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 | 16 | #include <linux/mm.h> |
64e1c807 | 17 | #include <linux/mmu_context.h> |
3a4d5c94 MT |
18 | #include <linux/miscdevice.h> |
19 | #include <linux/mutex.h> | |
3a4d5c94 MT |
20 | #include <linux/poll.h> |
21 | #include <linux/file.h> | |
22 | #include <linux/highmem.h> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
4de7255f | 24 | #include <linux/vmalloc.h> |
c23f3445 | 25 | #include <linux/kthread.h> |
9e3d1957 | 26 | #include <linux/cgroup.h> |
6ac1afbf | 27 | #include <linux/module.h> |
bcfeacab | 28 | #include <linux/sort.h> |
6e84f315 | 29 | #include <linux/sched/mm.h> |
174cd4b1 | 30 | #include <linux/sched/signal.h> |
a9709d68 | 31 | #include <linux/interval_tree_generic.h> |
ff002269 | 32 | #include <linux/nospec.h> |
3a4d5c94 | 33 | |
3a4d5c94 MT |
34 | #include "vhost.h" |
35 | ||
c9ce42f7 IM |
36 | static ushort max_mem_regions = 64; |
37 | module_param(max_mem_regions, ushort, 0444); | |
38 | MODULE_PARM_DESC(max_mem_regions, | |
39 | "Maximum number of memory regions in memory map. (default: 64)"); | |
6b1e6cc7 JW |
40 | static int max_iotlb_entries = 2048; |
41 | module_param(max_iotlb_entries, int, 0444); | |
42 | MODULE_PARM_DESC(max_iotlb_entries, | |
43 | "Maximum number of iotlb entries. (default: 2048)"); | |
c9ce42f7 | 44 | |
3a4d5c94 | 45 | enum { |
3a4d5c94 MT |
46 | VHOST_MEMORY_F_LOG = 0x1, |
47 | }; | |
48 | ||
3b1bbe89 MT |
49 | #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) |
50 | #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) | |
8ea8cf89 | 51 | |
a9709d68 JW |
52 | INTERVAL_TREE_DEFINE(struct vhost_umem_node, |
53 | rb, __u64, __subtree_last, | |
2f952c01 | 54 | START, LAST, static inline, vhost_umem_interval_tree); |
a9709d68 | 55 | |
2751c988 | 56 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
c5072037 | 57 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
58 | { |
59 | vq->user_be = !virtio_legacy_is_little_endian(); | |
60 | } | |
61 | ||
c5072037 GK |
62 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
63 | { | |
64 | vq->user_be = true; | |
65 | } | |
66 | ||
67 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) | |
68 | { | |
69 | vq->user_be = false; | |
70 | } | |
71 | ||
2751c988 GK |
72 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
73 | { | |
74 | struct vhost_vring_state s; | |
75 | ||
76 | if (vq->private_data) | |
77 | return -EBUSY; | |
78 | ||
79 | if (copy_from_user(&s, argp, sizeof(s))) | |
80 | return -EFAULT; | |
81 | ||
82 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && | |
83 | s.num != VHOST_VRING_BIG_ENDIAN) | |
84 | return -EINVAL; | |
85 | ||
c5072037 GK |
86 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
87 | vhost_enable_cross_endian_big(vq); | |
88 | else | |
89 | vhost_enable_cross_endian_little(vq); | |
2751c988 GK |
90 | |
91 | return 0; | |
92 | } | |
93 | ||
94 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
95 | int __user *argp) | |
96 | { | |
97 | struct vhost_vring_state s = { | |
98 | .index = idx, | |
99 | .num = vq->user_be | |
100 | }; | |
101 | ||
102 | if (copy_to_user(argp, &s, sizeof(s))) | |
103 | return -EFAULT; | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
108 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
109 | { | |
110 | /* Note for legacy virtio: user_be is initialized at reset time | |
111 | * according to the host endianness. If userspace does not set an | |
112 | * explicit endianness, the default behavior is native endian, as | |
113 | * expected by legacy virtio. | |
114 | */ | |
115 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; | |
116 | } | |
117 | #else | |
c5072037 | 118 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
119 | { |
120 | } | |
121 | ||
122 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) | |
123 | { | |
124 | return -ENOIOCTLCMD; | |
125 | } | |
126 | ||
127 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
128 | int __user *argp) | |
129 | { | |
130 | return -ENOIOCTLCMD; | |
131 | } | |
132 | ||
133 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
134 | { | |
cda8bba0 HP |
135 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) |
136 | || virtio_legacy_is_little_endian(); | |
2751c988 GK |
137 | } |
138 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ | |
139 | ||
c5072037 GK |
140 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
141 | { | |
cda8bba0 | 142 | vhost_init_is_le(vq); |
c5072037 GK |
143 | } |
144 | ||
7235acdb JW |
145 | struct vhost_flush_struct { |
146 | struct vhost_work work; | |
147 | struct completion wait_event; | |
148 | }; | |
149 | ||
150 | static void vhost_flush_work(struct vhost_work *work) | |
151 | { | |
152 | struct vhost_flush_struct *s; | |
153 | ||
154 | s = container_of(work, struct vhost_flush_struct, work); | |
155 | complete(&s->wait_event); | |
156 | } | |
157 | ||
3a4d5c94 MT |
158 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
159 | poll_table *pt) | |
160 | { | |
161 | struct vhost_poll *poll; | |
3a4d5c94 | 162 | |
d47effe1 | 163 | poll = container_of(pt, struct vhost_poll, table); |
3a4d5c94 MT |
164 | poll->wqh = wqh; |
165 | add_wait_queue(wqh, &poll->wait); | |
166 | } | |
167 | ||
ac6424b9 | 168 | static int vhost_poll_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, |
3a4d5c94 MT |
169 | void *key) |
170 | { | |
c23f3445 TH |
171 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
172 | ||
3ad6f93e | 173 | if (!(key_to_poll(key) & poll->mask)) |
3a4d5c94 MT |
174 | return 0; |
175 | ||
c23f3445 | 176 | vhost_poll_queue(poll); |
3a4d5c94 MT |
177 | return 0; |
178 | } | |
179 | ||
163049ae | 180 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
87d6a412 | 181 | { |
04b96e55 | 182 | clear_bit(VHOST_WORK_QUEUED, &work->flags); |
87d6a412 | 183 | work->fn = fn; |
87d6a412 | 184 | } |
6ac1afbf | 185 | EXPORT_SYMBOL_GPL(vhost_work_init); |
87d6a412 | 186 | |
3a4d5c94 | 187 | /* Init poll structure */ |
c23f3445 | 188 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
58e3b602 | 189 | __poll_t mask, struct vhost_dev *dev) |
3a4d5c94 | 190 | { |
3a4d5c94 MT |
191 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
192 | init_poll_funcptr(&poll->table, vhost_poll_func); | |
193 | poll->mask = mask; | |
c23f3445 | 194 | poll->dev = dev; |
2b8b328b | 195 | poll->wqh = NULL; |
c23f3445 | 196 | |
87d6a412 | 197 | vhost_work_init(&poll->work, fn); |
3a4d5c94 | 198 | } |
6ac1afbf | 199 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
3a4d5c94 MT |
200 | |
201 | /* Start polling a file. We add ourselves to file's wait queue. The caller must | |
202 | * keep a reference to a file until after vhost_poll_stop is called. */ | |
2b8b328b | 203 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
3a4d5c94 | 204 | { |
e6c8adca | 205 | __poll_t mask; |
2b8b328b | 206 | int ret = 0; |
d47effe1 | 207 | |
70181d51 JW |
208 | if (poll->wqh) |
209 | return 0; | |
210 | ||
9965ed17 | 211 | mask = vfs_poll(file, &poll->table); |
3a4d5c94 | 212 | if (mask) |
3ad6f93e | 213 | vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); |
a9a08845 | 214 | if (mask & EPOLLERR) { |
dc6455a7 | 215 | vhost_poll_stop(poll); |
2b8b328b JW |
216 | ret = -EINVAL; |
217 | } | |
218 | ||
219 | return ret; | |
3a4d5c94 | 220 | } |
6ac1afbf | 221 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
222 | |
223 | /* Stop polling a file. After this function returns, it becomes safe to drop the | |
224 | * file reference. You must also flush afterwards. */ | |
225 | void vhost_poll_stop(struct vhost_poll *poll) | |
226 | { | |
2b8b328b JW |
227 | if (poll->wqh) { |
228 | remove_wait_queue(poll->wqh, &poll->wait); | |
229 | poll->wqh = NULL; | |
230 | } | |
3a4d5c94 | 231 | } |
6ac1afbf | 232 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 233 | |
7235acdb | 234 | void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
0174b0c3 | 235 | { |
7235acdb | 236 | struct vhost_flush_struct flush; |
d47effe1 | 237 | |
7235acdb JW |
238 | if (dev->worker) { |
239 | init_completion(&flush.wait_event); | |
240 | vhost_work_init(&flush.work, vhost_flush_work); | |
0174b0c3 | 241 | |
7235acdb JW |
242 | vhost_work_queue(dev, &flush.work); |
243 | wait_for_completion(&flush.wait_event); | |
244 | } | |
3a4d5c94 | 245 | } |
6ac1afbf | 246 | EXPORT_SYMBOL_GPL(vhost_work_flush); |
3a4d5c94 | 247 | |
87d6a412 MT |
248 | /* Flush any work that has been scheduled. When calling this, don't hold any |
249 | * locks that are also used by the callback. */ | |
250 | void vhost_poll_flush(struct vhost_poll *poll) | |
251 | { | |
252 | vhost_work_flush(poll->dev, &poll->work); | |
253 | } | |
6ac1afbf | 254 | EXPORT_SYMBOL_GPL(vhost_poll_flush); |
87d6a412 | 255 | |
163049ae | 256 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 257 | { |
04b96e55 JW |
258 | if (!dev->worker) |
259 | return; | |
c23f3445 | 260 | |
04b96e55 JW |
261 | if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { |
262 | /* We can only add the work to the list after we're | |
263 | * sure it was not in the list. | |
635abf01 | 264 | * test_and_set_bit() implies a memory barrier. |
04b96e55 | 265 | */ |
04b96e55 | 266 | llist_add(&work->node, &dev->work_list); |
c23f3445 TH |
267 | wake_up_process(dev->worker); |
268 | } | |
3a4d5c94 | 269 | } |
6ac1afbf | 270 | EXPORT_SYMBOL_GPL(vhost_work_queue); |
3a4d5c94 | 271 | |
526d3e7f JW |
272 | /* A lockless hint for busy polling code to exit the loop */ |
273 | bool vhost_has_work(struct vhost_dev *dev) | |
274 | { | |
04b96e55 | 275 | return !llist_empty(&dev->work_list); |
526d3e7f JW |
276 | } |
277 | EXPORT_SYMBOL_GPL(vhost_has_work); | |
278 | ||
87d6a412 MT |
279 | void vhost_poll_queue(struct vhost_poll *poll) |
280 | { | |
281 | vhost_work_queue(poll->dev, &poll->work); | |
282 | } | |
6ac1afbf | 283 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 284 | |
f8894913 JW |
285 | static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq) |
286 | { | |
287 | int j; | |
288 | ||
289 | for (j = 0; j < VHOST_NUM_ADDRS; j++) | |
290 | vq->meta_iotlb[j] = NULL; | |
291 | } | |
292 | ||
293 | static void vhost_vq_meta_reset(struct vhost_dev *d) | |
294 | { | |
295 | int i; | |
296 | ||
86a07da3 | 297 | for (i = 0; i < d->nvqs; ++i) |
f8894913 JW |
298 | __vhost_vq_meta_reset(d->vqs[i]); |
299 | } | |
300 | ||
3a4d5c94 MT |
301 | static void vhost_vq_reset(struct vhost_dev *dev, |
302 | struct vhost_virtqueue *vq) | |
303 | { | |
304 | vq->num = 1; | |
305 | vq->desc = NULL; | |
306 | vq->avail = NULL; | |
307 | vq->used = NULL; | |
308 | vq->last_avail_idx = 0; | |
309 | vq->avail_idx = 0; | |
310 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
311 | vq->signalled_used = 0; |
312 | vq->signalled_used_valid = false; | |
3a4d5c94 | 313 | vq->used_flags = 0; |
3a4d5c94 MT |
314 | vq->log_used = false; |
315 | vq->log_addr = -1ull; | |
3a4d5c94 | 316 | vq->private_data = NULL; |
ea16c514 | 317 | vq->acked_features = 0; |
429711ae | 318 | vq->acked_backend_features = 0; |
3a4d5c94 MT |
319 | vq->log_base = NULL; |
320 | vq->error_ctx = NULL; | |
3a4d5c94 MT |
321 | vq->kick = NULL; |
322 | vq->call_ctx = NULL; | |
73a99f08 | 323 | vq->log_ctx = NULL; |
c5072037 GK |
324 | vhost_reset_is_le(vq); |
325 | vhost_disable_cross_endian(vq); | |
03088137 | 326 | vq->busyloop_timeout = 0; |
a9709d68 | 327 | vq->umem = NULL; |
6b1e6cc7 | 328 | vq->iotlb = NULL; |
f8894913 | 329 | __vhost_vq_meta_reset(vq); |
3a4d5c94 MT |
330 | } |
331 | ||
c23f3445 TH |
332 | static int vhost_worker(void *data) |
333 | { | |
334 | struct vhost_dev *dev = data; | |
04b96e55 JW |
335 | struct vhost_work *work, *work_next; |
336 | struct llist_node *node; | |
d7ffde35 | 337 | mm_segment_t oldfs = get_fs(); |
c23f3445 | 338 | |
d7ffde35 | 339 | set_fs(USER_DS); |
64e1c807 MT |
340 | use_mm(dev->mm); |
341 | ||
c23f3445 TH |
342 | for (;;) { |
343 | /* mb paired w/ kthread_stop */ | |
344 | set_current_state(TASK_INTERRUPTIBLE); | |
345 | ||
c23f3445 | 346 | if (kthread_should_stop()) { |
c23f3445 | 347 | __set_current_state(TASK_RUNNING); |
64e1c807 | 348 | break; |
c23f3445 | 349 | } |
04b96e55 JW |
350 | |
351 | node = llist_del_all(&dev->work_list); | |
352 | if (!node) | |
353 | schedule(); | |
354 | ||
355 | node = llist_reverse_order(node); | |
356 | /* make sure flag is seen after deletion */ | |
357 | smp_wmb(); | |
358 | llist_for_each_entry_safe(work, work_next, node, node) { | |
359 | clear_bit(VHOST_WORK_QUEUED, &work->flags); | |
c23f3445 TH |
360 | __set_current_state(TASK_RUNNING); |
361 | work->fn(work); | |
d550dda1 NHE |
362 | if (need_resched()) |
363 | schedule(); | |
04b96e55 | 364 | } |
c23f3445 | 365 | } |
64e1c807 | 366 | unuse_mm(dev->mm); |
d7ffde35 | 367 | set_fs(oldfs); |
64e1c807 | 368 | return 0; |
c23f3445 TH |
369 | } |
370 | ||
bab632d6 MT |
371 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
372 | { | |
373 | kfree(vq->indirect); | |
374 | vq->indirect = NULL; | |
375 | kfree(vq->log); | |
376 | vq->log = NULL; | |
377 | kfree(vq->heads); | |
378 | vq->heads = NULL; | |
bab632d6 MT |
379 | } |
380 | ||
e0e9b406 JW |
381 | /* Helper to allocate iovec buffers for all vqs. */ |
382 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
383 | { | |
6d5e6aa8 | 384 | struct vhost_virtqueue *vq; |
e0e9b406 | 385 | int i; |
d47effe1 | 386 | |
e0e9b406 | 387 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 | 388 | vq = dev->vqs[i]; |
6da2ec56 KC |
389 | vq->indirect = kmalloc_array(UIO_MAXIOV, |
390 | sizeof(*vq->indirect), | |
391 | GFP_KERNEL); | |
b46a0bf7 | 392 | vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), |
6da2ec56 | 393 | GFP_KERNEL); |
b46a0bf7 | 394 | vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), |
6da2ec56 | 395 | GFP_KERNEL); |
6d5e6aa8 | 396 | if (!vq->indirect || !vq->log || !vq->heads) |
e0e9b406 JW |
397 | goto err_nomem; |
398 | } | |
399 | return 0; | |
d47effe1 | 400 | |
e0e9b406 | 401 | err_nomem: |
bab632d6 | 402 | for (; i >= 0; --i) |
3ab2e420 | 403 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
404 | return -ENOMEM; |
405 | } | |
406 | ||
407 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
408 | { | |
409 | int i; | |
d47effe1 | 410 | |
bab632d6 | 411 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 412 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
413 | } |
414 | ||
e82b9b07 JW |
415 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, |
416 | int pkts, int total_len) | |
417 | { | |
418 | struct vhost_dev *dev = vq->dev; | |
419 | ||
420 | if ((dev->byte_weight && total_len >= dev->byte_weight) || | |
421 | pkts >= dev->weight) { | |
422 | vhost_poll_queue(&vq->poll); | |
423 | return true; | |
424 | } | |
425 | ||
426 | return false; | |
427 | } | |
428 | EXPORT_SYMBOL_GPL(vhost_exceeds_weight); | |
429 | ||
59566b6e | 430 | void vhost_dev_init(struct vhost_dev *dev, |
e82b9b07 JW |
431 | struct vhost_virtqueue **vqs, int nvqs, |
432 | int iov_limit, int weight, int byte_weight) | |
3a4d5c94 | 433 | { |
6d5e6aa8 | 434 | struct vhost_virtqueue *vq; |
3a4d5c94 | 435 | int i; |
c23f3445 | 436 | |
3a4d5c94 MT |
437 | dev->vqs = vqs; |
438 | dev->nvqs = nvqs; | |
439 | mutex_init(&dev->mutex); | |
440 | dev->log_ctx = NULL; | |
a9709d68 | 441 | dev->umem = NULL; |
6b1e6cc7 | 442 | dev->iotlb = NULL; |
3a4d5c94 | 443 | dev->mm = NULL; |
c23f3445 | 444 | dev->worker = NULL; |
b46a0bf7 | 445 | dev->iov_limit = iov_limit; |
e82b9b07 JW |
446 | dev->weight = weight; |
447 | dev->byte_weight = byte_weight; | |
04b96e55 | 448 | init_llist_head(&dev->work_list); |
6b1e6cc7 JW |
449 | init_waitqueue_head(&dev->wait); |
450 | INIT_LIST_HEAD(&dev->read_list); | |
451 | INIT_LIST_HEAD(&dev->pending_list); | |
452 | spin_lock_init(&dev->iotlb_lock); | |
04b96e55 | 453 | |
3a4d5c94 MT |
454 | |
455 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
456 | vq = dev->vqs[i]; |
457 | vq->log = NULL; | |
458 | vq->indirect = NULL; | |
459 | vq->heads = NULL; | |
460 | vq->dev = dev; | |
461 | mutex_init(&vq->mutex); | |
462 | vhost_vq_reset(dev, vq); | |
463 | if (vq->handle_kick) | |
464 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
a9a08845 | 465 | EPOLLIN, dev); |
3a4d5c94 | 466 | } |
3a4d5c94 | 467 | } |
6ac1afbf | 468 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
469 | |
470 | /* Caller should have device mutex */ | |
471 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
472 | { | |
473 | /* Are you the owner? If not, I don't think you mean to do that */ | |
474 | return dev->mm == current->mm ? 0 : -EPERM; | |
475 | } | |
6ac1afbf | 476 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 477 | |
87d6a412 | 478 | struct vhost_attach_cgroups_struct { |
d47effe1 KK |
479 | struct vhost_work work; |
480 | struct task_struct *owner; | |
481 | int ret; | |
87d6a412 MT |
482 | }; |
483 | ||
484 | static void vhost_attach_cgroups_work(struct vhost_work *work) | |
485 | { | |
d47effe1 KK |
486 | struct vhost_attach_cgroups_struct *s; |
487 | ||
488 | s = container_of(work, struct vhost_attach_cgroups_struct, work); | |
489 | s->ret = cgroup_attach_task_all(s->owner, current); | |
87d6a412 MT |
490 | } |
491 | ||
492 | static int vhost_attach_cgroups(struct vhost_dev *dev) | |
493 | { | |
d47effe1 KK |
494 | struct vhost_attach_cgroups_struct attach; |
495 | ||
496 | attach.owner = current; | |
497 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); | |
498 | vhost_work_queue(dev, &attach.work); | |
499 | vhost_work_flush(dev, &attach.work); | |
500 | return attach.ret; | |
87d6a412 MT |
501 | } |
502 | ||
05c05351 MT |
503 | /* Caller should have device mutex */ |
504 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
505 | { | |
506 | return dev->mm; | |
507 | } | |
6ac1afbf | 508 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 509 | |
3a4d5c94 | 510 | /* Caller should have device mutex */ |
54db63c2 | 511 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 512 | { |
c23f3445 TH |
513 | struct task_struct *worker; |
514 | int err; | |
d47effe1 | 515 | |
3a4d5c94 | 516 | /* Is there an owner already? */ |
05c05351 | 517 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
518 | err = -EBUSY; |
519 | goto err_mm; | |
520 | } | |
d47effe1 | 521 | |
3a4d5c94 MT |
522 | /* No owner, become one */ |
523 | dev->mm = get_task_mm(current); | |
c23f3445 TH |
524 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
525 | if (IS_ERR(worker)) { | |
526 | err = PTR_ERR(worker); | |
527 | goto err_worker; | |
528 | } | |
529 | ||
530 | dev->worker = worker; | |
87d6a412 MT |
531 | wake_up_process(worker); /* avoid contributing to loadavg */ |
532 | ||
533 | err = vhost_attach_cgroups(dev); | |
9e3d1957 MT |
534 | if (err) |
535 | goto err_cgroup; | |
c23f3445 | 536 | |
e0e9b406 JW |
537 | err = vhost_dev_alloc_iovecs(dev); |
538 | if (err) | |
539 | goto err_cgroup; | |
540 | ||
3a4d5c94 | 541 | return 0; |
9e3d1957 MT |
542 | err_cgroup: |
543 | kthread_stop(worker); | |
615cc221 | 544 | dev->worker = NULL; |
c23f3445 TH |
545 | err_worker: |
546 | if (dev->mm) | |
547 | mmput(dev->mm); | |
548 | dev->mm = NULL; | |
549 | err_mm: | |
550 | return err; | |
3a4d5c94 | 551 | } |
6ac1afbf | 552 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 553 | |
a9709d68 JW |
554 | struct vhost_umem *vhost_dev_reset_owner_prepare(void) |
555 | { | |
6c5ab651 | 556 | return kvzalloc(sizeof(struct vhost_umem), GFP_KERNEL); |
150b9e51 | 557 | } |
6ac1afbf | 558 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 559 | |
150b9e51 | 560 | /* Caller should have device mutex */ |
a9709d68 | 561 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_umem *umem) |
150b9e51 | 562 | { |
47283bef MT |
563 | int i; |
564 | ||
f6f93f75 | 565 | vhost_dev_cleanup(dev); |
3a4d5c94 | 566 | |
150b9e51 | 567 | /* Restore memory to default empty mapping. */ |
a9709d68 JW |
568 | INIT_LIST_HEAD(&umem->umem_list); |
569 | dev->umem = umem; | |
47283bef MT |
570 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
571 | * VQs aren't running. | |
572 | */ | |
573 | for (i = 0; i < dev->nvqs; ++i) | |
a9709d68 | 574 | dev->vqs[i]->umem = umem; |
3a4d5c94 | 575 | } |
6ac1afbf | 576 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 577 | |
b211616d | 578 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
579 | { |
580 | int i; | |
b211616d MT |
581 | |
582 | for (i = 0; i < dev->nvqs; ++i) { | |
3ab2e420 AH |
583 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) { |
584 | vhost_poll_stop(&dev->vqs[i]->poll); | |
585 | vhost_poll_flush(&dev->vqs[i]->poll); | |
b211616d | 586 | } |
bab632d6 | 587 | } |
bab632d6 | 588 | } |
6ac1afbf | 589 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 590 | |
6b1e6cc7 JW |
591 | static void vhost_umem_free(struct vhost_umem *umem, |
592 | struct vhost_umem_node *node) | |
593 | { | |
594 | vhost_umem_interval_tree_remove(node, &umem->umem_tree); | |
595 | list_del(&node->link); | |
596 | kfree(node); | |
597 | umem->numem--; | |
598 | } | |
599 | ||
a9709d68 JW |
600 | static void vhost_umem_clean(struct vhost_umem *umem) |
601 | { | |
602 | struct vhost_umem_node *node, *tmp; | |
603 | ||
604 | if (!umem) | |
605 | return; | |
606 | ||
6b1e6cc7 JW |
607 | list_for_each_entry_safe(node, tmp, &umem->umem_list, link) |
608 | vhost_umem_free(umem, node); | |
609 | ||
a9709d68 JW |
610 | kvfree(umem); |
611 | } | |
612 | ||
6b1e6cc7 JW |
613 | static void vhost_clear_msg(struct vhost_dev *dev) |
614 | { | |
615 | struct vhost_msg_node *node, *n; | |
616 | ||
617 | spin_lock(&dev->iotlb_lock); | |
618 | ||
619 | list_for_each_entry_safe(node, n, &dev->read_list, node) { | |
620 | list_del(&node->node); | |
621 | kfree(node); | |
622 | } | |
623 | ||
624 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { | |
625 | list_del(&node->node); | |
626 | kfree(node); | |
627 | } | |
628 | ||
629 | spin_unlock(&dev->iotlb_lock); | |
630 | } | |
631 | ||
f6f93f75 | 632 | void vhost_dev_cleanup(struct vhost_dev *dev) |
3a4d5c94 MT |
633 | { |
634 | int i; | |
d47effe1 | 635 | |
3a4d5c94 | 636 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
637 | if (dev->vqs[i]->error_ctx) |
638 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
3ab2e420 AH |
639 | if (dev->vqs[i]->kick) |
640 | fput(dev->vqs[i]->kick); | |
641 | if (dev->vqs[i]->call_ctx) | |
642 | eventfd_ctx_put(dev->vqs[i]->call_ctx); | |
3ab2e420 | 643 | vhost_vq_reset(dev, dev->vqs[i]); |
3a4d5c94 | 644 | } |
e0e9b406 | 645 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
646 | if (dev->log_ctx) |
647 | eventfd_ctx_put(dev->log_ctx); | |
648 | dev->log_ctx = NULL; | |
3a4d5c94 | 649 | /* No one will access memory at this point */ |
a9709d68 JW |
650 | vhost_umem_clean(dev->umem); |
651 | dev->umem = NULL; | |
6b1e6cc7 JW |
652 | vhost_umem_clean(dev->iotlb); |
653 | dev->iotlb = NULL; | |
654 | vhost_clear_msg(dev); | |
a9a08845 | 655 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
04b96e55 | 656 | WARN_ON(!llist_empty(&dev->work_list)); |
78b620ce ED |
657 | if (dev->worker) { |
658 | kthread_stop(dev->worker); | |
659 | dev->worker = NULL; | |
660 | } | |
533a19b4 MT |
661 | if (dev->mm) |
662 | mmput(dev->mm); | |
663 | dev->mm = NULL; | |
3a4d5c94 | 664 | } |
6ac1afbf | 665 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 | 666 | |
ddd3d408 | 667 | static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) |
3a4d5c94 MT |
668 | { |
669 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 670 | |
3a4d5c94 MT |
671 | /* Make sure 64 bit math will not overflow. */ |
672 | if (a > ULONG_MAX - (unsigned long)log_base || | |
673 | a + (unsigned long)log_base > ULONG_MAX) | |
ddd3d408 | 674 | return false; |
3a4d5c94 | 675 | |
96d4f267 | 676 | return access_ok(log_base + a, |
3a4d5c94 MT |
677 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); |
678 | } | |
679 | ||
ec33d031 MT |
680 | static bool vhost_overflow(u64 uaddr, u64 size) |
681 | { | |
682 | /* Make sure 64 bit math will not overflow. */ | |
683 | return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size; | |
684 | } | |
685 | ||
3a4d5c94 | 686 | /* Caller should have vq mutex and device mutex. */ |
ddd3d408 SH |
687 | static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, |
688 | int log_all) | |
3a4d5c94 | 689 | { |
a9709d68 | 690 | struct vhost_umem_node *node; |
179b284e | 691 | |
a9709d68 | 692 | if (!umem) |
ddd3d408 | 693 | return false; |
179b284e | 694 | |
a9709d68 JW |
695 | list_for_each_entry(node, &umem->umem_list, link) { |
696 | unsigned long a = node->userspace_addr; | |
697 | ||
ec33d031 | 698 | if (vhost_overflow(node->userspace_addr, node->size)) |
ddd3d408 | 699 | return false; |
ec33d031 MT |
700 | |
701 | ||
96d4f267 | 702 | if (!access_ok((void __user *)a, |
a9709d68 | 703 | node->size)) |
ddd3d408 | 704 | return false; |
3a4d5c94 | 705 | else if (log_all && !log_access_ok(log_base, |
a9709d68 JW |
706 | node->start, |
707 | node->size)) | |
ddd3d408 | 708 | return false; |
3a4d5c94 | 709 | } |
ddd3d408 | 710 | return true; |
3a4d5c94 MT |
711 | } |
712 | ||
f8894913 JW |
713 | static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, |
714 | u64 addr, unsigned int size, | |
715 | int type) | |
716 | { | |
717 | const struct vhost_umem_node *node = vq->meta_iotlb[type]; | |
718 | ||
719 | if (!node) | |
720 | return NULL; | |
721 | ||
722 | return (void *)(uintptr_t)(node->userspace_addr + addr - node->start); | |
723 | } | |
724 | ||
3a4d5c94 MT |
725 | /* Can we switch to this memory table? */ |
726 | /* Caller should have device mutex but not vq mutex */ | |
ddd3d408 SH |
727 | static bool memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, |
728 | int log_all) | |
3a4d5c94 MT |
729 | { |
730 | int i; | |
d47effe1 | 731 | |
3a4d5c94 | 732 | for (i = 0; i < d->nvqs; ++i) { |
ddd3d408 | 733 | bool ok; |
ea16c514 MT |
734 | bool log; |
735 | ||
3ab2e420 | 736 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 737 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 738 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 739 | if (d->vqs[i]->private_data) |
a9709d68 JW |
740 | ok = vq_memory_access_ok(d->vqs[i]->log_base, |
741 | umem, log); | |
3a4d5c94 | 742 | else |
ddd3d408 | 743 | ok = true; |
3ab2e420 | 744 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 | 745 | if (!ok) |
ddd3d408 | 746 | return false; |
3a4d5c94 | 747 | } |
ddd3d408 | 748 | return true; |
3a4d5c94 MT |
749 | } |
750 | ||
6b1e6cc7 JW |
751 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
752 | struct iovec iov[], int iov_size, int access); | |
bfe2bc51 | 753 | |
72952cc0 | 754 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, |
bfe2bc51 JW |
755 | const void *from, unsigned size) |
756 | { | |
6b1e6cc7 | 757 | int ret; |
bfe2bc51 | 758 | |
6b1e6cc7 JW |
759 | if (!vq->iotlb) |
760 | return __copy_to_user(to, from, size); | |
761 | else { | |
762 | /* This function should be called after iotlb | |
763 | * prefetch, which means we're sure that all vq | |
764 | * could be access through iotlb. So -EAGAIN should | |
765 | * not happen in this case. | |
766 | */ | |
6b1e6cc7 | 767 | struct iov_iter t; |
f8894913 JW |
768 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
769 | (u64)(uintptr_t)to, size, | |
7ced6c98 | 770 | VHOST_ADDR_USED); |
f8894913 JW |
771 | |
772 | if (uaddr) | |
773 | return __copy_to_user(uaddr, from, size); | |
774 | ||
6b1e6cc7 JW |
775 | ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, |
776 | ARRAY_SIZE(vq->iotlb_iov), | |
777 | VHOST_ACCESS_WO); | |
778 | if (ret < 0) | |
779 | goto out; | |
780 | iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size); | |
781 | ret = copy_to_iter(from, size, &t); | |
782 | if (ret == size) | |
783 | ret = 0; | |
784 | } | |
785 | out: | |
786 | return ret; | |
787 | } | |
bfe2bc51 JW |
788 | |
789 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, | |
72952cc0 | 790 | void __user *from, unsigned size) |
bfe2bc51 | 791 | { |
6b1e6cc7 JW |
792 | int ret; |
793 | ||
794 | if (!vq->iotlb) | |
795 | return __copy_from_user(to, from, size); | |
796 | else { | |
797 | /* This function should be called after iotlb | |
798 | * prefetch, which means we're sure that vq | |
799 | * could be access through iotlb. So -EAGAIN should | |
800 | * not happen in this case. | |
801 | */ | |
f8894913 JW |
802 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
803 | (u64)(uintptr_t)from, size, | |
804 | VHOST_ADDR_DESC); | |
6b1e6cc7 | 805 | struct iov_iter f; |
f8894913 JW |
806 | |
807 | if (uaddr) | |
808 | return __copy_from_user(to, uaddr, size); | |
809 | ||
6b1e6cc7 JW |
810 | ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, |
811 | ARRAY_SIZE(vq->iotlb_iov), | |
812 | VHOST_ACCESS_RO); | |
813 | if (ret < 0) { | |
814 | vq_err(vq, "IOTLB translation failure: uaddr " | |
815 | "%p size 0x%llx\n", from, | |
816 | (unsigned long long) size); | |
817 | goto out; | |
818 | } | |
819 | iov_iter_init(&f, READ, vq->iotlb_iov, ret, size); | |
820 | ret = copy_from_iter(to, size, &f); | |
821 | if (ret == size) | |
822 | ret = 0; | |
823 | } | |
824 | ||
825 | out: | |
826 | return ret; | |
827 | } | |
828 | ||
f8894913 JW |
829 | static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq, |
830 | void __user *addr, unsigned int size, | |
831 | int type) | |
6b1e6cc7 JW |
832 | { |
833 | int ret; | |
834 | ||
6b1e6cc7 JW |
835 | ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov, |
836 | ARRAY_SIZE(vq->iotlb_iov), | |
837 | VHOST_ACCESS_RO); | |
838 | if (ret < 0) { | |
839 | vq_err(vq, "IOTLB translation failure: uaddr " | |
840 | "%p size 0x%llx\n", addr, | |
841 | (unsigned long long) size); | |
842 | return NULL; | |
843 | } | |
844 | ||
845 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { | |
846 | vq_err(vq, "Non atomic userspace memory access: uaddr " | |
847 | "%p size 0x%llx\n", addr, | |
848 | (unsigned long long) size); | |
849 | return NULL; | |
850 | } | |
851 | ||
852 | return vq->iotlb_iov[0].iov_base; | |
853 | } | |
854 | ||
f8894913 JW |
855 | /* This function should be called after iotlb |
856 | * prefetch, which means we're sure that vq | |
857 | * could be access through iotlb. So -EAGAIN should | |
858 | * not happen in this case. | |
859 | */ | |
860 | static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, | |
861 | void *addr, unsigned int size, | |
862 | int type) | |
863 | { | |
864 | void __user *uaddr = vhost_vq_meta_fetch(vq, | |
865 | (u64)(uintptr_t)addr, size, type); | |
866 | if (uaddr) | |
867 | return uaddr; | |
868 | ||
869 | return __vhost_get_user_slow(vq, addr, size, type); | |
870 | } | |
871 | ||
872 | #define vhost_put_user(vq, x, ptr) \ | |
6b1e6cc7 JW |
873 | ({ \ |
874 | int ret = -EFAULT; \ | |
875 | if (!vq->iotlb) { \ | |
876 | ret = __put_user(x, ptr); \ | |
877 | } else { \ | |
878 | __typeof__(ptr) to = \ | |
f8894913 JW |
879 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
880 | sizeof(*ptr), VHOST_ADDR_USED); \ | |
6b1e6cc7 JW |
881 | if (to != NULL) \ |
882 | ret = __put_user(x, to); \ | |
883 | else \ | |
884 | ret = -EFAULT; \ | |
885 | } \ | |
886 | ret; \ | |
887 | }) | |
888 | ||
f8894913 | 889 | #define vhost_get_user(vq, x, ptr, type) \ |
6b1e6cc7 JW |
890 | ({ \ |
891 | int ret; \ | |
892 | if (!vq->iotlb) { \ | |
893 | ret = __get_user(x, ptr); \ | |
894 | } else { \ | |
895 | __typeof__(ptr) from = \ | |
f8894913 JW |
896 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
897 | sizeof(*ptr), \ | |
898 | type); \ | |
6b1e6cc7 JW |
899 | if (from != NULL) \ |
900 | ret = __get_user(x, from); \ | |
901 | else \ | |
902 | ret = -EFAULT; \ | |
903 | } \ | |
904 | ret; \ | |
905 | }) | |
906 | ||
f8894913 JW |
907 | #define vhost_get_avail(vq, x, ptr) \ |
908 | vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL) | |
909 | ||
910 | #define vhost_get_used(vq, x, ptr) \ | |
911 | vhost_get_user(vq, x, ptr, VHOST_ADDR_USED) | |
912 | ||
86a07da3 JW |
913 | static void vhost_dev_lock_vqs(struct vhost_dev *d) |
914 | { | |
915 | int i = 0; | |
916 | for (i = 0; i < d->nvqs; ++i) | |
917 | mutex_lock_nested(&d->vqs[i]->mutex, i); | |
918 | } | |
919 | ||
920 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) | |
921 | { | |
922 | int i = 0; | |
923 | for (i = 0; i < d->nvqs; ++i) | |
924 | mutex_unlock(&d->vqs[i]->mutex); | |
925 | } | |
926 | ||
6b1e6cc7 JW |
927 | static int vhost_new_umem_range(struct vhost_umem *umem, |
928 | u64 start, u64 size, u64 end, | |
929 | u64 userspace_addr, int perm) | |
930 | { | |
813dbeb6 | 931 | struct vhost_umem_node *tmp, *node; |
6b1e6cc7 | 932 | |
813dbeb6 JW |
933 | if (!size) |
934 | return -EFAULT; | |
935 | ||
936 | node = kmalloc(sizeof(*node), GFP_ATOMIC); | |
6b1e6cc7 JW |
937 | if (!node) |
938 | return -ENOMEM; | |
939 | ||
940 | if (umem->numem == max_iotlb_entries) { | |
941 | tmp = list_first_entry(&umem->umem_list, typeof(*tmp), link); | |
942 | vhost_umem_free(umem, tmp); | |
943 | } | |
944 | ||
945 | node->start = start; | |
946 | node->size = size; | |
947 | node->last = end; | |
948 | node->userspace_addr = userspace_addr; | |
949 | node->perm = perm; | |
950 | INIT_LIST_HEAD(&node->link); | |
951 | list_add_tail(&node->link, &umem->umem_list); | |
952 | vhost_umem_interval_tree_insert(node, &umem->umem_tree); | |
953 | umem->numem++; | |
954 | ||
955 | return 0; | |
956 | } | |
957 | ||
958 | static void vhost_del_umem_range(struct vhost_umem *umem, | |
959 | u64 start, u64 end) | |
960 | { | |
961 | struct vhost_umem_node *node; | |
962 | ||
963 | while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
964 | start, end))) | |
965 | vhost_umem_free(umem, node); | |
966 | } | |
967 | ||
968 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, | |
969 | struct vhost_iotlb_msg *msg) | |
970 | { | |
971 | struct vhost_msg_node *node, *n; | |
972 | ||
973 | spin_lock(&d->iotlb_lock); | |
974 | ||
975 | list_for_each_entry_safe(node, n, &d->pending_list, node) { | |
976 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; | |
977 | if (msg->iova <= vq_msg->iova && | |
2d66f997 | 978 | msg->iova + msg->size - 1 >= vq_msg->iova && |
6b1e6cc7 JW |
979 | vq_msg->type == VHOST_IOTLB_MISS) { |
980 | vhost_poll_queue(&node->vq->poll); | |
981 | list_del(&node->node); | |
982 | kfree(node); | |
983 | } | |
984 | } | |
985 | ||
986 | spin_unlock(&d->iotlb_lock); | |
987 | } | |
988 | ||
ddd3d408 | 989 | static bool umem_access_ok(u64 uaddr, u64 size, int access) |
6b1e6cc7 JW |
990 | { |
991 | unsigned long a = uaddr; | |
992 | ||
ec33d031 MT |
993 | /* Make sure 64 bit math will not overflow. */ |
994 | if (vhost_overflow(uaddr, size)) | |
ddd3d408 | 995 | return false; |
ec33d031 | 996 | |
6b1e6cc7 | 997 | if ((access & VHOST_ACCESS_RO) && |
96d4f267 | 998 | !access_ok((void __user *)a, size)) |
ddd3d408 | 999 | return false; |
6b1e6cc7 | 1000 | if ((access & VHOST_ACCESS_WO) && |
96d4f267 | 1001 | !access_ok((void __user *)a, size)) |
ddd3d408 SH |
1002 | return false; |
1003 | return true; | |
6b1e6cc7 JW |
1004 | } |
1005 | ||
72952cc0 MT |
1006 | static int vhost_process_iotlb_msg(struct vhost_dev *dev, |
1007 | struct vhost_iotlb_msg *msg) | |
6b1e6cc7 JW |
1008 | { |
1009 | int ret = 0; | |
1010 | ||
1b15ad68 | 1011 | mutex_lock(&dev->mutex); |
86a07da3 | 1012 | vhost_dev_lock_vqs(dev); |
6b1e6cc7 JW |
1013 | switch (msg->type) { |
1014 | case VHOST_IOTLB_UPDATE: | |
1015 | if (!dev->iotlb) { | |
1016 | ret = -EFAULT; | |
1017 | break; | |
1018 | } | |
ddd3d408 | 1019 | if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) { |
6b1e6cc7 JW |
1020 | ret = -EFAULT; |
1021 | break; | |
1022 | } | |
f8894913 | 1023 | vhost_vq_meta_reset(dev); |
6b1e6cc7 JW |
1024 | if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size, |
1025 | msg->iova + msg->size - 1, | |
1026 | msg->uaddr, msg->perm)) { | |
1027 | ret = -ENOMEM; | |
1028 | break; | |
1029 | } | |
1030 | vhost_iotlb_notify_vq(dev, msg); | |
1031 | break; | |
1032 | case VHOST_IOTLB_INVALIDATE: | |
6f3180af JW |
1033 | if (!dev->iotlb) { |
1034 | ret = -EFAULT; | |
1035 | break; | |
1036 | } | |
f8894913 | 1037 | vhost_vq_meta_reset(dev); |
6b1e6cc7 JW |
1038 | vhost_del_umem_range(dev->iotlb, msg->iova, |
1039 | msg->iova + msg->size - 1); | |
1040 | break; | |
1041 | default: | |
1042 | ret = -EINVAL; | |
1043 | break; | |
1044 | } | |
1045 | ||
86a07da3 | 1046 | vhost_dev_unlock_vqs(dev); |
1b15ad68 JW |
1047 | mutex_unlock(&dev->mutex); |
1048 | ||
6b1e6cc7 JW |
1049 | return ret; |
1050 | } | |
1051 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, | |
1052 | struct iov_iter *from) | |
1053 | { | |
429711ae JW |
1054 | struct vhost_iotlb_msg msg; |
1055 | size_t offset; | |
1056 | int type, ret; | |
6b1e6cc7 | 1057 | |
429711ae | 1058 | ret = copy_from_iter(&type, sizeof(type), from); |
74ad7419 PT |
1059 | if (ret != sizeof(type)) { |
1060 | ret = -EINVAL; | |
6b1e6cc7 | 1061 | goto done; |
74ad7419 | 1062 | } |
6b1e6cc7 | 1063 | |
429711ae | 1064 | switch (type) { |
6b1e6cc7 | 1065 | case VHOST_IOTLB_MSG: |
429711ae JW |
1066 | /* There maybe a hole after type for V1 message type, |
1067 | * so skip it here. | |
1068 | */ | |
1069 | offset = offsetof(struct vhost_msg, iotlb) - sizeof(int); | |
1070 | break; | |
1071 | case VHOST_IOTLB_MSG_V2: | |
1072 | offset = sizeof(__u32); | |
6b1e6cc7 JW |
1073 | break; |
1074 | default: | |
1075 | ret = -EINVAL; | |
429711ae | 1076 | goto done; |
6b1e6cc7 JW |
1077 | } |
1078 | ||
429711ae JW |
1079 | iov_iter_advance(from, offset); |
1080 | ret = copy_from_iter(&msg, sizeof(msg), from); | |
74ad7419 PT |
1081 | if (ret != sizeof(msg)) { |
1082 | ret = -EINVAL; | |
429711ae | 1083 | goto done; |
74ad7419 | 1084 | } |
429711ae JW |
1085 | if (vhost_process_iotlb_msg(dev, &msg)) { |
1086 | ret = -EFAULT; | |
1087 | goto done; | |
1088 | } | |
1089 | ||
1090 | ret = (type == VHOST_IOTLB_MSG) ? sizeof(struct vhost_msg) : | |
1091 | sizeof(struct vhost_msg_v2); | |
6b1e6cc7 JW |
1092 | done: |
1093 | return ret; | |
1094 | } | |
1095 | EXPORT_SYMBOL(vhost_chr_write_iter); | |
1096 | ||
afc9a42b | 1097 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
6b1e6cc7 JW |
1098 | poll_table *wait) |
1099 | { | |
afc9a42b | 1100 | __poll_t mask = 0; |
6b1e6cc7 JW |
1101 | |
1102 | poll_wait(file, &dev->wait, wait); | |
1103 | ||
1104 | if (!list_empty(&dev->read_list)) | |
a9a08845 | 1105 | mask |= EPOLLIN | EPOLLRDNORM; |
6b1e6cc7 JW |
1106 | |
1107 | return mask; | |
1108 | } | |
1109 | EXPORT_SYMBOL(vhost_chr_poll); | |
1110 | ||
1111 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, | |
1112 | int noblock) | |
1113 | { | |
1114 | DEFINE_WAIT(wait); | |
1115 | struct vhost_msg_node *node; | |
1116 | ssize_t ret = 0; | |
1117 | unsigned size = sizeof(struct vhost_msg); | |
1118 | ||
1119 | if (iov_iter_count(to) < size) | |
1120 | return 0; | |
1121 | ||
1122 | while (1) { | |
1123 | if (!noblock) | |
1124 | prepare_to_wait(&dev->wait, &wait, | |
1125 | TASK_INTERRUPTIBLE); | |
1126 | ||
1127 | node = vhost_dequeue_msg(dev, &dev->read_list); | |
1128 | if (node) | |
1129 | break; | |
1130 | if (noblock) { | |
1131 | ret = -EAGAIN; | |
1132 | break; | |
1133 | } | |
1134 | if (signal_pending(current)) { | |
1135 | ret = -ERESTARTSYS; | |
1136 | break; | |
1137 | } | |
1138 | if (!dev->iotlb) { | |
1139 | ret = -EBADFD; | |
1140 | break; | |
1141 | } | |
1142 | ||
1143 | schedule(); | |
1144 | } | |
1145 | ||
1146 | if (!noblock) | |
1147 | finish_wait(&dev->wait, &wait); | |
1148 | ||
1149 | if (node) { | |
429711ae JW |
1150 | struct vhost_iotlb_msg *msg; |
1151 | void *start = &node->msg; | |
6b1e6cc7 | 1152 | |
429711ae JW |
1153 | switch (node->msg.type) { |
1154 | case VHOST_IOTLB_MSG: | |
1155 | size = sizeof(node->msg); | |
1156 | msg = &node->msg.iotlb; | |
1157 | break; | |
1158 | case VHOST_IOTLB_MSG_V2: | |
1159 | size = sizeof(node->msg_v2); | |
1160 | msg = &node->msg_v2.iotlb; | |
1161 | break; | |
1162 | default: | |
1163 | BUG(); | |
1164 | break; | |
1165 | } | |
1166 | ||
1167 | ret = copy_to_iter(start, size, to); | |
1168 | if (ret != size || msg->type != VHOST_IOTLB_MISS) { | |
6b1e6cc7 JW |
1169 | kfree(node); |
1170 | return ret; | |
1171 | } | |
6b1e6cc7 JW |
1172 | vhost_enqueue_msg(dev, &dev->pending_list, node); |
1173 | } | |
1174 | ||
1175 | return ret; | |
1176 | } | |
1177 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); | |
1178 | ||
1179 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) | |
1180 | { | |
1181 | struct vhost_dev *dev = vq->dev; | |
1182 | struct vhost_msg_node *node; | |
1183 | struct vhost_iotlb_msg *msg; | |
429711ae | 1184 | bool v2 = vhost_backend_has_feature(vq, VHOST_BACKEND_F_IOTLB_MSG_V2); |
6b1e6cc7 | 1185 | |
429711ae | 1186 | node = vhost_new_msg(vq, v2 ? VHOST_IOTLB_MSG_V2 : VHOST_IOTLB_MSG); |
6b1e6cc7 JW |
1187 | if (!node) |
1188 | return -ENOMEM; | |
1189 | ||
429711ae JW |
1190 | if (v2) { |
1191 | node->msg_v2.type = VHOST_IOTLB_MSG_V2; | |
1192 | msg = &node->msg_v2.iotlb; | |
1193 | } else { | |
1194 | msg = &node->msg.iotlb; | |
1195 | } | |
1196 | ||
6b1e6cc7 JW |
1197 | msg->type = VHOST_IOTLB_MISS; |
1198 | msg->iova = iova; | |
1199 | msg->perm = access; | |
1200 | ||
1201 | vhost_enqueue_msg(dev, &dev->read_list, node); | |
1202 | ||
1203 | return 0; | |
bfe2bc51 JW |
1204 | } |
1205 | ||
ddd3d408 SH |
1206 | static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
1207 | struct vring_desc __user *desc, | |
1208 | struct vring_avail __user *avail, | |
1209 | struct vring_used __user *used) | |
6b1e6cc7 | 1210 | |
3a4d5c94 | 1211 | { |
cfdbb4ed | 1212 | size_t s __maybe_unused = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
6b1e6cc7 | 1213 | |
96d4f267 LT |
1214 | return access_ok(desc, num * sizeof *desc) && |
1215 | access_ok(avail, | |
8ea8cf89 | 1216 | sizeof *avail + num * sizeof *avail->ring + s) && |
96d4f267 | 1217 | access_ok(used, |
8ea8cf89 | 1218 | sizeof *used + num * sizeof *used->ring + s); |
3a4d5c94 MT |
1219 | } |
1220 | ||
f8894913 JW |
1221 | static void vhost_vq_meta_update(struct vhost_virtqueue *vq, |
1222 | const struct vhost_umem_node *node, | |
1223 | int type) | |
1224 | { | |
1225 | int access = (type == VHOST_ADDR_USED) ? | |
1226 | VHOST_ACCESS_WO : VHOST_ACCESS_RO; | |
1227 | ||
1228 | if (likely(node->perm & access)) | |
1229 | vq->meta_iotlb[type] = node; | |
1230 | } | |
1231 | ||
ddd3d408 SH |
1232 | static bool iotlb_access_ok(struct vhost_virtqueue *vq, |
1233 | int access, u64 addr, u64 len, int type) | |
6b1e6cc7 JW |
1234 | { |
1235 | const struct vhost_umem_node *node; | |
1236 | struct vhost_umem *umem = vq->iotlb; | |
ca2c5b33 | 1237 | u64 s = 0, size, orig_addr = addr, last = addr + len - 1; |
f8894913 JW |
1238 | |
1239 | if (vhost_vq_meta_fetch(vq, addr, len, type)) | |
1240 | return true; | |
6b1e6cc7 JW |
1241 | |
1242 | while (len > s) { | |
1243 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
1244 | addr, | |
ca2c5b33 | 1245 | last); |
6b1e6cc7 JW |
1246 | if (node == NULL || node->start > addr) { |
1247 | vhost_iotlb_miss(vq, addr, access); | |
1248 | return false; | |
1249 | } else if (!(node->perm & access)) { | |
1250 | /* Report the possible access violation by | |
1251 | * request another translation from userspace. | |
1252 | */ | |
1253 | return false; | |
1254 | } | |
1255 | ||
1256 | size = node->size - addr + node->start; | |
f8894913 JW |
1257 | |
1258 | if (orig_addr == addr && size >= len) | |
1259 | vhost_vq_meta_update(vq, node, type); | |
1260 | ||
6b1e6cc7 JW |
1261 | s += size; |
1262 | addr += size; | |
1263 | } | |
1264 | ||
1265 | return true; | |
1266 | } | |
1267 | ||
1268 | int vq_iotlb_prefetch(struct vhost_virtqueue *vq) | |
1269 | { | |
1270 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
1271 | unsigned int num = vq->num; | |
1272 | ||
1273 | if (!vq->iotlb) | |
1274 | return 1; | |
1275 | ||
1276 | return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc, | |
f8894913 | 1277 | num * sizeof(*vq->desc), VHOST_ADDR_DESC) && |
6b1e6cc7 JW |
1278 | iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail, |
1279 | sizeof *vq->avail + | |
f8894913 JW |
1280 | num * sizeof(*vq->avail->ring) + s, |
1281 | VHOST_ADDR_AVAIL) && | |
6b1e6cc7 JW |
1282 | iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used, |
1283 | sizeof *vq->used + | |
f8894913 JW |
1284 | num * sizeof(*vq->used->ring) + s, |
1285 | VHOST_ADDR_USED); | |
6b1e6cc7 JW |
1286 | } |
1287 | EXPORT_SYMBOL_GPL(vq_iotlb_prefetch); | |
1288 | ||
3a4d5c94 MT |
1289 | /* Can we log writes? */ |
1290 | /* Caller should have device mutex but not vq mutex */ | |
ddd3d408 | 1291 | bool vhost_log_access_ok(struct vhost_dev *dev) |
3a4d5c94 | 1292 | { |
a9709d68 | 1293 | return memory_access_ok(dev, dev->umem, 1); |
3a4d5c94 | 1294 | } |
6ac1afbf | 1295 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 MT |
1296 | |
1297 | /* Verify access for write logging. */ | |
1298 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 SH |
1299 | static bool vq_log_access_ok(struct vhost_virtqueue *vq, |
1300 | void __user *log_base) | |
3a4d5c94 | 1301 | { |
ea16c514 | 1302 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
28457ee6 | 1303 | |
a9709d68 | 1304 | return vq_memory_access_ok(log_base, vq->umem, |
ea16c514 | 1305 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
3a4d5c94 MT |
1306 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
1307 | sizeof *vq->used + | |
8ea8cf89 | 1308 | vq->num * sizeof *vq->used->ring + s)); |
3a4d5c94 MT |
1309 | } |
1310 | ||
1311 | /* Can we start vq? */ | |
1312 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 | 1313 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq) |
3a4d5c94 | 1314 | { |
d14d2b78 | 1315 | if (!vq_log_access_ok(vq, vq->log_base)) |
ddd3d408 | 1316 | return false; |
d65026c6 | 1317 | |
d14d2b78 SH |
1318 | /* Access validation occurs at prefetch time with IOTLB */ |
1319 | if (vq->iotlb) | |
ddd3d408 | 1320 | return true; |
d65026c6 JW |
1321 | |
1322 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); | |
3a4d5c94 | 1323 | } |
6ac1afbf | 1324 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 | 1325 | |
6b1e6cc7 JW |
1326 | static struct vhost_umem *vhost_umem_alloc(void) |
1327 | { | |
6c5ab651 | 1328 | struct vhost_umem *umem = kvzalloc(sizeof(*umem), GFP_KERNEL); |
6b1e6cc7 JW |
1329 | |
1330 | if (!umem) | |
1331 | return NULL; | |
1332 | ||
f808c13f | 1333 | umem->umem_tree = RB_ROOT_CACHED; |
6b1e6cc7 JW |
1334 | umem->numem = 0; |
1335 | INIT_LIST_HEAD(&umem->umem_list); | |
1336 | ||
1337 | return umem; | |
1338 | } | |
1339 | ||
3a4d5c94 MT |
1340 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
1341 | { | |
a9709d68 JW |
1342 | struct vhost_memory mem, *newmem; |
1343 | struct vhost_memory_region *region; | |
a9709d68 | 1344 | struct vhost_umem *newumem, *oldumem; |
3a4d5c94 | 1345 | unsigned long size = offsetof(struct vhost_memory, regions); |
98f9ca0a | 1346 | int i; |
d47effe1 | 1347 | |
7ad9c9d2 TY |
1348 | if (copy_from_user(&mem, m, size)) |
1349 | return -EFAULT; | |
3a4d5c94 MT |
1350 | if (mem.padding) |
1351 | return -EOPNOTSUPP; | |
c9ce42f7 | 1352 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 1353 | return -E2BIG; |
b2303d7b MW |
1354 | newmem = kvzalloc(struct_size(newmem, regions, mem.nregions), |
1355 | GFP_KERNEL); | |
3a4d5c94 MT |
1356 | if (!newmem) |
1357 | return -ENOMEM; | |
1358 | ||
1359 | memcpy(newmem, &mem, size); | |
7ad9c9d2 TY |
1360 | if (copy_from_user(newmem->regions, m->regions, |
1361 | mem.nregions * sizeof *m->regions)) { | |
bcfeacab | 1362 | kvfree(newmem); |
7ad9c9d2 | 1363 | return -EFAULT; |
3a4d5c94 MT |
1364 | } |
1365 | ||
6b1e6cc7 | 1366 | newumem = vhost_umem_alloc(); |
a9709d68 | 1367 | if (!newumem) { |
4de7255f | 1368 | kvfree(newmem); |
a9709d68 JW |
1369 | return -ENOMEM; |
1370 | } | |
1371 | ||
a9709d68 JW |
1372 | for (region = newmem->regions; |
1373 | region < newmem->regions + mem.nregions; | |
1374 | region++) { | |
6b1e6cc7 JW |
1375 | if (vhost_new_umem_range(newumem, |
1376 | region->guest_phys_addr, | |
1377 | region->memory_size, | |
1378 | region->guest_phys_addr + | |
1379 | region->memory_size - 1, | |
1380 | region->userspace_addr, | |
1381 | VHOST_ACCESS_RW)) | |
a9709d68 | 1382 | goto err; |
a02c3789 | 1383 | } |
a9709d68 JW |
1384 | |
1385 | if (!memory_access_ok(d, newumem, 0)) | |
1386 | goto err; | |
1387 | ||
1388 | oldumem = d->umem; | |
1389 | d->umem = newumem; | |
98f9ca0a | 1390 | |
47283bef | 1391 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
1392 | for (i = 0; i < d->nvqs; ++i) { |
1393 | mutex_lock(&d->vqs[i]->mutex); | |
a9709d68 | 1394 | d->vqs[i]->umem = newumem; |
98f9ca0a MT |
1395 | mutex_unlock(&d->vqs[i]->mutex); |
1396 | } | |
a9709d68 JW |
1397 | |
1398 | kvfree(newmem); | |
1399 | vhost_umem_clean(oldumem); | |
3a4d5c94 | 1400 | return 0; |
a9709d68 JW |
1401 | |
1402 | err: | |
1403 | vhost_umem_clean(newumem); | |
1404 | kvfree(newmem); | |
1405 | return -EFAULT; | |
3a4d5c94 MT |
1406 | } |
1407 | ||
26b36604 | 1408 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1409 | { |
cecb46f1 AV |
1410 | struct file *eventfp, *filep = NULL; |
1411 | bool pollstart = false, pollstop = false; | |
3a4d5c94 MT |
1412 | struct eventfd_ctx *ctx = NULL; |
1413 | u32 __user *idxp = argp; | |
1414 | struct vhost_virtqueue *vq; | |
1415 | struct vhost_vring_state s; | |
1416 | struct vhost_vring_file f; | |
1417 | struct vhost_vring_addr a; | |
1418 | u32 idx; | |
1419 | long r; | |
1420 | ||
1421 | r = get_user(idx, idxp); | |
1422 | if (r < 0) | |
1423 | return r; | |
0f3d9a17 | 1424 | if (idx >= d->nvqs) |
3a4d5c94 MT |
1425 | return -ENOBUFS; |
1426 | ||
ff002269 | 1427 | idx = array_index_nospec(idx, d->nvqs); |
3ab2e420 | 1428 | vq = d->vqs[idx]; |
3a4d5c94 MT |
1429 | |
1430 | mutex_lock(&vq->mutex); | |
1431 | ||
1432 | switch (ioctl) { | |
1433 | case VHOST_SET_VRING_NUM: | |
1434 | /* Resizing ring with an active backend? | |
1435 | * You don't want to do that. */ | |
1436 | if (vq->private_data) { | |
1437 | r = -EBUSY; | |
1438 | break; | |
1439 | } | |
7ad9c9d2 TY |
1440 | if (copy_from_user(&s, argp, sizeof s)) { |
1441 | r = -EFAULT; | |
3a4d5c94 | 1442 | break; |
7ad9c9d2 | 1443 | } |
3a4d5c94 MT |
1444 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) { |
1445 | r = -EINVAL; | |
1446 | break; | |
1447 | } | |
1448 | vq->num = s.num; | |
1449 | break; | |
1450 | case VHOST_SET_VRING_BASE: | |
1451 | /* Moving base with an active backend? | |
1452 | * You don't want to do that. */ | |
1453 | if (vq->private_data) { | |
1454 | r = -EBUSY; | |
1455 | break; | |
1456 | } | |
7ad9c9d2 TY |
1457 | if (copy_from_user(&s, argp, sizeof s)) { |
1458 | r = -EFAULT; | |
3a4d5c94 | 1459 | break; |
7ad9c9d2 | 1460 | } |
3a4d5c94 MT |
1461 | if (s.num > 0xffff) { |
1462 | r = -EINVAL; | |
1463 | break; | |
1464 | } | |
8d65843c | 1465 | vq->last_avail_idx = s.num; |
3a4d5c94 MT |
1466 | /* Forget the cached index value. */ |
1467 | vq->avail_idx = vq->last_avail_idx; | |
1468 | break; | |
1469 | case VHOST_GET_VRING_BASE: | |
1470 | s.index = idx; | |
1471 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
1472 | if (copy_to_user(argp, &s, sizeof s)) |
1473 | r = -EFAULT; | |
3a4d5c94 MT |
1474 | break; |
1475 | case VHOST_SET_VRING_ADDR: | |
7ad9c9d2 TY |
1476 | if (copy_from_user(&a, argp, sizeof a)) { |
1477 | r = -EFAULT; | |
3a4d5c94 | 1478 | break; |
7ad9c9d2 | 1479 | } |
3a4d5c94 MT |
1480 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) { |
1481 | r = -EOPNOTSUPP; | |
1482 | break; | |
1483 | } | |
1484 | /* For 32bit, verify that the top 32bits of the user | |
1485 | data are set to zero. */ | |
1486 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
1487 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
1488 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { | |
1489 | r = -EFAULT; | |
1490 | break; | |
1491 | } | |
5d9a07b0 MT |
1492 | |
1493 | /* Make sure it's safe to cast pointers to vring types. */ | |
1494 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
1495 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
1496 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
1497 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
d5424838 | 1498 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) { |
3a4d5c94 MT |
1499 | r = -EINVAL; |
1500 | break; | |
1501 | } | |
1502 | ||
1503 | /* We only verify access here if backend is configured. | |
1504 | * If it is not, we don't as size might not have been setup. | |
1505 | * We will verify when backend is configured. */ | |
1506 | if (vq->private_data) { | |
ea16c514 | 1507 | if (!vq_access_ok(vq, vq->num, |
3a4d5c94 MT |
1508 | (void __user *)(unsigned long)a.desc_user_addr, |
1509 | (void __user *)(unsigned long)a.avail_user_addr, | |
1510 | (void __user *)(unsigned long)a.used_user_addr)) { | |
1511 | r = -EINVAL; | |
1512 | break; | |
1513 | } | |
1514 | ||
1515 | /* Also validate log access for used ring if enabled. */ | |
1516 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && | |
1517 | !log_access_ok(vq->log_base, a.log_guest_addr, | |
1518 | sizeof *vq->used + | |
1519 | vq->num * sizeof *vq->used->ring)) { | |
1520 | r = -EINVAL; | |
1521 | break; | |
1522 | } | |
1523 | } | |
1524 | ||
3a4d5c94 MT |
1525 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); |
1526 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
1527 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
1528 | vq->log_addr = a.log_guest_addr; | |
1529 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
1530 | break; | |
1531 | case VHOST_SET_VRING_KICK: | |
7ad9c9d2 TY |
1532 | if (copy_from_user(&f, argp, sizeof f)) { |
1533 | r = -EFAULT; | |
3a4d5c94 | 1534 | break; |
7ad9c9d2 | 1535 | } |
3a4d5c94 | 1536 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1537 | if (IS_ERR(eventfp)) { |
1538 | r = PTR_ERR(eventfp); | |
1539 | break; | |
1540 | } | |
3a4d5c94 | 1541 | if (eventfp != vq->kick) { |
cecb46f1 AV |
1542 | pollstop = (filep = vq->kick) != NULL; |
1543 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
1544 | } else |
1545 | filep = eventfp; | |
1546 | break; | |
1547 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
1548 | if (copy_from_user(&f, argp, sizeof f)) { |
1549 | r = -EFAULT; | |
3a4d5c94 | 1550 | break; |
7ad9c9d2 | 1551 | } |
e050c7d9 EB |
1552 | ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); |
1553 | if (IS_ERR(ctx)) { | |
1554 | r = PTR_ERR(ctx); | |
535297a6 MT |
1555 | break; |
1556 | } | |
e050c7d9 | 1557 | swap(ctx, vq->call_ctx); |
3a4d5c94 MT |
1558 | break; |
1559 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
1560 | if (copy_from_user(&f, argp, sizeof f)) { |
1561 | r = -EFAULT; | |
3a4d5c94 | 1562 | break; |
7ad9c9d2 | 1563 | } |
09f332a5 EB |
1564 | ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); |
1565 | if (IS_ERR(ctx)) { | |
1566 | r = PTR_ERR(ctx); | |
535297a6 MT |
1567 | break; |
1568 | } | |
09f332a5 | 1569 | swap(ctx, vq->error_ctx); |
3a4d5c94 | 1570 | break; |
2751c988 GK |
1571 | case VHOST_SET_VRING_ENDIAN: |
1572 | r = vhost_set_vring_endian(vq, argp); | |
1573 | break; | |
1574 | case VHOST_GET_VRING_ENDIAN: | |
1575 | r = vhost_get_vring_endian(vq, idx, argp); | |
1576 | break; | |
03088137 JW |
1577 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1578 | if (copy_from_user(&s, argp, sizeof(s))) { | |
1579 | r = -EFAULT; | |
1580 | break; | |
1581 | } | |
1582 | vq->busyloop_timeout = s.num; | |
1583 | break; | |
1584 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
1585 | s.index = idx; | |
1586 | s.num = vq->busyloop_timeout; | |
1587 | if (copy_to_user(argp, &s, sizeof(s))) | |
1588 | r = -EFAULT; | |
1589 | break; | |
3a4d5c94 MT |
1590 | default: |
1591 | r = -ENOIOCTLCMD; | |
1592 | } | |
1593 | ||
1594 | if (pollstop && vq->handle_kick) | |
1595 | vhost_poll_stop(&vq->poll); | |
1596 | ||
e050c7d9 | 1597 | if (!IS_ERR_OR_NULL(ctx)) |
3a4d5c94 MT |
1598 | eventfd_ctx_put(ctx); |
1599 | if (filep) | |
1600 | fput(filep); | |
1601 | ||
1602 | if (pollstart && vq->handle_kick) | |
2b8b328b | 1603 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
1604 | |
1605 | mutex_unlock(&vq->mutex); | |
1606 | ||
1607 | if (pollstop && vq->handle_kick) | |
1608 | vhost_poll_flush(&vq->poll); | |
1609 | return r; | |
1610 | } | |
6ac1afbf | 1611 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 | 1612 | |
6b1e6cc7 JW |
1613 | int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled) |
1614 | { | |
1615 | struct vhost_umem *niotlb, *oiotlb; | |
1616 | int i; | |
1617 | ||
1618 | niotlb = vhost_umem_alloc(); | |
1619 | if (!niotlb) | |
1620 | return -ENOMEM; | |
1621 | ||
1622 | oiotlb = d->iotlb; | |
1623 | d->iotlb = niotlb; | |
1624 | ||
1625 | for (i = 0; i < d->nvqs; ++i) { | |
b13f9c63 JW |
1626 | struct vhost_virtqueue *vq = d->vqs[i]; |
1627 | ||
1628 | mutex_lock(&vq->mutex); | |
1629 | vq->iotlb = niotlb; | |
1630 | __vhost_vq_meta_reset(vq); | |
1631 | mutex_unlock(&vq->mutex); | |
6b1e6cc7 JW |
1632 | } |
1633 | ||
1634 | vhost_umem_clean(oiotlb); | |
1635 | ||
1636 | return 0; | |
1637 | } | |
1638 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); | |
1639 | ||
3a4d5c94 | 1640 | /* Caller must have device mutex */ |
935cdee7 | 1641 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1642 | { |
d25cc43c | 1643 | struct eventfd_ctx *ctx; |
3a4d5c94 MT |
1644 | u64 p; |
1645 | long r; | |
1646 | int i, fd; | |
1647 | ||
1648 | /* If you are not the owner, you can become one */ | |
1649 | if (ioctl == VHOST_SET_OWNER) { | |
1650 | r = vhost_dev_set_owner(d); | |
1651 | goto done; | |
1652 | } | |
1653 | ||
1654 | /* You must be the owner to do anything else */ | |
1655 | r = vhost_dev_check_owner(d); | |
1656 | if (r) | |
1657 | goto done; | |
1658 | ||
1659 | switch (ioctl) { | |
1660 | case VHOST_SET_MEM_TABLE: | |
1661 | r = vhost_set_memory(d, argp); | |
1662 | break; | |
1663 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
1664 | if (copy_from_user(&p, argp, sizeof p)) { |
1665 | r = -EFAULT; | |
3a4d5c94 | 1666 | break; |
7ad9c9d2 | 1667 | } |
3a4d5c94 MT |
1668 | if ((u64)(unsigned long)p != p) { |
1669 | r = -EFAULT; | |
1670 | break; | |
1671 | } | |
1672 | for (i = 0; i < d->nvqs; ++i) { | |
1673 | struct vhost_virtqueue *vq; | |
1674 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 1675 | vq = d->vqs[i]; |
3a4d5c94 MT |
1676 | mutex_lock(&vq->mutex); |
1677 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 1678 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
1679 | r = -EFAULT; |
1680 | else | |
1681 | vq->log_base = base; | |
1682 | mutex_unlock(&vq->mutex); | |
1683 | } | |
1684 | break; | |
1685 | case VHOST_SET_LOG_FD: | |
1686 | r = get_user(fd, (int __user *)argp); | |
1687 | if (r < 0) | |
1688 | break; | |
d25cc43c EB |
1689 | ctx = fd == -1 ? NULL : eventfd_ctx_fdget(fd); |
1690 | if (IS_ERR(ctx)) { | |
1691 | r = PTR_ERR(ctx); | |
3a4d5c94 MT |
1692 | break; |
1693 | } | |
d25cc43c | 1694 | swap(ctx, d->log_ctx); |
3a4d5c94 | 1695 | for (i = 0; i < d->nvqs; ++i) { |
3ab2e420 AH |
1696 | mutex_lock(&d->vqs[i]->mutex); |
1697 | d->vqs[i]->log_ctx = d->log_ctx; | |
1698 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
1699 | } |
1700 | if (ctx) | |
1701 | eventfd_ctx_put(ctx); | |
3a4d5c94 MT |
1702 | break; |
1703 | default: | |
935cdee7 | 1704 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
1705 | break; |
1706 | } | |
1707 | done: | |
1708 | return r; | |
1709 | } | |
6ac1afbf | 1710 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 | 1711 | |
3a4d5c94 MT |
1712 | /* TODO: This is really inefficient. We need something like get_user() |
1713 | * (instruction directly accesses the data, with an exception table entry | |
cb1aaebe | 1714 | * returning -EFAULT). See Documentation/x86/exception-tables.rst. |
3a4d5c94 MT |
1715 | */ |
1716 | static int set_bit_to_user(int nr, void __user *addr) | |
1717 | { | |
1718 | unsigned long log = (unsigned long)addr; | |
1719 | struct page *page; | |
1720 | void *base; | |
1721 | int bit = nr + (log % PAGE_SIZE) * 8; | |
1722 | int r; | |
d47effe1 | 1723 | |
73b0140b | 1724 | r = get_user_pages_fast(log, 1, FOLL_WRITE, &page); |
d6db3f5c | 1725 | if (r < 0) |
3a4d5c94 | 1726 | return r; |
d6db3f5c | 1727 | BUG_ON(r != 1); |
c6daa7ff | 1728 | base = kmap_atomic(page); |
3a4d5c94 | 1729 | set_bit(bit, base); |
c6daa7ff | 1730 | kunmap_atomic(base); |
3a4d5c94 MT |
1731 | set_page_dirty_lock(page); |
1732 | put_page(page); | |
1733 | return 0; | |
1734 | } | |
1735 | ||
1736 | static int log_write(void __user *log_base, | |
1737 | u64 write_address, u64 write_length) | |
1738 | { | |
28831ee6 | 1739 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 1740 | int r; |
d47effe1 | 1741 | |
3a4d5c94 MT |
1742 | if (!write_length) |
1743 | return 0; | |
3bf9be40 | 1744 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
1745 | for (;;) { |
1746 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
1747 | u64 log = base + write_page / 8; |
1748 | int bit = write_page % 8; | |
3a4d5c94 MT |
1749 | if ((u64)(unsigned long)log != log) |
1750 | return -EFAULT; | |
1751 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
1752 | if (r < 0) | |
1753 | return r; | |
1754 | if (write_length <= VHOST_PAGE_SIZE) | |
1755 | break; | |
1756 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 1757 | write_page += 1; |
3a4d5c94 MT |
1758 | } |
1759 | return r; | |
1760 | } | |
1761 | ||
cc5e7107 JW |
1762 | static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len) |
1763 | { | |
1764 | struct vhost_umem *umem = vq->umem; | |
1765 | struct vhost_umem_node *u; | |
1766 | u64 start, end, l, min; | |
1767 | int r; | |
1768 | bool hit = false; | |
1769 | ||
1770 | while (len) { | |
1771 | min = len; | |
1772 | /* More than one GPAs can be mapped into a single HVA. So | |
1773 | * iterate all possible umems here to be safe. | |
1774 | */ | |
1775 | list_for_each_entry(u, &umem->umem_list, link) { | |
1776 | if (u->userspace_addr > hva - 1 + len || | |
1777 | u->userspace_addr - 1 + u->size < hva) | |
1778 | continue; | |
1779 | start = max(u->userspace_addr, hva); | |
1780 | end = min(u->userspace_addr - 1 + u->size, | |
1781 | hva - 1 + len); | |
1782 | l = end - start + 1; | |
1783 | r = log_write(vq->log_base, | |
1784 | u->start + start - u->userspace_addr, | |
1785 | l); | |
1786 | if (r < 0) | |
1787 | return r; | |
1788 | hit = true; | |
1789 | min = min(l, min); | |
1790 | } | |
1791 | ||
1792 | if (!hit) | |
1793 | return -EFAULT; | |
1794 | ||
1795 | len -= min; | |
1796 | hva += min; | |
1797 | } | |
1798 | ||
1799 | return 0; | |
1800 | } | |
1801 | ||
1802 | static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) | |
1803 | { | |
1804 | struct iovec iov[64]; | |
1805 | int i, ret; | |
1806 | ||
1807 | if (!vq->iotlb) | |
1808 | return log_write(vq->log_base, vq->log_addr + used_offset, len); | |
1809 | ||
1810 | ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, | |
1811 | len, iov, 64, VHOST_ACCESS_WO); | |
816db766 | 1812 | if (ret < 0) |
cc5e7107 JW |
1813 | return ret; |
1814 | ||
1815 | for (i = 0; i < ret; i++) { | |
1816 | ret = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
1817 | iov[i].iov_len); | |
1818 | if (ret) | |
1819 | return ret; | |
1820 | } | |
1821 | ||
1822 | return 0; | |
1823 | } | |
1824 | ||
3a4d5c94 | 1825 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
cc5e7107 | 1826 | unsigned int log_num, u64 len, struct iovec *iov, int count) |
3a4d5c94 MT |
1827 | { |
1828 | int i, r; | |
1829 | ||
1830 | /* Make sure data written is seen before log. */ | |
5659338c | 1831 | smp_wmb(); |
cc5e7107 JW |
1832 | |
1833 | if (vq->iotlb) { | |
1834 | for (i = 0; i < count; i++) { | |
1835 | r = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
1836 | iov[i].iov_len); | |
1837 | if (r < 0) | |
1838 | return r; | |
1839 | } | |
1840 | return 0; | |
1841 | } | |
1842 | ||
3a4d5c94 MT |
1843 | for (i = 0; i < log_num; ++i) { |
1844 | u64 l = min(log[i].len, len); | |
1845 | r = log_write(vq->log_base, log[i].addr, l); | |
1846 | if (r < 0) | |
1847 | return r; | |
1848 | len -= l; | |
5786aee8 MT |
1849 | if (!len) { |
1850 | if (vq->log_ctx) | |
1851 | eventfd_signal(vq->log_ctx, 1); | |
3a4d5c94 | 1852 | return 0; |
5786aee8 | 1853 | } |
3a4d5c94 | 1854 | } |
3a4d5c94 MT |
1855 | /* Length written exceeds what we have stored. This is a bug. */ |
1856 | BUG(); | |
1857 | return 0; | |
1858 | } | |
6ac1afbf | 1859 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 1860 | |
2723feaa JW |
1861 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
1862 | { | |
1863 | void __user *used; | |
bfe2bc51 JW |
1864 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), |
1865 | &vq->used->flags) < 0) | |
2723feaa JW |
1866 | return -EFAULT; |
1867 | if (unlikely(vq->log_used)) { | |
1868 | /* Make sure the flag is seen before log. */ | |
1869 | smp_wmb(); | |
1870 | /* Log used flag write. */ | |
1871 | used = &vq->used->flags; | |
cc5e7107 JW |
1872 | log_used(vq, (used - (void __user *)vq->used), |
1873 | sizeof vq->used->flags); | |
2723feaa JW |
1874 | if (vq->log_ctx) |
1875 | eventfd_signal(vq->log_ctx, 1); | |
1876 | } | |
1877 | return 0; | |
1878 | } | |
1879 | ||
1880 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) | |
1881 | { | |
bfe2bc51 JW |
1882 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), |
1883 | vhost_avail_event(vq))) | |
2723feaa JW |
1884 | return -EFAULT; |
1885 | if (unlikely(vq->log_used)) { | |
1886 | void __user *used; | |
1887 | /* Make sure the event is seen before log. */ | |
1888 | smp_wmb(); | |
1889 | /* Log avail event write */ | |
1890 | used = vhost_avail_event(vq); | |
cc5e7107 JW |
1891 | log_used(vq, (used - (void __user *)vq->used), |
1892 | sizeof *vhost_avail_event(vq)); | |
2723feaa JW |
1893 | if (vq->log_ctx) |
1894 | eventfd_signal(vq->log_ctx, 1); | |
1895 | } | |
1896 | return 0; | |
1897 | } | |
1898 | ||
80f7d030 | 1899 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 1900 | { |
3b1bbe89 | 1901 | __virtio16 last_used_idx; |
2723feaa | 1902 | int r; |
e1f33be9 GK |
1903 | bool is_le = vq->is_le; |
1904 | ||
cda8bba0 | 1905 | if (!vq->private_data) |
2723feaa | 1906 | return 0; |
2751c988 GK |
1907 | |
1908 | vhost_init_is_le(vq); | |
2723feaa JW |
1909 | |
1910 | r = vhost_update_used_flags(vq); | |
1911 | if (r) | |
e1f33be9 | 1912 | goto err; |
2723feaa | 1913 | vq->signalled_used_valid = false; |
6b1e6cc7 | 1914 | if (!vq->iotlb && |
96d4f267 | 1915 | !access_ok(&vq->used->idx, sizeof vq->used->idx)) { |
e1f33be9 GK |
1916 | r = -EFAULT; |
1917 | goto err; | |
1918 | } | |
f8894913 | 1919 | r = vhost_get_used(vq, last_used_idx, &vq->used->idx); |
6b1e6cc7 JW |
1920 | if (r) { |
1921 | vq_err(vq, "Can't access used idx at %p\n", | |
1922 | &vq->used->idx); | |
e1f33be9 | 1923 | goto err; |
6b1e6cc7 | 1924 | } |
3b1bbe89 | 1925 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 1926 | return 0; |
6b1e6cc7 | 1927 | |
e1f33be9 GK |
1928 | err: |
1929 | vq->is_le = is_le; | |
1930 | return r; | |
2723feaa | 1931 | } |
80f7d030 | 1932 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 1933 | |
47283bef | 1934 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
6b1e6cc7 | 1935 | struct iovec iov[], int iov_size, int access) |
3a4d5c94 | 1936 | { |
a9709d68 | 1937 | const struct vhost_umem_node *node; |
6b1e6cc7 JW |
1938 | struct vhost_dev *dev = vq->dev; |
1939 | struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem; | |
3a4d5c94 MT |
1940 | struct iovec *_iov; |
1941 | u64 s = 0; | |
1942 | int ret = 0; | |
1943 | ||
3a4d5c94 MT |
1944 | while ((u64)len > s) { |
1945 | u64 size; | |
7b3384fc | 1946 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
1947 | ret = -ENOBUFS; |
1948 | break; | |
1949 | } | |
6b1e6cc7 | 1950 | |
a9709d68 JW |
1951 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, |
1952 | addr, addr + len - 1); | |
1953 | if (node == NULL || node->start > addr) { | |
6b1e6cc7 JW |
1954 | if (umem != dev->iotlb) { |
1955 | ret = -EFAULT; | |
1956 | break; | |
1957 | } | |
1958 | ret = -EAGAIN; | |
1959 | break; | |
1960 | } else if (!(node->perm & access)) { | |
1961 | ret = -EPERM; | |
3a4d5c94 MT |
1962 | break; |
1963 | } | |
6b1e6cc7 | 1964 | |
3a4d5c94 | 1965 | _iov = iov + ret; |
a9709d68 | 1966 | size = node->size - addr + node->start; |
bd97120f | 1967 | _iov->iov_len = min((u64)len - s, size); |
a8d3782f | 1968 | _iov->iov_base = (void __user *)(unsigned long) |
a9709d68 | 1969 | (node->userspace_addr + addr - node->start); |
3a4d5c94 MT |
1970 | s += size; |
1971 | addr += size; | |
1972 | ++ret; | |
1973 | } | |
1974 | ||
6b1e6cc7 JW |
1975 | if (ret == -EAGAIN) |
1976 | vhost_iotlb_miss(vq, addr, access); | |
3a4d5c94 MT |
1977 | return ret; |
1978 | } | |
1979 | ||
1980 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
1981 | * function returns the next descriptor in the chain, | |
1982 | * or -1U if we're at the end. */ | |
3b1bbe89 | 1983 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
1984 | { |
1985 | unsigned int next; | |
1986 | ||
1987 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 1988 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
1989 | return -1U; |
1990 | ||
1991 | /* Check they're not leading us off end of descriptors. */ | |
3a5db0b1 | 1992 | next = vhost16_to_cpu(vq, READ_ONCE(desc->next)); |
3a4d5c94 MT |
1993 | return next; |
1994 | } | |
1995 | ||
47283bef | 1996 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc MT |
1997 | struct iovec iov[], unsigned int iov_size, |
1998 | unsigned int *out_num, unsigned int *in_num, | |
1999 | struct vhost_log *log, unsigned int *log_num, | |
2000 | struct vring_desc *indirect) | |
3a4d5c94 MT |
2001 | { |
2002 | struct vring_desc desc; | |
2003 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 2004 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 2005 | struct iov_iter from; |
6b1e6cc7 | 2006 | int ret, access; |
3a4d5c94 MT |
2007 | |
2008 | /* Sanity check */ | |
3b1bbe89 | 2009 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
2010 | vq_err(vq, "Invalid length in indirect descriptor: " |
2011 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 2012 | (unsigned long long)len, |
3a4d5c94 MT |
2013 | sizeof desc); |
2014 | return -EINVAL; | |
2015 | } | |
2016 | ||
3b1bbe89 | 2017 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
6b1e6cc7 | 2018 | UIO_MAXIOV, VHOST_ACCESS_RO); |
7b3384fc | 2019 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2020 | if (ret != -EAGAIN) |
2021 | vq_err(vq, "Translation failure %d in indirect.\n", ret); | |
3a4d5c94 MT |
2022 | return ret; |
2023 | } | |
aad9a1ce | 2024 | iov_iter_init(&from, READ, vq->indirect, ret, len); |
3a4d5c94 MT |
2025 | |
2026 | /* We will use the result as an address to read from, so most | |
2027 | * architectures only need a compiler barrier here. */ | |
2028 | read_barrier_depends(); | |
2029 | ||
3b1bbe89 | 2030 | count = len / sizeof desc; |
3a4d5c94 MT |
2031 | /* Buffers are chained via a 16 bit next field, so |
2032 | * we can have at most 2^16 of these. */ | |
7b3384fc | 2033 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
2034 | vq_err(vq, "Indirect buffer length too big: %d\n", |
2035 | indirect->len); | |
2036 | return -E2BIG; | |
2037 | } | |
2038 | ||
2039 | do { | |
2040 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2041 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
2042 | vq_err(vq, "Loop detected: last one at %u " |
2043 | "indirect size %u\n", | |
2044 | i, count); | |
2045 | return -EINVAL; | |
2046 | } | |
cbbd26b8 | 2047 | if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) { |
3a4d5c94 | 2048 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2049 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2050 | return -EINVAL; |
2051 | } | |
3b1bbe89 | 2052 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 2053 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2054 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2055 | return -EINVAL; |
2056 | } | |
2057 | ||
6b1e6cc7 JW |
2058 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2059 | access = VHOST_ACCESS_WO; | |
2060 | else | |
2061 | access = VHOST_ACCESS_RO; | |
2062 | ||
3b1bbe89 MT |
2063 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2064 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2065 | iov_size - iov_count, access); |
7b3384fc | 2066 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2067 | if (ret != -EAGAIN) |
2068 | vq_err(vq, "Translation failure %d indirect idx %d\n", | |
2069 | ret, i); | |
3a4d5c94 MT |
2070 | return ret; |
2071 | } | |
2072 | /* If this is an input descriptor, increment that count. */ | |
6b1e6cc7 | 2073 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2074 | *in_num += ret; |
2075 | if (unlikely(log)) { | |
3b1bbe89 MT |
2076 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2077 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2078 | ++*log_num; |
2079 | } | |
2080 | } else { | |
2081 | /* If it's an output descriptor, they're all supposed | |
2082 | * to come before any input descriptors. */ | |
7b3384fc | 2083 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2084 | vq_err(vq, "Indirect descriptor " |
2085 | "has out after in: idx %d\n", i); | |
2086 | return -EINVAL; | |
2087 | } | |
2088 | *out_num += ret; | |
2089 | } | |
3b1bbe89 | 2090 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2091 | return 0; |
2092 | } | |
2093 | ||
2094 | /* This looks in the virtqueue and for the first available buffer, and converts | |
2095 | * it to an iovec for convenient access. Since descriptors consist of some | |
2096 | * number of output then some number of input descriptors, it's actually two | |
2097 | * iovecs, but we pack them into one and note how many of each there were. | |
2098 | * | |
d5675bd2 MT |
2099 | * This function returns the descriptor number found, or vq->num (which is |
2100 | * never a valid descriptor number) if none was found. A negative code is | |
2101 | * returned on error. */ | |
47283bef | 2102 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
2103 | struct iovec iov[], unsigned int iov_size, |
2104 | unsigned int *out_num, unsigned int *in_num, | |
2105 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
2106 | { |
2107 | struct vring_desc desc; | |
2108 | unsigned int i, head, found = 0; | |
2109 | u16 last_avail_idx; | |
3b1bbe89 MT |
2110 | __virtio16 avail_idx; |
2111 | __virtio16 ring_head; | |
6b1e6cc7 | 2112 | int ret, access; |
3a4d5c94 MT |
2113 | |
2114 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
2115 | last_avail_idx = vq->last_avail_idx; | |
3a4d5c94 | 2116 | |
e3b56cdd | 2117 | if (vq->avail_idx == vq->last_avail_idx) { |
f8894913 | 2118 | if (unlikely(vhost_get_avail(vq, avail_idx, &vq->avail->idx))) { |
e3b56cdd JW |
2119 | vq_err(vq, "Failed to access avail idx at %p\n", |
2120 | &vq->avail->idx); | |
2121 | return -EFAULT; | |
2122 | } | |
2123 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); | |
3a4d5c94 | 2124 | |
e3b56cdd JW |
2125 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
2126 | vq_err(vq, "Guest moved used index from %u to %u", | |
2127 | last_avail_idx, vq->avail_idx); | |
2128 | return -EFAULT; | |
2129 | } | |
2130 | ||
2131 | /* If there's nothing new since last we looked, return | |
2132 | * invalid. | |
2133 | */ | |
2134 | if (vq->avail_idx == last_avail_idx) | |
2135 | return vq->num; | |
3a4d5c94 | 2136 | |
e3b56cdd JW |
2137 | /* Only get avail ring entries after they have been |
2138 | * exposed by guest. | |
2139 | */ | |
2140 | smp_rmb(); | |
2141 | } | |
3a4d5c94 MT |
2142 | |
2143 | /* Grab the next descriptor number they're advertising, and increment | |
2144 | * the index we've seen. */ | |
f8894913 | 2145 | if (unlikely(vhost_get_avail(vq, ring_head, |
bfe2bc51 | 2146 | &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) { |
3a4d5c94 MT |
2147 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
2148 | last_avail_idx, | |
2149 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 2150 | return -EFAULT; |
3a4d5c94 MT |
2151 | } |
2152 | ||
3b1bbe89 MT |
2153 | head = vhost16_to_cpu(vq, ring_head); |
2154 | ||
3a4d5c94 | 2155 | /* If their number is silly, that's an error. */ |
7b3384fc | 2156 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
2157 | vq_err(vq, "Guest says index %u > %u is available", |
2158 | head, vq->num); | |
d5675bd2 | 2159 | return -EINVAL; |
3a4d5c94 MT |
2160 | } |
2161 | ||
2162 | /* When we start there are none of either input nor output. */ | |
2163 | *out_num = *in_num = 0; | |
2164 | if (unlikely(log)) | |
2165 | *log_num = 0; | |
2166 | ||
2167 | i = head; | |
2168 | do { | |
2169 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2170 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
2171 | vq_err(vq, "Desc index is %u > %u, head = %u", |
2172 | i, vq->num, head); | |
d5675bd2 | 2173 | return -EINVAL; |
3a4d5c94 | 2174 | } |
7b3384fc | 2175 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
2176 | vq_err(vq, "Loop detected: last one at %u " |
2177 | "vq size %u head %u\n", | |
2178 | i, vq->num, head); | |
d5675bd2 | 2179 | return -EINVAL; |
3a4d5c94 | 2180 | } |
bfe2bc51 JW |
2181 | ret = vhost_copy_from_user(vq, &desc, vq->desc + i, |
2182 | sizeof desc); | |
7b3384fc | 2183 | if (unlikely(ret)) { |
3a4d5c94 MT |
2184 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
2185 | i, vq->desc + i); | |
d5675bd2 | 2186 | return -EFAULT; |
3a4d5c94 | 2187 | } |
3b1bbe89 | 2188 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 2189 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
2190 | out_num, in_num, |
2191 | log, log_num, &desc); | |
7b3384fc | 2192 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2193 | if (ret != -EAGAIN) |
2194 | vq_err(vq, "Failure detected " | |
2195 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 2196 | return ret; |
3a4d5c94 MT |
2197 | } |
2198 | continue; | |
2199 | } | |
2200 | ||
6b1e6cc7 JW |
2201 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2202 | access = VHOST_ACCESS_WO; | |
2203 | else | |
2204 | access = VHOST_ACCESS_RO; | |
3b1bbe89 MT |
2205 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2206 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2207 | iov_size - iov_count, access); |
7b3384fc | 2208 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2209 | if (ret != -EAGAIN) |
2210 | vq_err(vq, "Translation failure %d descriptor idx %d\n", | |
2211 | ret, i); | |
d5675bd2 | 2212 | return ret; |
3a4d5c94 | 2213 | } |
6b1e6cc7 | 2214 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2215 | /* If this is an input descriptor, |
2216 | * increment that count. */ | |
2217 | *in_num += ret; | |
2218 | if (unlikely(log)) { | |
3b1bbe89 MT |
2219 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2220 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2221 | ++*log_num; |
2222 | } | |
2223 | } else { | |
2224 | /* If it's an output descriptor, they're all supposed | |
2225 | * to come before any input descriptors. */ | |
7b3384fc | 2226 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2227 | vq_err(vq, "Descriptor has out after in: " |
2228 | "idx %d\n", i); | |
d5675bd2 | 2229 | return -EINVAL; |
3a4d5c94 MT |
2230 | } |
2231 | *out_num += ret; | |
2232 | } | |
3b1bbe89 | 2233 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2234 | |
2235 | /* On success, increment avail index. */ | |
2236 | vq->last_avail_idx++; | |
8ea8cf89 MT |
2237 | |
2238 | /* Assume notifications from guest are disabled at this point, | |
2239 | * if they aren't we would need to update avail_event index. */ | |
2240 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
2241 | return head; |
2242 | } | |
6ac1afbf | 2243 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
2244 | |
2245 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 2246 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 2247 | { |
8dd014ad | 2248 | vq->last_avail_idx -= n; |
3a4d5c94 | 2249 | } |
6ac1afbf | 2250 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
2251 | |
2252 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2253 | * want to notify the guest, using eventfd. */ | |
2254 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
2255 | { | |
3b1bbe89 MT |
2256 | struct vring_used_elem heads = { |
2257 | cpu_to_vhost32(vq, head), | |
2258 | cpu_to_vhost32(vq, len) | |
2259 | }; | |
3a4d5c94 | 2260 | |
c49e4e57 | 2261 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 2262 | } |
6ac1afbf | 2263 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 2264 | |
8dd014ad DS |
2265 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2266 | struct vring_used_elem *heads, | |
2267 | unsigned count) | |
2268 | { | |
2269 | struct vring_used_elem __user *used; | |
8ea8cf89 | 2270 | u16 old, new; |
8dd014ad DS |
2271 | int start; |
2272 | ||
5fba13b5 | 2273 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 2274 | used = vq->used->ring + start; |
c49e4e57 | 2275 | if (count == 1) { |
bfe2bc51 | 2276 | if (vhost_put_user(vq, heads[0].id, &used->id)) { |
c49e4e57 JW |
2277 | vq_err(vq, "Failed to write used id"); |
2278 | return -EFAULT; | |
2279 | } | |
bfe2bc51 | 2280 | if (vhost_put_user(vq, heads[0].len, &used->len)) { |
c49e4e57 JW |
2281 | vq_err(vq, "Failed to write used len"); |
2282 | return -EFAULT; | |
2283 | } | |
bfe2bc51 | 2284 | } else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) { |
8dd014ad DS |
2285 | vq_err(vq, "Failed to write used"); |
2286 | return -EFAULT; | |
2287 | } | |
2288 | if (unlikely(vq->log_used)) { | |
2289 | /* Make sure data is seen before log. */ | |
2290 | smp_wmb(); | |
2291 | /* Log used ring entry write. */ | |
cc5e7107 JW |
2292 | log_used(vq, ((void __user *)used - (void __user *)vq->used), |
2293 | count * sizeof *used); | |
8dd014ad | 2294 | } |
8ea8cf89 MT |
2295 | old = vq->last_used_idx; |
2296 | new = (vq->last_used_idx += count); | |
2297 | /* If the driver never bothers to signal in a very long while, | |
2298 | * used index might wrap around. If that happens, invalidate | |
2299 | * signalled_used index we stored. TODO: make sure driver | |
2300 | * signals at least once in 2^16 and remove this. */ | |
2301 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
2302 | vq->signalled_used_valid = false; | |
8dd014ad DS |
2303 | return 0; |
2304 | } | |
2305 | ||
2306 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2307 | * want to notify the guest, using eventfd. */ | |
2308 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
2309 | unsigned count) | |
2310 | { | |
2311 | int start, n, r; | |
2312 | ||
5fba13b5 | 2313 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
2314 | n = vq->num - start; |
2315 | if (n < count) { | |
2316 | r = __vhost_add_used_n(vq, heads, n); | |
2317 | if (r < 0) | |
2318 | return r; | |
2319 | heads += n; | |
2320 | count -= n; | |
2321 | } | |
2322 | r = __vhost_add_used_n(vq, heads, count); | |
2323 | ||
2324 | /* Make sure buffer is written before we update index. */ | |
2325 | smp_wmb(); | |
bfe2bc51 JW |
2326 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), |
2327 | &vq->used->idx)) { | |
8dd014ad DS |
2328 | vq_err(vq, "Failed to increment used idx"); |
2329 | return -EFAULT; | |
2330 | } | |
2331 | if (unlikely(vq->log_used)) { | |
841df922 JW |
2332 | /* Make sure used idx is seen before log. */ |
2333 | smp_wmb(); | |
8dd014ad | 2334 | /* Log used index update. */ |
cc5e7107 JW |
2335 | log_used(vq, offsetof(struct vring_used, idx), |
2336 | sizeof vq->used->idx); | |
8dd014ad DS |
2337 | if (vq->log_ctx) |
2338 | eventfd_signal(vq->log_ctx, 1); | |
2339 | } | |
2340 | return r; | |
2341 | } | |
6ac1afbf | 2342 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 2343 | |
8ea8cf89 | 2344 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2345 | { |
3b1bbe89 MT |
2346 | __u16 old, new; |
2347 | __virtio16 event; | |
8ea8cf89 | 2348 | bool v; |
8d65843c JW |
2349 | /* Flush out used index updates. This is paired |
2350 | * with the barrier that the Guest executes when enabling | |
2351 | * interrupts. */ | |
2352 | smp_mb(); | |
0d499356 | 2353 | |
ea16c514 | 2354 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
2355 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2356 | return true; | |
2357 | ||
ea16c514 | 2358 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 2359 | __virtio16 flags; |
f8894913 | 2360 | if (vhost_get_avail(vq, flags, &vq->avail->flags)) { |
8ea8cf89 MT |
2361 | vq_err(vq, "Failed to get flags"); |
2362 | return true; | |
2363 | } | |
3b1bbe89 | 2364 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 2365 | } |
8ea8cf89 MT |
2366 | old = vq->signalled_used; |
2367 | v = vq->signalled_used_valid; | |
2368 | new = vq->signalled_used = vq->last_used_idx; | |
2369 | vq->signalled_used_valid = true; | |
3a4d5c94 | 2370 | |
8ea8cf89 MT |
2371 | if (unlikely(!v)) |
2372 | return true; | |
3a4d5c94 | 2373 | |
f8894913 | 2374 | if (vhost_get_avail(vq, event, vhost_used_event(vq))) { |
8ea8cf89 MT |
2375 | vq_err(vq, "Failed to get used event idx"); |
2376 | return true; | |
2377 | } | |
8d65843c | 2378 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
2379 | } |
2380 | ||
2381 | /* This actually signals the guest, using eventfd. */ | |
2382 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2383 | { | |
3a4d5c94 | 2384 | /* Signal the Guest tell them we used something up. */ |
8ea8cf89 | 2385 | if (vq->call_ctx && vhost_notify(dev, vq)) |
3a4d5c94 MT |
2386 | eventfd_signal(vq->call_ctx, 1); |
2387 | } | |
6ac1afbf | 2388 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
2389 | |
2390 | /* And here's the combo meal deal. Supersize me! */ | |
2391 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
2392 | struct vhost_virtqueue *vq, | |
2393 | unsigned int head, int len) | |
2394 | { | |
2395 | vhost_add_used(vq, head, len); | |
2396 | vhost_signal(dev, vq); | |
2397 | } | |
6ac1afbf | 2398 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 2399 | |
8dd014ad DS |
2400 | /* multi-buffer version of vhost_add_used_and_signal */ |
2401 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
2402 | struct vhost_virtqueue *vq, | |
2403 | struct vring_used_elem *heads, unsigned count) | |
2404 | { | |
2405 | vhost_add_used_n(vq, heads, count); | |
2406 | vhost_signal(dev, vq); | |
2407 | } | |
6ac1afbf | 2408 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 2409 | |
d4a60603 JW |
2410 | /* return true if we're sure that avaiable ring is empty */ |
2411 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2412 | { | |
2413 | __virtio16 avail_idx; | |
2414 | int r; | |
2415 | ||
275bf960 JW |
2416 | if (vq->avail_idx != vq->last_avail_idx) |
2417 | return false; | |
2418 | ||
f8894913 | 2419 | r = vhost_get_avail(vq, avail_idx, &vq->avail->idx); |
275bf960 | 2420 | if (unlikely(r)) |
d4a60603 | 2421 | return false; |
275bf960 | 2422 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
d4a60603 | 2423 | |
275bf960 | 2424 | return vq->avail_idx == vq->last_avail_idx; |
d4a60603 JW |
2425 | } |
2426 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
2427 | ||
3a4d5c94 | 2428 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 2429 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2430 | { |
3b1bbe89 | 2431 | __virtio16 avail_idx; |
3a4d5c94 | 2432 | int r; |
d47effe1 | 2433 | |
3a4d5c94 MT |
2434 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2435 | return false; | |
2436 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2437 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2438 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2439 | if (r) { |
2440 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2441 | &vq->used->flags, r); | |
2442 | return false; | |
2443 | } | |
2444 | } else { | |
2723feaa | 2445 | r = vhost_update_avail_event(vq, vq->avail_idx); |
8ea8cf89 MT |
2446 | if (r) { |
2447 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
2448 | vhost_avail_event(vq), r); | |
2449 | return false; | |
2450 | } | |
2451 | } | |
3a4d5c94 MT |
2452 | /* They could have slipped one in as we were doing that: make |
2453 | * sure it's written, then check again. */ | |
5659338c | 2454 | smp_mb(); |
f8894913 | 2455 | r = vhost_get_avail(vq, avail_idx, &vq->avail->idx); |
3a4d5c94 MT |
2456 | if (r) { |
2457 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
2458 | &vq->avail->idx, r); | |
2459 | return false; | |
2460 | } | |
2461 | ||
3b1bbe89 | 2462 | return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx; |
3a4d5c94 | 2463 | } |
6ac1afbf | 2464 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
2465 | |
2466 | /* We don't need to be notified again. */ | |
8ea8cf89 | 2467 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
2468 | { |
2469 | int r; | |
d47effe1 | 2470 | |
3a4d5c94 MT |
2471 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2472 | return; | |
2473 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2474 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2475 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2476 | if (r) |
2477 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2478 | &vq->used->flags, r); | |
2479 | } | |
3a4d5c94 | 2480 | } |
6ac1afbf AH |
2481 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2482 | ||
6b1e6cc7 JW |
2483 | /* Create a new message. */ |
2484 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) | |
2485 | { | |
2486 | struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL); | |
2487 | if (!node) | |
2488 | return NULL; | |
670ae9ca MT |
2489 | |
2490 | /* Make sure all padding within the structure is initialized. */ | |
2491 | memset(&node->msg, 0, sizeof node->msg); | |
6b1e6cc7 JW |
2492 | node->vq = vq; |
2493 | node->msg.type = type; | |
2494 | return node; | |
2495 | } | |
2496 | EXPORT_SYMBOL_GPL(vhost_new_msg); | |
2497 | ||
2498 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, | |
2499 | struct vhost_msg_node *node) | |
2500 | { | |
2501 | spin_lock(&dev->iotlb_lock); | |
2502 | list_add_tail(&node->node, head); | |
2503 | spin_unlock(&dev->iotlb_lock); | |
2504 | ||
a9a08845 | 2505 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
6b1e6cc7 JW |
2506 | } |
2507 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); | |
2508 | ||
2509 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, | |
2510 | struct list_head *head) | |
2511 | { | |
2512 | struct vhost_msg_node *node = NULL; | |
2513 | ||
2514 | spin_lock(&dev->iotlb_lock); | |
2515 | if (!list_empty(head)) { | |
2516 | node = list_first_entry(head, struct vhost_msg_node, | |
2517 | node); | |
2518 | list_del(&node->node); | |
2519 | } | |
2520 | spin_unlock(&dev->iotlb_lock); | |
2521 | ||
2522 | return node; | |
2523 | } | |
2524 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); | |
2525 | ||
2526 | ||
6ac1afbf AH |
2527 | static int __init vhost_init(void) |
2528 | { | |
2529 | return 0; | |
2530 | } | |
2531 | ||
2532 | static void __exit vhost_exit(void) | |
2533 | { | |
2534 | } | |
2535 | ||
2536 | module_init(vhost_init); | |
2537 | module_exit(vhost_exit); | |
2538 | ||
2539 | MODULE_VERSION("0.0.1"); | |
2540 | MODULE_LICENSE("GPL v2"); | |
2541 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
2542 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |