Commit | Line | Data |
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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 MT |
16 | #include <linux/mm.h> |
17 | #include <linux/miscdevice.h> | |
18 | #include <linux/mutex.h> | |
3a4d5c94 MT |
19 | #include <linux/poll.h> |
20 | #include <linux/file.h> | |
21 | #include <linux/highmem.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
4de7255f | 23 | #include <linux/vmalloc.h> |
c23f3445 | 24 | #include <linux/kthread.h> |
6ac1afbf | 25 | #include <linux/module.h> |
bcfeacab | 26 | #include <linux/sort.h> |
6e84f315 | 27 | #include <linux/sched/mm.h> |
174cd4b1 | 28 | #include <linux/sched/signal.h> |
6e890c5d | 29 | #include <linux/sched/vhost_task.h> |
a9709d68 | 30 | #include <linux/interval_tree_generic.h> |
ff002269 | 31 | #include <linux/nospec.h> |
8f6a7f96 | 32 | #include <linux/kcov.h> |
3a4d5c94 | 33 | |
3a4d5c94 MT |
34 | #include "vhost.h" |
35 | ||
c9ce42f7 IM |
36 | static ushort max_mem_regions = 64; |
37 | module_param(max_mem_regions, ushort, 0444); | |
38 | MODULE_PARM_DESC(max_mem_regions, | |
39 | "Maximum number of memory regions in memory map. (default: 64)"); | |
6b1e6cc7 JW |
40 | static int max_iotlb_entries = 2048; |
41 | module_param(max_iotlb_entries, int, 0444); | |
42 | MODULE_PARM_DESC(max_iotlb_entries, | |
43 | "Maximum number of iotlb entries. (default: 2048)"); | |
c9ce42f7 | 44 | |
3a4d5c94 | 45 | enum { |
3a4d5c94 MT |
46 | VHOST_MEMORY_F_LOG = 0x1, |
47 | }; | |
48 | ||
3b1bbe89 MT |
49 | #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) |
50 | #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) | |
8ea8cf89 | 51 | |
2751c988 | 52 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
c5072037 | 53 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
54 | { |
55 | vq->user_be = !virtio_legacy_is_little_endian(); | |
56 | } | |
57 | ||
c5072037 GK |
58 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
59 | { | |
60 | vq->user_be = true; | |
61 | } | |
62 | ||
63 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) | |
64 | { | |
65 | vq->user_be = false; | |
66 | } | |
67 | ||
2751c988 GK |
68 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
69 | { | |
70 | struct vhost_vring_state s; | |
71 | ||
72 | if (vq->private_data) | |
73 | return -EBUSY; | |
74 | ||
75 | if (copy_from_user(&s, argp, sizeof(s))) | |
76 | return -EFAULT; | |
77 | ||
78 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && | |
79 | s.num != VHOST_VRING_BIG_ENDIAN) | |
80 | return -EINVAL; | |
81 | ||
c5072037 GK |
82 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
83 | vhost_enable_cross_endian_big(vq); | |
84 | else | |
85 | vhost_enable_cross_endian_little(vq); | |
2751c988 GK |
86 | |
87 | return 0; | |
88 | } | |
89 | ||
90 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
91 | int __user *argp) | |
92 | { | |
93 | struct vhost_vring_state s = { | |
94 | .index = idx, | |
95 | .num = vq->user_be | |
96 | }; | |
97 | ||
98 | if (copy_to_user(argp, &s, sizeof(s))) | |
99 | return -EFAULT; | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
104 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
105 | { | |
106 | /* Note for legacy virtio: user_be is initialized at reset time | |
107 | * according to the host endianness. If userspace does not set an | |
108 | * explicit endianness, the default behavior is native endian, as | |
109 | * expected by legacy virtio. | |
110 | */ | |
111 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; | |
112 | } | |
113 | #else | |
c5072037 | 114 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
115 | { |
116 | } | |
117 | ||
118 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) | |
119 | { | |
120 | return -ENOIOCTLCMD; | |
121 | } | |
122 | ||
123 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
124 | int __user *argp) | |
125 | { | |
126 | return -ENOIOCTLCMD; | |
127 | } | |
128 | ||
129 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
130 | { | |
cda8bba0 HP |
131 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) |
132 | || virtio_legacy_is_little_endian(); | |
2751c988 GK |
133 | } |
134 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ | |
135 | ||
c5072037 GK |
136 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
137 | { | |
cda8bba0 | 138 | vhost_init_is_le(vq); |
c5072037 GK |
139 | } |
140 | ||
7235acdb JW |
141 | struct vhost_flush_struct { |
142 | struct vhost_work work; | |
143 | struct completion wait_event; | |
144 | }; | |
145 | ||
146 | static void vhost_flush_work(struct vhost_work *work) | |
147 | { | |
148 | struct vhost_flush_struct *s; | |
149 | ||
150 | s = container_of(work, struct vhost_flush_struct, work); | |
151 | complete(&s->wait_event); | |
152 | } | |
153 | ||
3a4d5c94 MT |
154 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
155 | poll_table *pt) | |
156 | { | |
157 | struct vhost_poll *poll; | |
3a4d5c94 | 158 | |
d47effe1 | 159 | poll = container_of(pt, struct vhost_poll, table); |
3a4d5c94 MT |
160 | poll->wqh = wqh; |
161 | add_wait_queue(wqh, &poll->wait); | |
162 | } | |
163 | ||
ac6424b9 | 164 | static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, |
3a4d5c94 MT |
165 | void *key) |
166 | { | |
c23f3445 | 167 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
01fcb1cb | 168 | struct vhost_work *work = &poll->work; |
c23f3445 | 169 | |
3ad6f93e | 170 | if (!(key_to_poll(key) & poll->mask)) |
3a4d5c94 MT |
171 | return 0; |
172 | ||
01fcb1cb JW |
173 | if (!poll->dev->use_worker) |
174 | work->fn(work); | |
175 | else | |
176 | vhost_poll_queue(poll); | |
177 | ||
3a4d5c94 MT |
178 | return 0; |
179 | } | |
180 | ||
163049ae | 181 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
87d6a412 | 182 | { |
04b96e55 | 183 | clear_bit(VHOST_WORK_QUEUED, &work->flags); |
87d6a412 | 184 | work->fn = fn; |
87d6a412 | 185 | } |
6ac1afbf | 186 | EXPORT_SYMBOL_GPL(vhost_work_init); |
87d6a412 | 187 | |
3a4d5c94 | 188 | /* Init poll structure */ |
c23f3445 | 189 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
493b94bf MC |
190 | __poll_t mask, struct vhost_dev *dev, |
191 | struct vhost_virtqueue *vq) | |
3a4d5c94 | 192 | { |
3a4d5c94 MT |
193 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
194 | init_poll_funcptr(&poll->table, vhost_poll_func); | |
195 | poll->mask = mask; | |
c23f3445 | 196 | poll->dev = dev; |
2b8b328b | 197 | poll->wqh = NULL; |
493b94bf | 198 | poll->vq = vq; |
c23f3445 | 199 | |
87d6a412 | 200 | vhost_work_init(&poll->work, fn); |
3a4d5c94 | 201 | } |
6ac1afbf | 202 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
3a4d5c94 MT |
203 | |
204 | /* Start polling a file. We add ourselves to file's wait queue. The caller must | |
205 | * keep a reference to a file until after vhost_poll_stop is called. */ | |
2b8b328b | 206 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
3a4d5c94 | 207 | { |
e6c8adca | 208 | __poll_t mask; |
d47effe1 | 209 | |
70181d51 JW |
210 | if (poll->wqh) |
211 | return 0; | |
212 | ||
9965ed17 | 213 | mask = vfs_poll(file, &poll->table); |
3a4d5c94 | 214 | if (mask) |
3ad6f93e | 215 | vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); |
a9a08845 | 216 | if (mask & EPOLLERR) { |
dc6455a7 | 217 | vhost_poll_stop(poll); |
896fc242 | 218 | return -EINVAL; |
2b8b328b JW |
219 | } |
220 | ||
896fc242 | 221 | return 0; |
3a4d5c94 | 222 | } |
6ac1afbf | 223 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
224 | |
225 | /* Stop polling a file. After this function returns, it becomes safe to drop the | |
226 | * file reference. You must also flush afterwards. */ | |
227 | void vhost_poll_stop(struct vhost_poll *poll) | |
228 | { | |
2b8b328b JW |
229 | if (poll->wqh) { |
230 | remove_wait_queue(poll->wqh, &poll->wait); | |
231 | poll->wqh = NULL; | |
232 | } | |
3a4d5c94 | 233 | } |
6ac1afbf | 234 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 235 | |
228a27cf | 236 | static void vhost_worker_queue(struct vhost_worker *worker, |
0921dddc | 237 | struct vhost_work *work) |
3a4d5c94 | 238 | { |
04b96e55 JW |
239 | if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { |
240 | /* We can only add the work to the list after we're | |
241 | * sure it was not in the list. | |
635abf01 | 242 | * test_and_set_bit() implies a memory barrier. |
04b96e55 | 243 | */ |
0921dddc MC |
244 | llist_add(&work->node, &worker->work_list); |
245 | vhost_task_wake(worker->vtsk); | |
c23f3445 | 246 | } |
3a4d5c94 | 247 | } |
0921dddc | 248 | |
0921dddc MC |
249 | bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work) |
250 | { | |
228a27cf MC |
251 | struct vhost_worker *worker; |
252 | bool queued = false; | |
253 | ||
254 | rcu_read_lock(); | |
255 | worker = rcu_dereference(vq->worker); | |
256 | if (worker) { | |
257 | queued = true; | |
258 | vhost_worker_queue(worker, work); | |
259 | } | |
260 | rcu_read_unlock(); | |
261 | ||
262 | return queued; | |
0921dddc MC |
263 | } |
264 | EXPORT_SYMBOL_GPL(vhost_vq_work_queue); | |
265 | ||
228a27cf | 266 | void vhost_vq_flush(struct vhost_virtqueue *vq) |
0921dddc MC |
267 | { |
268 | struct vhost_flush_struct flush; | |
269 | ||
270 | init_completion(&flush.wait_event); | |
271 | vhost_work_init(&flush.work, vhost_flush_work); | |
272 | ||
228a27cf | 273 | if (vhost_vq_work_queue(vq, &flush.work)) |
0921dddc MC |
274 | wait_for_completion(&flush.wait_event); |
275 | } | |
228a27cf | 276 | EXPORT_SYMBOL_GPL(vhost_vq_flush); |
a6fc0473 | 277 | |
228a27cf MC |
278 | /** |
279 | * vhost_worker_flush - flush a worker | |
280 | * @worker: worker to flush | |
281 | * | |
282 | * This does not use RCU to protect the worker, so the device or worker | |
283 | * mutex must be held. | |
284 | */ | |
285 | static void vhost_worker_flush(struct vhost_worker *worker) | |
a6fc0473 | 286 | { |
228a27cf MC |
287 | struct vhost_flush_struct flush; |
288 | ||
289 | init_completion(&flush.wait_event); | |
290 | vhost_work_init(&flush.work, vhost_flush_work); | |
291 | ||
292 | vhost_worker_queue(worker, &flush.work); | |
293 | wait_for_completion(&flush.wait_event); | |
a6fc0473 | 294 | } |
a6fc0473 MC |
295 | |
296 | void vhost_dev_flush(struct vhost_dev *dev) | |
297 | { | |
1cdaafa1 MC |
298 | struct vhost_worker *worker; |
299 | unsigned long i; | |
300 | ||
228a27cf MC |
301 | xa_for_each(&dev->worker_xa, i, worker) { |
302 | mutex_lock(&worker->mutex); | |
303 | if (!worker->attachment_cnt) { | |
304 | mutex_unlock(&worker->mutex); | |
305 | continue; | |
306 | } | |
1cdaafa1 | 307 | vhost_worker_flush(worker); |
228a27cf MC |
308 | mutex_unlock(&worker->mutex); |
309 | } | |
a6fc0473 | 310 | } |
0921dddc MC |
311 | EXPORT_SYMBOL_GPL(vhost_dev_flush); |
312 | ||
526d3e7f | 313 | /* A lockless hint for busy polling code to exit the loop */ |
9784df15 | 314 | bool vhost_vq_has_work(struct vhost_virtqueue *vq) |
526d3e7f | 315 | { |
228a27cf MC |
316 | struct vhost_worker *worker; |
317 | bool has_work = false; | |
318 | ||
319 | rcu_read_lock(); | |
320 | worker = rcu_dereference(vq->worker); | |
321 | if (worker && !llist_empty(&worker->work_list)) | |
322 | has_work = true; | |
323 | rcu_read_unlock(); | |
324 | ||
325 | return has_work; | |
526d3e7f | 326 | } |
9784df15 | 327 | EXPORT_SYMBOL_GPL(vhost_vq_has_work); |
526d3e7f | 328 | |
87d6a412 MT |
329 | void vhost_poll_queue(struct vhost_poll *poll) |
330 | { | |
493b94bf | 331 | vhost_vq_work_queue(poll->vq, &poll->work); |
87d6a412 | 332 | } |
6ac1afbf | 333 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 334 | |
f8894913 JW |
335 | static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq) |
336 | { | |
337 | int j; | |
338 | ||
339 | for (j = 0; j < VHOST_NUM_ADDRS; j++) | |
340 | vq->meta_iotlb[j] = NULL; | |
341 | } | |
342 | ||
343 | static void vhost_vq_meta_reset(struct vhost_dev *d) | |
344 | { | |
345 | int i; | |
346 | ||
86a07da3 | 347 | for (i = 0; i < d->nvqs; ++i) |
f8894913 JW |
348 | __vhost_vq_meta_reset(d->vqs[i]); |
349 | } | |
350 | ||
265a0ad8 ZL |
351 | static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx) |
352 | { | |
353 | call_ctx->ctx = NULL; | |
354 | memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer)); | |
265a0ad8 ZL |
355 | } |
356 | ||
6bcf3422 MC |
357 | bool vhost_vq_is_setup(struct vhost_virtqueue *vq) |
358 | { | |
359 | return vq->avail && vq->desc && vq->used && vhost_vq_access_ok(vq); | |
360 | } | |
361 | EXPORT_SYMBOL_GPL(vhost_vq_is_setup); | |
362 | ||
3a4d5c94 MT |
363 | static void vhost_vq_reset(struct vhost_dev *dev, |
364 | struct vhost_virtqueue *vq) | |
365 | { | |
366 | vq->num = 1; | |
367 | vq->desc = NULL; | |
368 | vq->avail = NULL; | |
369 | vq->used = NULL; | |
370 | vq->last_avail_idx = 0; | |
371 | vq->avail_idx = 0; | |
372 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
373 | vq->signalled_used = 0; |
374 | vq->signalled_used_valid = false; | |
3a4d5c94 | 375 | vq->used_flags = 0; |
3a4d5c94 MT |
376 | vq->log_used = false; |
377 | vq->log_addr = -1ull; | |
3a4d5c94 | 378 | vq->private_data = NULL; |
ea16c514 | 379 | vq->acked_features = 0; |
429711ae | 380 | vq->acked_backend_features = 0; |
3a4d5c94 MT |
381 | vq->log_base = NULL; |
382 | vq->error_ctx = NULL; | |
3a4d5c94 | 383 | vq->kick = NULL; |
73a99f08 | 384 | vq->log_ctx = NULL; |
c5072037 | 385 | vhost_disable_cross_endian(vq); |
beb691e6 | 386 | vhost_reset_is_le(vq); |
03088137 | 387 | vq->busyloop_timeout = 0; |
a9709d68 | 388 | vq->umem = NULL; |
6b1e6cc7 | 389 | vq->iotlb = NULL; |
228a27cf | 390 | rcu_assign_pointer(vq->worker, NULL); |
265a0ad8 | 391 | vhost_vring_call_reset(&vq->call_ctx); |
f8894913 | 392 | __vhost_vq_meta_reset(vq); |
3a4d5c94 MT |
393 | } |
394 | ||
f9010dbd | 395 | static bool vhost_worker(void *data) |
c23f3445 | 396 | { |
1a5f8090 | 397 | struct vhost_worker *worker = data; |
04b96e55 JW |
398 | struct vhost_work *work, *work_next; |
399 | struct llist_node *node; | |
c23f3445 | 400 | |
f9010dbd MC |
401 | node = llist_del_all(&worker->work_list); |
402 | if (node) { | |
4b13cbef MC |
403 | __set_current_state(TASK_RUNNING); |
404 | ||
04b96e55 JW |
405 | node = llist_reverse_order(node); |
406 | /* make sure flag is seen after deletion */ | |
407 | smp_wmb(); | |
408 | llist_for_each_entry_safe(work, work_next, node, node) { | |
409 | clear_bit(VHOST_WORK_QUEUED, &work->flags); | |
1a5f8090 | 410 | kcov_remote_start_common(worker->kcov_handle); |
c23f3445 | 411 | work->fn(work); |
8f6a7f96 | 412 | kcov_remote_stop(); |
05bfb338 | 413 | cond_resched(); |
04b96e55 | 414 | } |
c23f3445 | 415 | } |
6e890c5d | 416 | |
f9010dbd | 417 | return !!node; |
c23f3445 TH |
418 | } |
419 | ||
bab632d6 MT |
420 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
421 | { | |
422 | kfree(vq->indirect); | |
423 | vq->indirect = NULL; | |
424 | kfree(vq->log); | |
425 | vq->log = NULL; | |
426 | kfree(vq->heads); | |
427 | vq->heads = NULL; | |
bab632d6 MT |
428 | } |
429 | ||
e0e9b406 JW |
430 | /* Helper to allocate iovec buffers for all vqs. */ |
431 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
432 | { | |
6d5e6aa8 | 433 | struct vhost_virtqueue *vq; |
e0e9b406 | 434 | int i; |
d47effe1 | 435 | |
e0e9b406 | 436 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 | 437 | vq = dev->vqs[i]; |
6da2ec56 KC |
438 | vq->indirect = kmalloc_array(UIO_MAXIOV, |
439 | sizeof(*vq->indirect), | |
440 | GFP_KERNEL); | |
b46a0bf7 | 441 | vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), |
6da2ec56 | 442 | GFP_KERNEL); |
b46a0bf7 | 443 | vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), |
6da2ec56 | 444 | GFP_KERNEL); |
6d5e6aa8 | 445 | if (!vq->indirect || !vq->log || !vq->heads) |
e0e9b406 JW |
446 | goto err_nomem; |
447 | } | |
448 | return 0; | |
d47effe1 | 449 | |
e0e9b406 | 450 | err_nomem: |
bab632d6 | 451 | for (; i >= 0; --i) |
3ab2e420 | 452 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
453 | return -ENOMEM; |
454 | } | |
455 | ||
456 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
457 | { | |
458 | int i; | |
d47effe1 | 459 | |
bab632d6 | 460 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 461 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
462 | } |
463 | ||
e82b9b07 JW |
464 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, |
465 | int pkts, int total_len) | |
466 | { | |
467 | struct vhost_dev *dev = vq->dev; | |
468 | ||
469 | if ((dev->byte_weight && total_len >= dev->byte_weight) || | |
470 | pkts >= dev->weight) { | |
471 | vhost_poll_queue(&vq->poll); | |
472 | return true; | |
473 | } | |
474 | ||
475 | return false; | |
476 | } | |
477 | EXPORT_SYMBOL_GPL(vhost_exceeds_weight); | |
478 | ||
4942e825 JW |
479 | static size_t vhost_get_avail_size(struct vhost_virtqueue *vq, |
480 | unsigned int num) | |
481 | { | |
482 | size_t event __maybe_unused = | |
483 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
484 | ||
e4be66e5 | 485 | return size_add(struct_size(vq->avail, ring, num), event); |
4942e825 JW |
486 | } |
487 | ||
488 | static size_t vhost_get_used_size(struct vhost_virtqueue *vq, | |
489 | unsigned int num) | |
490 | { | |
491 | size_t event __maybe_unused = | |
492 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
493 | ||
e4be66e5 | 494 | return size_add(struct_size(vq->used, ring, num), event); |
4942e825 JW |
495 | } |
496 | ||
497 | static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, | |
498 | unsigned int num) | |
499 | { | |
500 | return sizeof(*vq->desc) * num; | |
501 | } | |
502 | ||
59566b6e | 503 | void vhost_dev_init(struct vhost_dev *dev, |
e82b9b07 | 504 | struct vhost_virtqueue **vqs, int nvqs, |
792a4f2e | 505 | int iov_limit, int weight, int byte_weight, |
01fcb1cb | 506 | bool use_worker, |
91233ad7 | 507 | int (*msg_handler)(struct vhost_dev *dev, u32 asid, |
792a4f2e | 508 | struct vhost_iotlb_msg *msg)) |
3a4d5c94 | 509 | { |
6d5e6aa8 | 510 | struct vhost_virtqueue *vq; |
3a4d5c94 | 511 | int i; |
c23f3445 | 512 | |
3a4d5c94 MT |
513 | dev->vqs = vqs; |
514 | dev->nvqs = nvqs; | |
515 | mutex_init(&dev->mutex); | |
516 | dev->log_ctx = NULL; | |
a9709d68 | 517 | dev->umem = NULL; |
6b1e6cc7 | 518 | dev->iotlb = NULL; |
3a4d5c94 | 519 | dev->mm = NULL; |
b46a0bf7 | 520 | dev->iov_limit = iov_limit; |
e82b9b07 JW |
521 | dev->weight = weight; |
522 | dev->byte_weight = byte_weight; | |
01fcb1cb | 523 | dev->use_worker = use_worker; |
792a4f2e | 524 | dev->msg_handler = msg_handler; |
6b1e6cc7 JW |
525 | init_waitqueue_head(&dev->wait); |
526 | INIT_LIST_HEAD(&dev->read_list); | |
527 | INIT_LIST_HEAD(&dev->pending_list); | |
528 | spin_lock_init(&dev->iotlb_lock); | |
1cdaafa1 | 529 | xa_init_flags(&dev->worker_xa, XA_FLAGS_ALLOC); |
3a4d5c94 MT |
530 | |
531 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
532 | vq = dev->vqs[i]; |
533 | vq->log = NULL; | |
534 | vq->indirect = NULL; | |
535 | vq->heads = NULL; | |
536 | vq->dev = dev; | |
537 | mutex_init(&vq->mutex); | |
538 | vhost_vq_reset(dev, vq); | |
539 | if (vq->handle_kick) | |
540 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
493b94bf | 541 | EPOLLIN, dev, vq); |
3a4d5c94 | 542 | } |
3a4d5c94 | 543 | } |
6ac1afbf | 544 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
545 | |
546 | /* Caller should have device mutex */ | |
547 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
548 | { | |
549 | /* Are you the owner? If not, I don't think you mean to do that */ | |
550 | return dev->mm == current->mm ? 0 : -EPERM; | |
551 | } | |
6ac1afbf | 552 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 553 | |
05c05351 MT |
554 | /* Caller should have device mutex */ |
555 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
556 | { | |
557 | return dev->mm; | |
558 | } | |
6ac1afbf | 559 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 560 | |
5ce995f3 JW |
561 | static void vhost_attach_mm(struct vhost_dev *dev) |
562 | { | |
563 | /* No owner, become one */ | |
564 | if (dev->use_worker) { | |
565 | dev->mm = get_task_mm(current); | |
566 | } else { | |
567 | /* vDPA device does not use worker thead, so there's | |
568 | * no need to hold the address space for mm. This help | |
569 | * to avoid deadlock in the case of mmap() which may | |
570 | * held the refcnt of the file and depends on release | |
571 | * method to remove vma. | |
572 | */ | |
573 | dev->mm = current->mm; | |
574 | mmgrab(dev->mm); | |
575 | } | |
576 | } | |
577 | ||
578 | static void vhost_detach_mm(struct vhost_dev *dev) | |
579 | { | |
580 | if (!dev->mm) | |
581 | return; | |
582 | ||
583 | if (dev->use_worker) | |
584 | mmput(dev->mm); | |
585 | else | |
586 | mmdrop(dev->mm); | |
587 | ||
588 | dev->mm = NULL; | |
589 | } | |
590 | ||
1cdaafa1 MC |
591 | static void vhost_worker_destroy(struct vhost_dev *dev, |
592 | struct vhost_worker *worker) | |
1a5f8090 | 593 | { |
1cdaafa1 | 594 | if (!worker) |
1a5f8090 MC |
595 | return; |
596 | ||
1cdaafa1 MC |
597 | WARN_ON(!llist_empty(&worker->work_list)); |
598 | xa_erase(&dev->worker_xa, worker->id); | |
599 | vhost_task_stop(worker->vtsk); | |
600 | kfree(worker); | |
601 | } | |
602 | ||
603 | static void vhost_workers_free(struct vhost_dev *dev) | |
604 | { | |
605 | struct vhost_worker *worker; | |
606 | unsigned long i; | |
607 | ||
608 | if (!dev->use_worker) | |
609 | return; | |
610 | ||
611 | for (i = 0; i < dev->nvqs; i++) | |
228a27cf | 612 | rcu_assign_pointer(dev->vqs[i]->worker, NULL); |
1cdaafa1 MC |
613 | /* |
614 | * Free the default worker we created and cleanup workers userspace | |
615 | * created but couldn't clean up (it forgot or crashed). | |
616 | */ | |
617 | xa_for_each(&dev->worker_xa, i, worker) | |
618 | vhost_worker_destroy(dev, worker); | |
619 | xa_destroy(&dev->worker_xa); | |
1a5f8090 MC |
620 | } |
621 | ||
737bdb64 | 622 | static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev) |
1a5f8090 | 623 | { |
c011bb66 | 624 | struct vhost_worker *worker; |
6e890c5d MC |
625 | struct vhost_task *vtsk; |
626 | char name[TASK_COMM_LEN]; | |
1cdaafa1 MC |
627 | int ret; |
628 | u32 id; | |
1a5f8090 | 629 | |
c011bb66 MC |
630 | worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT); |
631 | if (!worker) | |
737bdb64 | 632 | return NULL; |
c011bb66 | 633 | |
6e890c5d | 634 | snprintf(name, sizeof(name), "vhost-%d", current->pid); |
1a5f8090 | 635 | |
c011bb66 | 636 | vtsk = vhost_task_create(vhost_worker, worker, name); |
a284f09e | 637 | if (!vtsk) |
c011bb66 MC |
638 | goto free_worker; |
639 | ||
228a27cf | 640 | mutex_init(&worker->mutex); |
c011bb66 MC |
641 | init_llist_head(&worker->work_list); |
642 | worker->kcov_handle = kcov_common_handle(); | |
643 | worker->vtsk = vtsk; | |
1a5f8090 | 644 | |
6e890c5d | 645 | vhost_task_start(vtsk); |
1cdaafa1 MC |
646 | |
647 | ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL); | |
648 | if (ret < 0) | |
649 | goto stop_worker; | |
650 | worker->id = id; | |
651 | ||
737bdb64 | 652 | return worker; |
c011bb66 | 653 | |
1cdaafa1 MC |
654 | stop_worker: |
655 | vhost_task_stop(vtsk); | |
c011bb66 MC |
656 | free_worker: |
657 | kfree(worker); | |
737bdb64 | 658 | return NULL; |
1a5f8090 MC |
659 | } |
660 | ||
c1ecd8e9 MC |
661 | /* Caller must have device mutex */ |
662 | static void __vhost_vq_attach_worker(struct vhost_virtqueue *vq, | |
663 | struct vhost_worker *worker) | |
664 | { | |
228a27cf MC |
665 | struct vhost_worker *old_worker; |
666 | ||
667 | old_worker = rcu_dereference_check(vq->worker, | |
668 | lockdep_is_held(&vq->dev->mutex)); | |
669 | ||
670 | mutex_lock(&worker->mutex); | |
c1ecd8e9 | 671 | worker->attachment_cnt++; |
228a27cf MC |
672 | mutex_unlock(&worker->mutex); |
673 | rcu_assign_pointer(vq->worker, worker); | |
674 | ||
675 | if (!old_worker) | |
676 | return; | |
677 | /* | |
678 | * Take the worker mutex to make sure we see the work queued from | |
679 | * device wide flushes which doesn't use RCU for execution. | |
680 | */ | |
681 | mutex_lock(&old_worker->mutex); | |
682 | old_worker->attachment_cnt--; | |
683 | /* | |
684 | * We don't want to call synchronize_rcu for every vq during setup | |
685 | * because it will slow down VM startup. If we haven't done | |
686 | * VHOST_SET_VRING_KICK and not done the driver specific | |
687 | * SET_ENDPOINT/RUNNUNG then we can skip the sync since there will | |
688 | * not be any works queued for scsi and net. | |
689 | */ | |
690 | mutex_lock(&vq->mutex); | |
691 | if (!vhost_vq_get_backend(vq) && !vq->kick) { | |
692 | mutex_unlock(&vq->mutex); | |
693 | mutex_unlock(&old_worker->mutex); | |
694 | /* | |
695 | * vsock can queue anytime after VHOST_VSOCK_SET_GUEST_CID. | |
696 | * Warn if it adds support for multiple workers but forgets to | |
697 | * handle the early queueing case. | |
698 | */ | |
699 | WARN_ON(!old_worker->attachment_cnt && | |
700 | !llist_empty(&old_worker->work_list)); | |
701 | return; | |
702 | } | |
703 | mutex_unlock(&vq->mutex); | |
704 | ||
705 | /* Make sure new vq queue/flush/poll calls see the new worker */ | |
706 | synchronize_rcu(); | |
707 | /* Make sure whatever was queued gets run */ | |
708 | vhost_worker_flush(old_worker); | |
709 | mutex_unlock(&old_worker->mutex); | |
c1ecd8e9 MC |
710 | } |
711 | ||
228a27cf | 712 | /* Caller must have device mutex */ |
c1ecd8e9 MC |
713 | static int vhost_vq_attach_worker(struct vhost_virtqueue *vq, |
714 | struct vhost_vring_worker *info) | |
715 | { | |
716 | unsigned long index = info->worker_id; | |
717 | struct vhost_dev *dev = vq->dev; | |
718 | struct vhost_worker *worker; | |
719 | ||
720 | if (!dev->use_worker) | |
721 | return -EINVAL; | |
722 | ||
c1ecd8e9 MC |
723 | worker = xa_find(&dev->worker_xa, &index, UINT_MAX, XA_PRESENT); |
724 | if (!worker || worker->id != info->worker_id) | |
725 | return -ENODEV; | |
726 | ||
727 | __vhost_vq_attach_worker(vq, worker); | |
728 | return 0; | |
729 | } | |
730 | ||
731 | /* Caller must have device mutex */ | |
732 | static int vhost_new_worker(struct vhost_dev *dev, | |
733 | struct vhost_worker_state *info) | |
734 | { | |
735 | struct vhost_worker *worker; | |
736 | ||
737 | worker = vhost_worker_create(dev); | |
738 | if (!worker) | |
739 | return -ENOMEM; | |
740 | ||
741 | info->worker_id = worker->id; | |
742 | return 0; | |
743 | } | |
744 | ||
745 | /* Caller must have device mutex */ | |
746 | static int vhost_free_worker(struct vhost_dev *dev, | |
747 | struct vhost_worker_state *info) | |
748 | { | |
749 | unsigned long index = info->worker_id; | |
750 | struct vhost_worker *worker; | |
751 | ||
752 | worker = xa_find(&dev->worker_xa, &index, UINT_MAX, XA_PRESENT); | |
753 | if (!worker || worker->id != info->worker_id) | |
754 | return -ENODEV; | |
755 | ||
228a27cf MC |
756 | mutex_lock(&worker->mutex); |
757 | if (worker->attachment_cnt) { | |
758 | mutex_unlock(&worker->mutex); | |
c1ecd8e9 | 759 | return -EBUSY; |
228a27cf MC |
760 | } |
761 | mutex_unlock(&worker->mutex); | |
c1ecd8e9 MC |
762 | |
763 | vhost_worker_destroy(dev, worker); | |
764 | return 0; | |
765 | } | |
766 | ||
cef25866 MC |
767 | static int vhost_get_vq_from_user(struct vhost_dev *dev, void __user *argp, |
768 | struct vhost_virtqueue **vq, u32 *id) | |
769 | { | |
770 | u32 __user *idxp = argp; | |
771 | u32 idx; | |
772 | long r; | |
773 | ||
774 | r = get_user(idx, idxp); | |
775 | if (r < 0) | |
776 | return r; | |
777 | ||
778 | if (idx >= dev->nvqs) | |
779 | return -ENOBUFS; | |
780 | ||
781 | idx = array_index_nospec(idx, dev->nvqs); | |
782 | ||
783 | *vq = dev->vqs[idx]; | |
784 | *id = idx; | |
785 | return 0; | |
786 | } | |
787 | ||
c1ecd8e9 MC |
788 | /* Caller must have device mutex */ |
789 | long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl, | |
790 | void __user *argp) | |
791 | { | |
792 | struct vhost_vring_worker ring_worker; | |
793 | struct vhost_worker_state state; | |
228a27cf | 794 | struct vhost_worker *worker; |
c1ecd8e9 MC |
795 | struct vhost_virtqueue *vq; |
796 | long ret; | |
797 | u32 idx; | |
798 | ||
799 | if (!dev->use_worker) | |
800 | return -EINVAL; | |
801 | ||
802 | if (!vhost_dev_has_owner(dev)) | |
803 | return -EINVAL; | |
804 | ||
805 | ret = vhost_dev_check_owner(dev); | |
806 | if (ret) | |
807 | return ret; | |
808 | ||
809 | switch (ioctl) { | |
810 | /* dev worker ioctls */ | |
811 | case VHOST_NEW_WORKER: | |
812 | ret = vhost_new_worker(dev, &state); | |
813 | if (!ret && copy_to_user(argp, &state, sizeof(state))) | |
814 | ret = -EFAULT; | |
815 | return ret; | |
816 | case VHOST_FREE_WORKER: | |
817 | if (copy_from_user(&state, argp, sizeof(state))) | |
818 | return -EFAULT; | |
819 | return vhost_free_worker(dev, &state); | |
820 | /* vring worker ioctls */ | |
821 | case VHOST_ATTACH_VRING_WORKER: | |
822 | case VHOST_GET_VRING_WORKER: | |
823 | break; | |
824 | default: | |
825 | return -ENOIOCTLCMD; | |
826 | } | |
827 | ||
828 | ret = vhost_get_vq_from_user(dev, argp, &vq, &idx); | |
829 | if (ret) | |
830 | return ret; | |
831 | ||
c1ecd8e9 MC |
832 | switch (ioctl) { |
833 | case VHOST_ATTACH_VRING_WORKER: | |
834 | if (copy_from_user(&ring_worker, argp, sizeof(ring_worker))) { | |
835 | ret = -EFAULT; | |
836 | break; | |
837 | } | |
838 | ||
839 | ret = vhost_vq_attach_worker(vq, &ring_worker); | |
840 | break; | |
841 | case VHOST_GET_VRING_WORKER: | |
228a27cf MC |
842 | worker = rcu_dereference_check(vq->worker, |
843 | lockdep_is_held(&dev->mutex)); | |
844 | if (!worker) { | |
845 | ret = -EINVAL; | |
846 | break; | |
847 | } | |
848 | ||
c1ecd8e9 | 849 | ring_worker.index = idx; |
228a27cf | 850 | ring_worker.worker_id = worker->id; |
c1ecd8e9 MC |
851 | |
852 | if (copy_to_user(argp, &ring_worker, sizeof(ring_worker))) | |
853 | ret = -EFAULT; | |
854 | break; | |
855 | default: | |
856 | ret = -ENOIOCTLCMD; | |
857 | break; | |
858 | } | |
859 | ||
c1ecd8e9 MC |
860 | return ret; |
861 | } | |
862 | EXPORT_SYMBOL_GPL(vhost_worker_ioctl); | |
863 | ||
3a4d5c94 | 864 | /* Caller should have device mutex */ |
54db63c2 | 865 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 866 | { |
737bdb64 MC |
867 | struct vhost_worker *worker; |
868 | int err, i; | |
d47effe1 | 869 | |
3a4d5c94 | 870 | /* Is there an owner already? */ |
05c05351 | 871 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
872 | err = -EBUSY; |
873 | goto err_mm; | |
874 | } | |
d47effe1 | 875 | |
5ce995f3 JW |
876 | vhost_attach_mm(dev); |
877 | ||
3e11c6eb MC |
878 | err = vhost_dev_alloc_iovecs(dev); |
879 | if (err) | |
880 | goto err_iovecs; | |
881 | ||
01fcb1cb | 882 | if (dev->use_worker) { |
3e11c6eb MC |
883 | /* |
884 | * This should be done last, because vsock can queue work | |
885 | * before VHOST_SET_OWNER so it simplifies the failure path | |
886 | * below since we don't have to worry about vsock queueing | |
887 | * while we free the worker. | |
888 | */ | |
737bdb64 MC |
889 | worker = vhost_worker_create(dev); |
890 | if (!worker) { | |
891 | err = -ENOMEM; | |
1a5f8090 | 892 | goto err_worker; |
737bdb64 MC |
893 | } |
894 | ||
895 | for (i = 0; i < dev->nvqs; i++) | |
c1ecd8e9 | 896 | __vhost_vq_attach_worker(dev->vqs[i], worker); |
01fcb1cb | 897 | } |
c23f3445 | 898 | |
3a4d5c94 | 899 | return 0; |
3e11c6eb | 900 | |
c23f3445 | 901 | err_worker: |
3e11c6eb MC |
902 | vhost_dev_free_iovecs(dev); |
903 | err_iovecs: | |
5ce995f3 | 904 | vhost_detach_mm(dev); |
c23f3445 TH |
905 | err_mm: |
906 | return err; | |
3a4d5c94 | 907 | } |
6ac1afbf | 908 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 909 | |
0bbe3066 JW |
910 | static struct vhost_iotlb *iotlb_alloc(void) |
911 | { | |
912 | return vhost_iotlb_alloc(max_iotlb_entries, | |
913 | VHOST_IOTLB_FLAG_RETIRE); | |
914 | } | |
915 | ||
916 | struct vhost_iotlb *vhost_dev_reset_owner_prepare(void) | |
a9709d68 | 917 | { |
0bbe3066 | 918 | return iotlb_alloc(); |
150b9e51 | 919 | } |
6ac1afbf | 920 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 921 | |
150b9e51 | 922 | /* Caller should have device mutex */ |
0bbe3066 | 923 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *umem) |
150b9e51 | 924 | { |
47283bef MT |
925 | int i; |
926 | ||
f6f93f75 | 927 | vhost_dev_cleanup(dev); |
3a4d5c94 | 928 | |
a9709d68 | 929 | dev->umem = umem; |
47283bef MT |
930 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
931 | * VQs aren't running. | |
932 | */ | |
933 | for (i = 0; i < dev->nvqs; ++i) | |
a9709d68 | 934 | dev->vqs[i]->umem = umem; |
3a4d5c94 | 935 | } |
6ac1afbf | 936 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 937 | |
b211616d | 938 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
939 | { |
940 | int i; | |
b211616d MT |
941 | |
942 | for (i = 0; i < dev->nvqs; ++i) { | |
6ca84326 | 943 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) |
3ab2e420 | 944 | vhost_poll_stop(&dev->vqs[i]->poll); |
bab632d6 | 945 | } |
6ca84326 | 946 | |
b2ffa407 | 947 | vhost_dev_flush(dev); |
bab632d6 | 948 | } |
6ac1afbf | 949 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 950 | |
9526f9a2 | 951 | void vhost_clear_msg(struct vhost_dev *dev) |
6b1e6cc7 JW |
952 | { |
953 | struct vhost_msg_node *node, *n; | |
954 | ||
955 | spin_lock(&dev->iotlb_lock); | |
956 | ||
957 | list_for_each_entry_safe(node, n, &dev->read_list, node) { | |
958 | list_del(&node->node); | |
959 | kfree(node); | |
960 | } | |
961 | ||
962 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { | |
963 | list_del(&node->node); | |
964 | kfree(node); | |
965 | } | |
966 | ||
967 | spin_unlock(&dev->iotlb_lock); | |
968 | } | |
9526f9a2 | 969 | EXPORT_SYMBOL_GPL(vhost_clear_msg); |
6b1e6cc7 | 970 | |
f6f93f75 | 971 | void vhost_dev_cleanup(struct vhost_dev *dev) |
3a4d5c94 MT |
972 | { |
973 | int i; | |
d47effe1 | 974 | |
3a4d5c94 | 975 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
976 | if (dev->vqs[i]->error_ctx) |
977 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
3ab2e420 AH |
978 | if (dev->vqs[i]->kick) |
979 | fput(dev->vqs[i]->kick); | |
265a0ad8 ZL |
980 | if (dev->vqs[i]->call_ctx.ctx) |
981 | eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx); | |
3ab2e420 | 982 | vhost_vq_reset(dev, dev->vqs[i]); |
3a4d5c94 | 983 | } |
e0e9b406 | 984 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
985 | if (dev->log_ctx) |
986 | eventfd_ctx_put(dev->log_ctx); | |
987 | dev->log_ctx = NULL; | |
3a4d5c94 | 988 | /* No one will access memory at this point */ |
0bbe3066 | 989 | vhost_iotlb_free(dev->umem); |
a9709d68 | 990 | dev->umem = NULL; |
0bbe3066 | 991 | vhost_iotlb_free(dev->iotlb); |
6b1e6cc7 JW |
992 | dev->iotlb = NULL; |
993 | vhost_clear_msg(dev); | |
a9a08845 | 994 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
1cdaafa1 | 995 | vhost_workers_free(dev); |
5ce995f3 | 996 | vhost_detach_mm(dev); |
3a4d5c94 | 997 | } |
6ac1afbf | 998 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 | 999 | |
ddd3d408 | 1000 | static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) |
3a4d5c94 MT |
1001 | { |
1002 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 1003 | |
3a4d5c94 MT |
1004 | /* Make sure 64 bit math will not overflow. */ |
1005 | if (a > ULONG_MAX - (unsigned long)log_base || | |
1006 | a + (unsigned long)log_base > ULONG_MAX) | |
ddd3d408 | 1007 | return false; |
3a4d5c94 | 1008 | |
96d4f267 | 1009 | return access_ok(log_base + a, |
3a4d5c94 MT |
1010 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); |
1011 | } | |
1012 | ||
f7ad318e | 1013 | /* Make sure 64 bit math will not overflow. */ |
ec33d031 MT |
1014 | static bool vhost_overflow(u64 uaddr, u64 size) |
1015 | { | |
f7ad318e XY |
1016 | if (uaddr > ULONG_MAX || size > ULONG_MAX) |
1017 | return true; | |
1018 | ||
1019 | if (!size) | |
1020 | return false; | |
1021 | ||
1022 | return uaddr > ULONG_MAX - size + 1; | |
ec33d031 MT |
1023 | } |
1024 | ||
3a4d5c94 | 1025 | /* Caller should have vq mutex and device mutex. */ |
0bbe3066 | 1026 | static bool vq_memory_access_ok(void __user *log_base, struct vhost_iotlb *umem, |
ddd3d408 | 1027 | int log_all) |
3a4d5c94 | 1028 | { |
0bbe3066 | 1029 | struct vhost_iotlb_map *map; |
179b284e | 1030 | |
a9709d68 | 1031 | if (!umem) |
ddd3d408 | 1032 | return false; |
179b284e | 1033 | |
0bbe3066 JW |
1034 | list_for_each_entry(map, &umem->list, link) { |
1035 | unsigned long a = map->addr; | |
a9709d68 | 1036 | |
0bbe3066 | 1037 | if (vhost_overflow(map->addr, map->size)) |
ddd3d408 | 1038 | return false; |
ec33d031 MT |
1039 | |
1040 | ||
0bbe3066 | 1041 | if (!access_ok((void __user *)a, map->size)) |
ddd3d408 | 1042 | return false; |
3a4d5c94 | 1043 | else if (log_all && !log_access_ok(log_base, |
0bbe3066 JW |
1044 | map->start, |
1045 | map->size)) | |
ddd3d408 | 1046 | return false; |
3a4d5c94 | 1047 | } |
ddd3d408 | 1048 | return true; |
3a4d5c94 MT |
1049 | } |
1050 | ||
f8894913 JW |
1051 | static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, |
1052 | u64 addr, unsigned int size, | |
1053 | int type) | |
1054 | { | |
0bbe3066 | 1055 | const struct vhost_iotlb_map *map = vq->meta_iotlb[type]; |
f8894913 | 1056 | |
0bbe3066 | 1057 | if (!map) |
f8894913 JW |
1058 | return NULL; |
1059 | ||
1b0be99f | 1060 | return (void __user *)(uintptr_t)(map->addr + addr - map->start); |
f8894913 JW |
1061 | } |
1062 | ||
3a4d5c94 MT |
1063 | /* Can we switch to this memory table? */ |
1064 | /* Caller should have device mutex but not vq mutex */ | |
0bbe3066 | 1065 | static bool memory_access_ok(struct vhost_dev *d, struct vhost_iotlb *umem, |
ddd3d408 | 1066 | int log_all) |
3a4d5c94 MT |
1067 | { |
1068 | int i; | |
d47effe1 | 1069 | |
3a4d5c94 | 1070 | for (i = 0; i < d->nvqs; ++i) { |
ddd3d408 | 1071 | bool ok; |
ea16c514 MT |
1072 | bool log; |
1073 | ||
3ab2e420 | 1074 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 1075 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 1076 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 1077 | if (d->vqs[i]->private_data) |
a9709d68 JW |
1078 | ok = vq_memory_access_ok(d->vqs[i]->log_base, |
1079 | umem, log); | |
3a4d5c94 | 1080 | else |
ddd3d408 | 1081 | ok = true; |
3ab2e420 | 1082 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 | 1083 | if (!ok) |
ddd3d408 | 1084 | return false; |
3a4d5c94 | 1085 | } |
ddd3d408 | 1086 | return true; |
3a4d5c94 MT |
1087 | } |
1088 | ||
6b1e6cc7 JW |
1089 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
1090 | struct iovec iov[], int iov_size, int access); | |
bfe2bc51 | 1091 | |
72952cc0 | 1092 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, |
bfe2bc51 JW |
1093 | const void *from, unsigned size) |
1094 | { | |
6b1e6cc7 | 1095 | int ret; |
bfe2bc51 | 1096 | |
6b1e6cc7 JW |
1097 | if (!vq->iotlb) |
1098 | return __copy_to_user(to, from, size); | |
1099 | else { | |
1100 | /* This function should be called after iotlb | |
1101 | * prefetch, which means we're sure that all vq | |
1102 | * could be access through iotlb. So -EAGAIN should | |
1103 | * not happen in this case. | |
1104 | */ | |
6b1e6cc7 | 1105 | struct iov_iter t; |
f8894913 JW |
1106 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
1107 | (u64)(uintptr_t)to, size, | |
7ced6c98 | 1108 | VHOST_ADDR_USED); |
f8894913 JW |
1109 | |
1110 | if (uaddr) | |
1111 | return __copy_to_user(uaddr, from, size); | |
1112 | ||
6b1e6cc7 JW |
1113 | ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, |
1114 | ARRAY_SIZE(vq->iotlb_iov), | |
1115 | VHOST_ACCESS_WO); | |
1116 | if (ret < 0) | |
1117 | goto out; | |
de4eda9d | 1118 | iov_iter_init(&t, ITER_DEST, vq->iotlb_iov, ret, size); |
6b1e6cc7 JW |
1119 | ret = copy_to_iter(from, size, &t); |
1120 | if (ret == size) | |
1121 | ret = 0; | |
1122 | } | |
1123 | out: | |
1124 | return ret; | |
1125 | } | |
bfe2bc51 JW |
1126 | |
1127 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, | |
72952cc0 | 1128 | void __user *from, unsigned size) |
bfe2bc51 | 1129 | { |
6b1e6cc7 JW |
1130 | int ret; |
1131 | ||
1132 | if (!vq->iotlb) | |
1133 | return __copy_from_user(to, from, size); | |
1134 | else { | |
1135 | /* This function should be called after iotlb | |
1136 | * prefetch, which means we're sure that vq | |
1137 | * could be access through iotlb. So -EAGAIN should | |
1138 | * not happen in this case. | |
1139 | */ | |
f8894913 JW |
1140 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
1141 | (u64)(uintptr_t)from, size, | |
1142 | VHOST_ADDR_DESC); | |
6b1e6cc7 | 1143 | struct iov_iter f; |
f8894913 JW |
1144 | |
1145 | if (uaddr) | |
1146 | return __copy_from_user(to, uaddr, size); | |
1147 | ||
6b1e6cc7 JW |
1148 | ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, |
1149 | ARRAY_SIZE(vq->iotlb_iov), | |
1150 | VHOST_ACCESS_RO); | |
1151 | if (ret < 0) { | |
1152 | vq_err(vq, "IOTLB translation failure: uaddr " | |
1153 | "%p size 0x%llx\n", from, | |
1154 | (unsigned long long) size); | |
1155 | goto out; | |
1156 | } | |
de4eda9d | 1157 | iov_iter_init(&f, ITER_SOURCE, vq->iotlb_iov, ret, size); |
6b1e6cc7 JW |
1158 | ret = copy_from_iter(to, size, &f); |
1159 | if (ret == size) | |
1160 | ret = 0; | |
1161 | } | |
1162 | ||
1163 | out: | |
1164 | return ret; | |
1165 | } | |
1166 | ||
f8894913 JW |
1167 | static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq, |
1168 | void __user *addr, unsigned int size, | |
1169 | int type) | |
6b1e6cc7 JW |
1170 | { |
1171 | int ret; | |
1172 | ||
6b1e6cc7 JW |
1173 | ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov, |
1174 | ARRAY_SIZE(vq->iotlb_iov), | |
1175 | VHOST_ACCESS_RO); | |
1176 | if (ret < 0) { | |
1177 | vq_err(vq, "IOTLB translation failure: uaddr " | |
1178 | "%p size 0x%llx\n", addr, | |
1179 | (unsigned long long) size); | |
1180 | return NULL; | |
1181 | } | |
1182 | ||
1183 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { | |
1184 | vq_err(vq, "Non atomic userspace memory access: uaddr " | |
1185 | "%p size 0x%llx\n", addr, | |
1186 | (unsigned long long) size); | |
1187 | return NULL; | |
1188 | } | |
1189 | ||
1190 | return vq->iotlb_iov[0].iov_base; | |
1191 | } | |
1192 | ||
f8894913 JW |
1193 | /* This function should be called after iotlb |
1194 | * prefetch, which means we're sure that vq | |
1195 | * could be access through iotlb. So -EAGAIN should | |
1196 | * not happen in this case. | |
1197 | */ | |
1198 | static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, | |
1b0be99f | 1199 | void __user *addr, unsigned int size, |
f8894913 JW |
1200 | int type) |
1201 | { | |
1202 | void __user *uaddr = vhost_vq_meta_fetch(vq, | |
1203 | (u64)(uintptr_t)addr, size, type); | |
1204 | if (uaddr) | |
1205 | return uaddr; | |
1206 | ||
1207 | return __vhost_get_user_slow(vq, addr, size, type); | |
1208 | } | |
1209 | ||
1210 | #define vhost_put_user(vq, x, ptr) \ | |
6b1e6cc7 | 1211 | ({ \ |
002ef18e | 1212 | int ret; \ |
6b1e6cc7 JW |
1213 | if (!vq->iotlb) { \ |
1214 | ret = __put_user(x, ptr); \ | |
1215 | } else { \ | |
1216 | __typeof__(ptr) to = \ | |
f8894913 JW |
1217 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
1218 | sizeof(*ptr), VHOST_ADDR_USED); \ | |
6b1e6cc7 JW |
1219 | if (to != NULL) \ |
1220 | ret = __put_user(x, to); \ | |
1221 | else \ | |
1222 | ret = -EFAULT; \ | |
1223 | } \ | |
1224 | ret; \ | |
1225 | }) | |
1226 | ||
7b5d753e JW |
1227 | static inline int vhost_put_avail_event(struct vhost_virtqueue *vq) |
1228 | { | |
1229 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), | |
1230 | vhost_avail_event(vq)); | |
1231 | } | |
1232 | ||
1233 | static inline int vhost_put_used(struct vhost_virtqueue *vq, | |
1234 | struct vring_used_elem *head, int idx, | |
1235 | int count) | |
1236 | { | |
1237 | return vhost_copy_to_user(vq, vq->used->ring + idx, head, | |
1238 | count * sizeof(*head)); | |
1239 | } | |
1240 | ||
1241 | static inline int vhost_put_used_flags(struct vhost_virtqueue *vq) | |
1242 | ||
1243 | { | |
1244 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), | |
1245 | &vq->used->flags); | |
1246 | } | |
1247 | ||
1248 | static inline int vhost_put_used_idx(struct vhost_virtqueue *vq) | |
1249 | ||
1250 | { | |
1251 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), | |
1252 | &vq->used->idx); | |
1253 | } | |
1254 | ||
f8894913 | 1255 | #define vhost_get_user(vq, x, ptr, type) \ |
6b1e6cc7 JW |
1256 | ({ \ |
1257 | int ret; \ | |
1258 | if (!vq->iotlb) { \ | |
1259 | ret = __get_user(x, ptr); \ | |
1260 | } else { \ | |
1261 | __typeof__(ptr) from = \ | |
f8894913 JW |
1262 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
1263 | sizeof(*ptr), \ | |
1264 | type); \ | |
6b1e6cc7 JW |
1265 | if (from != NULL) \ |
1266 | ret = __get_user(x, from); \ | |
1267 | else \ | |
1268 | ret = -EFAULT; \ | |
1269 | } \ | |
1270 | ret; \ | |
1271 | }) | |
1272 | ||
f8894913 JW |
1273 | #define vhost_get_avail(vq, x, ptr) \ |
1274 | vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL) | |
1275 | ||
1276 | #define vhost_get_used(vq, x, ptr) \ | |
1277 | vhost_get_user(vq, x, ptr, VHOST_ADDR_USED) | |
1278 | ||
86a07da3 JW |
1279 | static void vhost_dev_lock_vqs(struct vhost_dev *d) |
1280 | { | |
1281 | int i = 0; | |
1282 | for (i = 0; i < d->nvqs; ++i) | |
1283 | mutex_lock_nested(&d->vqs[i]->mutex, i); | |
1284 | } | |
1285 | ||
1286 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) | |
1287 | { | |
1288 | int i = 0; | |
1289 | for (i = 0; i < d->nvqs; ++i) | |
1290 | mutex_unlock(&d->vqs[i]->mutex); | |
1291 | } | |
1292 | ||
7b5d753e JW |
1293 | static inline int vhost_get_avail_idx(struct vhost_virtqueue *vq, |
1294 | __virtio16 *idx) | |
1295 | { | |
1296 | return vhost_get_avail(vq, *idx, &vq->avail->idx); | |
1297 | } | |
1298 | ||
1299 | static inline int vhost_get_avail_head(struct vhost_virtqueue *vq, | |
1300 | __virtio16 *head, int idx) | |
1301 | { | |
1302 | return vhost_get_avail(vq, *head, | |
1303 | &vq->avail->ring[idx & (vq->num - 1)]); | |
1304 | } | |
1305 | ||
1306 | static inline int vhost_get_avail_flags(struct vhost_virtqueue *vq, | |
1307 | __virtio16 *flags) | |
1308 | { | |
1309 | return vhost_get_avail(vq, *flags, &vq->avail->flags); | |
1310 | } | |
1311 | ||
1312 | static inline int vhost_get_used_event(struct vhost_virtqueue *vq, | |
1313 | __virtio16 *event) | |
1314 | { | |
1315 | return vhost_get_avail(vq, *event, vhost_used_event(vq)); | |
1316 | } | |
1317 | ||
1318 | static inline int vhost_get_used_idx(struct vhost_virtqueue *vq, | |
1319 | __virtio16 *idx) | |
1320 | { | |
1321 | return vhost_get_used(vq, *idx, &vq->used->idx); | |
1322 | } | |
1323 | ||
1324 | static inline int vhost_get_desc(struct vhost_virtqueue *vq, | |
1325 | struct vring_desc *desc, int idx) | |
1326 | { | |
1327 | return vhost_copy_from_user(vq, desc, vq->desc + idx, sizeof(*desc)); | |
1328 | } | |
1329 | ||
6b1e6cc7 JW |
1330 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, |
1331 | struct vhost_iotlb_msg *msg) | |
1332 | { | |
1333 | struct vhost_msg_node *node, *n; | |
1334 | ||
1335 | spin_lock(&d->iotlb_lock); | |
1336 | ||
1337 | list_for_each_entry_safe(node, n, &d->pending_list, node) { | |
1338 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; | |
1339 | if (msg->iova <= vq_msg->iova && | |
2d66f997 | 1340 | msg->iova + msg->size - 1 >= vq_msg->iova && |
6b1e6cc7 JW |
1341 | vq_msg->type == VHOST_IOTLB_MISS) { |
1342 | vhost_poll_queue(&node->vq->poll); | |
1343 | list_del(&node->node); | |
1344 | kfree(node); | |
1345 | } | |
1346 | } | |
1347 | ||
1348 | spin_unlock(&d->iotlb_lock); | |
1349 | } | |
1350 | ||
ddd3d408 | 1351 | static bool umem_access_ok(u64 uaddr, u64 size, int access) |
6b1e6cc7 JW |
1352 | { |
1353 | unsigned long a = uaddr; | |
1354 | ||
ec33d031 MT |
1355 | /* Make sure 64 bit math will not overflow. */ |
1356 | if (vhost_overflow(uaddr, size)) | |
ddd3d408 | 1357 | return false; |
ec33d031 | 1358 | |
6b1e6cc7 | 1359 | if ((access & VHOST_ACCESS_RO) && |
96d4f267 | 1360 | !access_ok((void __user *)a, size)) |
ddd3d408 | 1361 | return false; |
6b1e6cc7 | 1362 | if ((access & VHOST_ACCESS_WO) && |
96d4f267 | 1363 | !access_ok((void __user *)a, size)) |
ddd3d408 SH |
1364 | return false; |
1365 | return true; | |
6b1e6cc7 JW |
1366 | } |
1367 | ||
91233ad7 | 1368 | static int vhost_process_iotlb_msg(struct vhost_dev *dev, u32 asid, |
72952cc0 | 1369 | struct vhost_iotlb_msg *msg) |
6b1e6cc7 JW |
1370 | { |
1371 | int ret = 0; | |
1372 | ||
91233ad7 GD |
1373 | if (asid != 0) |
1374 | return -EINVAL; | |
1375 | ||
1b15ad68 | 1376 | mutex_lock(&dev->mutex); |
86a07da3 | 1377 | vhost_dev_lock_vqs(dev); |
6b1e6cc7 JW |
1378 | switch (msg->type) { |
1379 | case VHOST_IOTLB_UPDATE: | |
1380 | if (!dev->iotlb) { | |
1381 | ret = -EFAULT; | |
1382 | break; | |
1383 | } | |
ddd3d408 | 1384 | if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) { |
6b1e6cc7 JW |
1385 | ret = -EFAULT; |
1386 | break; | |
1387 | } | |
f8894913 | 1388 | vhost_vq_meta_reset(dev); |
0bbe3066 JW |
1389 | if (vhost_iotlb_add_range(dev->iotlb, msg->iova, |
1390 | msg->iova + msg->size - 1, | |
1391 | msg->uaddr, msg->perm)) { | |
6b1e6cc7 JW |
1392 | ret = -ENOMEM; |
1393 | break; | |
1394 | } | |
1395 | vhost_iotlb_notify_vq(dev, msg); | |
1396 | break; | |
1397 | case VHOST_IOTLB_INVALIDATE: | |
6f3180af JW |
1398 | if (!dev->iotlb) { |
1399 | ret = -EFAULT; | |
1400 | break; | |
1401 | } | |
f8894913 | 1402 | vhost_vq_meta_reset(dev); |
0bbe3066 JW |
1403 | vhost_iotlb_del_range(dev->iotlb, msg->iova, |
1404 | msg->iova + msg->size - 1); | |
6b1e6cc7 JW |
1405 | break; |
1406 | default: | |
1407 | ret = -EINVAL; | |
1408 | break; | |
1409 | } | |
1410 | ||
86a07da3 | 1411 | vhost_dev_unlock_vqs(dev); |
1b15ad68 JW |
1412 | mutex_unlock(&dev->mutex); |
1413 | ||
6b1e6cc7 JW |
1414 | return ret; |
1415 | } | |
1416 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, | |
1417 | struct iov_iter *from) | |
1418 | { | |
429711ae JW |
1419 | struct vhost_iotlb_msg msg; |
1420 | size_t offset; | |
1421 | int type, ret; | |
91233ad7 | 1422 | u32 asid = 0; |
6b1e6cc7 | 1423 | |
429711ae | 1424 | ret = copy_from_iter(&type, sizeof(type), from); |
74ad7419 PT |
1425 | if (ret != sizeof(type)) { |
1426 | ret = -EINVAL; | |
6b1e6cc7 | 1427 | goto done; |
74ad7419 | 1428 | } |
6b1e6cc7 | 1429 | |
429711ae | 1430 | switch (type) { |
6b1e6cc7 | 1431 | case VHOST_IOTLB_MSG: |
429711ae JW |
1432 | /* There maybe a hole after type for V1 message type, |
1433 | * so skip it here. | |
1434 | */ | |
1435 | offset = offsetof(struct vhost_msg, iotlb) - sizeof(int); | |
1436 | break; | |
1437 | case VHOST_IOTLB_MSG_V2: | |
91233ad7 GD |
1438 | if (vhost_backend_has_feature(dev->vqs[0], |
1439 | VHOST_BACKEND_F_IOTLB_ASID)) { | |
1440 | ret = copy_from_iter(&asid, sizeof(asid), from); | |
1441 | if (ret != sizeof(asid)) { | |
1442 | ret = -EINVAL; | |
1443 | goto done; | |
1444 | } | |
aaca8373 | 1445 | offset = 0; |
91233ad7 GD |
1446 | } else |
1447 | offset = sizeof(__u32); | |
6b1e6cc7 JW |
1448 | break; |
1449 | default: | |
1450 | ret = -EINVAL; | |
429711ae | 1451 | goto done; |
6b1e6cc7 JW |
1452 | } |
1453 | ||
429711ae JW |
1454 | iov_iter_advance(from, offset); |
1455 | ret = copy_from_iter(&msg, sizeof(msg), from); | |
74ad7419 PT |
1456 | if (ret != sizeof(msg)) { |
1457 | ret = -EINVAL; | |
429711ae | 1458 | goto done; |
74ad7419 | 1459 | } |
792a4f2e | 1460 | |
ca50ec37 | 1461 | if (msg.type == VHOST_IOTLB_UPDATE && msg.size == 0) { |
e2ae38cf AR |
1462 | ret = -EINVAL; |
1463 | goto done; | |
1464 | } | |
1465 | ||
792a4f2e | 1466 | if (dev->msg_handler) |
91233ad7 | 1467 | ret = dev->msg_handler(dev, asid, &msg); |
792a4f2e | 1468 | else |
91233ad7 | 1469 | ret = vhost_process_iotlb_msg(dev, asid, &msg); |
792a4f2e | 1470 | if (ret) { |
429711ae JW |
1471 | ret = -EFAULT; |
1472 | goto done; | |
1473 | } | |
1474 | ||
1475 | ret = (type == VHOST_IOTLB_MSG) ? sizeof(struct vhost_msg) : | |
1476 | sizeof(struct vhost_msg_v2); | |
6b1e6cc7 JW |
1477 | done: |
1478 | return ret; | |
1479 | } | |
1480 | EXPORT_SYMBOL(vhost_chr_write_iter); | |
1481 | ||
afc9a42b | 1482 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
6b1e6cc7 JW |
1483 | poll_table *wait) |
1484 | { | |
afc9a42b | 1485 | __poll_t mask = 0; |
6b1e6cc7 JW |
1486 | |
1487 | poll_wait(file, &dev->wait, wait); | |
1488 | ||
1489 | if (!list_empty(&dev->read_list)) | |
a9a08845 | 1490 | mask |= EPOLLIN | EPOLLRDNORM; |
6b1e6cc7 JW |
1491 | |
1492 | return mask; | |
1493 | } | |
1494 | EXPORT_SYMBOL(vhost_chr_poll); | |
1495 | ||
1496 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, | |
1497 | int noblock) | |
1498 | { | |
1499 | DEFINE_WAIT(wait); | |
1500 | struct vhost_msg_node *node; | |
1501 | ssize_t ret = 0; | |
1502 | unsigned size = sizeof(struct vhost_msg); | |
1503 | ||
1504 | if (iov_iter_count(to) < size) | |
1505 | return 0; | |
1506 | ||
1507 | while (1) { | |
1508 | if (!noblock) | |
1509 | prepare_to_wait(&dev->wait, &wait, | |
1510 | TASK_INTERRUPTIBLE); | |
1511 | ||
1512 | node = vhost_dequeue_msg(dev, &dev->read_list); | |
1513 | if (node) | |
1514 | break; | |
1515 | if (noblock) { | |
1516 | ret = -EAGAIN; | |
1517 | break; | |
1518 | } | |
1519 | if (signal_pending(current)) { | |
1520 | ret = -ERESTARTSYS; | |
1521 | break; | |
1522 | } | |
1523 | if (!dev->iotlb) { | |
1524 | ret = -EBADFD; | |
1525 | break; | |
1526 | } | |
1527 | ||
1528 | schedule(); | |
1529 | } | |
1530 | ||
1531 | if (!noblock) | |
1532 | finish_wait(&dev->wait, &wait); | |
1533 | ||
1534 | if (node) { | |
429711ae JW |
1535 | struct vhost_iotlb_msg *msg; |
1536 | void *start = &node->msg; | |
6b1e6cc7 | 1537 | |
429711ae JW |
1538 | switch (node->msg.type) { |
1539 | case VHOST_IOTLB_MSG: | |
1540 | size = sizeof(node->msg); | |
1541 | msg = &node->msg.iotlb; | |
1542 | break; | |
1543 | case VHOST_IOTLB_MSG_V2: | |
1544 | size = sizeof(node->msg_v2); | |
1545 | msg = &node->msg_v2.iotlb; | |
1546 | break; | |
1547 | default: | |
1548 | BUG(); | |
1549 | break; | |
1550 | } | |
1551 | ||
1552 | ret = copy_to_iter(start, size, to); | |
1553 | if (ret != size || msg->type != VHOST_IOTLB_MISS) { | |
6b1e6cc7 JW |
1554 | kfree(node); |
1555 | return ret; | |
1556 | } | |
6b1e6cc7 JW |
1557 | vhost_enqueue_msg(dev, &dev->pending_list, node); |
1558 | } | |
1559 | ||
1560 | return ret; | |
1561 | } | |
1562 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); | |
1563 | ||
1564 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) | |
1565 | { | |
1566 | struct vhost_dev *dev = vq->dev; | |
1567 | struct vhost_msg_node *node; | |
1568 | struct vhost_iotlb_msg *msg; | |
429711ae | 1569 | bool v2 = vhost_backend_has_feature(vq, VHOST_BACKEND_F_IOTLB_MSG_V2); |
6b1e6cc7 | 1570 | |
429711ae | 1571 | node = vhost_new_msg(vq, v2 ? VHOST_IOTLB_MSG_V2 : VHOST_IOTLB_MSG); |
6b1e6cc7 JW |
1572 | if (!node) |
1573 | return -ENOMEM; | |
1574 | ||
429711ae JW |
1575 | if (v2) { |
1576 | node->msg_v2.type = VHOST_IOTLB_MSG_V2; | |
1577 | msg = &node->msg_v2.iotlb; | |
1578 | } else { | |
1579 | msg = &node->msg.iotlb; | |
1580 | } | |
1581 | ||
6b1e6cc7 JW |
1582 | msg->type = VHOST_IOTLB_MISS; |
1583 | msg->iova = iova; | |
1584 | msg->perm = access; | |
1585 | ||
1586 | vhost_enqueue_msg(dev, &dev->read_list, node); | |
1587 | ||
1588 | return 0; | |
bfe2bc51 JW |
1589 | } |
1590 | ||
ddd3d408 | 1591 | static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
a865e420 MT |
1592 | vring_desc_t __user *desc, |
1593 | vring_avail_t __user *avail, | |
1594 | vring_used_t __user *used) | |
6b1e6cc7 | 1595 | |
3a4d5c94 | 1596 | { |
0210a8db GK |
1597 | /* If an IOTLB device is present, the vring addresses are |
1598 | * GIOVAs. Access validation occurs at prefetch time. */ | |
1599 | if (vq->iotlb) | |
1600 | return true; | |
1601 | ||
4942e825 JW |
1602 | return access_ok(desc, vhost_get_desc_size(vq, num)) && |
1603 | access_ok(avail, vhost_get_avail_size(vq, num)) && | |
1604 | access_ok(used, vhost_get_used_size(vq, num)); | |
3a4d5c94 MT |
1605 | } |
1606 | ||
f8894913 | 1607 | static void vhost_vq_meta_update(struct vhost_virtqueue *vq, |
0bbe3066 | 1608 | const struct vhost_iotlb_map *map, |
f8894913 JW |
1609 | int type) |
1610 | { | |
1611 | int access = (type == VHOST_ADDR_USED) ? | |
1612 | VHOST_ACCESS_WO : VHOST_ACCESS_RO; | |
1613 | ||
0bbe3066 JW |
1614 | if (likely(map->perm & access)) |
1615 | vq->meta_iotlb[type] = map; | |
f8894913 JW |
1616 | } |
1617 | ||
ddd3d408 SH |
1618 | static bool iotlb_access_ok(struct vhost_virtqueue *vq, |
1619 | int access, u64 addr, u64 len, int type) | |
6b1e6cc7 | 1620 | { |
0bbe3066 JW |
1621 | const struct vhost_iotlb_map *map; |
1622 | struct vhost_iotlb *umem = vq->iotlb; | |
ca2c5b33 | 1623 | u64 s = 0, size, orig_addr = addr, last = addr + len - 1; |
f8894913 JW |
1624 | |
1625 | if (vhost_vq_meta_fetch(vq, addr, len, type)) | |
1626 | return true; | |
6b1e6cc7 JW |
1627 | |
1628 | while (len > s) { | |
0bbe3066 JW |
1629 | map = vhost_iotlb_itree_first(umem, addr, last); |
1630 | if (map == NULL || map->start > addr) { | |
6b1e6cc7 JW |
1631 | vhost_iotlb_miss(vq, addr, access); |
1632 | return false; | |
0bbe3066 | 1633 | } else if (!(map->perm & access)) { |
6b1e6cc7 JW |
1634 | /* Report the possible access violation by |
1635 | * request another translation from userspace. | |
1636 | */ | |
1637 | return false; | |
1638 | } | |
1639 | ||
0bbe3066 | 1640 | size = map->size - addr + map->start; |
f8894913 JW |
1641 | |
1642 | if (orig_addr == addr && size >= len) | |
0bbe3066 | 1643 | vhost_vq_meta_update(vq, map, type); |
f8894913 | 1644 | |
6b1e6cc7 JW |
1645 | s += size; |
1646 | addr += size; | |
1647 | } | |
1648 | ||
1649 | return true; | |
1650 | } | |
1651 | ||
9b5e830b | 1652 | int vq_meta_prefetch(struct vhost_virtqueue *vq) |
6b1e6cc7 | 1653 | { |
6b1e6cc7 JW |
1654 | unsigned int num = vq->num; |
1655 | ||
3d2c7d37 | 1656 | if (!vq->iotlb) |
6b1e6cc7 JW |
1657 | return 1; |
1658 | ||
0bbe3066 | 1659 | return iotlb_access_ok(vq, VHOST_MAP_RO, (u64)(uintptr_t)vq->desc, |
4942e825 | 1660 | vhost_get_desc_size(vq, num), VHOST_ADDR_DESC) && |
0bbe3066 | 1661 | iotlb_access_ok(vq, VHOST_MAP_RO, (u64)(uintptr_t)vq->avail, |
4942e825 | 1662 | vhost_get_avail_size(vq, num), |
f8894913 | 1663 | VHOST_ADDR_AVAIL) && |
0bbe3066 | 1664 | iotlb_access_ok(vq, VHOST_MAP_WO, (u64)(uintptr_t)vq->used, |
4942e825 | 1665 | vhost_get_used_size(vq, num), VHOST_ADDR_USED); |
6b1e6cc7 | 1666 | } |
9b5e830b | 1667 | EXPORT_SYMBOL_GPL(vq_meta_prefetch); |
6b1e6cc7 | 1668 | |
3a4d5c94 MT |
1669 | /* Can we log writes? */ |
1670 | /* Caller should have device mutex but not vq mutex */ | |
ddd3d408 | 1671 | bool vhost_log_access_ok(struct vhost_dev *dev) |
3a4d5c94 | 1672 | { |
a9709d68 | 1673 | return memory_access_ok(dev, dev->umem, 1); |
3a4d5c94 | 1674 | } |
6ac1afbf | 1675 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 | 1676 | |
ab512251 GK |
1677 | static bool vq_log_used_access_ok(struct vhost_virtqueue *vq, |
1678 | void __user *log_base, | |
1679 | bool log_used, | |
1680 | u64 log_addr) | |
1681 | { | |
1682 | /* If an IOTLB device is present, log_addr is a GIOVA that | |
1683 | * will never be logged by log_used(). */ | |
1684 | if (vq->iotlb) | |
1685 | return true; | |
1686 | ||
1687 | return !log_used || log_access_ok(log_base, log_addr, | |
1688 | vhost_get_used_size(vq, vq->num)); | |
1689 | } | |
1690 | ||
3a4d5c94 MT |
1691 | /* Verify access for write logging. */ |
1692 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 SH |
1693 | static bool vq_log_access_ok(struct vhost_virtqueue *vq, |
1694 | void __user *log_base) | |
3a4d5c94 | 1695 | { |
a9709d68 | 1696 | return vq_memory_access_ok(log_base, vq->umem, |
ea16c514 | 1697 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
ab512251 | 1698 | vq_log_used_access_ok(vq, log_base, vq->log_used, vq->log_addr); |
3a4d5c94 MT |
1699 | } |
1700 | ||
1701 | /* Can we start vq? */ | |
1702 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 | 1703 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq) |
3a4d5c94 | 1704 | { |
d14d2b78 | 1705 | if (!vq_log_access_ok(vq, vq->log_base)) |
ddd3d408 | 1706 | return false; |
d65026c6 | 1707 | |
d65026c6 | 1708 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); |
3a4d5c94 | 1709 | } |
6ac1afbf | 1710 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 MT |
1711 | |
1712 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) | |
1713 | { | |
a9709d68 JW |
1714 | struct vhost_memory mem, *newmem; |
1715 | struct vhost_memory_region *region; | |
0bbe3066 | 1716 | struct vhost_iotlb *newumem, *oldumem; |
3a4d5c94 | 1717 | unsigned long size = offsetof(struct vhost_memory, regions); |
98f9ca0a | 1718 | int i; |
d47effe1 | 1719 | |
7ad9c9d2 TY |
1720 | if (copy_from_user(&mem, m, size)) |
1721 | return -EFAULT; | |
3a4d5c94 MT |
1722 | if (mem.padding) |
1723 | return -EOPNOTSUPP; | |
c9ce42f7 | 1724 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 1725 | return -E2BIG; |
b2303d7b MW |
1726 | newmem = kvzalloc(struct_size(newmem, regions, mem.nregions), |
1727 | GFP_KERNEL); | |
3a4d5c94 MT |
1728 | if (!newmem) |
1729 | return -ENOMEM; | |
1730 | ||
1731 | memcpy(newmem, &mem, size); | |
7ad9c9d2 | 1732 | if (copy_from_user(newmem->regions, m->regions, |
bf11d71a | 1733 | flex_array_size(newmem, regions, mem.nregions))) { |
bcfeacab | 1734 | kvfree(newmem); |
7ad9c9d2 | 1735 | return -EFAULT; |
3a4d5c94 MT |
1736 | } |
1737 | ||
0bbe3066 | 1738 | newumem = iotlb_alloc(); |
a9709d68 | 1739 | if (!newumem) { |
4de7255f | 1740 | kvfree(newmem); |
a9709d68 JW |
1741 | return -ENOMEM; |
1742 | } | |
1743 | ||
a9709d68 JW |
1744 | for (region = newmem->regions; |
1745 | region < newmem->regions + mem.nregions; | |
1746 | region++) { | |
0bbe3066 JW |
1747 | if (vhost_iotlb_add_range(newumem, |
1748 | region->guest_phys_addr, | |
1749 | region->guest_phys_addr + | |
1750 | region->memory_size - 1, | |
1751 | region->userspace_addr, | |
1752 | VHOST_MAP_RW)) | |
a9709d68 | 1753 | goto err; |
a02c3789 | 1754 | } |
a9709d68 JW |
1755 | |
1756 | if (!memory_access_ok(d, newumem, 0)) | |
1757 | goto err; | |
1758 | ||
1759 | oldumem = d->umem; | |
1760 | d->umem = newumem; | |
98f9ca0a | 1761 | |
47283bef | 1762 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
1763 | for (i = 0; i < d->nvqs; ++i) { |
1764 | mutex_lock(&d->vqs[i]->mutex); | |
a9709d68 | 1765 | d->vqs[i]->umem = newumem; |
98f9ca0a MT |
1766 | mutex_unlock(&d->vqs[i]->mutex); |
1767 | } | |
a9709d68 JW |
1768 | |
1769 | kvfree(newmem); | |
0bbe3066 | 1770 | vhost_iotlb_free(oldumem); |
3a4d5c94 | 1771 | return 0; |
a9709d68 JW |
1772 | |
1773 | err: | |
0bbe3066 | 1774 | vhost_iotlb_free(newumem); |
a9709d68 JW |
1775 | kvfree(newmem); |
1776 | return -EFAULT; | |
3a4d5c94 MT |
1777 | } |
1778 | ||
feebcaea JW |
1779 | static long vhost_vring_set_num(struct vhost_dev *d, |
1780 | struct vhost_virtqueue *vq, | |
1781 | void __user *argp) | |
1782 | { | |
1783 | struct vhost_vring_state s; | |
1784 | ||
1785 | /* Resizing ring with an active backend? | |
1786 | * You don't want to do that. */ | |
1787 | if (vq->private_data) | |
1788 | return -EBUSY; | |
1789 | ||
1790 | if (copy_from_user(&s, argp, sizeof s)) | |
1791 | return -EFAULT; | |
1792 | ||
1793 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) | |
1794 | return -EINVAL; | |
1795 | vq->num = s.num; | |
1796 | ||
1797 | return 0; | |
1798 | } | |
1799 | ||
1800 | static long vhost_vring_set_addr(struct vhost_dev *d, | |
1801 | struct vhost_virtqueue *vq, | |
1802 | void __user *argp) | |
1803 | { | |
1804 | struct vhost_vring_addr a; | |
1805 | ||
1806 | if (copy_from_user(&a, argp, sizeof a)) | |
1807 | return -EFAULT; | |
1808 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) | |
1809 | return -EOPNOTSUPP; | |
1810 | ||
1811 | /* For 32bit, verify that the top 32bits of the user | |
1812 | data are set to zero. */ | |
1813 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
1814 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
1815 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) | |
1816 | return -EFAULT; | |
1817 | ||
1818 | /* Make sure it's safe to cast pointers to vring types. */ | |
1819 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
1820 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
1821 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
1822 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
1823 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) | |
1824 | return -EINVAL; | |
1825 | ||
1826 | /* We only verify access here if backend is configured. | |
1827 | * If it is not, we don't as size might not have been setup. | |
1828 | * We will verify when backend is configured. */ | |
1829 | if (vq->private_data) { | |
1830 | if (!vq_access_ok(vq, vq->num, | |
1831 | (void __user *)(unsigned long)a.desc_user_addr, | |
1832 | (void __user *)(unsigned long)a.avail_user_addr, | |
1833 | (void __user *)(unsigned long)a.used_user_addr)) | |
1834 | return -EINVAL; | |
1835 | ||
1836 | /* Also validate log access for used ring if enabled. */ | |
ab512251 GK |
1837 | if (!vq_log_used_access_ok(vq, vq->log_base, |
1838 | a.flags & (0x1 << VHOST_VRING_F_LOG), | |
1839 | a.log_guest_addr)) | |
feebcaea JW |
1840 | return -EINVAL; |
1841 | } | |
1842 | ||
1843 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); | |
1844 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
1845 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
1846 | vq->log_addr = a.log_guest_addr; | |
1847 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
1848 | ||
1849 | return 0; | |
1850 | } | |
1851 | ||
1852 | static long vhost_vring_set_num_addr(struct vhost_dev *d, | |
1853 | struct vhost_virtqueue *vq, | |
1854 | unsigned int ioctl, | |
1855 | void __user *argp) | |
1856 | { | |
1857 | long r; | |
1858 | ||
1859 | mutex_lock(&vq->mutex); | |
1860 | ||
1861 | switch (ioctl) { | |
1862 | case VHOST_SET_VRING_NUM: | |
1863 | r = vhost_vring_set_num(d, vq, argp); | |
1864 | break; | |
1865 | case VHOST_SET_VRING_ADDR: | |
1866 | r = vhost_vring_set_addr(d, vq, argp); | |
1867 | break; | |
1868 | default: | |
1869 | BUG(); | |
1870 | } | |
1871 | ||
1872 | mutex_unlock(&vq->mutex); | |
1873 | ||
1874 | return r; | |
1875 | } | |
26b36604 | 1876 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1877 | { |
cecb46f1 AV |
1878 | struct file *eventfp, *filep = NULL; |
1879 | bool pollstart = false, pollstop = false; | |
3a4d5c94 | 1880 | struct eventfd_ctx *ctx = NULL; |
3a4d5c94 MT |
1881 | struct vhost_virtqueue *vq; |
1882 | struct vhost_vring_state s; | |
1883 | struct vhost_vring_file f; | |
3a4d5c94 MT |
1884 | u32 idx; |
1885 | long r; | |
1886 | ||
cef25866 | 1887 | r = vhost_get_vq_from_user(d, argp, &vq, &idx); |
3a4d5c94 MT |
1888 | if (r < 0) |
1889 | return r; | |
3a4d5c94 | 1890 | |
feebcaea JW |
1891 | if (ioctl == VHOST_SET_VRING_NUM || |
1892 | ioctl == VHOST_SET_VRING_ADDR) { | |
1893 | return vhost_vring_set_num_addr(d, vq, ioctl, argp); | |
1894 | } | |
1895 | ||
3a4d5c94 MT |
1896 | mutex_lock(&vq->mutex); |
1897 | ||
1898 | switch (ioctl) { | |
3a4d5c94 MT |
1899 | case VHOST_SET_VRING_BASE: |
1900 | /* Moving base with an active backend? | |
1901 | * You don't want to do that. */ | |
1902 | if (vq->private_data) { | |
1903 | r = -EBUSY; | |
1904 | break; | |
1905 | } | |
7ad9c9d2 TY |
1906 | if (copy_from_user(&s, argp, sizeof s)) { |
1907 | r = -EFAULT; | |
3a4d5c94 | 1908 | break; |
7ad9c9d2 | 1909 | } |
55d8122f SN |
1910 | if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { |
1911 | vq->last_avail_idx = s.num & 0xffff; | |
1912 | vq->last_used_idx = (s.num >> 16) & 0xffff; | |
1913 | } else { | |
1914 | if (s.num > 0xffff) { | |
1915 | r = -EINVAL; | |
1916 | break; | |
1917 | } | |
1918 | vq->last_avail_idx = s.num; | |
3a4d5c94 | 1919 | } |
3a4d5c94 MT |
1920 | /* Forget the cached index value. */ |
1921 | vq->avail_idx = vq->last_avail_idx; | |
1922 | break; | |
1923 | case VHOST_GET_VRING_BASE: | |
1924 | s.index = idx; | |
55d8122f SN |
1925 | if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) |
1926 | s.num = (u32)vq->last_avail_idx | ((u32)vq->last_used_idx << 16); | |
1927 | else | |
1928 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
1929 | if (copy_to_user(argp, &s, sizeof s)) |
1930 | r = -EFAULT; | |
3a4d5c94 | 1931 | break; |
3a4d5c94 | 1932 | case VHOST_SET_VRING_KICK: |
7ad9c9d2 TY |
1933 | if (copy_from_user(&f, argp, sizeof f)) { |
1934 | r = -EFAULT; | |
3a4d5c94 | 1935 | break; |
7ad9c9d2 | 1936 | } |
e0136c16 | 1937 | eventfp = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1938 | if (IS_ERR(eventfp)) { |
1939 | r = PTR_ERR(eventfp); | |
1940 | break; | |
1941 | } | |
3a4d5c94 | 1942 | if (eventfp != vq->kick) { |
cecb46f1 AV |
1943 | pollstop = (filep = vq->kick) != NULL; |
1944 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
1945 | } else |
1946 | filep = eventfp; | |
1947 | break; | |
1948 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
1949 | if (copy_from_user(&f, argp, sizeof f)) { |
1950 | r = -EFAULT; | |
3a4d5c94 | 1951 | break; |
7ad9c9d2 | 1952 | } |
e0136c16 | 1953 | ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(f.fd); |
e050c7d9 EB |
1954 | if (IS_ERR(ctx)) { |
1955 | r = PTR_ERR(ctx); | |
535297a6 MT |
1956 | break; |
1957 | } | |
265a0ad8 | 1958 | |
265a0ad8 | 1959 | swap(ctx, vq->call_ctx.ctx); |
3a4d5c94 MT |
1960 | break; |
1961 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
1962 | if (copy_from_user(&f, argp, sizeof f)) { |
1963 | r = -EFAULT; | |
3a4d5c94 | 1964 | break; |
7ad9c9d2 | 1965 | } |
e0136c16 | 1966 | ctx = f.fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(f.fd); |
09f332a5 EB |
1967 | if (IS_ERR(ctx)) { |
1968 | r = PTR_ERR(ctx); | |
535297a6 MT |
1969 | break; |
1970 | } | |
09f332a5 | 1971 | swap(ctx, vq->error_ctx); |
3a4d5c94 | 1972 | break; |
2751c988 GK |
1973 | case VHOST_SET_VRING_ENDIAN: |
1974 | r = vhost_set_vring_endian(vq, argp); | |
1975 | break; | |
1976 | case VHOST_GET_VRING_ENDIAN: | |
1977 | r = vhost_get_vring_endian(vq, idx, argp); | |
1978 | break; | |
03088137 JW |
1979 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1980 | if (copy_from_user(&s, argp, sizeof(s))) { | |
1981 | r = -EFAULT; | |
1982 | break; | |
1983 | } | |
1984 | vq->busyloop_timeout = s.num; | |
1985 | break; | |
1986 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
1987 | s.index = idx; | |
1988 | s.num = vq->busyloop_timeout; | |
1989 | if (copy_to_user(argp, &s, sizeof(s))) | |
1990 | r = -EFAULT; | |
1991 | break; | |
3a4d5c94 MT |
1992 | default: |
1993 | r = -ENOIOCTLCMD; | |
1994 | } | |
1995 | ||
1996 | if (pollstop && vq->handle_kick) | |
1997 | vhost_poll_stop(&vq->poll); | |
1998 | ||
e050c7d9 | 1999 | if (!IS_ERR_OR_NULL(ctx)) |
3a4d5c94 MT |
2000 | eventfd_ctx_put(ctx); |
2001 | if (filep) | |
2002 | fput(filep); | |
2003 | ||
2004 | if (pollstart && vq->handle_kick) | |
2b8b328b | 2005 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
2006 | |
2007 | mutex_unlock(&vq->mutex); | |
2008 | ||
2009 | if (pollstop && vq->handle_kick) | |
b2ffa407 | 2010 | vhost_dev_flush(vq->poll.dev); |
3a4d5c94 MT |
2011 | return r; |
2012 | } | |
6ac1afbf | 2013 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 | 2014 | |
759aba1e | 2015 | int vhost_init_device_iotlb(struct vhost_dev *d) |
6b1e6cc7 | 2016 | { |
0bbe3066 | 2017 | struct vhost_iotlb *niotlb, *oiotlb; |
6b1e6cc7 JW |
2018 | int i; |
2019 | ||
0bbe3066 | 2020 | niotlb = iotlb_alloc(); |
6b1e6cc7 JW |
2021 | if (!niotlb) |
2022 | return -ENOMEM; | |
2023 | ||
2024 | oiotlb = d->iotlb; | |
2025 | d->iotlb = niotlb; | |
2026 | ||
2027 | for (i = 0; i < d->nvqs; ++i) { | |
b13f9c63 JW |
2028 | struct vhost_virtqueue *vq = d->vqs[i]; |
2029 | ||
2030 | mutex_lock(&vq->mutex); | |
2031 | vq->iotlb = niotlb; | |
2032 | __vhost_vq_meta_reset(vq); | |
2033 | mutex_unlock(&vq->mutex); | |
6b1e6cc7 JW |
2034 | } |
2035 | ||
0bbe3066 | 2036 | vhost_iotlb_free(oiotlb); |
6b1e6cc7 JW |
2037 | |
2038 | return 0; | |
2039 | } | |
2040 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); | |
2041 | ||
3a4d5c94 | 2042 | /* Caller must have device mutex */ |
935cdee7 | 2043 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 2044 | { |
d25cc43c | 2045 | struct eventfd_ctx *ctx; |
3a4d5c94 MT |
2046 | u64 p; |
2047 | long r; | |
2048 | int i, fd; | |
2049 | ||
2050 | /* If you are not the owner, you can become one */ | |
2051 | if (ioctl == VHOST_SET_OWNER) { | |
2052 | r = vhost_dev_set_owner(d); | |
2053 | goto done; | |
2054 | } | |
2055 | ||
2056 | /* You must be the owner to do anything else */ | |
2057 | r = vhost_dev_check_owner(d); | |
2058 | if (r) | |
2059 | goto done; | |
2060 | ||
2061 | switch (ioctl) { | |
2062 | case VHOST_SET_MEM_TABLE: | |
2063 | r = vhost_set_memory(d, argp); | |
2064 | break; | |
2065 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
2066 | if (copy_from_user(&p, argp, sizeof p)) { |
2067 | r = -EFAULT; | |
3a4d5c94 | 2068 | break; |
7ad9c9d2 | 2069 | } |
3a4d5c94 MT |
2070 | if ((u64)(unsigned long)p != p) { |
2071 | r = -EFAULT; | |
2072 | break; | |
2073 | } | |
2074 | for (i = 0; i < d->nvqs; ++i) { | |
2075 | struct vhost_virtqueue *vq; | |
2076 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 2077 | vq = d->vqs[i]; |
3a4d5c94 MT |
2078 | mutex_lock(&vq->mutex); |
2079 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 2080 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
2081 | r = -EFAULT; |
2082 | else | |
2083 | vq->log_base = base; | |
2084 | mutex_unlock(&vq->mutex); | |
2085 | } | |
2086 | break; | |
2087 | case VHOST_SET_LOG_FD: | |
2088 | r = get_user(fd, (int __user *)argp); | |
2089 | if (r < 0) | |
2090 | break; | |
e0136c16 | 2091 | ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd); |
d25cc43c EB |
2092 | if (IS_ERR(ctx)) { |
2093 | r = PTR_ERR(ctx); | |
3a4d5c94 MT |
2094 | break; |
2095 | } | |
d25cc43c | 2096 | swap(ctx, d->log_ctx); |
3a4d5c94 | 2097 | for (i = 0; i < d->nvqs; ++i) { |
3ab2e420 AH |
2098 | mutex_lock(&d->vqs[i]->mutex); |
2099 | d->vqs[i]->log_ctx = d->log_ctx; | |
2100 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
2101 | } |
2102 | if (ctx) | |
2103 | eventfd_ctx_put(ctx); | |
3a4d5c94 MT |
2104 | break; |
2105 | default: | |
935cdee7 | 2106 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
2107 | break; |
2108 | } | |
2109 | done: | |
2110 | return r; | |
2111 | } | |
6ac1afbf | 2112 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 | 2113 | |
3a4d5c94 MT |
2114 | /* TODO: This is really inefficient. We need something like get_user() |
2115 | * (instruction directly accesses the data, with an exception table entry | |
ff61f079 | 2116 | * returning -EFAULT). See Documentation/arch/x86/exception-tables.rst. |
3a4d5c94 MT |
2117 | */ |
2118 | static int set_bit_to_user(int nr, void __user *addr) | |
2119 | { | |
2120 | unsigned long log = (unsigned long)addr; | |
2121 | struct page *page; | |
2122 | void *base; | |
2123 | int bit = nr + (log % PAGE_SIZE) * 8; | |
2124 | int r; | |
d47effe1 | 2125 | |
690623e1 | 2126 | r = pin_user_pages_fast(log, 1, FOLL_WRITE, &page); |
d6db3f5c | 2127 | if (r < 0) |
3a4d5c94 | 2128 | return r; |
d6db3f5c | 2129 | BUG_ON(r != 1); |
c6daa7ff | 2130 | base = kmap_atomic(page); |
3a4d5c94 | 2131 | set_bit(bit, base); |
c6daa7ff | 2132 | kunmap_atomic(base); |
690623e1 | 2133 | unpin_user_pages_dirty_lock(&page, 1, true); |
3a4d5c94 MT |
2134 | return 0; |
2135 | } | |
2136 | ||
2137 | static int log_write(void __user *log_base, | |
2138 | u64 write_address, u64 write_length) | |
2139 | { | |
28831ee6 | 2140 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 2141 | int r; |
d47effe1 | 2142 | |
3a4d5c94 MT |
2143 | if (!write_length) |
2144 | return 0; | |
3bf9be40 | 2145 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
2146 | for (;;) { |
2147 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
2148 | u64 log = base + write_page / 8; |
2149 | int bit = write_page % 8; | |
3a4d5c94 MT |
2150 | if ((u64)(unsigned long)log != log) |
2151 | return -EFAULT; | |
2152 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
2153 | if (r < 0) | |
2154 | return r; | |
2155 | if (write_length <= VHOST_PAGE_SIZE) | |
2156 | break; | |
2157 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 2158 | write_page += 1; |
3a4d5c94 MT |
2159 | } |
2160 | return r; | |
2161 | } | |
2162 | ||
cc5e7107 JW |
2163 | static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len) |
2164 | { | |
0bbe3066 JW |
2165 | struct vhost_iotlb *umem = vq->umem; |
2166 | struct vhost_iotlb_map *u; | |
cc5e7107 JW |
2167 | u64 start, end, l, min; |
2168 | int r; | |
2169 | bool hit = false; | |
2170 | ||
2171 | while (len) { | |
2172 | min = len; | |
2173 | /* More than one GPAs can be mapped into a single HVA. So | |
2174 | * iterate all possible umems here to be safe. | |
2175 | */ | |
0bbe3066 JW |
2176 | list_for_each_entry(u, &umem->list, link) { |
2177 | if (u->addr > hva - 1 + len || | |
2178 | u->addr - 1 + u->size < hva) | |
cc5e7107 | 2179 | continue; |
0bbe3066 JW |
2180 | start = max(u->addr, hva); |
2181 | end = min(u->addr - 1 + u->size, hva - 1 + len); | |
cc5e7107 JW |
2182 | l = end - start + 1; |
2183 | r = log_write(vq->log_base, | |
0bbe3066 | 2184 | u->start + start - u->addr, |
cc5e7107 JW |
2185 | l); |
2186 | if (r < 0) | |
2187 | return r; | |
2188 | hit = true; | |
2189 | min = min(l, min); | |
2190 | } | |
2191 | ||
2192 | if (!hit) | |
2193 | return -EFAULT; | |
2194 | ||
2195 | len -= min; | |
2196 | hva += min; | |
2197 | } | |
2198 | ||
2199 | return 0; | |
2200 | } | |
2201 | ||
2202 | static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) | |
2203 | { | |
5e5e8736 | 2204 | struct iovec *iov = vq->log_iov; |
cc5e7107 JW |
2205 | int i, ret; |
2206 | ||
2207 | if (!vq->iotlb) | |
2208 | return log_write(vq->log_base, vq->log_addr + used_offset, len); | |
2209 | ||
2210 | ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, | |
2211 | len, iov, 64, VHOST_ACCESS_WO); | |
816db766 | 2212 | if (ret < 0) |
cc5e7107 JW |
2213 | return ret; |
2214 | ||
2215 | for (i = 0; i < ret; i++) { | |
2216 | ret = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
2217 | iov[i].iov_len); | |
2218 | if (ret) | |
2219 | return ret; | |
2220 | } | |
2221 | ||
2222 | return 0; | |
2223 | } | |
2224 | ||
3a4d5c94 | 2225 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
cc5e7107 | 2226 | unsigned int log_num, u64 len, struct iovec *iov, int count) |
3a4d5c94 MT |
2227 | { |
2228 | int i, r; | |
2229 | ||
2230 | /* Make sure data written is seen before log. */ | |
5659338c | 2231 | smp_wmb(); |
cc5e7107 JW |
2232 | |
2233 | if (vq->iotlb) { | |
2234 | for (i = 0; i < count; i++) { | |
2235 | r = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
2236 | iov[i].iov_len); | |
2237 | if (r < 0) | |
2238 | return r; | |
2239 | } | |
2240 | return 0; | |
2241 | } | |
2242 | ||
3a4d5c94 MT |
2243 | for (i = 0; i < log_num; ++i) { |
2244 | u64 l = min(log[i].len, len); | |
2245 | r = log_write(vq->log_base, log[i].addr, l); | |
2246 | if (r < 0) | |
2247 | return r; | |
2248 | len -= l; | |
5786aee8 MT |
2249 | if (!len) { |
2250 | if (vq->log_ctx) | |
3652117f | 2251 | eventfd_signal(vq->log_ctx); |
3a4d5c94 | 2252 | return 0; |
5786aee8 | 2253 | } |
3a4d5c94 | 2254 | } |
3a4d5c94 MT |
2255 | /* Length written exceeds what we have stored. This is a bug. */ |
2256 | BUG(); | |
2257 | return 0; | |
2258 | } | |
6ac1afbf | 2259 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 2260 | |
2723feaa JW |
2261 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
2262 | { | |
2263 | void __user *used; | |
7b5d753e | 2264 | if (vhost_put_used_flags(vq)) |
2723feaa JW |
2265 | return -EFAULT; |
2266 | if (unlikely(vq->log_used)) { | |
2267 | /* Make sure the flag is seen before log. */ | |
2268 | smp_wmb(); | |
2269 | /* Log used flag write. */ | |
2270 | used = &vq->used->flags; | |
cc5e7107 JW |
2271 | log_used(vq, (used - (void __user *)vq->used), |
2272 | sizeof vq->used->flags); | |
2723feaa | 2273 | if (vq->log_ctx) |
3652117f | 2274 | eventfd_signal(vq->log_ctx); |
2723feaa JW |
2275 | } |
2276 | return 0; | |
2277 | } | |
2278 | ||
4c809363 | 2279 | static int vhost_update_avail_event(struct vhost_virtqueue *vq) |
2723feaa | 2280 | { |
7b5d753e | 2281 | if (vhost_put_avail_event(vq)) |
2723feaa JW |
2282 | return -EFAULT; |
2283 | if (unlikely(vq->log_used)) { | |
2284 | void __user *used; | |
2285 | /* Make sure the event is seen before log. */ | |
2286 | smp_wmb(); | |
2287 | /* Log avail event write */ | |
2288 | used = vhost_avail_event(vq); | |
cc5e7107 JW |
2289 | log_used(vq, (used - (void __user *)vq->used), |
2290 | sizeof *vhost_avail_event(vq)); | |
2723feaa | 2291 | if (vq->log_ctx) |
3652117f | 2292 | eventfd_signal(vq->log_ctx); |
2723feaa JW |
2293 | } |
2294 | return 0; | |
2295 | } | |
2296 | ||
80f7d030 | 2297 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 2298 | { |
3b1bbe89 | 2299 | __virtio16 last_used_idx; |
2723feaa | 2300 | int r; |
e1f33be9 GK |
2301 | bool is_le = vq->is_le; |
2302 | ||
cda8bba0 | 2303 | if (!vq->private_data) |
2723feaa | 2304 | return 0; |
2751c988 GK |
2305 | |
2306 | vhost_init_is_le(vq); | |
2723feaa JW |
2307 | |
2308 | r = vhost_update_used_flags(vq); | |
2309 | if (r) | |
e1f33be9 | 2310 | goto err; |
2723feaa | 2311 | vq->signalled_used_valid = false; |
6b1e6cc7 | 2312 | if (!vq->iotlb && |
96d4f267 | 2313 | !access_ok(&vq->used->idx, sizeof vq->used->idx)) { |
e1f33be9 GK |
2314 | r = -EFAULT; |
2315 | goto err; | |
2316 | } | |
7b5d753e | 2317 | r = vhost_get_used_idx(vq, &last_used_idx); |
6b1e6cc7 JW |
2318 | if (r) { |
2319 | vq_err(vq, "Can't access used idx at %p\n", | |
2320 | &vq->used->idx); | |
e1f33be9 | 2321 | goto err; |
6b1e6cc7 | 2322 | } |
3b1bbe89 | 2323 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 2324 | return 0; |
6b1e6cc7 | 2325 | |
e1f33be9 GK |
2326 | err: |
2327 | vq->is_le = is_le; | |
2328 | return r; | |
2723feaa | 2329 | } |
80f7d030 | 2330 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 2331 | |
47283bef | 2332 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
6b1e6cc7 | 2333 | struct iovec iov[], int iov_size, int access) |
3a4d5c94 | 2334 | { |
0bbe3066 | 2335 | const struct vhost_iotlb_map *map; |
6b1e6cc7 | 2336 | struct vhost_dev *dev = vq->dev; |
0bbe3066 | 2337 | struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem; |
3a4d5c94 | 2338 | struct iovec *_iov; |
98047313 | 2339 | u64 s = 0, last = addr + len - 1; |
3a4d5c94 MT |
2340 | int ret = 0; |
2341 | ||
3a4d5c94 MT |
2342 | while ((u64)len > s) { |
2343 | u64 size; | |
7b3384fc | 2344 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
2345 | ret = -ENOBUFS; |
2346 | break; | |
2347 | } | |
6b1e6cc7 | 2348 | |
98047313 | 2349 | map = vhost_iotlb_itree_first(umem, addr, last); |
0bbe3066 | 2350 | if (map == NULL || map->start > addr) { |
6b1e6cc7 JW |
2351 | if (umem != dev->iotlb) { |
2352 | ret = -EFAULT; | |
2353 | break; | |
2354 | } | |
2355 | ret = -EAGAIN; | |
2356 | break; | |
0bbe3066 | 2357 | } else if (!(map->perm & access)) { |
6b1e6cc7 | 2358 | ret = -EPERM; |
3a4d5c94 MT |
2359 | break; |
2360 | } | |
6b1e6cc7 | 2361 | |
3a4d5c94 | 2362 | _iov = iov + ret; |
0bbe3066 | 2363 | size = map->size - addr + map->start; |
bd97120f | 2364 | _iov->iov_len = min((u64)len - s, size); |
0d4a3f2a | 2365 | _iov->iov_base = (void __user *)(unsigned long) |
0bbe3066 | 2366 | (map->addr + addr - map->start); |
3a4d5c94 MT |
2367 | s += size; |
2368 | addr += size; | |
2369 | ++ret; | |
2370 | } | |
2371 | ||
6b1e6cc7 JW |
2372 | if (ret == -EAGAIN) |
2373 | vhost_iotlb_miss(vq, addr, access); | |
3a4d5c94 MT |
2374 | return ret; |
2375 | } | |
2376 | ||
2377 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
2378 | * function returns the next descriptor in the chain, | |
2379 | * or -1U if we're at the end. */ | |
3b1bbe89 | 2380 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
2381 | { |
2382 | unsigned int next; | |
2383 | ||
2384 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 2385 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
2386 | return -1U; |
2387 | ||
2388 | /* Check they're not leading us off end of descriptors. */ | |
3a5db0b1 | 2389 | next = vhost16_to_cpu(vq, READ_ONCE(desc->next)); |
3a4d5c94 MT |
2390 | return next; |
2391 | } | |
2392 | ||
47283bef | 2393 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc MT |
2394 | struct iovec iov[], unsigned int iov_size, |
2395 | unsigned int *out_num, unsigned int *in_num, | |
2396 | struct vhost_log *log, unsigned int *log_num, | |
2397 | struct vring_desc *indirect) | |
3a4d5c94 MT |
2398 | { |
2399 | struct vring_desc desc; | |
2400 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 2401 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 2402 | struct iov_iter from; |
6b1e6cc7 | 2403 | int ret, access; |
3a4d5c94 MT |
2404 | |
2405 | /* Sanity check */ | |
3b1bbe89 | 2406 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
2407 | vq_err(vq, "Invalid length in indirect descriptor: " |
2408 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 2409 | (unsigned long long)len, |
3a4d5c94 MT |
2410 | sizeof desc); |
2411 | return -EINVAL; | |
2412 | } | |
2413 | ||
3b1bbe89 | 2414 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
6b1e6cc7 | 2415 | UIO_MAXIOV, VHOST_ACCESS_RO); |
7b3384fc | 2416 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2417 | if (ret != -EAGAIN) |
2418 | vq_err(vq, "Translation failure %d in indirect.\n", ret); | |
3a4d5c94 MT |
2419 | return ret; |
2420 | } | |
de4eda9d | 2421 | iov_iter_init(&from, ITER_SOURCE, vq->indirect, ret, len); |
3b1bbe89 | 2422 | count = len / sizeof desc; |
3a4d5c94 MT |
2423 | /* Buffers are chained via a 16 bit next field, so |
2424 | * we can have at most 2^16 of these. */ | |
7b3384fc | 2425 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
2426 | vq_err(vq, "Indirect buffer length too big: %d\n", |
2427 | indirect->len); | |
2428 | return -E2BIG; | |
2429 | } | |
2430 | ||
2431 | do { | |
2432 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2433 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
2434 | vq_err(vq, "Loop detected: last one at %u " |
2435 | "indirect size %u\n", | |
2436 | i, count); | |
2437 | return -EINVAL; | |
2438 | } | |
cbbd26b8 | 2439 | if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) { |
3a4d5c94 | 2440 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2441 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2442 | return -EINVAL; |
2443 | } | |
3b1bbe89 | 2444 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 2445 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2446 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2447 | return -EINVAL; |
2448 | } | |
2449 | ||
6b1e6cc7 JW |
2450 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2451 | access = VHOST_ACCESS_WO; | |
2452 | else | |
2453 | access = VHOST_ACCESS_RO; | |
2454 | ||
3b1bbe89 MT |
2455 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2456 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2457 | iov_size - iov_count, access); |
7b3384fc | 2458 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2459 | if (ret != -EAGAIN) |
2460 | vq_err(vq, "Translation failure %d indirect idx %d\n", | |
2461 | ret, i); | |
3a4d5c94 MT |
2462 | return ret; |
2463 | } | |
2464 | /* If this is an input descriptor, increment that count. */ | |
6b1e6cc7 | 2465 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 | 2466 | *in_num += ret; |
060423bf | 2467 | if (unlikely(log && ret)) { |
3b1bbe89 MT |
2468 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2469 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2470 | ++*log_num; |
2471 | } | |
2472 | } else { | |
2473 | /* If it's an output descriptor, they're all supposed | |
2474 | * to come before any input descriptors. */ | |
7b3384fc | 2475 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2476 | vq_err(vq, "Indirect descriptor " |
2477 | "has out after in: idx %d\n", i); | |
2478 | return -EINVAL; | |
2479 | } | |
2480 | *out_num += ret; | |
2481 | } | |
3b1bbe89 | 2482 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2483 | return 0; |
2484 | } | |
2485 | ||
2486 | /* This looks in the virtqueue and for the first available buffer, and converts | |
2487 | * it to an iovec for convenient access. Since descriptors consist of some | |
2488 | * number of output then some number of input descriptors, it's actually two | |
2489 | * iovecs, but we pack them into one and note how many of each there were. | |
2490 | * | |
d5675bd2 MT |
2491 | * This function returns the descriptor number found, or vq->num (which is |
2492 | * never a valid descriptor number) if none was found. A negative code is | |
2493 | * returned on error. */ | |
47283bef | 2494 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
2495 | struct iovec iov[], unsigned int iov_size, |
2496 | unsigned int *out_num, unsigned int *in_num, | |
2497 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
2498 | { |
2499 | struct vring_desc desc; | |
2500 | unsigned int i, head, found = 0; | |
2501 | u16 last_avail_idx; | |
3b1bbe89 MT |
2502 | __virtio16 avail_idx; |
2503 | __virtio16 ring_head; | |
6b1e6cc7 | 2504 | int ret, access; |
3a4d5c94 MT |
2505 | |
2506 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
2507 | last_avail_idx = vq->last_avail_idx; | |
3a4d5c94 | 2508 | |
e3b56cdd | 2509 | if (vq->avail_idx == vq->last_avail_idx) { |
7b5d753e | 2510 | if (unlikely(vhost_get_avail_idx(vq, &avail_idx))) { |
e3b56cdd JW |
2511 | vq_err(vq, "Failed to access avail idx at %p\n", |
2512 | &vq->avail->idx); | |
2513 | return -EFAULT; | |
2514 | } | |
2515 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); | |
3a4d5c94 | 2516 | |
e3b56cdd | 2517 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
76f40853 | 2518 | vq_err(vq, "Guest moved avail index from %u to %u", |
e3b56cdd JW |
2519 | last_avail_idx, vq->avail_idx); |
2520 | return -EFAULT; | |
2521 | } | |
2522 | ||
2523 | /* If there's nothing new since last we looked, return | |
2524 | * invalid. | |
2525 | */ | |
2526 | if (vq->avail_idx == last_avail_idx) | |
2527 | return vq->num; | |
3a4d5c94 | 2528 | |
e3b56cdd JW |
2529 | /* Only get avail ring entries after they have been |
2530 | * exposed by guest. | |
2531 | */ | |
2532 | smp_rmb(); | |
2533 | } | |
3a4d5c94 MT |
2534 | |
2535 | /* Grab the next descriptor number they're advertising, and increment | |
2536 | * the index we've seen. */ | |
7b5d753e | 2537 | if (unlikely(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) { |
3a4d5c94 MT |
2538 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
2539 | last_avail_idx, | |
2540 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 2541 | return -EFAULT; |
3a4d5c94 MT |
2542 | } |
2543 | ||
3b1bbe89 MT |
2544 | head = vhost16_to_cpu(vq, ring_head); |
2545 | ||
3a4d5c94 | 2546 | /* If their number is silly, that's an error. */ |
7b3384fc | 2547 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
2548 | vq_err(vq, "Guest says index %u > %u is available", |
2549 | head, vq->num); | |
d5675bd2 | 2550 | return -EINVAL; |
3a4d5c94 MT |
2551 | } |
2552 | ||
2553 | /* When we start there are none of either input nor output. */ | |
2554 | *out_num = *in_num = 0; | |
2555 | if (unlikely(log)) | |
2556 | *log_num = 0; | |
2557 | ||
2558 | i = head; | |
2559 | do { | |
2560 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2561 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
2562 | vq_err(vq, "Desc index is %u > %u, head = %u", |
2563 | i, vq->num, head); | |
d5675bd2 | 2564 | return -EINVAL; |
3a4d5c94 | 2565 | } |
7b3384fc | 2566 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
2567 | vq_err(vq, "Loop detected: last one at %u " |
2568 | "vq size %u head %u\n", | |
2569 | i, vq->num, head); | |
d5675bd2 | 2570 | return -EINVAL; |
3a4d5c94 | 2571 | } |
7b5d753e | 2572 | ret = vhost_get_desc(vq, &desc, i); |
7b3384fc | 2573 | if (unlikely(ret)) { |
3a4d5c94 MT |
2574 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
2575 | i, vq->desc + i); | |
d5675bd2 | 2576 | return -EFAULT; |
3a4d5c94 | 2577 | } |
3b1bbe89 | 2578 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 2579 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
2580 | out_num, in_num, |
2581 | log, log_num, &desc); | |
7b3384fc | 2582 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2583 | if (ret != -EAGAIN) |
2584 | vq_err(vq, "Failure detected " | |
2585 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 2586 | return ret; |
3a4d5c94 MT |
2587 | } |
2588 | continue; | |
2589 | } | |
2590 | ||
6b1e6cc7 JW |
2591 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2592 | access = VHOST_ACCESS_WO; | |
2593 | else | |
2594 | access = VHOST_ACCESS_RO; | |
3b1bbe89 MT |
2595 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2596 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2597 | iov_size - iov_count, access); |
7b3384fc | 2598 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2599 | if (ret != -EAGAIN) |
2600 | vq_err(vq, "Translation failure %d descriptor idx %d\n", | |
2601 | ret, i); | |
d5675bd2 | 2602 | return ret; |
3a4d5c94 | 2603 | } |
6b1e6cc7 | 2604 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2605 | /* If this is an input descriptor, |
2606 | * increment that count. */ | |
2607 | *in_num += ret; | |
060423bf | 2608 | if (unlikely(log && ret)) { |
3b1bbe89 MT |
2609 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2610 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2611 | ++*log_num; |
2612 | } | |
2613 | } else { | |
2614 | /* If it's an output descriptor, they're all supposed | |
2615 | * to come before any input descriptors. */ | |
7b3384fc | 2616 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2617 | vq_err(vq, "Descriptor has out after in: " |
2618 | "idx %d\n", i); | |
d5675bd2 | 2619 | return -EINVAL; |
3a4d5c94 MT |
2620 | } |
2621 | *out_num += ret; | |
2622 | } | |
3b1bbe89 | 2623 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2624 | |
2625 | /* On success, increment avail index. */ | |
2626 | vq->last_avail_idx++; | |
8ea8cf89 MT |
2627 | |
2628 | /* Assume notifications from guest are disabled at this point, | |
2629 | * if they aren't we would need to update avail_event index. */ | |
2630 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
2631 | return head; |
2632 | } | |
6ac1afbf | 2633 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
2634 | |
2635 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 2636 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 2637 | { |
8dd014ad | 2638 | vq->last_avail_idx -= n; |
3a4d5c94 | 2639 | } |
6ac1afbf | 2640 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
2641 | |
2642 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2643 | * want to notify the guest, using eventfd. */ | |
2644 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
2645 | { | |
3b1bbe89 MT |
2646 | struct vring_used_elem heads = { |
2647 | cpu_to_vhost32(vq, head), | |
2648 | cpu_to_vhost32(vq, len) | |
2649 | }; | |
3a4d5c94 | 2650 | |
c49e4e57 | 2651 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 2652 | } |
6ac1afbf | 2653 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 2654 | |
8dd014ad DS |
2655 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2656 | struct vring_used_elem *heads, | |
2657 | unsigned count) | |
2658 | { | |
a865e420 | 2659 | vring_used_elem_t __user *used; |
8ea8cf89 | 2660 | u16 old, new; |
8dd014ad DS |
2661 | int start; |
2662 | ||
5fba13b5 | 2663 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 2664 | used = vq->used->ring + start; |
7b5d753e | 2665 | if (vhost_put_used(vq, heads, start, count)) { |
8dd014ad DS |
2666 | vq_err(vq, "Failed to write used"); |
2667 | return -EFAULT; | |
2668 | } | |
2669 | if (unlikely(vq->log_used)) { | |
2670 | /* Make sure data is seen before log. */ | |
2671 | smp_wmb(); | |
2672 | /* Log used ring entry write. */ | |
cc5e7107 JW |
2673 | log_used(vq, ((void __user *)used - (void __user *)vq->used), |
2674 | count * sizeof *used); | |
8dd014ad | 2675 | } |
8ea8cf89 MT |
2676 | old = vq->last_used_idx; |
2677 | new = (vq->last_used_idx += count); | |
2678 | /* If the driver never bothers to signal in a very long while, | |
2679 | * used index might wrap around. If that happens, invalidate | |
2680 | * signalled_used index we stored. TODO: make sure driver | |
2681 | * signals at least once in 2^16 and remove this. */ | |
2682 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
2683 | vq->signalled_used_valid = false; | |
8dd014ad DS |
2684 | return 0; |
2685 | } | |
2686 | ||
2687 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2688 | * want to notify the guest, using eventfd. */ | |
2689 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
2690 | unsigned count) | |
2691 | { | |
2692 | int start, n, r; | |
2693 | ||
5fba13b5 | 2694 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
2695 | n = vq->num - start; |
2696 | if (n < count) { | |
2697 | r = __vhost_add_used_n(vq, heads, n); | |
2698 | if (r < 0) | |
2699 | return r; | |
2700 | heads += n; | |
2701 | count -= n; | |
2702 | } | |
2703 | r = __vhost_add_used_n(vq, heads, count); | |
2704 | ||
2705 | /* Make sure buffer is written before we update index. */ | |
2706 | smp_wmb(); | |
7b5d753e | 2707 | if (vhost_put_used_idx(vq)) { |
8dd014ad DS |
2708 | vq_err(vq, "Failed to increment used idx"); |
2709 | return -EFAULT; | |
2710 | } | |
2711 | if (unlikely(vq->log_used)) { | |
841df922 JW |
2712 | /* Make sure used idx is seen before log. */ |
2713 | smp_wmb(); | |
8dd014ad | 2714 | /* Log used index update. */ |
cc5e7107 JW |
2715 | log_used(vq, offsetof(struct vring_used, idx), |
2716 | sizeof vq->used->idx); | |
8dd014ad | 2717 | if (vq->log_ctx) |
3652117f | 2718 | eventfd_signal(vq->log_ctx); |
8dd014ad DS |
2719 | } |
2720 | return r; | |
2721 | } | |
6ac1afbf | 2722 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 2723 | |
8ea8cf89 | 2724 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2725 | { |
3b1bbe89 MT |
2726 | __u16 old, new; |
2727 | __virtio16 event; | |
8ea8cf89 | 2728 | bool v; |
8d65843c JW |
2729 | /* Flush out used index updates. This is paired |
2730 | * with the barrier that the Guest executes when enabling | |
2731 | * interrupts. */ | |
2732 | smp_mb(); | |
0d499356 | 2733 | |
ea16c514 | 2734 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
2735 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2736 | return true; | |
2737 | ||
ea16c514 | 2738 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 2739 | __virtio16 flags; |
7b5d753e | 2740 | if (vhost_get_avail_flags(vq, &flags)) { |
8ea8cf89 MT |
2741 | vq_err(vq, "Failed to get flags"); |
2742 | return true; | |
2743 | } | |
3b1bbe89 | 2744 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 2745 | } |
8ea8cf89 MT |
2746 | old = vq->signalled_used; |
2747 | v = vq->signalled_used_valid; | |
2748 | new = vq->signalled_used = vq->last_used_idx; | |
2749 | vq->signalled_used_valid = true; | |
3a4d5c94 | 2750 | |
8ea8cf89 MT |
2751 | if (unlikely(!v)) |
2752 | return true; | |
3a4d5c94 | 2753 | |
7b5d753e | 2754 | if (vhost_get_used_event(vq, &event)) { |
8ea8cf89 MT |
2755 | vq_err(vq, "Failed to get used event idx"); |
2756 | return true; | |
2757 | } | |
8d65843c | 2758 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
2759 | } |
2760 | ||
2761 | /* This actually signals the guest, using eventfd. */ | |
2762 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2763 | { | |
3a4d5c94 | 2764 | /* Signal the Guest tell them we used something up. */ |
265a0ad8 | 2765 | if (vq->call_ctx.ctx && vhost_notify(dev, vq)) |
3652117f | 2766 | eventfd_signal(vq->call_ctx.ctx); |
3a4d5c94 | 2767 | } |
6ac1afbf | 2768 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
2769 | |
2770 | /* And here's the combo meal deal. Supersize me! */ | |
2771 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
2772 | struct vhost_virtqueue *vq, | |
2773 | unsigned int head, int len) | |
2774 | { | |
2775 | vhost_add_used(vq, head, len); | |
2776 | vhost_signal(dev, vq); | |
2777 | } | |
6ac1afbf | 2778 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 2779 | |
8dd014ad DS |
2780 | /* multi-buffer version of vhost_add_used_and_signal */ |
2781 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
2782 | struct vhost_virtqueue *vq, | |
2783 | struct vring_used_elem *heads, unsigned count) | |
2784 | { | |
2785 | vhost_add_used_n(vq, heads, count); | |
2786 | vhost_signal(dev, vq); | |
2787 | } | |
6ac1afbf | 2788 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 2789 | |
d4a60603 JW |
2790 | /* return true if we're sure that avaiable ring is empty */ |
2791 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2792 | { | |
2793 | __virtio16 avail_idx; | |
2794 | int r; | |
2795 | ||
275bf960 JW |
2796 | if (vq->avail_idx != vq->last_avail_idx) |
2797 | return false; | |
2798 | ||
7b5d753e | 2799 | r = vhost_get_avail_idx(vq, &avail_idx); |
275bf960 | 2800 | if (unlikely(r)) |
d4a60603 | 2801 | return false; |
22e1992c | 2802 | |
275bf960 | 2803 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
22e1992c GS |
2804 | if (vq->avail_idx != vq->last_avail_idx) { |
2805 | /* Since we have updated avail_idx, the following | |
2806 | * call to vhost_get_vq_desc() will read available | |
2807 | * ring entries. Make sure that read happens after | |
2808 | * the avail_idx read. | |
2809 | */ | |
2810 | smp_rmb(); | |
2811 | return false; | |
2812 | } | |
d4a60603 | 2813 | |
22e1992c | 2814 | return true; |
d4a60603 JW |
2815 | } |
2816 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
2817 | ||
3a4d5c94 | 2818 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 2819 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2820 | { |
3b1bbe89 | 2821 | __virtio16 avail_idx; |
3a4d5c94 | 2822 | int r; |
d47effe1 | 2823 | |
3a4d5c94 MT |
2824 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2825 | return false; | |
2826 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2827 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2828 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2829 | if (r) { |
2830 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2831 | &vq->used->flags, r); | |
2832 | return false; | |
2833 | } | |
2834 | } else { | |
4c809363 | 2835 | r = vhost_update_avail_event(vq); |
8ea8cf89 MT |
2836 | if (r) { |
2837 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
2838 | vhost_avail_event(vq), r); | |
2839 | return false; | |
2840 | } | |
2841 | } | |
3a4d5c94 MT |
2842 | /* They could have slipped one in as we were doing that: make |
2843 | * sure it's written, then check again. */ | |
5659338c | 2844 | smp_mb(); |
7b5d753e | 2845 | r = vhost_get_avail_idx(vq, &avail_idx); |
3a4d5c94 MT |
2846 | if (r) { |
2847 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
2848 | &vq->avail->idx, r); | |
2849 | return false; | |
2850 | } | |
df9ace76 | 2851 | |
d3bb267b | 2852 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
df9ace76 GS |
2853 | if (vq->avail_idx != vq->last_avail_idx) { |
2854 | /* Since we have updated avail_idx, the following | |
2855 | * call to vhost_get_vq_desc() will read available | |
2856 | * ring entries. Make sure that read happens after | |
2857 | * the avail_idx read. | |
2858 | */ | |
2859 | smp_rmb(); | |
2860 | return true; | |
2861 | } | |
3a4d5c94 | 2862 | |
df9ace76 | 2863 | return false; |
3a4d5c94 | 2864 | } |
6ac1afbf | 2865 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
2866 | |
2867 | /* We don't need to be notified again. */ | |
8ea8cf89 | 2868 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
2869 | { |
2870 | int r; | |
d47effe1 | 2871 | |
3a4d5c94 MT |
2872 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2873 | return; | |
2874 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2875 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2876 | r = vhost_update_used_flags(vq); |
8ea8cf89 | 2877 | if (r) |
ae6961de | 2878 | vq_err(vq, "Failed to disable notification at %p: %d\n", |
8ea8cf89 MT |
2879 | &vq->used->flags, r); |
2880 | } | |
3a4d5c94 | 2881 | } |
6ac1afbf AH |
2882 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2883 | ||
6b1e6cc7 JW |
2884 | /* Create a new message. */ |
2885 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) | |
2886 | { | |
4d8df0f5 PB |
2887 | /* Make sure all padding within the structure is initialized. */ |
2888 | struct vhost_msg_node *node = kzalloc(sizeof(*node), GFP_KERNEL); | |
6b1e6cc7 JW |
2889 | if (!node) |
2890 | return NULL; | |
670ae9ca | 2891 | |
6b1e6cc7 JW |
2892 | node->vq = vq; |
2893 | node->msg.type = type; | |
2894 | return node; | |
2895 | } | |
2896 | EXPORT_SYMBOL_GPL(vhost_new_msg); | |
2897 | ||
2898 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, | |
2899 | struct vhost_msg_node *node) | |
2900 | { | |
2901 | spin_lock(&dev->iotlb_lock); | |
2902 | list_add_tail(&node->node, head); | |
2903 | spin_unlock(&dev->iotlb_lock); | |
2904 | ||
a9a08845 | 2905 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
6b1e6cc7 JW |
2906 | } |
2907 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); | |
2908 | ||
2909 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, | |
2910 | struct list_head *head) | |
2911 | { | |
2912 | struct vhost_msg_node *node = NULL; | |
2913 | ||
2914 | spin_lock(&dev->iotlb_lock); | |
2915 | if (!list_empty(head)) { | |
2916 | node = list_first_entry(head, struct vhost_msg_node, | |
2917 | node); | |
2918 | list_del(&node->node); | |
2919 | } | |
2920 | spin_unlock(&dev->iotlb_lock); | |
2921 | ||
2922 | return node; | |
2923 | } | |
2924 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); | |
2925 | ||
460f7ce1 JW |
2926 | void vhost_set_backend_features(struct vhost_dev *dev, u64 features) |
2927 | { | |
2928 | struct vhost_virtqueue *vq; | |
2929 | int i; | |
2930 | ||
2931 | mutex_lock(&dev->mutex); | |
2932 | for (i = 0; i < dev->nvqs; ++i) { | |
2933 | vq = dev->vqs[i]; | |
2934 | mutex_lock(&vq->mutex); | |
2935 | vq->acked_backend_features = features; | |
2936 | mutex_unlock(&vq->mutex); | |
2937 | } | |
2938 | mutex_unlock(&dev->mutex); | |
2939 | } | |
2940 | EXPORT_SYMBOL_GPL(vhost_set_backend_features); | |
6b1e6cc7 | 2941 | |
6ac1afbf AH |
2942 | static int __init vhost_init(void) |
2943 | { | |
2944 | return 0; | |
2945 | } | |
2946 | ||
2947 | static void __exit vhost_exit(void) | |
2948 | { | |
2949 | } | |
2950 | ||
2951 | module_init(vhost_init); | |
2952 | module_exit(vhost_exit); | |
2953 | ||
2954 | MODULE_VERSION("0.0.1"); | |
2955 | MODULE_LICENSE("GPL v2"); | |
2956 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
2957 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |