORY_F_LOG = 0x1, |
48 | }; | |
49 | ||
3b1bbe89 MT |
50 | #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) |
51 | #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) | |
8ea8cf89 | 52 | |
2751c988 | 53 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
c5072037 | 54 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
55 | { |
56 | vq->user_be = !virtio_legacy_is_little_endian(); | |
57 | } | |
58 | ||
c5072037 GK |
59 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
60 | { | |
61 | vq->user_be = true; | |
62 | } | |
63 | ||
64 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) | |
65 | { | |
66 | vq->user_be = false; | |
67 | } | |
68 | ||
2751c988 GK |
69 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
70 | { | |
71 | struct vhost_vring_state s; | |
72 | ||
73 | if (vq->private_data) | |
74 | return -EBUSY; | |
75 | ||
76 | if (copy_from_user(&s, argp, sizeof(s))) | |
77 | return -EFAULT; | |
78 | ||
79 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && | |
80 | s.num != VHOST_VRING_BIG_ENDIAN) | |
81 | return -EINVAL; | |
82 | ||
c5072037 GK |
83 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
84 | vhost_enable_cross_endian_big(vq); | |
85 | else | |
86 | vhost_enable_cross_endian_little(vq); | |
2751c988 GK |
87 | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
92 | int __user *argp) | |
93 | { | |
94 | struct vhost_vring_state s = { | |
95 | .index = idx, | |
96 | .num = vq->user_be | |
97 | }; | |
98 | ||
99 | if (copy_to_user(argp, &s, sizeof(s))) | |
100 | return -EFAULT; | |
101 | ||
102 | return 0; | |
103 | } | |
104 | ||
105 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
106 | { | |
107 | /* Note for legacy virtio: user_be is initialized at reset time | |
108 | * according to the host endianness. If userspace does not set an | |
109 | * explicit endianness, the default behavior is native endian, as | |
110 | * expected by legacy virtio. | |
111 | */ | |
112 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; | |
113 | } | |
114 | #else | |
c5072037 | 115 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
116 | { |
117 | } | |
118 | ||
119 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) | |
120 | { | |
121 | return -ENOIOCTLCMD; | |
122 | } | |
123 | ||
124 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
125 | int __user *argp) | |
126 | { | |
127 | return -ENOIOCTLCMD; | |
128 | } | |
129 | ||
130 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
131 | { | |
cda8bba0 HP |
132 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) |
133 | || virtio_legacy_is_little_endian(); | |
2751c988 GK |
134 | } |
135 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ | |
136 | ||
c5072037 GK |
137 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
138 | { | |
cda8bba0 | 139 | vhost_init_is_le(vq); |
c5072037 GK |
140 | } |
141 | ||
7235acdb JW |
142 | struct vhost_flush_struct { |
143 | struct vhost_work work; | |
144 | struct completion wait_event; | |
145 | }; | |
146 | ||
147 | static void vhost_flush_work(struct vhost_work *work) | |
148 | { | |
149 | struct vhost_flush_struct *s; | |
150 | ||
151 | s = container_of(work, struct vhost_flush_struct, work); | |
152 | complete(&s->wait_event); | |
153 | } | |
154 | ||
3a4d5c94 MT |
155 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
156 | poll_table *pt) | |
157 | { | |
158 | struct vhost_poll *poll; | |
3a4d5c94 | 159 | |
d47effe1 | 160 | poll = container_of(pt, struct vhost_poll, table); |
3a4d5c94 MT |
161 | poll->wqh = wqh; |
162 | add_wait_queue(wqh, &poll->wait); | |
163 | } | |
164 | ||
ac6424b9 | 165 | static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, |
3a4d5c94 MT |
166 | void *key) |
167 | { | |
c23f3445 TH |
168 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
169 | ||
3ad6f93e | 170 | if (!(key_to_poll(key) & poll->mask)) |
3a4d5c94 MT |
171 | return 0; |
172 | ||
c23f3445 | 173 | vhost_poll_queue(poll); |
3a4d5c94 MT |
174 | return 0; |
175 | } | |
176 | ||
163049ae | 177 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
87d6a412 | 178 | { |
04b96e55 | 179 | clear_bit(VHOST_WORK_QUEUED, &work->flags); |
87d6a412 | 180 | work->fn = fn; |
87d6a412 | 181 | } |
6ac1afbf | 182 | EXPORT_SYMBOL_GPL(vhost_work_init); |
87d6a412 | 183 | |
3a4d5c94 | 184 | /* Init poll structure */ |
c23f3445 | 185 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
58e3b602 | 186 | __poll_t mask, struct vhost_dev *dev) |
3a4d5c94 | 187 | { |
3a4d5c94 MT |
188 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
189 | init_poll_funcptr(&poll->table, vhost_poll_func); | |
190 | poll->mask = mask; | |
c23f3445 | 191 | poll->dev = dev; |
2b8b328b | 192 | poll->wqh = NULL; |
c23f3445 | 193 | |
87d6a412 | 194 | vhost_work_init(&poll->work, fn); |
3a4d5c94 | 195 | } |
6ac1afbf | 196 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
3a4d5c94 MT |
197 | |
198 | /* Start polling a file. We add ourselves to file's wait queue. The caller must | |
199 | * keep a reference to a file until after vhost_poll_stop is called. */ | |
2b8b328b | 200 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
3a4d5c94 | 201 | { |
e6c8adca | 202 | __poll_t mask; |
d47effe1 | 203 | |
70181d51 JW |
204 | if (poll->wqh) |
205 | return 0; | |
206 | ||
9965ed17 | 207 | mask = vfs_poll(file, &poll->table); |
3a4d5c94 | 208 | if (mask) |
3ad6f93e | 209 | vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); |
a9a08845 | 210 | if (mask & EPOLLERR) { |
dc6455a7 | 211 | vhost_poll_stop(poll); |
896fc242 | 212 | return -EINVAL; |
2b8b328b JW |
213 | } |
214 | ||
896fc242 | 215 | return 0; |
3a4d5c94 | 216 | } |
6ac1afbf | 217 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
218 | |
219 | /* Stop polling a file. After this function returns, it becomes safe to drop the | |
220 | * file reference. You must also flush afterwards. */ | |
221 | void vhost_poll_stop(struct vhost_poll *poll) | |
222 | { | |
2b8b328b JW |
223 | if (poll->wqh) { |
224 | remove_wait_queue(poll->wqh, &poll->wait); | |
225 | poll->wqh = NULL; | |
226 | } | |
3a4d5c94 | 227 | } |
6ac1afbf | 228 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 229 | |
7235acdb | 230 | void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
0174b0c3 | 231 | { |
7235acdb | 232 | struct vhost_flush_struct flush; |
d47effe1 | 233 | |
7235acdb JW |
234 | if (dev->worker) { |
235 | init_completion(&flush.wait_event); | |
236 | vhost_work_init(&flush.work, vhost_flush_work); | |
0174b0c3 | 237 | |
7235acdb JW |
238 | vhost_work_queue(dev, &flush.work); |
239 | wait_for_completion(&flush.wait_event); | |
240 | } | |
3a4d5c94 | 241 | } |
6ac1afbf | 242 | EXPORT_SYMBOL_GPL(vhost_work_flush); |
3a4d5c94 | 243 | |
87d6a412 MT |
244 | /* Flush any work that has been scheduled. When calling this, don't hold any |
245 | * locks that are also used by the callback. */ | |
246 | void vhost_poll_flush(struct vhost_poll *poll) | |
247 | { | |
248 | vhost_work_flush(poll->dev, &poll->work); | |
249 | } | |
6ac1afbf | 250 | EXPORT_SYMBOL_GPL(vhost_poll_flush); |
87d6a412 | 251 | |
163049ae | 252 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 253 | { |
04b96e55 JW |
254 | if (!dev->worker) |
255 | return; | |
c23f3445 | 256 | |
04b96e55 JW |
257 | if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { |
258 | /* We can only add the work to the list after we're | |
259 | * sure it was not in the list. | |
635abf01 | 260 | * test_and_set_bit() implies a memory barrier. |
04b96e55 | 261 | */ |
04b96e55 | 262 | llist_add(&work->node, &dev->work_list); |
c23f3445 TH |
263 | wake_up_process(dev->worker); |
264 | } | |
3a4d5c94 | 265 | } |
6ac1afbf | 266 | EXPORT_SYMBOL_GPL(vhost_work_queue); |
3a4d5c94 | 267 | |
526d3e7f JW |
268 | /* A lockless hint for busy polling code to exit the loop */ |
269 | bool vhost_has_work(struct vhost_dev *dev) | |
270 | { | |
04b96e55 | 271 | return !llist_empty(&dev->work_list); |
526d3e7f JW |
272 | } |
273 | EXPORT_SYMBOL_GPL(vhost_has_work); | |
274 | ||
87d6a412 MT |
275 | void vhost_poll_queue(struct vhost_poll *poll) |
276 | { | |
277 | vhost_work_queue(poll->dev, &poll->work); | |
278 | } | |
6ac1afbf | 279 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 280 | |
f8894913 JW |
281 | static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq) |
282 | { | |
283 | int j; | |
284 | ||
285 | for (j = 0; j < VHOST_NUM_ADDRS; j++) | |
286 | vq->meta_iotlb[j] = NULL; | |
287 | } | |
288 | ||
289 | static void vhost_vq_meta_reset(struct vhost_dev *d) | |
290 | { | |
291 | int i; | |
292 | ||
86a07da3 | 293 | for (i = 0; i < d->nvqs; ++i) |
f8894913 JW |
294 | __vhost_vq_meta_reset(d->vqs[i]); |
295 | } | |
296 | ||
3a4d5c94 MT |
297 | static void vhost_vq_reset(struct vhost_dev *dev, |
298 | struct vhost_virtqueue *vq) | |
299 | { | |
300 | vq->num = 1; | |
301 | vq->desc = NULL; | |
302 | vq->avail = NULL; | |
303 | vq->used = NULL; | |
304 | vq->last_avail_idx = 0; | |
305 | vq->avail_idx = 0; | |
306 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
307 | vq->signalled_used = 0; |
308 | vq->signalled_used_valid = false; | |
3a4d5c94 | 309 | vq->used_flags = 0; |
3a4d5c94 MT |
310 | vq->log_used = false; |
311 | vq->log_addr = -1ull; | |
3a4d5c94 | 312 | vq->private_data = NULL; |
ea16c514 | 313 | vq->acked_features = 0; |
429711ae | 314 | vq->acked_backend_features = 0; |
3a4d5c94 MT |
315 | vq->log_base = NULL; |
316 | vq->error_ctx = NULL; | |
3a4d5c94 MT |
317 | vq->kick = NULL; |
318 | vq->call_ctx = NULL; | |
73a99f08 | 319 | vq->log_ctx = NULL; |
c5072037 GK |
320 | vhost_reset_is_le(vq); |
321 | vhost_disable_cross_endian(vq); | |
03088137 | 322 | vq->busyloop_timeout = 0; |
a9709d68 | 323 | vq->umem = NULL; |
6b1e6cc7 | 324 | vq->iotlb = NULL; |
f8894913 | 325 | __vhost_vq_meta_reset(vq); |
3a4d5c94 MT |
326 | } |
327 | ||
c23f3445 TH |
328 | static int vhost_worker(void *data) |
329 | { | |
330 | struct vhost_dev *dev = data; | |
04b96e55 JW |
331 | struct vhost_work *work, *work_next; |
332 | struct llist_node *node; | |
d7ffde35 | 333 | mm_segment_t oldfs = get_fs(); |
c23f3445 | 334 | |
d7ffde35 | 335 | set_fs(USER_DS); |
64e1c807 MT |
336 | use_mm(dev->mm); |
337 | ||
c23f3445 TH |
338 | for (;;) { |
339 | /* mb paired w/ kthread_stop */ | |
340 | set_current_state(TASK_INTERRUPTIBLE); | |
341 | ||
c23f3445 | 342 | if (kthread_should_stop()) { |
c23f3445 | 343 | __set_current_state(TASK_RUNNING); |
64e1c807 | 344 | break; |
c23f3445 | 345 | } |
04b96e55 JW |
346 | |
347 | node = llist_del_all(&dev->work_list); | |
348 | if (!node) | |
349 | schedule(); | |
350 | ||
351 | node = llist_reverse_order(node); | |
352 | /* make sure flag is seen after deletion */ | |
353 | smp_wmb(); | |
354 | llist_for_each_entry_safe(work, work_next, node, node) { | |
355 | clear_bit(VHOST_WORK_QUEUED, &work->flags); | |
c23f3445 | 356 | __set_current_state(TASK_RUNNING); |
8f6a7f96 | 357 | kcov_remote_start_common(dev->kcov_handle); |
c23f3445 | 358 | work->fn(work); |
8f6a7f96 | 359 | kcov_remote_stop(); |
d550dda1 NHE |
360 | if (need_resched()) |
361 | schedule(); | |
04b96e55 | 362 | } |
c23f3445 | 363 | } |
64e1c807 | 364 | unuse_mm(dev->mm); |
d7ffde35 | 365 | set_fs(oldfs); |
64e1c807 | 366 | return 0; |
c23f3445 TH |
367 | } |
368 | ||
bab632d6 MT |
369 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
370 | { | |
371 | kfree(vq->indirect); | |
372 | vq->indirect = NULL; | |
373 | kfree(vq->log); | |
374 | vq->log = NULL; | |
375 | kfree(vq->heads); | |
376 | vq->heads = NULL; | |
bab632d6 MT |
377 | } |
378 | ||
e0e9b406 JW |
379 | /* Helper to allocate iovec buffers for all vqs. */ |
380 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
381 | { | |
6d5e6aa8 | 382 | struct vhost_virtqueue *vq; |
e0e9b406 | 383 | int i; |
d47effe1 | 384 | |
e0e9b406 | 385 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 | 386 | vq = dev->vqs[i]; |
6da2ec56 KC |
387 | vq->indirect = kmalloc_array(UIO_MAXIOV, |
388 | sizeof(*vq->indirect), | |
389 | GFP_KERNEL); | |
b46a0bf7 | 390 | vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), |
6da2ec56 | 391 | GFP_KERNEL); |
b46a0bf7 | 392 | vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), |
6da2ec56 | 393 | GFP_KERNEL); |
6d5e6aa8 | 394 | if (!vq->indirect || !vq->log || !vq->heads) |
e0e9b406 JW |
395 | goto err_nomem; |
396 | } | |
397 | return 0; | |
d47effe1 | 398 | |
e0e9b406 | 399 | err_nomem: |
bab632d6 | 400 | for (; i >= 0; --i) |
3ab2e420 | 401 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
402 | return -ENOMEM; |
403 | } | |
404 | ||
405 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
406 | { | |
407 | int i; | |
d47effe1 | 408 | |
bab632d6 | 409 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 410 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
411 | } |
412 | ||
e82b9b07 JW |
413 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, |
414 | int pkts, int total_len) | |
415 | { | |
416 | struct vhost_dev *dev = vq->dev; | |
417 | ||
418 | if ((dev->byte_weight && total_len >= dev->byte_weight) || | |
419 | pkts >= dev->weight) { | |
420 | vhost_poll_queue(&vq->poll); | |
421 | return true; | |
422 | } | |
423 | ||
424 | return false; | |
425 | } | |
426 | EXPORT_SYMBOL_GPL(vhost_exceeds_weight); | |
427 | ||
4942e825 JW |
428 | static size_t vhost_get_avail_size(struct vhost_virtqueue *vq, |
429 | unsigned int num) | |
430 | { | |
431 | size_t event __maybe_unused = | |
432 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
433 | ||
434 | return sizeof(*vq->avail) + | |
435 | sizeof(*vq->avail->ring) * num + event; | |
436 | } | |
437 | ||
438 | static size_t vhost_get_used_size(struct vhost_virtqueue *vq, | |
439 | unsigned int num) | |
440 | { | |
441 | size_t event __maybe_unused = | |
442 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
443 | ||
444 | return sizeof(*vq->used) + | |
445 | sizeof(*vq->used->ring) * num + event; | |
446 | } | |
447 | ||
448 | static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, | |
449 | unsigned int num) | |
450 | { | |
451 | return sizeof(*vq->desc) * num; | |
452 | } | |
453 | ||
59566b6e | 454 | void vhost_dev_init(struct vhost_dev *dev, |
e82b9b07 | 455 | struct vhost_virtqueue **vqs, int nvqs, |
792a4f2e JW |
456 | int iov_limit, int weight, int byte_weight, |
457 | int (*msg_handler)(struct vhost_dev *dev, | |
458 | struct vhost_iotlb_msg *msg)) | |
3a4d5c94 | 459 | { |
6d5e6aa8 | 460 | struct vhost_virtqueue *vq; |
3a4d5c94 | 461 | int i; |
c23f3445 | 462 | |
3a4d5c94 MT |
463 | dev->vqs = vqs; |
464 | dev->nvqs = nvqs; | |
465 | mutex_init(&dev->mutex); | |
466 | dev->log_ctx = NULL; | |
a9709d68 | 467 | dev->umem = NULL; |
6b1e6cc7 | 468 | dev->iotlb = NULL; |
3a4d5c94 | 469 | dev->mm = NULL; |
c23f3445 | 470 | dev->worker = NULL; |
b46a0bf7 | 471 | dev->iov_limit = iov_limit; |
e82b9b07 JW |
472 | dev->weight = weight; |
473 | dev->byte_weight = byte_weight; | |
792a4f2e | 474 | dev->msg_handler = msg_handler; |
04b96e55 | 475 | init_llist_head(&dev->work_list); |
6b1e6cc7 JW |
476 | init_waitqueue_head(&dev->wait); |
477 | INIT_LIST_HEAD(&dev->read_list); | |
478 | INIT_LIST_HEAD(&dev->pending_list); | |
479 | spin_lock_init(&dev->iotlb_lock); | |
3d2c7d37 | 480 | |
3a4d5c94 MT |
481 | |
482 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
483 | vq = dev->vqs[i]; |
484 | vq->log = NULL; | |
485 | vq->indirect = NULL; | |
486 | vq->heads = NULL; | |
487 | vq->dev = dev; | |
488 | mutex_init(&vq->mutex); | |
489 | vhost_vq_reset(dev, vq); | |
490 | if (vq->handle_kick) | |
491 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
a9a08845 | 492 | EPOLLIN, dev); |
3a4d5c94 | 493 | } |
3a4d5c94 | 494 | } |
6ac1afbf | 495 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
496 | |
497 | /* Caller should have device mutex */ | |
498 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
499 | { | |
500 | /* Are you the owner? If not, I don't think you mean to do that */ | |
501 | return dev->mm == current->mm ? 0 : -EPERM; | |
502 | } | |
6ac1afbf | 503 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 504 | |
87d6a412 | 505 | struct vhost_attach_cgroups_struct { |
d47effe1 KK |
506 | struct vhost_work work; |
507 | struct task_struct *owner; | |
508 | int ret; | |
87d6a412 MT |
509 | }; |
510 | ||
511 | static void vhost_attach_cgroups_work(struct vhost_work *work) | |
512 | { | |
d47effe1 KK |
513 | struct vhost_attach_cgroups_struct *s; |
514 | ||
515 | s = container_of(work, struct vhost_attach_cgroups_struct, work); | |
516 | s->ret = cgroup_attach_task_all(s->owner, current); | |
87d6a412 MT |
517 | } |
518 | ||
519 | static int vhost_attach_cgroups(struct vhost_dev *dev) | |
520 | { | |
d47effe1 KK |
521 | struct vhost_attach_cgroups_struct attach; |
522 | ||
523 | attach.owner = current; | |
524 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); | |
525 | vhost_work_queue(dev, &attach.work); | |
526 | vhost_work_flush(dev, &attach.work); | |
527 | return attach.ret; | |
87d6a412 MT |
528 | } |
529 | ||
05c05351 MT |
530 | /* Caller should have device mutex */ |
531 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
532 | { | |
533 | return dev->mm; | |
534 | } | |
6ac1afbf | 535 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 536 | |
3a4d5c94 | 537 | /* Caller should have device mutex */ |
54db63c2 | 538 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 539 | { |
c23f3445 TH |
540 | struct task_struct *worker; |
541 | int err; | |
d47effe1 | 542 | |
3a4d5c94 | 543 | /* Is there an owner already? */ |
05c05351 | 544 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
545 | err = -EBUSY; |
546 | goto err_mm; | |
547 | } | |
d47effe1 | 548 | |
3a4d5c94 MT |
549 | /* No owner, become one */ |
550 | dev->mm = get_task_mm(current); | |
8f6a7f96 | 551 | dev->kcov_handle = kcov_common_handle(); |
c23f3445 TH |
552 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
553 | if (IS_ERR(worker)) { | |
554 | err = PTR_ERR(worker); | |
555 | goto err_worker; | |
556 | } | |
557 | ||
558 | dev->worker = worker; | |
87d6a412 MT |
559 | wake_up_process(worker); /* avoid contributing to loadavg */ |
560 | ||
561 | err = vhost_attach_cgroups(dev); | |
9e3d1957 MT |
562 | if (err) |
563 | goto err_cgroup; | |
c23f3445 | 564 | |
e0e9b406 JW |
565 | err = vhost_dev_alloc_iovecs(dev); |
566 | if (err) | |
567 | goto err_cgroup; | |
568 | ||
3a4d5c94 | 569 | return 0; |
9e3d1957 MT |
570 | err_cgroup: |
571 | kthread_stop(worker); | |
615cc221 | 572 | dev->worker = NULL; |
c23f3445 TH |
573 | err_worker: |
574 | if (dev->mm) | |
575 | mmput(dev->mm); | |
576 | dev->mm = NULL; | |
8f6a7f96 | 577 | dev->kcov_handle = 0; |
c23f3445 TH |
578 | err_mm: |
579 | return err; | |
3a4d5c94 | 580 | } |
6ac1afbf | 581 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 582 | |
0bbe3066 JW |
583 | static struct vhost_iotlb *iotlb_alloc(void) |
584 | { | |
585 | return vhost_iotlb_alloc(max_iotlb_entries, | |
586 | VHOST_IOTLB_FLAG_RETIRE); | |
587 | } | |
588 | ||
589 | struct vhost_iotlb *vhost_dev_reset_owner_prepare(void) | |
a9709d68 | 590 | { |
0bbe3066 | 591 | return iotlb_alloc(); |
150b9e51 | 592 | } |
6ac1afbf | 593 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 594 | |
150b9e51 | 595 | /* Caller should have device mutex */ |
0bbe3066 | 596 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *umem) |
150b9e51 | 597 | { |
47283bef MT |
598 | int i; |
599 | ||
f6f93f75 | 600 | vhost_dev_cleanup(dev); |
3a4d5c94 | 601 | |
a9709d68 | 602 | dev->umem = umem; |
47283bef MT |
603 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
604 | * VQs aren't running. | |
605 | */ | |
606 | for (i = 0; i < dev->nvqs; ++i) | |
a9709d68 | 607 | dev->vqs[i]->umem = umem; |
3a4d5c94 | 608 | } |
6ac1afbf | 609 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 610 | |
b211616d | 611 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
612 | { |
613 | int i; | |
b211616d MT |
614 | |
615 | for (i = 0; i < dev->nvqs; ++i) { | |
3ab2e420 AH |
616 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) { |
617 | vhost_poll_stop(&dev->vqs[i]->poll); | |
618 | vhost_poll_flush(&dev->vqs[i]->poll); | |
b211616d | 619 | } |
bab632d6 | 620 | } |
bab632d6 | 621 | } |
6ac1afbf | 622 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 623 | |
6b1e6cc7 JW |
624 | static void vhost_clear_msg(struct vhost_dev *dev) |
625 | { | |
626 | struct vhost_msg_node *node, *n; | |
627 | ||
628 | spin_lock(&dev->iotlb_lock); | |
629 | ||
630 | list_for_each_entry_safe(node, n, &dev->read_list, node) { | |
631 | list_del(&node->node); | |
632 | kfree(node); | |
633 | } | |
634 | ||
635 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { | |
636 | list_del(&node->node); | |
637 | kfree(node); | |
638 | } | |
639 | ||
640 | spin_unlock(&dev->iotlb_lock); | |
641 | } | |
642 | ||
f6f93f75 | 643 | void vhost_dev_cleanup(struct vhost_dev *dev) |
3a4d5c94 MT |
644 | { |
645 | int i; | |
d47effe1 | 646 | |
3a4d5c94 | 647 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
648 | if (dev->vqs[i]->error_ctx) |
649 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
3ab2e420 AH |
650 | if (dev->vqs[i]->kick) |
651 | fput(dev->vqs[i]->kick); | |
652 | if (dev->vqs[i]->call_ctx) | |
653 | eventfd_ctx_put(dev->vqs[i]->call_ctx); | |
3ab2e420 | 654 | vhost_vq_reset(dev, dev->vqs[i]); |
3a4d5c94 | 655 | } |
e0e9b406 | 656 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
657 | if (dev->log_ctx) |
658 | eventfd_ctx_put(dev->log_ctx); | |
659 | dev->log_ctx = NULL; | |
3a4d5c94 | 660 | /* No one will access memory at this point */ |
0bbe3066 | 661 | vhost_iotlb_free(dev->umem); |
a9709d68 | 662 | dev->umem = NULL; |
0bbe3066 | 663 | vhost_iotlb_free(dev->iotlb); |
6b1e6cc7 JW |
664 | dev->iotlb = NULL; |
665 | vhost_clear_msg(dev); | |
a9a08845 | 666 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
04b96e55 | 667 | WARN_ON(!llist_empty(&dev->work_list)); |
78b620ce ED |
668 | if (dev->worker) { |
669 | kthread_stop(dev->worker); | |
670 | dev->worker = NULL; | |
8f6a7f96 | 671 | dev->kcov_handle = 0; |
78b620ce | 672 | } |
3d2c7d37 | 673 | if (dev->mm) |
533a19b4 MT |
674 | mmput(dev->mm); |
675 | dev->mm = NULL; | |
3a4d5c94 | 676 | } |
6ac1afbf | 677 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 | 678 | |
ddd3d408 | 679 | static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) |
3a4d5c94 MT |
680 | { |
681 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 682 | |
3a4d5c94 MT |
683 | /* Make sure 64 bit math will not overflow. */ |
684 | if (a > ULONG_MAX - (unsigned long)log_base || | |
685 | a + (unsigned long)log_base > ULONG_MAX) | |
ddd3d408 | 686 | return false; |
3a4d5c94 | 687 | |
96d4f267 | 688 | return access_ok(log_base + a, |
3a4d5c94 MT |
689 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); |
690 | } | |
691 | ||
ec33d031 MT |
692 | static bool vhost_overflow(u64 uaddr, u64 size) |
693 | { | |
694 | /* Make sure 64 bit math will not overflow. */ | |
695 | return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size; | |
696 | } | |
697 | ||
3a4d5c94 | 698 | /* Caller should have vq mutex and device mutex. */ |
0bbe3066 | 699 | static bool vq_memory_access_ok(void __user *log_base, struct vhost_iotlb *umem, |
ddd3d408 | 700 | int log_all) |
3a4d5c94 | 701 | { |
0bbe3066 | 702 | struct vhost_iotlb_map *map; |
179b284e | 703 | |
a9709d68 | 704 | if (!umem) |
ddd3d408 | 705 | return false; |
179b284e | 706 | |
0bbe3066 JW |
707 | list_for_each_entry(map, &umem->list, link) { |
708 | unsigned long a = map->addr; | |
a9709d68 | 709 | |
0bbe3066 | 710 | if (vhost_overflow(map->addr, map->size)) |
ddd3d408 | 711 | return false; |
ec33d031 MT |
712 | |
713 | ||
0bbe3066 | 714 | if (!access_ok((void __user *)a, map->size)) |
ddd3d408 | 715 | return false; |
3a4d5c94 | 716 | else if (log_all && !log_access_ok(log_base, |
0bbe3066 JW |
717 | map->start, |
718 | map->size)) | |
ddd3d408 | 719 | return false; |
3a4d5c94 | 720 | } |
ddd3d408 | 721 | return true; |
3a4d5c94 MT |
722 | } |
723 | ||
f8894913 JW |
724 | static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, |
725 | u64 addr, unsigned int size, | |
726 | int type) | |
727 | { | |
0bbe3066 | 728 | const struct vhost_iotlb_map *map = vq->meta_iotlb[type]; |
f8894913 | 729 | |
0bbe3066 | 730 | if (!map) |
f8894913 JW |
731 | return NULL; |
732 | ||
1b0be99f | 733 | return (void __user *)(uintptr_t)(map->addr + addr - map->start); |
f8894913 JW |
734 | } |
735 | ||
3a4d5c94 MT |
736 | /* Can we switch to this memory table? */ |
737 | /* Caller should have device mutex but not vq mutex */ | |
0bbe3066 | 738 | static bool memory_access_ok(struct vhost_dev *d, struct vhost_iotlb *umem, |
ddd3d408 | 739 | int log_all) |
3a4d5c94 MT |
740 | { |
741 | int i; | |
d47effe1 | 742 | |
3a4d5c94 | 743 | for (i = 0; i < d->nvqs; ++i) { |
ddd3d408 | 744 | bool ok; |
ea16c514 MT |
745 | bool log; |
746 | ||
3ab2e420 | 747 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 748 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 749 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 750 | if (d->vqs[i]->private_data) |
a9709d68 JW |
751 | ok = vq_memory_access_ok(d->vqs[i]->log_base, |
752 | umem, log); | |
3a4d5c94 | 753 | else |
ddd3d408 | 754 | ok = true; |
3ab2e420 | 755 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 | 756 | if (!ok) |
ddd3d408 | 757 | return false; |
3a4d5c94 | 758 | } |
ddd3d408 | 759 | return true; |
3a4d5c94 MT |
760 | } |
761 | ||
6b1e6cc7 JW |
762 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
763 | struct iovec iov[], int iov_size, int access); | |
bfe2bc51 | 764 | |
72952cc0 | 765 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, |
bfe2bc51 JW |
766 | const void *from, unsigned size) |
767 | { | |
6b1e6cc7 | 768 | int ret; |
bfe2bc51 | 769 | |
6b1e6cc7 JW |
770 | if (!vq->iotlb) |
771 | return __copy_to_user(to, from, size); | |
772 | else { | |
773 | /* This function should be called after iotlb | |
774 | * prefetch, which means we're sure that all vq | |
775 | * could be access through iotlb. So -EAGAIN should | |
776 | * not happen in this case. | |
777 | */ | |
6b1e6cc7 | 778 | struct iov_iter t; |
f8894913 JW |
779 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
780 | (u64)(uintptr_t)to, size, | |
7ced6c98 | 781 | VHOST_ADDR_USED); |
f8894913 JW |
782 | |
783 | if (uaddr) | |
784 | return __copy_to_user(uaddr, from, size); | |
785 | ||
6b1e6cc7 JW |
786 | ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, |
787 | ARRAY_SIZE(vq->iotlb_iov), | |
788 | VHOST_ACCESS_WO); | |
789 | if (ret < 0) | |
790 | goto out; | |
791 | iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size); | |
792 | ret = copy_to_iter(from, size, &t); | |
793 | if (ret == size) | |
794 | ret = 0; | |
795 | } | |
796 | out: | |
797 | return ret; | |
798 | } | |
bfe2bc51 JW |
799 | |
800 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, | |
72952cc0 | 801 | void __user *from, unsigned size) |
bfe2bc51 | 802 | { |
6b1e6cc7 JW |
803 | int ret; |
804 | ||
805 | if (!vq->iotlb) | |
806 | return __copy_from_user(to, from, size); | |
807 | else { | |
808 | /* This function should be called after iotlb | |
809 | * prefetch, which means we're sure that vq | |
810 | * could be access through iotlb. So -EAGAIN should | |
811 | * not happen in this case. | |
812 | */ | |
f8894913 JW |
813 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
814 | (u64)(uintptr_t)from, size, | |
815 | VHOST_ADDR_DESC); | |
6b1e6cc7 | 816 | struct iov_iter f; |
f8894913 JW |
817 | |
818 | if (uaddr) | |
819 | return __copy_from_user(to, uaddr, size); | |
820 | ||
6b1e6cc7 JW |
821 | ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, |
822 | ARRAY_SIZE(vq->iotlb_iov), | |
823 | VHOST_ACCESS_RO); | |
824 | if (ret < 0) { | |
825 | vq_err(vq, "IOTLB translation failure: uaddr " | |
826 | "%p size 0x%llx\n", from, | |
827 | (unsigned long long) size); | |
828 | goto out; | |
829 | } | |
830 | iov_iter_init(&f, READ, vq->iotlb_iov, ret, size); | |
831 | ret = copy_from_iter(to, size, &f); | |
832 | if (ret == size) | |
833 | ret = 0; | |
834 | } | |
835 | ||
836 | out: | |
837 | return ret; | |
838 | } | |
839 | ||
f8894913 JW |
840 | static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq, |
841 | void __user *addr, unsigned int size, | |
842 | int type) | |
6b1e6cc7 JW |
843 | { |
844 | int ret; | |
845 | ||
6b1e6cc7 JW |
846 | ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov, |
847 | ARRAY_SIZE(vq->iotlb_iov), | |
848 | VHOST_ACCESS_RO); | |
849 | if (ret < 0) { | |
850 | vq_err(vq, "IOTLB translation failure: uaddr " | |
851 | "%p size 0x%llx\n", addr, | |
852 | (unsigned long long) size); | |
853 | return NULL; | |
854 | } | |
855 | ||
856 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { | |
857 | vq_err(vq, "Non atomic userspace memory access: uaddr " | |
858 | "%p size 0x%llx\n", addr, | |
859 | (unsigned long long) size); | |
860 | return NULL; | |
861 | } | |
862 | ||
863 | return vq->iotlb_iov[0].iov_base; | |
864 | } | |
865 | ||
f8894913 JW |
866 | /* This function should be called after iotlb |
867 | * prefetch, which means we're sure that vq | |
868 | * could be access through iotlb. So -EAGAIN should | |
869 | * not happen in this case. | |
870 | */ | |
871 | static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, | |
1b0be99f | 872 | void __user *addr, unsigned int size, |
f8894913 JW |
873 | int type) |
874 | { | |
875 | void __user *uaddr = vhost_vq_meta_fetch(vq, | |
876 | (u64)(uintptr_t)addr, size, type); | |
877 | if (uaddr) | |
878 | return uaddr; | |
879 | ||
880 | return __vhost_get_user_slow(vq, addr, size, type); | |
881 | } | |
882 | ||
883 | #define vhost_put_user(vq, x, ptr) \ | |
6b1e6cc7 JW |
884 | ({ \ |
885 | int ret = -EFAULT; \ | |
886 | if (!vq->iotlb) { \ | |
887 | ret = __put_user(x, ptr); \ | |
888 | } else { \ | |
889 | __typeof__(ptr) to = \ | |
f8894913 JW |
890 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
891 | sizeof(*ptr), VHOST_ADDR_USED); \ | |
6b1e6cc7 JW |
892 | if (to != NULL) \ |
893 | ret = __put_user(x, to); \ | |
894 | else \ | |
895 | ret = -EFAULT; \ | |
896 | } \ | |
897 | ret; \ | |
898 | }) | |
899 | ||
7b5d753e JW |
900 | static inline int vhost_put_avail_event(struct vhost_virtqueue *vq) |
901 | { | |
902 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), | |
903 | vhost_avail_event(vq)); | |
904 | } | |
905 | ||
906 | static inline int vhost_put_used(struct vhost_virtqueue *vq, | |
907 | struct vring_used_elem *head, int idx, | |
908 | int count) | |
909 | { | |
910 | return vhost_copy_to_user(vq, vq->used->ring + idx, head, | |
911 | count * sizeof(*head)); | |
912 | } | |
913 | ||
914 | static inline int vhost_put_used_flags(struct vhost_virtqueue *vq) | |
915 | ||
916 | { | |
917 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), | |
918 | &vq->used->flags); | |
919 | } | |
920 | ||
921 | static inline int vhost_put_used_idx(struct vhost_virtqueue *vq) | |
922 | ||
923 | { | |
924 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), | |
925 | &vq->used->idx); | |
926 | } | |
927 | ||
f8894913 | 928 | #define vhost_get_user(vq, x, ptr, type) \ |
6b1e6cc7 JW |
929 | ({ \ |
930 | int ret; \ | |
931 | if (!vq->iotlb) { \ | |
932 | ret = __get_user(x, ptr); \ | |
933 | } else { \ | |
934 | __typeof__(ptr) from = \ | |
f8894913 JW |
935 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
936 | sizeof(*ptr), \ | |
937 | type); \ | |
6b1e6cc7 JW |
938 | if (from != NULL) \ |
939 | ret = __get_user(x, from); \ | |
940 | else \ | |
941 | ret = -EFAULT; \ | |
942 | } \ | |
943 | ret; \ | |
944 | }) | |
945 | ||
f8894913 JW |
946 | #define vhost_get_avail(vq, x, ptr) \ |
947 | vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL) | |
948 | ||
949 | #define vhost_get_used(vq, x, ptr) \ | |
950 | vhost_get_user(vq, x, ptr, VHOST_ADDR_USED) | |
951 | ||
86a07da3 JW |
952 | static void vhost_dev_lock_vqs(struct vhost_dev *d) |
953 | { | |
954 | int i = 0; | |
955 | for (i = 0; i < d->nvqs; ++i) | |
956 | mutex_lock_nested(&d->vqs[i]->mutex, i); | |
957 | } | |
958 | ||
959 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) | |
960 | { | |
961 | int i = 0; | |
962 | for (i = 0; i < d->nvqs; ++i) | |
963 | mutex_unlock(&d->vqs[i]->mutex); | |
964 | } | |
965 | ||
7b5d753e JW |
966 | static inline int vhost_get_avail_idx(struct vhost_virtqueue *vq, |
967 | __virtio16 *idx) | |
968 | { | |
969 | return vhost_get_avail(vq, *idx, &vq->avail->idx); | |
970 | } | |
971 | ||
972 | static inline int vhost_get_avail_head(struct vhost_virtqueue *vq, | |
973 | __virtio16 *head, int idx) | |
974 | { | |
975 | return vhost_get_avail(vq, *head, | |
976 | &vq->avail->ring[idx & (vq->num - 1)]); | |
977 | } | |
978 | ||
979 | static inline int vhost_get_avail_flags(struct vhost_virtqueue *vq, | |
980 | __virtio16 *flags) | |
981 | { | |
982 | return vhost_get_avail(vq, *flags, &vq->avail->flags); | |
983 | } | |
984 | ||
985 | static inline int vhost_get_used_event(struct vhost_virtqueue *vq, | |
986 | __virtio16 *event) | |
987 | { | |
988 | return vhost_get_avail(vq, *event, vhost_used_event(vq)); | |
989 | } | |
990 | ||
991 | static inline int vhost_get_used_idx(struct vhost_virtqueue *vq, | |
992 | __virtio16 *idx) | |
993 | { | |
994 | return vhost_get_used(vq, *idx, &vq->used->idx); | |
995 | } | |
996 | ||
997 | static inline int vhost_get_desc(struct vhost_virtqueue *vq, | |
998 | struct vring_desc *desc, int idx) | |
999 | { | |
1000 | return vhost_copy_from_user(vq, desc, vq->desc + idx, sizeof(*desc)); | |
1001 | } | |
1002 | ||
6b1e6cc7 JW |
1003 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, |
1004 | struct vhost_iotlb_msg *msg) | |
1005 | { | |
1006 | struct vhost_msg_node *node, *n; | |
1007 | ||
1008 | spin_lock(&d->iotlb_lock); | |
1009 | ||
1010 | list_for_each_entry_safe(node, n, &d->pending_list, node) { | |
1011 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; | |
1012 | if (msg->iova <= vq_msg->iova && | |
2d66f997 | 1013 | msg->iova + msg->size - 1 >= vq_msg->iova && |
6b1e6cc7 JW |
1014 | vq_msg->type == VHOST_IOTLB_MISS) { |
1015 | vhost_poll_queue(&node->vq->poll); | |
1016 | list_del(&node->node); | |
1017 | kfree(node); | |
1018 | } | |
1019 | } | |
1020 | ||
1021 | spin_unlock(&d->iotlb_lock); | |
1022 | } | |
1023 | ||
ddd3d408 | 1024 | static bool umem_access_ok(u64 uaddr, u64 size, int access) |
6b1e6cc7 JW |
1025 | { |
1026 | unsigned long a = uaddr; | |
1027 | ||
ec33d031 MT |
1028 | /* Make sure 64 bit math will not overflow. */ |
1029 | if (vhost_overflow(uaddr, size)) | |
ddd3d408 | 1030 | return false; |
ec33d031 | 1031 | |
6b1e6cc7 | 1032 | if ((access & VHOST_ACCESS_RO) && |
96d4f267 | 1033 | !access_ok((void __user *)a, size)) |
ddd3d408 | 1034 | return false; |
6b1e6cc7 | 1035 | if ((access & VHOST_ACCESS_WO) && |
96d4f267 | 1036 | !access_ok((void __user *)a, size)) |
ddd3d408 SH |
1037 | return false; |
1038 | return true; | |
6b1e6cc7 JW |
1039 | } |
1040 | ||
72952cc0 MT |
1041 | static int vhost_process_iotlb_msg(struct vhost_dev *dev, |
1042 | struct vhost_iotlb_msg *msg) | |
6b1e6cc7 JW |
1043 | { |
1044 | int ret = 0; | |
1045 | ||
1b15ad68 | 1046 | mutex_lock(&dev->mutex); |
86a07da3 | 1047 | vhost_dev_lock_vqs(dev); |
6b1e6cc7 JW |
1048 | switch (msg->type) { |
1049 | case VHOST_IOTLB_UPDATE: | |
1050 | if (!dev->iotlb) { | |
1051 | ret = -EFAULT; | |
1052 | break; | |
1053 | } | |
ddd3d408 | 1054 | if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) { |
6b1e6cc7 JW |
1055 | ret = -EFAULT; |
1056 | break; | |
1057 | } | |
f8894913 | 1058 | vhost_vq_meta_reset(dev); |
0bbe3066 JW |
1059 | if (vhost_iotlb_add_range(dev->iotlb, msg->iova, |
1060 | msg->iova + msg->size - 1, | |
1061 | msg->uaddr, msg->perm)) { | |
6b1e6cc7 JW |
1062 | ret = -ENOMEM; |
1063 | break; | |
1064 | } | |
1065 | vhost_iotlb_notify_vq(dev, msg); | |
1066 | break; | |
1067 | case VHOST_IOTLB_INVALIDATE: | |
6f3180af JW |
1068 | if (!dev->iotlb) { |
1069 | ret = -EFAULT; | |
1070 | break; | |
1071 | } | |
f8894913 | 1072 | vhost_vq_meta_reset(dev); |
0bbe3066 JW |
1073 | vhost_iotlb_del_range(dev->iotlb, msg->iova, |
1074 | msg->iova + msg->size - 1); | |
6b1e6cc7 JW |
1075 | break; |
1076 | default: | |
1077 | ret = -EINVAL; | |
1078 | break; | |
1079 | } | |
1080 | ||
86a07da3 | 1081 | vhost_dev_unlock_vqs(dev); |
1b15ad68 JW |
1082 | mutex_unlock(&dev->mutex); |
1083 | ||
6b1e6cc7 JW |
1084 | return ret; |
1085 | } | |
1086 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, | |
1087 | struct iov_iter *from) | |
1088 | { | |
429711ae JW |
1089 | struct vhost_iotlb_msg msg; |
1090 | size_t offset; | |
1091 | int type, ret; | |
6b1e6cc7 | 1092 | |
429711ae | 1093 | ret = copy_from_iter(&type, sizeof(type), from); |
74ad7419 PT |
1094 | if (ret != sizeof(type)) { |
1095 | ret = -EINVAL; | |
6b1e6cc7 | 1096 | goto done; |
74ad7419 | 1097 | } |
6b1e6cc7 | 1098 | |
429711ae | 1099 | switch (type) { |
6b1e6cc7 | 1100 | case VHOST_IOTLB_MSG: |
429711ae JW |
1101 | /* There maybe a hole after type for V1 message type, |
1102 | * so skip it here. | |
1103 | */ | |
1104 | offset = offsetof(struct vhost_msg, iotlb) - sizeof(int); | |
1105 | break; | |
1106 | case VHOST_IOTLB_MSG_V2: | |
1107 | offset = sizeof(__u32); | |
6b1e6cc7 JW |
1108 | break; |
1109 | default: | |
1110 | ret = -EINVAL; | |
429711ae | 1111 | goto done; |
6b1e6cc7 JW |
1112 | } |
1113 | ||
429711ae JW |
1114 | iov_iter_advance(from, offset); |
1115 | ret = copy_from_iter(&msg, sizeof(msg), from); | |
74ad7419 PT |
1116 | if (ret != sizeof(msg)) { |
1117 | ret = -EINVAL; | |
429711ae | 1118 | goto done; |
74ad7419 | 1119 | } |
792a4f2e JW |
1120 | |
1121 | if (dev->msg_handler) | |
1122 | ret = dev->msg_handler(dev, &msg); | |
1123 | else | |
1124 | ret = vhost_process_iotlb_msg(dev, &msg); | |
1125 | if (ret) { | |
429711ae JW |
1126 | ret = -EFAULT; |
1127 | goto done; | |
1128 | } | |
1129 | ||
1130 | ret = (type == VHOST_IOTLB_MSG) ? sizeof(struct vhost_msg) : | |
1131 | sizeof(struct vhost_msg_v2); | |
6b1e6cc7 JW |
1132 | done: |
1133 | return ret; | |
1134 | } | |
1135 | EXPORT_SYMBOL(vhost_chr_write_iter); | |
1136 | ||
afc9a42b | 1137 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
6b1e6cc7 JW |
1138 | poll_table *wait) |
1139 | { | |
afc9a42b | 1140 | __poll_t mask = 0; |
6b1e6cc7 JW |
1141 | |
1142 | poll_wait(file, &dev->wait, wait); | |
1143 | ||
1144 | if (!list_empty(&dev->read_list)) | |
a9a08845 | 1145 | mask |= EPOLLIN | EPOLLRDNORM; |
6b1e6cc7 JW |
1146 | |
1147 | return mask; | |
1148 | } | |
1149 | EXPORT_SYMBOL(vhost_chr_poll); | |
1150 | ||
1151 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, | |
1152 | int noblock) | |
1153 | { | |
1154 | DEFINE_WAIT(wait); | |
1155 | struct vhost_msg_node *node; | |
1156 | ssize_t ret = 0; | |
1157 | unsigned size = sizeof(struct vhost_msg); | |
1158 | ||
1159 | if (iov_iter_count(to) < size) | |
1160 | return 0; | |
1161 | ||
1162 | while (1) { | |
1163 | if (!noblock) | |
1164 | prepare_to_wait(&dev->wait, &wait, | |
1165 | TASK_INTERRUPTIBLE); | |
1166 | ||
1167 | node = vhost_dequeue_msg(dev, &dev->read_list); | |
1168 | if (node) | |
1169 | break; | |
1170 | if (noblock) { | |
1171 | ret = -EAGAIN; | |
1172 | break; | |
1173 | } | |
1174 | if (signal_pending(current)) { | |
1175 | ret = -ERESTARTSYS; | |
1176 | break; | |
1177 | } | |
1178 | if (!dev->iotlb) { | |
1179 | ret = -EBADFD; | |
1180 | break; | |
1181 | } | |
1182 | ||
1183 | schedule(); | |
1184 | } | |
1185 | ||
1186 | if (!noblock) | |
1187 | finish_wait(&dev->wait, &wait); | |
1188 | ||
1189 | if (node) { | |
429711ae JW |
1190 | struct vhost_iotlb_msg *msg; |
1191 | void *start = &node->msg; | |
6b1e6cc7 | 1192 | |
429711ae JW |
1193 | switch (node->msg.type) { |
1194 | case VHOST_IOTLB_MSG: | |
1195 | size = sizeof(node->msg); | |
1196 | msg = &node->msg.iotlb; | |
1197 | break; | |
1198 | case VHOST_IOTLB_MSG_V2: | |
1199 | size = sizeof(node->msg_v2); | |
1200 | msg = &node->msg_v2.iotlb; | |
1201 | break; | |
1202 | default: | |
1203 | BUG(); | |
1204 | break; | |
1205 | } | |
1206 | ||
1207 | ret = copy_to_iter(start, size, to); | |
1208 | if (ret != size || msg->type != VHOST_IOTLB_MISS) { | |
6b1e6cc7 JW |
1209 | kfree(node); |
1210 | return ret; | |
1211 | } | |
6b1e6cc7 JW |
1212 | vhost_enqueue_msg(dev, &dev->pending_list, node); |
1213 | } | |
1214 | ||
1215 | return ret; | |
1216 | } | |
1217 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); | |
1218 | ||
1219 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) | |
1220 | { | |
1221 | struct vhost_dev *dev = vq->dev; | |
1222 | struct vhost_msg_node *node; | |
1223 | struct vhost_iotlb_msg *msg; | |
429711ae | 1224 | bool v2 = vhost_backend_has_feature(vq, VHOST_BACKEND_F_IOTLB_MSG_V2); |
6b1e6cc7 | 1225 | |
429711ae | 1226 | node = vhost_new_msg(vq, v2 ? VHOST_IOTLB_MSG_V2 : VHOST_IOTLB_MSG); |
6b1e6cc7 JW |
1227 | if (!node) |
1228 | return -ENOMEM; | |
1229 | ||
429711ae JW |
1230 | if (v2) { |
1231 | node->msg_v2.type = VHOST_IOTLB_MSG_V2; | |
1232 | msg = &node->msg_v2.iotlb; | |
1233 | } else { | |
1234 | msg = &node->msg.iotlb; | |
1235 | } | |
1236 | ||
6b1e6cc7 JW |
1237 | msg->type = VHOST_IOTLB_MISS; |
1238 | msg->iova = iova; | |
1239 | msg->perm = access; | |
1240 | ||
1241 | vhost_enqueue_msg(dev, &dev->read_list, node); | |
1242 | ||
1243 | return 0; | |
bfe2bc51 JW |
1244 | } |
1245 | ||
ddd3d408 SH |
1246 | static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
1247 | struct vring_desc __user *desc, | |
1248 | struct vring_avail __user *avail, | |
1249 | struct vring_used __user *used) | |
6b1e6cc7 | 1250 | |
3a4d5c94 | 1251 | { |
4942e825 JW |
1252 | return access_ok(desc, vhost_get_desc_size(vq, num)) && |
1253 | access_ok(avail, vhost_get_avail_size(vq, num)) && | |
1254 | access_ok(used, vhost_get_used_size(vq, num)); | |
3a4d5c94 MT |
1255 | } |
1256 | ||
f8894913 | 1257 | static void vhost_vq_meta_update(struct vhost_virtqueue *vq, |
0bbe3066 | 1258 | const struct vhost_iotlb_map *map, |
f8894913 JW |
1259 | int type) |
1260 | { | |
1261 | int access = (type == VHOST_ADDR_USED) ? | |
1262 | VHOST_ACCESS_WO : VHOST_ACCESS_RO; | |
1263 | ||
0bbe3066 JW |
1264 | if (likely(map->perm & access)) |
1265 | vq->meta_iotlb[type] = map; | |
f8894913 JW |
1266 | } |
1267 | ||
ddd3d408 SH |
1268 | static bool iotlb_access_ok(struct vhost_virtqueue *vq, |
1269 | int access, u64 addr, u64 len, int type) | |
6b1e6cc7 | 1270 | { |
0bbe3066 JW |
1271 | const struct vhost_iotlb_map *map; |
1272 | struct vhost_iotlb *umem = vq->iotlb; | |
ca2c5b33 | 1273 | u64 s = 0, size, orig_addr = addr, last = addr + len - 1; |
f8894913 JW |
1274 | |
1275 | if (vhost_vq_meta_fetch(vq, addr, len, type)) | |
1276 | return true; | |
6b1e6cc7 JW |
1277 | |
1278 | while (len > s) { | |
0bbe3066 JW |
1279 | map = vhost_iotlb_itree_first(umem, addr, last); |
1280 | if (map == NULL || map->start > addr) { | |
6b1e6cc7 JW |
1281 | vhost_iotlb_miss(vq, addr, access); |
1282 | return false; | |
0bbe3066 | 1283 | } else if (!(map->perm & access)) { |
6b1e6cc7 JW |
1284 | /* Report the possible access violation by |
1285 | * request another translation from userspace. | |
1286 | */ | |
1287 | return false; | |
1288 | } | |
1289 | ||
0bbe3066 | 1290 | size = map->size - addr + map->start; |
f8894913 JW |
1291 | |
1292 | if (orig_addr == addr && size >= len) | |
0bbe3066 | 1293 | vhost_vq_meta_update(vq, map, type); |
f8894913 | 1294 | |
6b1e6cc7 JW |
1295 | s += size; |
1296 | addr += size; | |
1297 | } | |
1298 | ||
1299 | return true; | |
1300 | } | |
1301 | ||
9b5e830b | 1302 | int vq_meta_prefetch(struct vhost_virtqueue *vq) |
6b1e6cc7 | 1303 | { |
6b1e6cc7 JW |
1304 | unsigned int num = vq->num; |
1305 | ||
3d2c7d37 | 1306 | if (!vq->iotlb) |
6b1e6cc7 JW |
1307 | return 1; |
1308 | ||
0bbe3066 | 1309 | return iotlb_access_ok(vq, VHOST_MAP_RO, (u64)(uintptr_t)vq->desc, |
4942e825 | 1310 | vhost_get_desc_size(vq, num), VHOST_ADDR_DESC) && |
0bbe3066 | 1311 | iotlb_access_ok(vq, VHOST_MAP_RO, (u64)(uintptr_t)vq->avail, |
4942e825 | 1312 | vhost_get_avail_size(vq, num), |
f8894913 | 1313 | VHOST_ADDR_AVAIL) && |
0bbe3066 | 1314 | iotlb_access_ok(vq, VHOST_MAP_WO, (u64)(uintptr_t)vq->used, |
4942e825 | 1315 | vhost_get_used_size(vq, num), VHOST_ADDR_USED); |
6b1e6cc7 | 1316 | } |
9b5e830b | 1317 | EXPORT_SYMBOL_GPL(vq_meta_prefetch); |
6b1e6cc7 | 1318 | |
3a4d5c94 MT |
1319 | /* Can we log writes? */ |
1320 | /* Caller should have device mutex but not vq mutex */ | |
ddd3d408 | 1321 | bool vhost_log_access_ok(struct vhost_dev *dev) |
3a4d5c94 | 1322 | { |
a9709d68 | 1323 | return memory_access_ok(dev, dev->umem, 1); |
3a4d5c94 | 1324 | } |
6ac1afbf | 1325 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 MT |
1326 | |
1327 | /* Verify access for write logging. */ | |
1328 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 SH |
1329 | static bool vq_log_access_ok(struct vhost_virtqueue *vq, |
1330 | void __user *log_base) | |
3a4d5c94 | 1331 | { |
a9709d68 | 1332 | return vq_memory_access_ok(log_base, vq->umem, |
ea16c514 | 1333 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
3a4d5c94 | 1334 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
4942e825 | 1335 | vhost_get_used_size(vq, vq->num))); |
3a4d5c94 MT |
1336 | } |
1337 | ||
1338 | /* Can we start vq? */ | |
1339 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 | 1340 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq) |
3a4d5c94 | 1341 | { |
d14d2b78 | 1342 | if (!vq_log_access_ok(vq, vq->log_base)) |
ddd3d408 | 1343 | return false; |
d65026c6 | 1344 | |
d14d2b78 SH |
1345 | /* Access validation occurs at prefetch time with IOTLB */ |
1346 | if (vq->iotlb) | |
ddd3d408 | 1347 | return true; |
d65026c6 JW |
1348 | |
1349 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); | |
3a4d5c94 | 1350 | } |
6ac1afbf | 1351 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 MT |
1352 | |
1353 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) | |
1354 | { | |
a9709d68 JW |
1355 | struct vhost_memory mem, *newmem; |
1356 | struct vhost_memory_region *region; | |
0bbe3066 | 1357 | struct vhost_iotlb *newumem, *oldumem; |
3a4d5c94 | 1358 | unsigned long size = offsetof(struct vhost_memory, regions); |
98f9ca0a | 1359 | int i; |
d47effe1 | 1360 | |
7ad9c9d2 TY |
1361 | if (copy_from_user(&mem, m, size)) |
1362 | return -EFAULT; | |
3a4d5c94 MT |
1363 | if (mem.padding) |
1364 | return -EOPNOTSUPP; | |
c9ce42f7 | 1365 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 1366 | return -E2BIG; |
b2303d7b MW |
1367 | newmem = kvzalloc(struct_size(newmem, regions, mem.nregions), |
1368 | GFP_KERNEL); | |
3a4d5c94 MT |
1369 | if (!newmem) |
1370 | return -ENOMEM; | |
1371 | ||
1372 | memcpy(newmem, &mem, size); | |
7ad9c9d2 TY |
1373 | if (copy_from_user(newmem->regions, m->regions, |
1374 | mem.nregions * sizeof *m->regions)) { | |
bcfeacab | 1375 | kvfree(newmem); |
7ad9c9d2 | 1376 | return -EFAULT; |
3a4d5c94 MT |
1377 | } |
1378 | ||
0bbe3066 | 1379 | newumem = iotlb_alloc(); |
a9709d68 | 1380 | if (!newumem) { |
4de7255f | 1381 | kvfree(newmem); |
a9709d68 JW |
1382 | return -ENOMEM; |
1383 | } | |
1384 | ||
a9709d68 JW |
1385 | for (region = newmem->regions; |
1386 | region < newmem->regions + mem.nregions; | |
1387 | region++) { | |
0bbe3066 JW |
1388 | if (vhost_iotlb_add_range(newumem, |
1389 | region->guest_phys_addr, | |
1390 | region->guest_phys_addr + | |
1391 | region->memory_size - 1, | |
1392 | region->userspace_addr, | |
1393 | VHOST_MAP_RW)) | |
a9709d68 | 1394 | goto err; |
a02c3789 | 1395 | } |
a9709d68 JW |
1396 | |
1397 | if (!memory_access_ok(d, newumem, 0)) | |
1398 | goto err; | |
1399 | ||
1400 | oldumem = d->umem; | |
1401 | d->umem = newumem; | |
98f9ca0a | 1402 | |
47283bef | 1403 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
1404 | for (i = 0; i < d->nvqs; ++i) { |
1405 | mutex_lock(&d->vqs[i]->mutex); | |
a9709d68 | 1406 | d->vqs[i]->umem = newumem; |
98f9ca0a MT |
1407 | mutex_unlock(&d->vqs[i]->mutex); |
1408 | } | |
a9709d68 JW |
1409 | |
1410 | kvfree(newmem); | |
0bbe3066 | 1411 | vhost_iotlb_free(oldumem); |
3a4d5c94 | 1412 | return 0; |
a9709d68 JW |
1413 | |
1414 | err: | |
0bbe3066 | 1415 | vhost_iotlb_free(newumem); |
a9709d68 JW |
1416 | kvfree(newmem); |
1417 | return -EFAULT; | |
3a4d5c94 MT |
1418 | } |
1419 | ||
feebcaea JW |
1420 | static long vhost_vring_set_num(struct vhost_dev *d, |
1421 | struct vhost_virtqueue *vq, | |
1422 | void __user *argp) | |
1423 | { | |
1424 | struct vhost_vring_state s; | |
1425 | ||
1426 | /* Resizing ring with an active backend? | |
1427 | * You don't want to do that. */ | |
1428 | if (vq->private_data) | |
1429 | return -EBUSY; | |
1430 | ||
1431 | if (copy_from_user(&s, argp, sizeof s)) | |
1432 | return -EFAULT; | |
1433 | ||
1434 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) | |
1435 | return -EINVAL; | |
1436 | vq->num = s.num; | |
1437 | ||
1438 | return 0; | |
1439 | } | |
1440 | ||
1441 | static long vhost_vring_set_addr(struct vhost_dev *d, | |
1442 | struct vhost_virtqueue *vq, | |
1443 | void __user *argp) | |
1444 | { | |
1445 | struct vhost_vring_addr a; | |
1446 | ||
1447 | if (copy_from_user(&a, argp, sizeof a)) | |
1448 | return -EFAULT; | |
1449 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) | |
1450 | return -EOPNOTSUPP; | |
1451 | ||
1452 | /* For 32bit, verify that the top 32bits of the user | |
1453 | data are set to zero. */ | |
1454 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
1455 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
1456 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) | |
1457 | return -EFAULT; | |
1458 | ||
1459 | /* Make sure it's safe to cast pointers to vring types. */ | |
1460 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
1461 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
1462 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
1463 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
1464 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) | |
1465 | return -EINVAL; | |
1466 | ||
1467 | /* We only verify access here if backend is configured. | |
1468 | * If it is not, we don't as size might not have been setup. | |
1469 | * We will verify when backend is configured. */ | |
1470 | if (vq->private_data) { | |
1471 | if (!vq_access_ok(vq, vq->num, | |
1472 | (void __user *)(unsigned long)a.desc_user_addr, | |
1473 | (void __user *)(unsigned long)a.avail_user_addr, | |
1474 | (void __user *)(unsigned long)a.used_user_addr)) | |
1475 | return -EINVAL; | |
1476 | ||
1477 | /* Also validate log access for used ring if enabled. */ | |
1478 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && | |
1479 | !log_access_ok(vq->log_base, a.log_guest_addr, | |
1480 | sizeof *vq->used + | |
1481 | vq->num * sizeof *vq->used->ring)) | |
1482 | return -EINVAL; | |
1483 | } | |
1484 | ||
1485 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); | |
1486 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
1487 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
1488 | vq->log_addr = a.log_guest_addr; | |
1489 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
1490 | ||
1491 | return 0; | |
1492 | } | |
1493 | ||
1494 | static long vhost_vring_set_num_addr(struct vhost_dev *d, | |
1495 | struct vhost_virtqueue *vq, | |
1496 | unsigned int ioctl, | |
1497 | void __user *argp) | |
1498 | { | |
1499 | long r; | |
1500 | ||
1501 | mutex_lock(&vq->mutex); | |
1502 | ||
1503 | switch (ioctl) { | |
1504 | case VHOST_SET_VRING_NUM: | |
1505 | r = vhost_vring_set_num(d, vq, argp); | |
1506 | break; | |
1507 | case VHOST_SET_VRING_ADDR: | |
1508 | r = vhost_vring_set_addr(d, vq, argp); | |
1509 | break; | |
1510 | default: | |
1511 | BUG(); | |
1512 | } | |
1513 | ||
1514 | mutex_unlock(&vq->mutex); | |
1515 | ||
1516 | return r; | |
1517 | } | |
26b36604 | 1518 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1519 | { |
cecb46f1 AV |
1520 | struct file *eventfp, *filep = NULL; |
1521 | bool pollstart = false, pollstop = false; | |
3a4d5c94 MT |
1522 | struct eventfd_ctx *ctx = NULL; |
1523 | u32 __user *idxp = argp; | |
1524 | struct vhost_virtqueue *vq; | |
1525 | struct vhost_vring_state s; | |
1526 | struct vhost_vring_file f; | |
3a4d5c94 MT |
1527 | u32 idx; |
1528 | long r; | |
1529 | ||
1530 | r = get_user(idx, idxp); | |
1531 | if (r < 0) | |
1532 | return r; | |
0f3d9a17 | 1533 | if (idx >= d->nvqs) |
3a4d5c94 MT |
1534 | return -ENOBUFS; |
1535 | ||
ff002269 | 1536 | idx = array_index_nospec(idx, d->nvqs); |
3ab2e420 | 1537 | vq = d->vqs[idx]; |
3a4d5c94 | 1538 | |
feebcaea JW |
1539 | if (ioctl == VHOST_SET_VRING_NUM || |
1540 | ioctl == VHOST_SET_VRING_ADDR) { | |
1541 | return vhost_vring_set_num_addr(d, vq, ioctl, argp); | |
1542 | } | |
1543 | ||
3a4d5c94 MT |
1544 | mutex_lock(&vq->mutex); |
1545 | ||
1546 | switch (ioctl) { | |
3a4d5c94 MT |
1547 | case VHOST_SET_VRING_BASE: |
1548 | /* Moving base with an active backend? | |
1549 | * You don't want to do that. */ | |
1550 | if (vq->private_data) { | |
1551 | r = -EBUSY; | |
1552 | break; | |
1553 | } | |
7ad9c9d2 TY |
1554 | if (copy_from_user(&s, argp, sizeof s)) { |
1555 | r = -EFAULT; | |
3a4d5c94 | 1556 | break; |
7ad9c9d2 | 1557 | } |
3a4d5c94 MT |
1558 | if (s.num > 0xffff) { |
1559 | r = -EINVAL; | |
1560 | break; | |
1561 | } | |
8d65843c | 1562 | vq->last_avail_idx = s.num; |
3a4d5c94 MT |
1563 | /* Forget the cached index value. */ |
1564 | vq->avail_idx = vq->last_avail_idx; | |
1565 | break; | |
1566 | case VHOST_GET_VRING_BASE: | |
1567 | s.index = idx; | |
1568 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
1569 | if (copy_to_user(argp, &s, sizeof s)) |
1570 | r = -EFAULT; | |
3a4d5c94 | 1571 | break; |
3a4d5c94 | 1572 | case VHOST_SET_VRING_KICK: |
7ad9c9d2 TY |
1573 | if (copy_from_user(&f, argp, sizeof f)) { |
1574 | r = -EFAULT; | |
3a4d5c94 | 1575 | break; |
7ad9c9d2 | 1576 | } |
3a4d5c94 | 1577 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1578 | if (IS_ERR(eventfp)) { |
1579 | r = PTR_ERR(eventfp); | |
1580 | break; | |
1581 | } | |
3a4d5c94 | 1582 | if (eventfp != vq->kick) { |
cecb46f1 AV |
1583 | pollstop = (filep = vq->kick) != NULL; |
1584 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
1585 | } else |
1586 | filep = eventfp; | |
1587 | break; | |
1588 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
1589 | if (copy_from_user(&f, argp, sizeof f)) { |
1590 | r = -EFAULT; | |
3a4d5c94 | 1591 | break; |
7ad9c9d2 | 1592 | } |
e050c7d9 EB |
1593 | ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); |
1594 | if (IS_ERR(ctx)) { | |
1595 | r = PTR_ERR(ctx); | |
535297a6 MT |
1596 | break; |
1597 | } | |
e050c7d9 | 1598 | swap(ctx, vq->call_ctx); |
3a4d5c94 MT |
1599 | break; |
1600 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
1601 | if (copy_from_user(&f, argp, sizeof f)) { |
1602 | r = -EFAULT; | |
3a4d5c94 | 1603 | break; |
7ad9c9d2 | 1604 | } |
09f332a5 EB |
1605 | ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); |
1606 | if (IS_ERR(ctx)) { | |
1607 | r = PTR_ERR(ctx); | |
535297a6 MT |
1608 | break; |
1609 | } | |
09f332a5 | 1610 | swap(ctx, vq->error_ctx); |
3a4d5c94 | 1611 | break; |
2751c988 GK |
1612 | case VHOST_SET_VRING_ENDIAN: |
1613 | r = vhost_set_vring_endian(vq, argp); | |
1614 | break; | |
1615 | case VHOST_GET_VRING_ENDIAN: | |
1616 | r = vhost_get_vring_endian(vq, idx, argp); | |
1617 | break; | |
03088137 JW |
1618 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1619 | if (copy_from_user(&s, argp, sizeof(s))) { | |
1620 | r = -EFAULT; | |
1621 | break; | |
1622 | } | |
1623 | vq->busyloop_timeout = s.num; | |
1624 | break; | |
1625 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
1626 | s.index = idx; | |
1627 | s.num = vq->busyloop_timeout; | |
1628 | if (copy_to_user(argp, &s, sizeof(s))) | |
1629 | r = -EFAULT; | |
1630 | break; | |
3a4d5c94 MT |
1631 | default: |
1632 | r = -ENOIOCTLCMD; | |
1633 | } | |
1634 | ||
1635 | if (pollstop && vq->handle_kick) | |
1636 | vhost_poll_stop(&vq->poll); | |
1637 | ||
e050c7d9 | 1638 | if (!IS_ERR_OR_NULL(ctx)) |
3a4d5c94 MT |
1639 | eventfd_ctx_put(ctx); |
1640 | if (filep) | |
1641 | fput(filep); | |
1642 | ||
1643 | if (pollstart && vq->handle_kick) | |
2b8b328b | 1644 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
1645 | |
1646 | mutex_unlock(&vq->mutex); | |
1647 | ||
1648 | if (pollstop && vq->handle_kick) | |
1649 | vhost_poll_flush(&vq->poll); | |
1650 | return r; | |
1651 | } | |
6ac1afbf | 1652 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 | 1653 | |
6b1e6cc7 JW |
1654 | int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled) |
1655 | { | |
0bbe3066 | 1656 | struct vhost_iotlb *niotlb, *oiotlb; |
6b1e6cc7 JW |
1657 | int i; |
1658 | ||
0bbe3066 | 1659 | niotlb = iotlb_alloc(); |
6b1e6cc7 JW |
1660 | if (!niotlb) |
1661 | return -ENOMEM; | |
1662 | ||
1663 | oiotlb = d->iotlb; | |
1664 | d->iotlb = niotlb; | |
1665 | ||
1666 | for (i = 0; i < d->nvqs; ++i) { | |
b13f9c63 JW |
1667 | struct vhost_virtqueue *vq = d->vqs[i]; |
1668 | ||
1669 | mutex_lock(&vq->mutex); | |
1670 | vq->iotlb = niotlb; | |
1671 | __vhost_vq_meta_reset(vq); | |
1672 | mutex_unlock(&vq->mutex); | |
6b1e6cc7 JW |
1673 | } |
1674 | ||
0bbe3066 | 1675 | vhost_iotlb_free(oiotlb); |
6b1e6cc7 JW |
1676 | |
1677 | return 0; | |
1678 | } | |
1679 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); | |
1680 | ||
3a4d5c94 | 1681 | /* Caller must have device mutex */ |
935cdee7 | 1682 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1683 | { |
d25cc43c | 1684 | struct eventfd_ctx *ctx; |
3a4d5c94 MT |
1685 | u64 p; |
1686 | long r; | |
1687 | int i, fd; | |
1688 | ||
1689 | /* If you are not the owner, you can become one */ | |
1690 | if (ioctl == VHOST_SET_OWNER) { | |
1691 | r = vhost_dev_set_owner(d); | |
1692 | goto done; | |
1693 | } | |
1694 | ||
1695 | /* You must be the owner to do anything else */ | |
1696 | r = vhost_dev_check_owner(d); | |
1697 | if (r) | |
1698 | goto done; | |
1699 | ||
1700 | switch (ioctl) { | |
1701 | case VHOST_SET_MEM_TABLE: | |
1702 | r = vhost_set_memory(d, argp); | |
1703 | break; | |
1704 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
1705 | if (copy_from_user(&p, argp, sizeof p)) { |
1706 | r = -EFAULT; | |
3a4d5c94 | 1707 | break; |
7ad9c9d2 | 1708 | } |
3a4d5c94 MT |
1709 | if ((u64)(unsigned long)p != p) { |
1710 | r = -EFAULT; | |
1711 | break; | |
1712 | } | |
1713 | for (i = 0; i < d->nvqs; ++i) { | |
1714 | struct vhost_virtqueue *vq; | |
1715 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 1716 | vq = d->vqs[i]; |
3a4d5c94 MT |
1717 | mutex_lock(&vq->mutex); |
1718 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 1719 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
1720 | r = -EFAULT; |
1721 | else | |
1722 | vq->log_base = base; | |
1723 | mutex_unlock(&vq->mutex); | |
1724 | } | |
1725 | break; | |
1726 | case VHOST_SET_LOG_FD: | |
1727 | r = get_user(fd, (int __user *)argp); | |
1728 | if (r < 0) | |
1729 | break; | |
d25cc43c EB |
1730 | ctx = fd == -1 ? NULL : eventfd_ctx_fdget(fd); |
1731 | if (IS_ERR(ctx)) { | |
1732 | r = PTR_ERR(ctx); | |
3a4d5c94 MT |
1733 | break; |
1734 | } | |
d25cc43c | 1735 | swap(ctx, d->log_ctx); |
3a4d5c94 | 1736 | for (i = 0; i < d->nvqs; ++i) { |
3ab2e420 AH |
1737 | mutex_lock(&d->vqs[i]->mutex); |
1738 | d->vqs[i]->log_ctx = d->log_ctx; | |
1739 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
1740 | } |
1741 | if (ctx) | |
1742 | eventfd_ctx_put(ctx); | |
3a4d5c94 MT |
1743 | break; |
1744 | default: | |
935cdee7 | 1745 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
1746 | break; |
1747 | } | |
1748 | done: | |
1749 | return r; | |
1750 | } | |
6ac1afbf | 1751 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 | 1752 | |
3a4d5c94 MT |
1753 | /* TODO: This is really inefficient. We need something like get_user() |
1754 | * (instruction directly accesses the data, with an exception table entry | |
cb1aaebe | 1755 | * returning -EFAULT). See Documentation/x86/exception-tables.rst. |
3a4d5c94 MT |
1756 | */ |
1757 | static int set_bit_to_user(int nr, void __user *addr) | |
1758 | { | |
1759 | unsigned long log = (unsigned long)addr; | |
1760 | struct page *page; | |
1761 | void *base; | |
1762 | int bit = nr + (log % PAGE_SIZE) * 8; | |
1763 | int r; | |
d47effe1 | 1764 | |
73b0140b | 1765 | r = get_user_pages_fast(log, 1, FOLL_WRITE, &page); |
d6db3f5c | 1766 | if (r < 0) |
3a4d5c94 | 1767 | return r; |
d6db3f5c | 1768 | BUG_ON(r != 1); |
c6daa7ff | 1769 | base = kmap_atomic(page); |
3a4d5c94 | 1770 | set_bit(bit, base); |
c6daa7ff | 1771 | kunmap_atomic(base); |
3a4d5c94 MT |
1772 | set_page_dirty_lock(page); |
1773 | put_page(page); | |
1774 | return 0; | |
1775 | } | |
1776 | ||
1777 | static int log_write(void __user *log_base, | |
1778 | u64 write_address, u64 write_length) | |
1779 | { | |
28831ee6 | 1780 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 1781 | int r; |
d47effe1 | 1782 | |
3a4d5c94 MT |
1783 | if (!write_length) |
1784 | return 0; | |
3bf9be40 | 1785 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
1786 | for (;;) { |
1787 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
1788 | u64 log = base + write_page / 8; |
1789 | int bit = write_page % 8; | |
3a4d5c94 MT |
1790 | if ((u64)(unsigned long)log != log) |
1791 | return -EFAULT; | |
1792 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
1793 | if (r < 0) | |
1794 | return r; | |
1795 | if (write_length <= VHOST_PAGE_SIZE) | |
1796 | break; | |
1797 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 1798 | write_page += 1; |
3a4d5c94 MT |
1799 | } |
1800 | return r; | |
1801 | } | |
1802 | ||
cc5e7107 JW |
1803 | static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len) |
1804 | { | |
0bbe3066 JW |
1805 | struct vhost_iotlb *umem = vq->umem; |
1806 | struct vhost_iotlb_map *u; | |
cc5e7107 JW |
1807 | u64 start, end, l, min; |
1808 | int r; | |
1809 | bool hit = false; | |
1810 | ||
1811 | while (len) { | |
1812 | min = len; | |
1813 | /* More than one GPAs can be mapped into a single HVA. So | |
1814 | * iterate all possible umems here to be safe. | |
1815 | */ | |
0bbe3066 JW |
1816 | list_for_each_entry(u, &umem->list, link) { |
1817 | if (u->addr > hva - 1 + len || | |
1818 | u->addr - 1 + u->size < hva) | |
cc5e7107 | 1819 | continue; |
0bbe3066 JW |
1820 | start = max(u->addr, hva); |
1821 | end = min(u->addr - 1 + u->size, hva - 1 + len); | |
cc5e7107 JW |
1822 | l = end - start + 1; |
1823 | r = log_write(vq->log_base, | |
0bbe3066 | 1824 | u->start + start - u->addr, |
cc5e7107 JW |
1825 | l); |
1826 | if (r < 0) | |
1827 | return r; | |
1828 | hit = true; | |
1829 | min = min(l, min); | |
1830 | } | |
1831 | ||
1832 | if (!hit) | |
1833 | return -EFAULT; | |
1834 | ||
1835 | len -= min; | |
1836 | hva += min; | |
1837 | } | |
1838 | ||
1839 | return 0; | |
1840 | } | |
1841 | ||
1842 | static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) | |
1843 | { | |
1844 | struct iovec iov[64]; | |
1845 | int i, ret; | |
1846 | ||
1847 | if (!vq->iotlb) | |
1848 | return log_write(vq->log_base, vq->log_addr + used_offset, len); | |
1849 | ||
1850 | ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, | |
1851 | len, iov, 64, VHOST_ACCESS_WO); | |
816db766 | 1852 | if (ret < 0) |
cc5e7107 JW |
1853 | return ret; |
1854 | ||
1855 | for (i = 0; i < ret; i++) { | |
1856 | ret = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
1857 | iov[i].iov_len); | |
1858 | if (ret) | |
1859 | return ret; | |
1860 | } | |
1861 | ||
1862 | return 0; | |
1863 | } | |
1864 | ||
3a4d5c94 | 1865 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
cc5e7107 | 1866 | unsigned int log_num, u64 len, struct iovec *iov, int count) |
3a4d5c94 MT |
1867 | { |
1868 | int i, r; | |
1869 | ||
1870 | /* Make sure data written is seen before log. */ | |
5659338c | 1871 | smp_wmb(); |
cc5e7107 JW |
1872 | |
1873 | if (vq->iotlb) { | |
1874 | for (i = 0; i < count; i++) { | |
1875 | r = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
1876 | iov[i].iov_len); | |
1877 | if (r < 0) | |
1878 | return r; | |
1879 | } | |
1880 | return 0; | |
1881 | } | |
1882 | ||
3a4d5c94 MT |
1883 | for (i = 0; i < log_num; ++i) { |
1884 | u64 l = min(log[i].len, len); | |
1885 | r = log_write(vq->log_base, log[i].addr, l); | |
1886 | if (r < 0) | |
1887 | return r; | |
1888 | len -= l; | |
5786aee8 MT |
1889 | if (!len) { |
1890 | if (vq->log_ctx) | |
1891 | eventfd_signal(vq->log_ctx, 1); | |
3a4d5c94 | 1892 | return 0; |
5786aee8 | 1893 | } |
3a4d5c94 | 1894 | } |
3a4d5c94 MT |
1895 | /* Length written exceeds what we have stored. This is a bug. */ |
1896 | BUG(); | |
1897 | return 0; | |
1898 | } | |
6ac1afbf | 1899 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 1900 | |
2723feaa JW |
1901 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
1902 | { | |
1903 | void __user *used; | |
7b5d753e | 1904 | if (vhost_put_used_flags(vq)) |
2723feaa JW |
1905 | return -EFAULT; |
1906 | if (unlikely(vq->log_used)) { | |
1907 | /* Make sure the flag is seen before log. */ | |
1908 | smp_wmb(); | |
1909 | /* Log used flag write. */ | |
1910 | used = &vq->used->flags; | |
cc5e7107 JW |
1911 | log_used(vq, (used - (void __user *)vq->used), |
1912 | sizeof vq->used->flags); | |
2723feaa JW |
1913 | if (vq->log_ctx) |
1914 | eventfd_signal(vq->log_ctx, 1); | |
1915 | } | |
1916 | return 0; | |
1917 | } | |
1918 | ||
1919 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) | |
1920 | { | |
7b5d753e | 1921 | if (vhost_put_avail_event(vq)) |
2723feaa JW |
1922 | return -EFAULT; |
1923 | if (unlikely(vq->log_used)) { | |
1924 | void __user *used; | |
1925 | /* Make sure the event is seen before log. */ | |
1926 | smp_wmb(); | |
1927 | /* Log avail event write */ | |
1928 | used = vhost_avail_event(vq); | |
cc5e7107 JW |
1929 | log_used(vq, (used - (void __user *)vq->used), |
1930 | sizeof *vhost_avail_event(vq)); | |
2723feaa JW |
1931 | if (vq->log_ctx) |
1932 | eventfd_signal(vq->log_ctx, 1); | |
1933 | } | |
1934 | return 0; | |
1935 | } | |
1936 | ||
80f7d030 | 1937 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 1938 | { |
3b1bbe89 | 1939 | __virtio16 last_used_idx; |
2723feaa | 1940 | int r; |
e1f33be9 GK |
1941 | bool is_le = vq->is_le; |
1942 | ||
cda8bba0 | 1943 | if (!vq->private_data) |
2723feaa | 1944 | return 0; |
2751c988 GK |
1945 | |
1946 | vhost_init_is_le(vq); | |
2723feaa JW |
1947 | |
1948 | r = vhost_update_used_flags(vq); | |
1949 | if (r) | |
e1f33be9 | 1950 | goto err; |
2723feaa | 1951 | vq->signalled_used_valid = false; |
6b1e6cc7 | 1952 | if (!vq->iotlb && |
96d4f267 | 1953 | !access_ok(&vq->used->idx, sizeof vq->used->idx)) { |
e1f33be9 GK |
1954 | r = -EFAULT; |
1955 | goto err; | |
1956 | } | |
7b5d753e | 1957 | r = vhost_get_used_idx(vq, &last_used_idx); |
6b1e6cc7 JW |
1958 | if (r) { |
1959 | vq_err(vq, "Can't access used idx at %p\n", | |
1960 | &vq->used->idx); | |
e1f33be9 | 1961 | goto err; |
6b1e6cc7 | 1962 | } |
3b1bbe89 | 1963 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 1964 | return 0; |
6b1e6cc7 | 1965 | |
e1f33be9 GK |
1966 | err: |
1967 | vq->is_le = is_le; | |
1968 | return r; | |
2723feaa | 1969 | } |
80f7d030 | 1970 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 1971 | |
47283bef | 1972 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
6b1e6cc7 | 1973 | struct iovec iov[], int iov_size, int access) |
3a4d5c94 | 1974 | { |
0bbe3066 | 1975 | const struct vhost_iotlb_map *map; |
6b1e6cc7 | 1976 | struct vhost_dev *dev = vq->dev; |
0bbe3066 | 1977 | struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem; |
3a4d5c94 MT |
1978 | struct iovec *_iov; |
1979 | u64 s = 0; | |
1980 | int ret = 0; | |
1981 | ||
3a4d5c94 MT |
1982 | while ((u64)len > s) { |
1983 | u64 size; | |
7b3384fc | 1984 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
1985 | ret = -ENOBUFS; |
1986 | break; | |
1987 | } | |
6b1e6cc7 | 1988 | |
0bbe3066 JW |
1989 | map = vhost_iotlb_itree_first(umem, addr, addr + len - 1); |
1990 | if (map == NULL || map->start > addr) { | |
6b1e6cc7 JW |
1991 | if (umem != dev->iotlb) { |
1992 | ret = -EFAULT; | |
1993 | break; | |
1994 | } | |
1995 | ret = -EAGAIN; | |
1996 | break; | |
0bbe3066 | 1997 | } else if (!(map->perm & access)) { |
6b1e6cc7 | 1998 | ret = -EPERM; |
3a4d5c94 MT |
1999 | break; |
2000 | } | |
6b1e6cc7 | 2001 | |
3a4d5c94 | 2002 | _iov = iov + ret; |
0bbe3066 | 2003 | size = map->size - addr + map->start; |
bd97120f | 2004 | _iov->iov_len = min((u64)len - s, size); |
0d4a3f2a | 2005 | _iov->iov_base = (void __user *)(unsigned long) |
0bbe3066 | 2006 | (map->addr + addr - map->start); |
3a4d5c94 MT |
2007 | s += size; |
2008 | addr += size; | |
2009 | ++ret; | |
2010 | } | |
2011 | ||
6b1e6cc7 JW |
2012 | if (ret == -EAGAIN) |
2013 | vhost_iotlb_miss(vq, addr, access); | |
3a4d5c94 MT |
2014 | return ret; |
2015 | } | |
2016 | ||
2017 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
2018 | * function returns the next descriptor in the chain, | |
2019 | * or -1U if we're at the end. */ | |
3b1bbe89 | 2020 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
2021 | { |
2022 | unsigned int next; | |
2023 | ||
2024 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 2025 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
2026 | return -1U; |
2027 | ||
2028 | /* Check they're not leading us off end of descriptors. */ | |
3a5db0b1 | 2029 | next = vhost16_to_cpu(vq, READ_ONCE(desc->next)); |
3a4d5c94 MT |
2030 | return next; |
2031 | } | |
2032 | ||
47283bef | 2033 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc MT |
2034 | struct iovec iov[], unsigned int iov_size, |
2035 | unsigned int *out_num, unsigned int *in_num, | |
2036 | struct vhost_log *log, unsigned int *log_num, | |
2037 | struct vring_desc *indirect) | |
3a4d5c94 MT |
2038 | { |
2039 | struct vring_desc desc; | |
2040 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 2041 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 2042 | struct iov_iter from; |
6b1e6cc7 | 2043 | int ret, access; |
3a4d5c94 MT |
2044 | |
2045 | /* Sanity check */ | |
3b1bbe89 | 2046 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
2047 | vq_err(vq, "Invalid length in indirect descriptor: " |
2048 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 2049 | (unsigned long long)len, |
3a4d5c94 MT |
2050 | sizeof desc); |
2051 | return -EINVAL; | |
2052 | } | |
2053 | ||
3b1bbe89 | 2054 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
6b1e6cc7 | 2055 | UIO_MAXIOV, VHOST_ACCESS_RO); |
7b3384fc | 2056 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2057 | if (ret != -EAGAIN) |
2058 | vq_err(vq, "Translation failure %d in indirect.\n", ret); | |
3a4d5c94 MT |
2059 | return ret; |
2060 | } | |
aad9a1ce | 2061 | iov_iter_init(&from, READ, vq->indirect, ret, len); |
3a4d5c94 MT |
2062 | |
2063 | /* We will use the result as an address to read from, so most | |
2064 | * architectures only need a compiler barrier here. */ | |
2065 | read_barrier_depends(); | |
2066 | ||
3b1bbe89 | 2067 | count = len / sizeof desc; |
3a4d5c94 MT |
2068 | /* Buffers are chained via a 16 bit next field, so |
2069 | * we can have at most 2^16 of these. */ | |
7b3384fc | 2070 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
2071 | vq_err(vq, "Indirect buffer length too big: %d\n", |
2072 | indirect->len); | |
2073 | return -E2BIG; | |
2074 | } | |
2075 | ||
2076 | do { | |
2077 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2078 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
2079 | vq_err(vq, "Loop detected: last one at %u " |
2080 | "indirect size %u\n", | |
2081 | i, count); | |
2082 | return -EINVAL; | |
2083 | } | |
cbbd26b8 | 2084 | if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) { |
3a4d5c94 | 2085 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2086 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2087 | return -EINVAL; |
2088 | } | |
3b1bbe89 | 2089 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 2090 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2091 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2092 | return -EINVAL; |
2093 | } | |
2094 | ||
6b1e6cc7 JW |
2095 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2096 | access = VHOST_ACCESS_WO; | |
2097 | else | |
2098 | access = VHOST_ACCESS_RO; | |
2099 | ||
3b1bbe89 MT |
2100 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2101 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2102 | iov_size - iov_count, access); |
7b3384fc | 2103 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2104 | if (ret != -EAGAIN) |
2105 | vq_err(vq, "Translation failure %d indirect idx %d\n", | |
2106 | ret, i); | |
3a4d5c94 MT |
2107 | return ret; |
2108 | } | |
2109 | /* If this is an input descriptor, increment that count. */ | |
6b1e6cc7 | 2110 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 | 2111 | *in_num += ret; |
060423bf | 2112 | if (unlikely(log && ret)) { |
3b1bbe89 MT |
2113 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2114 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2115 | ++*log_num; |
2116 | } | |
2117 | } else { | |
2118 | /* If it's an output descriptor, they're all supposed | |
2119 | * to come before any input descriptors. */ | |
7b3384fc | 2120 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2121 | vq_err(vq, "Indirect descriptor " |
2122 | "has out after in: idx %d\n", i); | |
2123 | return -EINVAL; | |
2124 | } | |
2125 | *out_num += ret; | |
2126 | } | |
3b1bbe89 | 2127 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2128 | return 0; |
2129 | } | |
2130 | ||
2131 | /* This looks in the virtqueue and for the first available buffer, and converts | |
2132 | * it to an iovec for convenient access. Since descriptors consist of some | |
2133 | * number of output then some number of input descriptors, it's actually two | |
2134 | * iovecs, but we pack them into one and note how many of each there were. | |
2135 | * | |
d5675bd2 MT |
2136 | * This function returns the descriptor number found, or vq->num (which is |
2137 | * never a valid descriptor number) if none was found. A negative code is | |
2138 | * returned on error. */ | |
47283bef | 2139 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
2140 | struct iovec iov[], unsigned int iov_size, |
2141 | unsigned int *out_num, unsigned int *in_num, | |
2142 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
2143 | { |
2144 | struct vring_desc desc; | |
2145 | unsigned int i, head, found = 0; | |
2146 | u16 last_avail_idx; | |
3b1bbe89 MT |
2147 | __virtio16 avail_idx; |
2148 | __virtio16 ring_head; | |
6b1e6cc7 | 2149 | int ret, access; |
3a4d5c94 MT |
2150 | |
2151 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
2152 | last_avail_idx = vq->last_avail_idx; | |
3a4d5c94 | 2153 | |
e3b56cdd | 2154 | if (vq->avail_idx == vq->last_avail_idx) { |
7b5d753e | 2155 | if (unlikely(vhost_get_avail_idx(vq, &avail_idx))) { |
e3b56cdd JW |
2156 | vq_err(vq, "Failed to access avail idx at %p\n", |
2157 | &vq->avail->idx); | |
2158 | return -EFAULT; | |
2159 | } | |
2160 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); | |
3a4d5c94 | 2161 | |
e3b56cdd JW |
2162 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
2163 | vq_err(vq, "Guest moved used index from %u to %u", | |
2164 | last_avail_idx, vq->avail_idx); | |
2165 | return -EFAULT; | |
2166 | } | |
2167 | ||
2168 | /* If there's nothing new since last we looked, return | |
2169 | * invalid. | |
2170 | */ | |
2171 | if (vq->avail_idx == last_avail_idx) | |
2172 | return vq->num; | |
3a4d5c94 | 2173 | |
e3b56cdd JW |
2174 | /* Only get avail ring entries after they have been |
2175 | * exposed by guest. | |
2176 | */ | |
2177 | smp_rmb(); | |
2178 | } | |
3a4d5c94 MT |
2179 | |
2180 | /* Grab the next descriptor number they're advertising, and increment | |
2181 | * the index we've seen. */ | |
7b5d753e | 2182 | if (unlikely(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) { |
3a4d5c94 MT |
2183 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
2184 | last_avail_idx, | |
2185 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 2186 | return -EFAULT; |
3a4d5c94 MT |
2187 | } |
2188 | ||
3b1bbe89 MT |
2189 | head = vhost16_to_cpu(vq, ring_head); |
2190 | ||
3a4d5c94 | 2191 | /* If their number is silly, that's an error. */ |
7b3384fc | 2192 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
2193 | vq_err(vq, "Guest says index %u > %u is available", |
2194 | head, vq->num); | |
d5675bd2 | 2195 | return -EINVAL; |
3a4d5c94 MT |
2196 | } |
2197 | ||
2198 | /* When we start there are none of either input nor output. */ | |
2199 | *out_num = *in_num = 0; | |
2200 | if (unlikely(log)) | |
2201 | *log_num = 0; | |
2202 | ||
2203 | i = head; | |
2204 | do { | |
2205 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2206 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
2207 | vq_err(vq, "Desc index is %u > %u, head = %u", |
2208 | i, vq->num, head); | |
d5675bd2 | 2209 | return -EINVAL; |
3a4d5c94 | 2210 | } |
7b3384fc | 2211 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
2212 | vq_err(vq, "Loop detected: last one at %u " |
2213 | "vq size %u head %u\n", | |
2214 | i, vq->num, head); | |
d5675bd2 | 2215 | return -EINVAL; |
3a4d5c94 | 2216 | } |
7b5d753e | 2217 | ret = vhost_get_desc(vq, &desc, i); |
7b3384fc | 2218 | if (unlikely(ret)) { |
3a4d5c94 MT |
2219 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
2220 | i, vq->desc + i); | |
d5675bd2 | 2221 | return -EFAULT; |
3a4d5c94 | 2222 | } |
3b1bbe89 | 2223 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 2224 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
2225 | out_num, in_num, |
2226 | log, log_num, &desc); | |
7b3384fc | 2227 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2228 | if (ret != -EAGAIN) |
2229 | vq_err(vq, "Failure detected " | |
2230 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 2231 | return ret; |
3a4d5c94 MT |
2232 | } |
2233 | continue; | |
2234 | } | |
2235 | ||
6b1e6cc7 JW |
2236 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2237 | access = VHOST_ACCESS_WO; | |
2238 | else | |
2239 | access = VHOST_ACCESS_RO; | |
3b1bbe89 MT |
2240 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2241 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2242 | iov_size - iov_count, access); |
7b3384fc | 2243 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2244 | if (ret != -EAGAIN) |
2245 | vq_err(vq, "Translation failure %d descriptor idx %d\n", | |
2246 | ret, i); | |
d5675bd2 | 2247 | return ret; |
3a4d5c94 | 2248 | } |
6b1e6cc7 | 2249 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2250 | /* If this is an input descriptor, |
2251 | * increment that count. */ | |
2252 | *in_num += ret; | |
060423bf | 2253 | if (unlikely(log && ret)) { |
3b1bbe89 MT |
2254 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2255 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2256 | ++*log_num; |
2257 | } | |
2258 | } else { | |
2259 | /* If it's an output descriptor, they're all supposed | |
2260 | * to come before any input descriptors. */ | |
7b3384fc | 2261 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2262 | vq_err(vq, "Descriptor has out after in: " |
2263 | "idx %d\n", i); | |
d5675bd2 | 2264 | return -EINVAL; |
3a4d5c94 MT |
2265 | } |
2266 | *out_num += ret; | |
2267 | } | |
3b1bbe89 | 2268 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2269 | |
2270 | /* On success, increment avail index. */ | |
2271 | vq->last_avail_idx++; | |
8ea8cf89 MT |
2272 | |
2273 | /* Assume notifications from guest are disabled at this point, | |
2274 | * if they aren't we would need to update avail_event index. */ | |
2275 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
2276 | return head; |
2277 | } | |
6ac1afbf | 2278 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
2279 | |
2280 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 2281 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 2282 | { |
8dd014ad | 2283 | vq->last_avail_idx -= n; |
3a4d5c94 | 2284 | } |
6ac1afbf | 2285 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
2286 | |
2287 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2288 | * want to notify the guest, using eventfd. */ | |
2289 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
2290 | { | |
3b1bbe89 MT |
2291 | struct vring_used_elem heads = { |
2292 | cpu_to_vhost32(vq, head), | |
2293 | cpu_to_vhost32(vq, len) | |
2294 | }; | |
3a4d5c94 | 2295 | |
c49e4e57 | 2296 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 2297 | } |
6ac1afbf | 2298 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 2299 | |
8dd014ad DS |
2300 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2301 | struct vring_used_elem *heads, | |
2302 | unsigned count) | |
2303 | { | |
2304 | struct vring_used_elem __user *used; | |
8ea8cf89 | 2305 | u16 old, new; |
8dd014ad DS |
2306 | int start; |
2307 | ||
5fba13b5 | 2308 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 2309 | used = vq->used->ring + start; |
7b5d753e | 2310 | if (vhost_put_used(vq, heads, start, count)) { |
8dd014ad DS |
2311 | vq_err(vq, "Failed to write used"); |
2312 | return -EFAULT; | |
2313 | } | |
2314 | if (unlikely(vq->log_used)) { | |
2315 | /* Make sure data is seen before log. */ | |
2316 | smp_wmb(); | |
2317 | /* Log used ring entry write. */ | |
cc5e7107 JW |
2318 | log_used(vq, ((void __user *)used - (void __user *)vq->used), |
2319 | count * sizeof *used); | |
8dd014ad | 2320 | } |
8ea8cf89 MT |
2321 | old = vq->last_used_idx; |
2322 | new = (vq->last_used_idx += count); | |
2323 | /* If the driver never bothers to signal in a very long while, | |
2324 | * used index might wrap around. If that happens, invalidate | |
2325 | * signalled_used index we stored. TODO: make sure driver | |
2326 | * signals at least once in 2^16 and remove this. */ | |
2327 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
2328 | vq->signalled_used_valid = false; | |
8dd014ad DS |
2329 | return 0; |
2330 | } | |
2331 | ||
2332 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2333 | * want to notify the guest, using eventfd. */ | |
2334 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
2335 | unsigned count) | |
2336 | { | |
2337 | int start, n, r; | |
2338 | ||
5fba13b5 | 2339 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
2340 | n = vq->num - start; |
2341 | if (n < count) { | |
2342 | r = __vhost_add_used_n(vq, heads, n); | |
2343 | if (r < 0) | |
2344 | return r; | |
2345 | heads += n; | |
2346 | count -= n; | |
2347 | } | |
2348 | r = __vhost_add_used_n(vq, heads, count); | |
2349 | ||
2350 | /* Make sure buffer is written before we update index. */ | |
2351 | smp_wmb(); | |
7b5d753e | 2352 | if (vhost_put_used_idx(vq)) { |
8dd014ad DS |
2353 | vq_err(vq, "Failed to increment used idx"); |
2354 | return -EFAULT; | |
2355 | } | |
2356 | if (unlikely(vq->log_used)) { | |
841df922 JW |
2357 | /* Make sure used idx is seen before log. */ |
2358 | smp_wmb(); | |
8dd014ad | 2359 | /* Log used index update. */ |
cc5e7107 JW |
2360 | log_used(vq, offsetof(struct vring_used, idx), |
2361 | sizeof vq->used->idx); | |
8dd014ad DS |
2362 | if (vq->log_ctx) |
2363 | eventfd_signal(vq->log_ctx, 1); | |
2364 | } | |
2365 | return r; | |
2366 | } | |
6ac1afbf | 2367 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 2368 | |
8ea8cf89 | 2369 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2370 | { |
3b1bbe89 MT |
2371 | __u16 old, new; |
2372 | __virtio16 event; | |
8ea8cf89 | 2373 | bool v; |
8d65843c JW |
2374 | /* Flush out used index updates. This is paired |
2375 | * with the barrier that the Guest executes when enabling | |
2376 | * interrupts. */ | |
2377 | smp_mb(); | |
0d499356 | 2378 | |
ea16c514 | 2379 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
2380 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2381 | return true; | |
2382 | ||
ea16c514 | 2383 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 2384 | __virtio16 flags; |
7b5d753e | 2385 | if (vhost_get_avail_flags(vq, &flags)) { |
8ea8cf89 MT |
2386 | vq_err(vq, "Failed to get flags"); |
2387 | return true; | |
2388 | } | |
3b1bbe89 | 2389 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 2390 | } |
8ea8cf89 MT |
2391 | old = vq->signalled_used; |
2392 | v = vq->signalled_used_valid; | |
2393 | new = vq->signalled_used = vq->last_used_idx; | |
2394 | vq->signalled_used_valid = true; | |
3a4d5c94 | 2395 | |
8ea8cf89 MT |
2396 | if (unlikely(!v)) |
2397 | return true; | |
3a4d5c94 | 2398 | |
7b5d753e | 2399 | if (vhost_get_used_event(vq, &event)) { |
8ea8cf89 MT |
2400 | vq_err(vq, "Failed to get used event idx"); |
2401 | return true; | |
2402 | } | |
8d65843c | 2403 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
2404 | } |
2405 | ||
2406 | /* This actually signals the guest, using eventfd. */ | |
2407 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2408 | { | |
3a4d5c94 | 2409 | /* Signal the Guest tell them we used something up. */ |
8ea8cf89 | 2410 | if (vq->call_ctx && vhost_notify(dev, vq)) |
3a4d5c94 MT |
2411 | eventfd_signal(vq->call_ctx, 1); |
2412 | } | |
6ac1afbf | 2413 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
2414 | |
2415 | /* And here's the combo meal deal. Supersize me! */ | |
2416 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
2417 | struct vhost_virtqueue *vq, | |
2418 | unsigned int head, int len) | |
2419 | { | |
2420 | vhost_add_used(vq, head, len); | |
2421 | vhost_signal(dev, vq); | |
2422 | } | |
6ac1afbf | 2423 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 2424 | |
8dd014ad DS |
2425 | /* multi-buffer version of vhost_add_used_and_signal */ |
2426 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
2427 | struct vhost_virtqueue *vq, | |
2428 | struct vring_used_elem *heads, unsigned count) | |
2429 | { | |
2430 | vhost_add_used_n(vq, heads, count); | |
2431 | vhost_signal(dev, vq); | |
2432 | } | |
6ac1afbf | 2433 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 2434 | |
d4a60603 JW |
2435 | /* return true if we're sure that avaiable ring is empty */ |
2436 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2437 | { | |
2438 | __virtio16 avail_idx; | |
2439 | int r; | |
2440 | ||
275bf960 JW |
2441 | if (vq->avail_idx != vq->last_avail_idx) |
2442 | return false; | |
2443 | ||
7b5d753e | 2444 | r = vhost_get_avail_idx(vq, &avail_idx); |
275bf960 | 2445 | if (unlikely(r)) |
d4a60603 | 2446 | return false; |
275bf960 | 2447 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
d4a60603 | 2448 | |
275bf960 | 2449 | return vq->avail_idx == vq->last_avail_idx; |
d4a60603 JW |
2450 | } |
2451 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
2452 | ||
3a4d5c94 | 2453 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 2454 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2455 | { |
3b1bbe89 | 2456 | __virtio16 avail_idx; |
3a4d5c94 | 2457 | int r; |
d47effe1 | 2458 | |
3a4d5c94 MT |
2459 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2460 | return false; | |
2461 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2462 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2463 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2464 | if (r) { |
2465 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2466 | &vq->used->flags, r); | |
2467 | return false; | |
2468 | } | |
2469 | } else { | |
2723feaa | 2470 | r = vhost_update_avail_event(vq, vq->avail_idx); |
8ea8cf89 MT |
2471 | if (r) { |
2472 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
2473 | vhost_avail_event(vq), r); | |
2474 | return false; | |
2475 | } | |
2476 | } | |
3a4d5c94 MT |
2477 | /* They could have slipped one in as we were doing that: make |
2478 | * sure it's written, then check again. */ | |
5659338c | 2479 | smp_mb(); |
7b5d753e | 2480 | r = vhost_get_avail_idx(vq, &avail_idx); |
3a4d5c94 MT |
2481 | if (r) { |
2482 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
2483 | &vq->avail->idx, r); | |
2484 | return false; | |
2485 | } | |
2486 | ||
3b1bbe89 | 2487 | return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx; |
3a4d5c94 | 2488 | } |
6ac1afbf | 2489 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
2490 | |
2491 | /* We don't need to be notified again. */ | |
8ea8cf89 | 2492 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
2493 | { |
2494 | int r; | |
d47effe1 | 2495 | |
3a4d5c94 MT |
2496 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2497 | return; | |
2498 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2499 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2500 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2501 | if (r) |
2502 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2503 | &vq->used->flags, r); | |
2504 | } | |
3a4d5c94 | 2505 | } |
6ac1afbf AH |
2506 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2507 | ||
6b1e6cc7 JW |
2508 | /* Create a new message. */ |
2509 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) | |
2510 | { | |
2511 | struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL); | |
2512 | if (!node) | |
2513 | return NULL; | |
670ae9ca MT |
2514 | |
2515 | /* Make sure all padding within the structure is initialized. */ | |
2516 | memset(&node->msg, 0, sizeof node->msg); | |
6b1e6cc7 JW |
2517 | node->vq = vq; |
2518 | node->msg.type = type; | |
2519 | return node; | |
2520 | } | |
2521 | EXPORT_SYMBOL_GPL(vhost_new_msg); | |
2522 | ||
2523 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, | |
2524 | struct vhost_msg_node *node) | |
2525 | { | |
2526 | spin_lock(&dev->iotlb_lock); | |
2527 | list_add_tail(&node->node, head); | |
2528 | spin_unlock(&dev->iotlb_lock); | |
2529 | ||
a9a08845 | 2530 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
6b1e6cc7 JW |
2531 | } |
2532 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); | |
2533 | ||
2534 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, | |
2535 | struct list_head *head) | |
2536 | { | |
2537 | struct vhost_msg_node *node = NULL; | |
2538 | ||
2539 | spin_lock(&dev->iotlb_lock); | |
2540 | if (!list_empty(head)) { | |
2541 | node = list_first_entry(head, struct vhost_msg_node, | |
2542 | node); | |
2543 | list_del(&node->node); | |
2544 | } | |
2545 | spin_unlock(&dev->iotlb_lock); | |
2546 | ||
2547 | return node; | |
2548 | } | |
2549 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); | |
2550 | ||
2551 | ||
6ac1afbf AH |
2552 | static int __init vhost_init(void) |
2553 | { | |
2554 | return 0; | |
2555 | } | |
2556 | ||
2557 | static void __exit vhost_exit(void) | |
2558 | { | |
2559 | } | |
2560 | ||
2561 | module_init(vhost_init); | |
2562 | module_exit(vhost_exit); | |
2563 | ||
2564 | MODULE_VERSION("0.0.1"); | |
2565 | MODULE_LICENSE("GPL v2"); | |
2566 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
2567 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |