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; |
d47effe1 | 206 | |
70181d51 JW |
207 | if (poll->wqh) |
208 | return 0; | |
209 | ||
9965ed17 | 210 | mask = vfs_poll(file, &poll->table); |
3a4d5c94 | 211 | if (mask) |
3ad6f93e | 212 | vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask)); |
a9a08845 | 213 | if (mask & EPOLLERR) { |
dc6455a7 | 214 | vhost_poll_stop(poll); |
896fc242 | 215 | return -EINVAL; |
2b8b328b JW |
216 | } |
217 | ||
896fc242 | 218 | return 0; |
3a4d5c94 | 219 | } |
6ac1afbf | 220 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
221 | |
222 | /* Stop polling a file. After this function returns, it becomes safe to drop the | |
223 | * file reference. You must also flush afterwards. */ | |
224 | void vhost_poll_stop(struct vhost_poll *poll) | |
225 | { | |
2b8b328b JW |
226 | if (poll->wqh) { |
227 | remove_wait_queue(poll->wqh, &poll->wait); | |
228 | poll->wqh = NULL; | |
229 | } | |
3a4d5c94 | 230 | } |
6ac1afbf | 231 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 232 | |
7235acdb | 233 | void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
0174b0c3 | 234 | { |
7235acdb | 235 | struct vhost_flush_struct flush; |
d47effe1 | 236 | |
7235acdb JW |
237 | if (dev->worker) { |
238 | init_completion(&flush.wait_event); | |
239 | vhost_work_init(&flush.work, vhost_flush_work); | |
0174b0c3 | 240 | |
7235acdb JW |
241 | vhost_work_queue(dev, &flush.work); |
242 | wait_for_completion(&flush.wait_event); | |
243 | } | |
3a4d5c94 | 244 | } |
6ac1afbf | 245 | EXPORT_SYMBOL_GPL(vhost_work_flush); |
3a4d5c94 | 246 | |
87d6a412 MT |
247 | /* Flush any work that has been scheduled. When calling this, don't hold any |
248 | * locks that are also used by the callback. */ | |
249 | void vhost_poll_flush(struct vhost_poll *poll) | |
250 | { | |
251 | vhost_work_flush(poll->dev, &poll->work); | |
252 | } | |
6ac1afbf | 253 | EXPORT_SYMBOL_GPL(vhost_poll_flush); |
87d6a412 | 254 | |
163049ae | 255 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 256 | { |
04b96e55 JW |
257 | if (!dev->worker) |
258 | return; | |
c23f3445 | 259 | |
04b96e55 JW |
260 | if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { |
261 | /* We can only add the work to the list after we're | |
262 | * sure it was not in the list. | |
635abf01 | 263 | * test_and_set_bit() implies a memory barrier. |
04b96e55 | 264 | */ |
04b96e55 | 265 | llist_add(&work->node, &dev->work_list); |
c23f3445 TH |
266 | wake_up_process(dev->worker); |
267 | } | |
3a4d5c94 | 268 | } |
6ac1afbf | 269 | EXPORT_SYMBOL_GPL(vhost_work_queue); |
3a4d5c94 | 270 | |
526d3e7f JW |
271 | /* A lockless hint for busy polling code to exit the loop */ |
272 | bool vhost_has_work(struct vhost_dev *dev) | |
273 | { | |
04b96e55 | 274 | return !llist_empty(&dev->work_list); |
526d3e7f JW |
275 | } |
276 | EXPORT_SYMBOL_GPL(vhost_has_work); | |
277 | ||
87d6a412 MT |
278 | void vhost_poll_queue(struct vhost_poll *poll) |
279 | { | |
280 | vhost_work_queue(poll->dev, &poll->work); | |
281 | } | |
6ac1afbf | 282 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 283 | |
f8894913 JW |
284 | static void __vhost_vq_meta_reset(struct vhost_virtqueue *vq) |
285 | { | |
286 | int j; | |
287 | ||
288 | for (j = 0; j < VHOST_NUM_ADDRS; j++) | |
289 | vq->meta_iotlb[j] = NULL; | |
290 | } | |
291 | ||
292 | static void vhost_vq_meta_reset(struct vhost_dev *d) | |
293 | { | |
294 | int i; | |
295 | ||
86a07da3 | 296 | for (i = 0; i < d->nvqs; ++i) |
f8894913 JW |
297 | __vhost_vq_meta_reset(d->vqs[i]); |
298 | } | |
299 | ||
3a4d5c94 MT |
300 | static void vhost_vq_reset(struct vhost_dev *dev, |
301 | struct vhost_virtqueue *vq) | |
302 | { | |
303 | vq->num = 1; | |
304 | vq->desc = NULL; | |
305 | vq->avail = NULL; | |
306 | vq->used = NULL; | |
307 | vq->last_avail_idx = 0; | |
308 | vq->avail_idx = 0; | |
309 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
310 | vq->signalled_used = 0; |
311 | vq->signalled_used_valid = false; | |
3a4d5c94 | 312 | vq->used_flags = 0; |
3a4d5c94 MT |
313 | vq->log_used = false; |
314 | vq->log_addr = -1ull; | |
3a4d5c94 | 315 | vq->private_data = NULL; |
ea16c514 | 316 | vq->acked_features = 0; |
429711ae | 317 | vq->acked_backend_features = 0; |
3a4d5c94 MT |
318 | vq->log_base = NULL; |
319 | vq->error_ctx = NULL; | |
3a4d5c94 MT |
320 | vq->kick = NULL; |
321 | vq->call_ctx = NULL; | |
73a99f08 | 322 | vq->log_ctx = NULL; |
c5072037 GK |
323 | vhost_reset_is_le(vq); |
324 | vhost_disable_cross_endian(vq); | |
03088137 | 325 | vq->busyloop_timeout = 0; |
a9709d68 | 326 | vq->umem = NULL; |
6b1e6cc7 | 327 | vq->iotlb = NULL; |
f8894913 | 328 | __vhost_vq_meta_reset(vq); |
3a4d5c94 MT |
329 | } |
330 | ||
c23f3445 TH |
331 | static int vhost_worker(void *data) |
332 | { | |
333 | struct vhost_dev *dev = data; | |
04b96e55 JW |
334 | struct vhost_work *work, *work_next; |
335 | struct llist_node *node; | |
d7ffde35 | 336 | mm_segment_t oldfs = get_fs(); |
c23f3445 | 337 | |
d7ffde35 | 338 | set_fs(USER_DS); |
64e1c807 MT |
339 | use_mm(dev->mm); |
340 | ||
c23f3445 TH |
341 | for (;;) { |
342 | /* mb paired w/ kthread_stop */ | |
343 | set_current_state(TASK_INTERRUPTIBLE); | |
344 | ||
c23f3445 | 345 | if (kthread_should_stop()) { |
c23f3445 | 346 | __set_current_state(TASK_RUNNING); |
64e1c807 | 347 | break; |
c23f3445 | 348 | } |
04b96e55 JW |
349 | |
350 | node = llist_del_all(&dev->work_list); | |
351 | if (!node) | |
352 | schedule(); | |
353 | ||
354 | node = llist_reverse_order(node); | |
355 | /* make sure flag is seen after deletion */ | |
356 | smp_wmb(); | |
357 | llist_for_each_entry_safe(work, work_next, node, node) { | |
358 | clear_bit(VHOST_WORK_QUEUED, &work->flags); | |
c23f3445 TH |
359 | __set_current_state(TASK_RUNNING); |
360 | work->fn(work); | |
d550dda1 NHE |
361 | if (need_resched()) |
362 | schedule(); | |
04b96e55 | 363 | } |
c23f3445 | 364 | } |
64e1c807 | 365 | unuse_mm(dev->mm); |
d7ffde35 | 366 | set_fs(oldfs); |
64e1c807 | 367 | return 0; |
c23f3445 TH |
368 | } |
369 | ||
bab632d6 MT |
370 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
371 | { | |
372 | kfree(vq->indirect); | |
373 | vq->indirect = NULL; | |
374 | kfree(vq->log); | |
375 | vq->log = NULL; | |
376 | kfree(vq->heads); | |
377 | vq->heads = NULL; | |
bab632d6 MT |
378 | } |
379 | ||
e0e9b406 JW |
380 | /* Helper to allocate iovec buffers for all vqs. */ |
381 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
382 | { | |
6d5e6aa8 | 383 | struct vhost_virtqueue *vq; |
e0e9b406 | 384 | int i; |
d47effe1 | 385 | |
e0e9b406 | 386 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 | 387 | vq = dev->vqs[i]; |
6da2ec56 KC |
388 | vq->indirect = kmalloc_array(UIO_MAXIOV, |
389 | sizeof(*vq->indirect), | |
390 | GFP_KERNEL); | |
b46a0bf7 | 391 | vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), |
6da2ec56 | 392 | GFP_KERNEL); |
b46a0bf7 | 393 | vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), |
6da2ec56 | 394 | GFP_KERNEL); |
6d5e6aa8 | 395 | if (!vq->indirect || !vq->log || !vq->heads) |
e0e9b406 JW |
396 | goto err_nomem; |
397 | } | |
398 | return 0; | |
d47effe1 | 399 | |
e0e9b406 | 400 | err_nomem: |
bab632d6 | 401 | for (; i >= 0; --i) |
3ab2e420 | 402 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
403 | return -ENOMEM; |
404 | } | |
405 | ||
406 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
407 | { | |
408 | int i; | |
d47effe1 | 409 | |
bab632d6 | 410 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 411 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
412 | } |
413 | ||
e82b9b07 JW |
414 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, |
415 | int pkts, int total_len) | |
416 | { | |
417 | struct vhost_dev *dev = vq->dev; | |
418 | ||
419 | if ((dev->byte_weight && total_len >= dev->byte_weight) || | |
420 | pkts >= dev->weight) { | |
421 | vhost_poll_queue(&vq->poll); | |
422 | return true; | |
423 | } | |
424 | ||
425 | return false; | |
426 | } | |
427 | EXPORT_SYMBOL_GPL(vhost_exceeds_weight); | |
428 | ||
4942e825 JW |
429 | static size_t vhost_get_avail_size(struct vhost_virtqueue *vq, |
430 | unsigned int num) | |
431 | { | |
432 | size_t event __maybe_unused = | |
433 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
434 | ||
435 | return sizeof(*vq->avail) + | |
436 | sizeof(*vq->avail->ring) * num + event; | |
437 | } | |
438 | ||
439 | static size_t vhost_get_used_size(struct vhost_virtqueue *vq, | |
440 | unsigned int num) | |
441 | { | |
442 | size_t event __maybe_unused = | |
443 | vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
444 | ||
445 | return sizeof(*vq->used) + | |
446 | sizeof(*vq->used->ring) * num + event; | |
447 | } | |
448 | ||
449 | static size_t vhost_get_desc_size(struct vhost_virtqueue *vq, | |
450 | unsigned int num) | |
451 | { | |
452 | return sizeof(*vq->desc) * num; | |
453 | } | |
454 | ||
59566b6e | 455 | void vhost_dev_init(struct vhost_dev *dev, |
e82b9b07 JW |
456 | struct vhost_virtqueue **vqs, int nvqs, |
457 | int iov_limit, int weight, int byte_weight) | |
3a4d5c94 | 458 | { |
6d5e6aa8 | 459 | struct vhost_virtqueue *vq; |
3a4d5c94 | 460 | int i; |
c23f3445 | 461 | |
3a4d5c94 MT |
462 | dev->vqs = vqs; |
463 | dev->nvqs = nvqs; | |
464 | mutex_init(&dev->mutex); | |
465 | dev->log_ctx = NULL; | |
a9709d68 | 466 | dev->umem = NULL; |
6b1e6cc7 | 467 | dev->iotlb = NULL; |
3a4d5c94 | 468 | dev->mm = NULL; |
c23f3445 | 469 | dev->worker = NULL; |
b46a0bf7 | 470 | dev->iov_limit = iov_limit; |
e82b9b07 JW |
471 | dev->weight = weight; |
472 | dev->byte_weight = byte_weight; | |
04b96e55 | 473 | init_llist_head(&dev->work_list); |
6b1e6cc7 JW |
474 | init_waitqueue_head(&dev->wait); |
475 | INIT_LIST_HEAD(&dev->read_list); | |
476 | INIT_LIST_HEAD(&dev->pending_list); | |
477 | spin_lock_init(&dev->iotlb_lock); | |
3d2c7d37 | 478 | |
3a4d5c94 MT |
479 | |
480 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
481 | vq = dev->vqs[i]; |
482 | vq->log = NULL; | |
483 | vq->indirect = NULL; | |
484 | vq->heads = NULL; | |
485 | vq->dev = dev; | |
486 | mutex_init(&vq->mutex); | |
487 | vhost_vq_reset(dev, vq); | |
488 | if (vq->handle_kick) | |
489 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
a9a08845 | 490 | EPOLLIN, dev); |
3a4d5c94 | 491 | } |
3a4d5c94 | 492 | } |
6ac1afbf | 493 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
494 | |
495 | /* Caller should have device mutex */ | |
496 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
497 | { | |
498 | /* Are you the owner? If not, I don't think you mean to do that */ | |
499 | return dev->mm == current->mm ? 0 : -EPERM; | |
500 | } | |
6ac1afbf | 501 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 502 | |
87d6a412 | 503 | struct vhost_attach_cgroups_struct { |
d47effe1 KK |
504 | struct vhost_work work; |
505 | struct task_struct *owner; | |
506 | int ret; | |
87d6a412 MT |
507 | }; |
508 | ||
509 | static void vhost_attach_cgroups_work(struct vhost_work *work) | |
510 | { | |
d47effe1 KK |
511 | struct vhost_attach_cgroups_struct *s; |
512 | ||
513 | s = container_of(work, struct vhost_attach_cgroups_struct, work); | |
514 | s->ret = cgroup_attach_task_all(s->owner, current); | |
87d6a412 MT |
515 | } |
516 | ||
517 | static int vhost_attach_cgroups(struct vhost_dev *dev) | |
518 | { | |
d47effe1 KK |
519 | struct vhost_attach_cgroups_struct attach; |
520 | ||
521 | attach.owner = current; | |
522 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); | |
523 | vhost_work_queue(dev, &attach.work); | |
524 | vhost_work_flush(dev, &attach.work); | |
525 | return attach.ret; | |
87d6a412 MT |
526 | } |
527 | ||
05c05351 MT |
528 | /* Caller should have device mutex */ |
529 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
530 | { | |
531 | return dev->mm; | |
532 | } | |
6ac1afbf | 533 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 534 | |
3a4d5c94 | 535 | /* Caller should have device mutex */ |
54db63c2 | 536 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 537 | { |
c23f3445 TH |
538 | struct task_struct *worker; |
539 | int err; | |
d47effe1 | 540 | |
3a4d5c94 | 541 | /* Is there an owner already? */ |
05c05351 | 542 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
543 | err = -EBUSY; |
544 | goto err_mm; | |
545 | } | |
d47effe1 | 546 | |
3a4d5c94 MT |
547 | /* No owner, become one */ |
548 | dev->mm = get_task_mm(current); | |
c23f3445 TH |
549 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
550 | if (IS_ERR(worker)) { | |
551 | err = PTR_ERR(worker); | |
552 | goto err_worker; | |
553 | } | |
554 | ||
555 | dev->worker = worker; | |
87d6a412 MT |
556 | wake_up_process(worker); /* avoid contributing to loadavg */ |
557 | ||
558 | err = vhost_attach_cgroups(dev); | |
9e3d1957 MT |
559 | if (err) |
560 | goto err_cgroup; | |
c23f3445 | 561 | |
e0e9b406 JW |
562 | err = vhost_dev_alloc_iovecs(dev); |
563 | if (err) | |
564 | goto err_cgroup; | |
565 | ||
3a4d5c94 | 566 | return 0; |
9e3d1957 MT |
567 | err_cgroup: |
568 | kthread_stop(worker); | |
615cc221 | 569 | dev->worker = NULL; |
c23f3445 TH |
570 | err_worker: |
571 | if (dev->mm) | |
572 | mmput(dev->mm); | |
573 | dev->mm = NULL; | |
574 | err_mm: | |
575 | return err; | |
3a4d5c94 | 576 | } |
6ac1afbf | 577 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 578 | |
a9709d68 JW |
579 | struct vhost_umem *vhost_dev_reset_owner_prepare(void) |
580 | { | |
6c5ab651 | 581 | return kvzalloc(sizeof(struct vhost_umem), GFP_KERNEL); |
150b9e51 | 582 | } |
6ac1afbf | 583 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 584 | |
150b9e51 | 585 | /* Caller should have device mutex */ |
a9709d68 | 586 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_umem *umem) |
150b9e51 | 587 | { |
47283bef MT |
588 | int i; |
589 | ||
f6f93f75 | 590 | vhost_dev_cleanup(dev); |
3a4d5c94 | 591 | |
150b9e51 | 592 | /* Restore memory to default empty mapping. */ |
a9709d68 JW |
593 | INIT_LIST_HEAD(&umem->umem_list); |
594 | dev->umem = umem; | |
47283bef MT |
595 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
596 | * VQs aren't running. | |
597 | */ | |
598 | for (i = 0; i < dev->nvqs; ++i) | |
a9709d68 | 599 | dev->vqs[i]->umem = umem; |
3a4d5c94 | 600 | } |
6ac1afbf | 601 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 602 | |
b211616d | 603 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
604 | { |
605 | int i; | |
b211616d MT |
606 | |
607 | for (i = 0; i < dev->nvqs; ++i) { | |
3ab2e420 AH |
608 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) { |
609 | vhost_poll_stop(&dev->vqs[i]->poll); | |
610 | vhost_poll_flush(&dev->vqs[i]->poll); | |
b211616d | 611 | } |
bab632d6 | 612 | } |
bab632d6 | 613 | } |
6ac1afbf | 614 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 615 | |
6b1e6cc7 JW |
616 | static void vhost_umem_free(struct vhost_umem *umem, |
617 | struct vhost_umem_node *node) | |
618 | { | |
619 | vhost_umem_interval_tree_remove(node, &umem->umem_tree); | |
620 | list_del(&node->link); | |
621 | kfree(node); | |
622 | umem->numem--; | |
623 | } | |
624 | ||
a9709d68 JW |
625 | static void vhost_umem_clean(struct vhost_umem *umem) |
626 | { | |
627 | struct vhost_umem_node *node, *tmp; | |
628 | ||
629 | if (!umem) | |
630 | return; | |
631 | ||
6b1e6cc7 JW |
632 | list_for_each_entry_safe(node, tmp, &umem->umem_list, link) |
633 | vhost_umem_free(umem, node); | |
634 | ||
a9709d68 JW |
635 | kvfree(umem); |
636 | } | |
637 | ||
6b1e6cc7 JW |
638 | static void vhost_clear_msg(struct vhost_dev *dev) |
639 | { | |
640 | struct vhost_msg_node *node, *n; | |
641 | ||
642 | spin_lock(&dev->iotlb_lock); | |
643 | ||
644 | list_for_each_entry_safe(node, n, &dev->read_list, node) { | |
645 | list_del(&node->node); | |
646 | kfree(node); | |
647 | } | |
648 | ||
649 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { | |
650 | list_del(&node->node); | |
651 | kfree(node); | |
652 | } | |
653 | ||
654 | spin_unlock(&dev->iotlb_lock); | |
655 | } | |
656 | ||
f6f93f75 | 657 | void vhost_dev_cleanup(struct vhost_dev *dev) |
3a4d5c94 MT |
658 | { |
659 | int i; | |
d47effe1 | 660 | |
3a4d5c94 | 661 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
662 | if (dev->vqs[i]->error_ctx) |
663 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
3ab2e420 AH |
664 | if (dev->vqs[i]->kick) |
665 | fput(dev->vqs[i]->kick); | |
666 | if (dev->vqs[i]->call_ctx) | |
667 | eventfd_ctx_put(dev->vqs[i]->call_ctx); | |
3ab2e420 | 668 | vhost_vq_reset(dev, dev->vqs[i]); |
3a4d5c94 | 669 | } |
e0e9b406 | 670 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
671 | if (dev->log_ctx) |
672 | eventfd_ctx_put(dev->log_ctx); | |
673 | dev->log_ctx = NULL; | |
3a4d5c94 | 674 | /* No one will access memory at this point */ |
a9709d68 JW |
675 | vhost_umem_clean(dev->umem); |
676 | dev->umem = NULL; | |
6b1e6cc7 JW |
677 | vhost_umem_clean(dev->iotlb); |
678 | dev->iotlb = NULL; | |
679 | vhost_clear_msg(dev); | |
a9a08845 | 680 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
04b96e55 | 681 | WARN_ON(!llist_empty(&dev->work_list)); |
78b620ce ED |
682 | if (dev->worker) { |
683 | kthread_stop(dev->worker); | |
684 | dev->worker = NULL; | |
685 | } | |
3d2c7d37 | 686 | if (dev->mm) |
533a19b4 MT |
687 | mmput(dev->mm); |
688 | dev->mm = NULL; | |
3a4d5c94 | 689 | } |
6ac1afbf | 690 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 | 691 | |
ddd3d408 | 692 | static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz) |
3a4d5c94 MT |
693 | { |
694 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 695 | |
3a4d5c94 MT |
696 | /* Make sure 64 bit math will not overflow. */ |
697 | if (a > ULONG_MAX - (unsigned long)log_base || | |
698 | a + (unsigned long)log_base > ULONG_MAX) | |
ddd3d408 | 699 | return false; |
3a4d5c94 | 700 | |
96d4f267 | 701 | return access_ok(log_base + a, |
3a4d5c94 MT |
702 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); |
703 | } | |
704 | ||
ec33d031 MT |
705 | static bool vhost_overflow(u64 uaddr, u64 size) |
706 | { | |
707 | /* Make sure 64 bit math will not overflow. */ | |
708 | return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size; | |
709 | } | |
710 | ||
3a4d5c94 | 711 | /* Caller should have vq mutex and device mutex. */ |
ddd3d408 SH |
712 | static bool vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, |
713 | int log_all) | |
3a4d5c94 | 714 | { |
a9709d68 | 715 | struct vhost_umem_node *node; |
179b284e | 716 | |
a9709d68 | 717 | if (!umem) |
ddd3d408 | 718 | return false; |
179b284e | 719 | |
a9709d68 JW |
720 | list_for_each_entry(node, &umem->umem_list, link) { |
721 | unsigned long a = node->userspace_addr; | |
722 | ||
ec33d031 | 723 | if (vhost_overflow(node->userspace_addr, node->size)) |
ddd3d408 | 724 | return false; |
ec33d031 MT |
725 | |
726 | ||
96d4f267 | 727 | if (!access_ok((void __user *)a, |
a9709d68 | 728 | node->size)) |
ddd3d408 | 729 | return false; |
3a4d5c94 | 730 | else if (log_all && !log_access_ok(log_base, |
a9709d68 JW |
731 | node->start, |
732 | node->size)) | |
ddd3d408 | 733 | return false; |
3a4d5c94 | 734 | } |
ddd3d408 | 735 | return true; |
3a4d5c94 MT |
736 | } |
737 | ||
f8894913 JW |
738 | static inline void __user *vhost_vq_meta_fetch(struct vhost_virtqueue *vq, |
739 | u64 addr, unsigned int size, | |
740 | int type) | |
741 | { | |
742 | const struct vhost_umem_node *node = vq->meta_iotlb[type]; | |
743 | ||
744 | if (!node) | |
745 | return NULL; | |
746 | ||
747 | return (void *)(uintptr_t)(node->userspace_addr + addr - node->start); | |
748 | } | |
749 | ||
3a4d5c94 MT |
750 | /* Can we switch to this memory table? */ |
751 | /* Caller should have device mutex but not vq mutex */ | |
ddd3d408 SH |
752 | static bool memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, |
753 | int log_all) | |
3a4d5c94 MT |
754 | { |
755 | int i; | |
d47effe1 | 756 | |
3a4d5c94 | 757 | for (i = 0; i < d->nvqs; ++i) { |
ddd3d408 | 758 | bool ok; |
ea16c514 MT |
759 | bool log; |
760 | ||
3ab2e420 | 761 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 762 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 763 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 764 | if (d->vqs[i]->private_data) |
a9709d68 JW |
765 | ok = vq_memory_access_ok(d->vqs[i]->log_base, |
766 | umem, log); | |
3a4d5c94 | 767 | else |
ddd3d408 | 768 | ok = true; |
3ab2e420 | 769 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 | 770 | if (!ok) |
ddd3d408 | 771 | return false; |
3a4d5c94 | 772 | } |
ddd3d408 | 773 | return true; |
3a4d5c94 MT |
774 | } |
775 | ||
6b1e6cc7 JW |
776 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
777 | struct iovec iov[], int iov_size, int access); | |
bfe2bc51 | 778 | |
72952cc0 | 779 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, |
bfe2bc51 JW |
780 | const void *from, unsigned size) |
781 | { | |
6b1e6cc7 | 782 | int ret; |
bfe2bc51 | 783 | |
6b1e6cc7 JW |
784 | if (!vq->iotlb) |
785 | return __copy_to_user(to, from, size); | |
786 | else { | |
787 | /* This function should be called after iotlb | |
788 | * prefetch, which means we're sure that all vq | |
789 | * could be access through iotlb. So -EAGAIN should | |
790 | * not happen in this case. | |
791 | */ | |
6b1e6cc7 | 792 | struct iov_iter t; |
f8894913 JW |
793 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
794 | (u64)(uintptr_t)to, size, | |
7ced6c98 | 795 | VHOST_ADDR_USED); |
f8894913 JW |
796 | |
797 | if (uaddr) | |
798 | return __copy_to_user(uaddr, from, size); | |
799 | ||
6b1e6cc7 JW |
800 | ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, |
801 | ARRAY_SIZE(vq->iotlb_iov), | |
802 | VHOST_ACCESS_WO); | |
803 | if (ret < 0) | |
804 | goto out; | |
805 | iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size); | |
806 | ret = copy_to_iter(from, size, &t); | |
807 | if (ret == size) | |
808 | ret = 0; | |
809 | } | |
810 | out: | |
811 | return ret; | |
812 | } | |
bfe2bc51 JW |
813 | |
814 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, | |
72952cc0 | 815 | void __user *from, unsigned size) |
bfe2bc51 | 816 | { |
6b1e6cc7 JW |
817 | int ret; |
818 | ||
819 | if (!vq->iotlb) | |
820 | return __copy_from_user(to, from, size); | |
821 | else { | |
822 | /* This function should be called after iotlb | |
823 | * prefetch, which means we're sure that vq | |
824 | * could be access through iotlb. So -EAGAIN should | |
825 | * not happen in this case. | |
826 | */ | |
f8894913 JW |
827 | void __user *uaddr = vhost_vq_meta_fetch(vq, |
828 | (u64)(uintptr_t)from, size, | |
829 | VHOST_ADDR_DESC); | |
6b1e6cc7 | 830 | struct iov_iter f; |
f8894913 JW |
831 | |
832 | if (uaddr) | |
833 | return __copy_from_user(to, uaddr, size); | |
834 | ||
6b1e6cc7 JW |
835 | ret = translate_desc(vq, (u64)(uintptr_t)from, 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", from, | |
841 | (unsigned long long) size); | |
842 | goto out; | |
843 | } | |
844 | iov_iter_init(&f, READ, vq->iotlb_iov, ret, size); | |
845 | ret = copy_from_iter(to, size, &f); | |
846 | if (ret == size) | |
847 | ret = 0; | |
848 | } | |
849 | ||
850 | out: | |
851 | return ret; | |
852 | } | |
853 | ||
f8894913 JW |
854 | static void __user *__vhost_get_user_slow(struct vhost_virtqueue *vq, |
855 | void __user *addr, unsigned int size, | |
856 | int type) | |
6b1e6cc7 JW |
857 | { |
858 | int ret; | |
859 | ||
6b1e6cc7 JW |
860 | ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov, |
861 | ARRAY_SIZE(vq->iotlb_iov), | |
862 | VHOST_ACCESS_RO); | |
863 | if (ret < 0) { | |
864 | vq_err(vq, "IOTLB translation failure: uaddr " | |
865 | "%p size 0x%llx\n", addr, | |
866 | (unsigned long long) size); | |
867 | return NULL; | |
868 | } | |
869 | ||
870 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { | |
871 | vq_err(vq, "Non atomic userspace memory access: uaddr " | |
872 | "%p size 0x%llx\n", addr, | |
873 | (unsigned long long) size); | |
874 | return NULL; | |
875 | } | |
876 | ||
877 | return vq->iotlb_iov[0].iov_base; | |
878 | } | |
879 | ||
f8894913 JW |
880 | /* This function should be called after iotlb |
881 | * prefetch, which means we're sure that vq | |
882 | * could be access through iotlb. So -EAGAIN should | |
883 | * not happen in this case. | |
884 | */ | |
885 | static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, | |
886 | void *addr, unsigned int size, | |
887 | int type) | |
888 | { | |
889 | void __user *uaddr = vhost_vq_meta_fetch(vq, | |
890 | (u64)(uintptr_t)addr, size, type); | |
891 | if (uaddr) | |
892 | return uaddr; | |
893 | ||
894 | return __vhost_get_user_slow(vq, addr, size, type); | |
895 | } | |
896 | ||
897 | #define vhost_put_user(vq, x, ptr) \ | |
6b1e6cc7 JW |
898 | ({ \ |
899 | int ret = -EFAULT; \ | |
900 | if (!vq->iotlb) { \ | |
901 | ret = __put_user(x, ptr); \ | |
902 | } else { \ | |
903 | __typeof__(ptr) to = \ | |
f8894913 JW |
904 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
905 | sizeof(*ptr), VHOST_ADDR_USED); \ | |
6b1e6cc7 JW |
906 | if (to != NULL) \ |
907 | ret = __put_user(x, to); \ | |
908 | else \ | |
909 | ret = -EFAULT; \ | |
910 | } \ | |
911 | ret; \ | |
912 | }) | |
913 | ||
7b5d753e JW |
914 | static inline int vhost_put_avail_event(struct vhost_virtqueue *vq) |
915 | { | |
916 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), | |
917 | vhost_avail_event(vq)); | |
918 | } | |
919 | ||
920 | static inline int vhost_put_used(struct vhost_virtqueue *vq, | |
921 | struct vring_used_elem *head, int idx, | |
922 | int count) | |
923 | { | |
924 | return vhost_copy_to_user(vq, vq->used->ring + idx, head, | |
925 | count * sizeof(*head)); | |
926 | } | |
927 | ||
928 | static inline int vhost_put_used_flags(struct vhost_virtqueue *vq) | |
929 | ||
930 | { | |
931 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), | |
932 | &vq->used->flags); | |
933 | } | |
934 | ||
935 | static inline int vhost_put_used_idx(struct vhost_virtqueue *vq) | |
936 | ||
937 | { | |
938 | return vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), | |
939 | &vq->used->idx); | |
940 | } | |
941 | ||
f8894913 | 942 | #define vhost_get_user(vq, x, ptr, type) \ |
6b1e6cc7 JW |
943 | ({ \ |
944 | int ret; \ | |
945 | if (!vq->iotlb) { \ | |
946 | ret = __get_user(x, ptr); \ | |
947 | } else { \ | |
948 | __typeof__(ptr) from = \ | |
f8894913 JW |
949 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ |
950 | sizeof(*ptr), \ | |
951 | type); \ | |
6b1e6cc7 JW |
952 | if (from != NULL) \ |
953 | ret = __get_user(x, from); \ | |
954 | else \ | |
955 | ret = -EFAULT; \ | |
956 | } \ | |
957 | ret; \ | |
958 | }) | |
959 | ||
f8894913 JW |
960 | #define vhost_get_avail(vq, x, ptr) \ |
961 | vhost_get_user(vq, x, ptr, VHOST_ADDR_AVAIL) | |
962 | ||
963 | #define vhost_get_used(vq, x, ptr) \ | |
964 | vhost_get_user(vq, x, ptr, VHOST_ADDR_USED) | |
965 | ||
86a07da3 JW |
966 | static void vhost_dev_lock_vqs(struct vhost_dev *d) |
967 | { | |
968 | int i = 0; | |
969 | for (i = 0; i < d->nvqs; ++i) | |
970 | mutex_lock_nested(&d->vqs[i]->mutex, i); | |
971 | } | |
972 | ||
973 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) | |
974 | { | |
975 | int i = 0; | |
976 | for (i = 0; i < d->nvqs; ++i) | |
977 | mutex_unlock(&d->vqs[i]->mutex); | |
978 | } | |
979 | ||
7b5d753e JW |
980 | static inline int vhost_get_avail_idx(struct vhost_virtqueue *vq, |
981 | __virtio16 *idx) | |
982 | { | |
983 | return vhost_get_avail(vq, *idx, &vq->avail->idx); | |
984 | } | |
985 | ||
986 | static inline int vhost_get_avail_head(struct vhost_virtqueue *vq, | |
987 | __virtio16 *head, int idx) | |
988 | { | |
989 | return vhost_get_avail(vq, *head, | |
990 | &vq->avail->ring[idx & (vq->num - 1)]); | |
991 | } | |
992 | ||
993 | static inline int vhost_get_avail_flags(struct vhost_virtqueue *vq, | |
994 | __virtio16 *flags) | |
995 | { | |
996 | return vhost_get_avail(vq, *flags, &vq->avail->flags); | |
997 | } | |
998 | ||
999 | static inline int vhost_get_used_event(struct vhost_virtqueue *vq, | |
1000 | __virtio16 *event) | |
1001 | { | |
1002 | return vhost_get_avail(vq, *event, vhost_used_event(vq)); | |
1003 | } | |
1004 | ||
1005 | static inline int vhost_get_used_idx(struct vhost_virtqueue *vq, | |
1006 | __virtio16 *idx) | |
1007 | { | |
1008 | return vhost_get_used(vq, *idx, &vq->used->idx); | |
1009 | } | |
1010 | ||
1011 | static inline int vhost_get_desc(struct vhost_virtqueue *vq, | |
1012 | struct vring_desc *desc, int idx) | |
1013 | { | |
1014 | return vhost_copy_from_user(vq, desc, vq->desc + idx, sizeof(*desc)); | |
1015 | } | |
1016 | ||
6b1e6cc7 JW |
1017 | static int vhost_new_umem_range(struct vhost_umem *umem, |
1018 | u64 start, u64 size, u64 end, | |
1019 | u64 userspace_addr, int perm) | |
1020 | { | |
813dbeb6 | 1021 | struct vhost_umem_node *tmp, *node; |
6b1e6cc7 | 1022 | |
813dbeb6 JW |
1023 | if (!size) |
1024 | return -EFAULT; | |
1025 | ||
1026 | node = kmalloc(sizeof(*node), GFP_ATOMIC); | |
6b1e6cc7 JW |
1027 | if (!node) |
1028 | return -ENOMEM; | |
1029 | ||
1030 | if (umem->numem == max_iotlb_entries) { | |
1031 | tmp = list_first_entry(&umem->umem_list, typeof(*tmp), link); | |
1032 | vhost_umem_free(umem, tmp); | |
1033 | } | |
1034 | ||
1035 | node->start = start; | |
1036 | node->size = size; | |
1037 | node->last = end; | |
1038 | node->userspace_addr = userspace_addr; | |
1039 | node->perm = perm; | |
1040 | INIT_LIST_HEAD(&node->link); | |
1041 | list_add_tail(&node->link, &umem->umem_list); | |
1042 | vhost_umem_interval_tree_insert(node, &umem->umem_tree); | |
1043 | umem->numem++; | |
1044 | ||
1045 | return 0; | |
1046 | } | |
1047 | ||
1048 | static void vhost_del_umem_range(struct vhost_umem *umem, | |
1049 | u64 start, u64 end) | |
1050 | { | |
1051 | struct vhost_umem_node *node; | |
1052 | ||
1053 | while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
1054 | start, end))) | |
1055 | vhost_umem_free(umem, node); | |
1056 | } | |
1057 | ||
1058 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, | |
1059 | struct vhost_iotlb_msg *msg) | |
1060 | { | |
1061 | struct vhost_msg_node *node, *n; | |
1062 | ||
1063 | spin_lock(&d->iotlb_lock); | |
1064 | ||
1065 | list_for_each_entry_safe(node, n, &d->pending_list, node) { | |
1066 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; | |
1067 | if (msg->iova <= vq_msg->iova && | |
2d66f997 | 1068 | msg->iova + msg->size - 1 >= vq_msg->iova && |
6b1e6cc7 JW |
1069 | vq_msg->type == VHOST_IOTLB_MISS) { |
1070 | vhost_poll_queue(&node->vq->poll); | |
1071 | list_del(&node->node); | |
1072 | kfree(node); | |
1073 | } | |
1074 | } | |
1075 | ||
1076 | spin_unlock(&d->iotlb_lock); | |
1077 | } | |
1078 | ||
ddd3d408 | 1079 | static bool umem_access_ok(u64 uaddr, u64 size, int access) |
6b1e6cc7 JW |
1080 | { |
1081 | unsigned long a = uaddr; | |
1082 | ||
ec33d031 MT |
1083 | /* Make sure 64 bit math will not overflow. */ |
1084 | if (vhost_overflow(uaddr, size)) | |
ddd3d408 | 1085 | return false; |
ec33d031 | 1086 | |
6b1e6cc7 | 1087 | if ((access & VHOST_ACCESS_RO) && |
96d4f267 | 1088 | !access_ok((void __user *)a, size)) |
ddd3d408 | 1089 | return false; |
6b1e6cc7 | 1090 | if ((access & VHOST_ACCESS_WO) && |
96d4f267 | 1091 | !access_ok((void __user *)a, size)) |
ddd3d408 SH |
1092 | return false; |
1093 | return true; | |
6b1e6cc7 JW |
1094 | } |
1095 | ||
72952cc0 MT |
1096 | static int vhost_process_iotlb_msg(struct vhost_dev *dev, |
1097 | struct vhost_iotlb_msg *msg) | |
6b1e6cc7 JW |
1098 | { |
1099 | int ret = 0; | |
1100 | ||
1b15ad68 | 1101 | mutex_lock(&dev->mutex); |
86a07da3 | 1102 | vhost_dev_lock_vqs(dev); |
6b1e6cc7 JW |
1103 | switch (msg->type) { |
1104 | case VHOST_IOTLB_UPDATE: | |
1105 | if (!dev->iotlb) { | |
1106 | ret = -EFAULT; | |
1107 | break; | |
1108 | } | |
ddd3d408 | 1109 | if (!umem_access_ok(msg->uaddr, msg->size, msg->perm)) { |
6b1e6cc7 JW |
1110 | ret = -EFAULT; |
1111 | break; | |
1112 | } | |
f8894913 | 1113 | vhost_vq_meta_reset(dev); |
6b1e6cc7 JW |
1114 | if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size, |
1115 | msg->iova + msg->size - 1, | |
1116 | msg->uaddr, msg->perm)) { | |
1117 | ret = -ENOMEM; | |
1118 | break; | |
1119 | } | |
1120 | vhost_iotlb_notify_vq(dev, msg); | |
1121 | break; | |
1122 | case VHOST_IOTLB_INVALIDATE: | |
6f3180af JW |
1123 | if (!dev->iotlb) { |
1124 | ret = -EFAULT; | |
1125 | break; | |
1126 | } | |
f8894913 | 1127 | vhost_vq_meta_reset(dev); |
6b1e6cc7 JW |
1128 | vhost_del_umem_range(dev->iotlb, msg->iova, |
1129 | msg->iova + msg->size - 1); | |
1130 | break; | |
1131 | default: | |
1132 | ret = -EINVAL; | |
1133 | break; | |
1134 | } | |
1135 | ||
86a07da3 | 1136 | vhost_dev_unlock_vqs(dev); |
1b15ad68 JW |
1137 | mutex_unlock(&dev->mutex); |
1138 | ||
6b1e6cc7 JW |
1139 | return ret; |
1140 | } | |
1141 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, | |
1142 | struct iov_iter *from) | |
1143 | { | |
429711ae JW |
1144 | struct vhost_iotlb_msg msg; |
1145 | size_t offset; | |
1146 | int type, ret; | |
6b1e6cc7 | 1147 | |
429711ae | 1148 | ret = copy_from_iter(&type, sizeof(type), from); |
74ad7419 PT |
1149 | if (ret != sizeof(type)) { |
1150 | ret = -EINVAL; | |
6b1e6cc7 | 1151 | goto done; |
74ad7419 | 1152 | } |
6b1e6cc7 | 1153 | |
429711ae | 1154 | switch (type) { |
6b1e6cc7 | 1155 | case VHOST_IOTLB_MSG: |
429711ae JW |
1156 | /* There maybe a hole after type for V1 message type, |
1157 | * so skip it here. | |
1158 | */ | |
1159 | offset = offsetof(struct vhost_msg, iotlb) - sizeof(int); | |
1160 | break; | |
1161 | case VHOST_IOTLB_MSG_V2: | |
1162 | offset = sizeof(__u32); | |
6b1e6cc7 JW |
1163 | break; |
1164 | default: | |
1165 | ret = -EINVAL; | |
429711ae | 1166 | goto done; |
6b1e6cc7 JW |
1167 | } |
1168 | ||
429711ae JW |
1169 | iov_iter_advance(from, offset); |
1170 | ret = copy_from_iter(&msg, sizeof(msg), from); | |
74ad7419 PT |
1171 | if (ret != sizeof(msg)) { |
1172 | ret = -EINVAL; | |
429711ae | 1173 | goto done; |
74ad7419 | 1174 | } |
429711ae JW |
1175 | if (vhost_process_iotlb_msg(dev, &msg)) { |
1176 | ret = -EFAULT; | |
1177 | goto done; | |
1178 | } | |
1179 | ||
1180 | ret = (type == VHOST_IOTLB_MSG) ? sizeof(struct vhost_msg) : | |
1181 | sizeof(struct vhost_msg_v2); | |
6b1e6cc7 JW |
1182 | done: |
1183 | return ret; | |
1184 | } | |
1185 | EXPORT_SYMBOL(vhost_chr_write_iter); | |
1186 | ||
afc9a42b | 1187 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
6b1e6cc7 JW |
1188 | poll_table *wait) |
1189 | { | |
afc9a42b | 1190 | __poll_t mask = 0; |
6b1e6cc7 JW |
1191 | |
1192 | poll_wait(file, &dev->wait, wait); | |
1193 | ||
1194 | if (!list_empty(&dev->read_list)) | |
a9a08845 | 1195 | mask |= EPOLLIN | EPOLLRDNORM; |
6b1e6cc7 JW |
1196 | |
1197 | return mask; | |
1198 | } | |
1199 | EXPORT_SYMBOL(vhost_chr_poll); | |
1200 | ||
1201 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, | |
1202 | int noblock) | |
1203 | { | |
1204 | DEFINE_WAIT(wait); | |
1205 | struct vhost_msg_node *node; | |
1206 | ssize_t ret = 0; | |
1207 | unsigned size = sizeof(struct vhost_msg); | |
1208 | ||
1209 | if (iov_iter_count(to) < size) | |
1210 | return 0; | |
1211 | ||
1212 | while (1) { | |
1213 | if (!noblock) | |
1214 | prepare_to_wait(&dev->wait, &wait, | |
1215 | TASK_INTERRUPTIBLE); | |
1216 | ||
1217 | node = vhost_dequeue_msg(dev, &dev->read_list); | |
1218 | if (node) | |
1219 | break; | |
1220 | if (noblock) { | |
1221 | ret = -EAGAIN; | |
1222 | break; | |
1223 | } | |
1224 | if (signal_pending(current)) { | |
1225 | ret = -ERESTARTSYS; | |
1226 | break; | |
1227 | } | |
1228 | if (!dev->iotlb) { | |
1229 | ret = -EBADFD; | |
1230 | break; | |
1231 | } | |
1232 | ||
1233 | schedule(); | |
1234 | } | |
1235 | ||
1236 | if (!noblock) | |
1237 | finish_wait(&dev->wait, &wait); | |
1238 | ||
1239 | if (node) { | |
429711ae JW |
1240 | struct vhost_iotlb_msg *msg; |
1241 | void *start = &node->msg; | |
6b1e6cc7 | 1242 | |
429711ae JW |
1243 | switch (node->msg.type) { |
1244 | case VHOST_IOTLB_MSG: | |
1245 | size = sizeof(node->msg); | |
1246 | msg = &node->msg.iotlb; | |
1247 | break; | |
1248 | case VHOST_IOTLB_MSG_V2: | |
1249 | size = sizeof(node->msg_v2); | |
1250 | msg = &node->msg_v2.iotlb; | |
1251 | break; | |
1252 | default: | |
1253 | BUG(); | |
1254 | break; | |
1255 | } | |
1256 | ||
1257 | ret = copy_to_iter(start, size, to); | |
1258 | if (ret != size || msg->type != VHOST_IOTLB_MISS) { | |
6b1e6cc7 JW |
1259 | kfree(node); |
1260 | return ret; | |
1261 | } | |
6b1e6cc7 JW |
1262 | vhost_enqueue_msg(dev, &dev->pending_list, node); |
1263 | } | |
1264 | ||
1265 | return ret; | |
1266 | } | |
1267 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); | |
1268 | ||
1269 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) | |
1270 | { | |
1271 | struct vhost_dev *dev = vq->dev; | |
1272 | struct vhost_msg_node *node; | |
1273 | struct vhost_iotlb_msg *msg; | |
429711ae | 1274 | bool v2 = vhost_backend_has_feature(vq, VHOST_BACKEND_F_IOTLB_MSG_V2); |
6b1e6cc7 | 1275 | |
429711ae | 1276 | node = vhost_new_msg(vq, v2 ? VHOST_IOTLB_MSG_V2 : VHOST_IOTLB_MSG); |
6b1e6cc7 JW |
1277 | if (!node) |
1278 | return -ENOMEM; | |
1279 | ||
429711ae JW |
1280 | if (v2) { |
1281 | node->msg_v2.type = VHOST_IOTLB_MSG_V2; | |
1282 | msg = &node->msg_v2.iotlb; | |
1283 | } else { | |
1284 | msg = &node->msg.iotlb; | |
1285 | } | |
1286 | ||
6b1e6cc7 JW |
1287 | msg->type = VHOST_IOTLB_MISS; |
1288 | msg->iova = iova; | |
1289 | msg->perm = access; | |
1290 | ||
1291 | vhost_enqueue_msg(dev, &dev->read_list, node); | |
1292 | ||
1293 | return 0; | |
bfe2bc51 JW |
1294 | } |
1295 | ||
ddd3d408 SH |
1296 | static bool vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
1297 | struct vring_desc __user *desc, | |
1298 | struct vring_avail __user *avail, | |
1299 | struct vring_used __user *used) | |
6b1e6cc7 | 1300 | |
3a4d5c94 | 1301 | { |
4942e825 JW |
1302 | return access_ok(desc, vhost_get_desc_size(vq, num)) && |
1303 | access_ok(avail, vhost_get_avail_size(vq, num)) && | |
1304 | access_ok(used, vhost_get_used_size(vq, num)); | |
3a4d5c94 MT |
1305 | } |
1306 | ||
f8894913 JW |
1307 | static void vhost_vq_meta_update(struct vhost_virtqueue *vq, |
1308 | const struct vhost_umem_node *node, | |
1309 | int type) | |
1310 | { | |
1311 | int access = (type == VHOST_ADDR_USED) ? | |
1312 | VHOST_ACCESS_WO : VHOST_ACCESS_RO; | |
1313 | ||
1314 | if (likely(node->perm & access)) | |
1315 | vq->meta_iotlb[type] = node; | |
1316 | } | |
1317 | ||
ddd3d408 SH |
1318 | static bool iotlb_access_ok(struct vhost_virtqueue *vq, |
1319 | int access, u64 addr, u64 len, int type) | |
6b1e6cc7 JW |
1320 | { |
1321 | const struct vhost_umem_node *node; | |
1322 | struct vhost_umem *umem = vq->iotlb; | |
ca2c5b33 | 1323 | u64 s = 0, size, orig_addr = addr, last = addr + len - 1; |
f8894913 JW |
1324 | |
1325 | if (vhost_vq_meta_fetch(vq, addr, len, type)) | |
1326 | return true; | |
6b1e6cc7 JW |
1327 | |
1328 | while (len > s) { | |
1329 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
1330 | addr, | |
ca2c5b33 | 1331 | last); |
6b1e6cc7 JW |
1332 | if (node == NULL || node->start > addr) { |
1333 | vhost_iotlb_miss(vq, addr, access); | |
1334 | return false; | |
1335 | } else if (!(node->perm & access)) { | |
1336 | /* Report the possible access violation by | |
1337 | * request another translation from userspace. | |
1338 | */ | |
1339 | return false; | |
1340 | } | |
1341 | ||
1342 | size = node->size - addr + node->start; | |
f8894913 JW |
1343 | |
1344 | if (orig_addr == addr && size >= len) | |
1345 | vhost_vq_meta_update(vq, node, type); | |
1346 | ||
6b1e6cc7 JW |
1347 | s += size; |
1348 | addr += size; | |
1349 | } | |
1350 | ||
1351 | return true; | |
1352 | } | |
1353 | ||
9b5e830b | 1354 | int vq_meta_prefetch(struct vhost_virtqueue *vq) |
6b1e6cc7 | 1355 | { |
6b1e6cc7 JW |
1356 | unsigned int num = vq->num; |
1357 | ||
3d2c7d37 | 1358 | if (!vq->iotlb) |
6b1e6cc7 JW |
1359 | return 1; |
1360 | ||
1361 | return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc, | |
4942e825 | 1362 | vhost_get_desc_size(vq, num), VHOST_ADDR_DESC) && |
6b1e6cc7 | 1363 | iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail, |
4942e825 | 1364 | vhost_get_avail_size(vq, num), |
f8894913 | 1365 | VHOST_ADDR_AVAIL) && |
6b1e6cc7 | 1366 | iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used, |
4942e825 | 1367 | vhost_get_used_size(vq, num), VHOST_ADDR_USED); |
6b1e6cc7 | 1368 | } |
9b5e830b | 1369 | EXPORT_SYMBOL_GPL(vq_meta_prefetch); |
6b1e6cc7 | 1370 | |
3a4d5c94 MT |
1371 | /* Can we log writes? */ |
1372 | /* Caller should have device mutex but not vq mutex */ | |
ddd3d408 | 1373 | bool vhost_log_access_ok(struct vhost_dev *dev) |
3a4d5c94 | 1374 | { |
a9709d68 | 1375 | return memory_access_ok(dev, dev->umem, 1); |
3a4d5c94 | 1376 | } |
6ac1afbf | 1377 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 MT |
1378 | |
1379 | /* Verify access for write logging. */ | |
1380 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 SH |
1381 | static bool vq_log_access_ok(struct vhost_virtqueue *vq, |
1382 | void __user *log_base) | |
3a4d5c94 | 1383 | { |
a9709d68 | 1384 | return vq_memory_access_ok(log_base, vq->umem, |
ea16c514 | 1385 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
3a4d5c94 | 1386 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
4942e825 | 1387 | vhost_get_used_size(vq, vq->num))); |
3a4d5c94 MT |
1388 | } |
1389 | ||
1390 | /* Can we start vq? */ | |
1391 | /* Caller should have vq mutex and device mutex */ | |
ddd3d408 | 1392 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq) |
3a4d5c94 | 1393 | { |
d14d2b78 | 1394 | if (!vq_log_access_ok(vq, vq->log_base)) |
ddd3d408 | 1395 | return false; |
d65026c6 | 1396 | |
d14d2b78 SH |
1397 | /* Access validation occurs at prefetch time with IOTLB */ |
1398 | if (vq->iotlb) | |
ddd3d408 | 1399 | return true; |
d65026c6 JW |
1400 | |
1401 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); | |
3a4d5c94 | 1402 | } |
6ac1afbf | 1403 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 | 1404 | |
6b1e6cc7 JW |
1405 | static struct vhost_umem *vhost_umem_alloc(void) |
1406 | { | |
6c5ab651 | 1407 | struct vhost_umem *umem = kvzalloc(sizeof(*umem), GFP_KERNEL); |
6b1e6cc7 JW |
1408 | |
1409 | if (!umem) | |
1410 | return NULL; | |
1411 | ||
f808c13f | 1412 | umem->umem_tree = RB_ROOT_CACHED; |
6b1e6cc7 JW |
1413 | umem->numem = 0; |
1414 | INIT_LIST_HEAD(&umem->umem_list); | |
1415 | ||
1416 | return umem; | |
1417 | } | |
1418 | ||
3a4d5c94 MT |
1419 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
1420 | { | |
a9709d68 JW |
1421 | struct vhost_memory mem, *newmem; |
1422 | struct vhost_memory_region *region; | |
a9709d68 | 1423 | struct vhost_umem *newumem, *oldumem; |
3a4d5c94 | 1424 | unsigned long size = offsetof(struct vhost_memory, regions); |
98f9ca0a | 1425 | int i; |
d47effe1 | 1426 | |
7ad9c9d2 TY |
1427 | if (copy_from_user(&mem, m, size)) |
1428 | return -EFAULT; | |
3a4d5c94 MT |
1429 | if (mem.padding) |
1430 | return -EOPNOTSUPP; | |
c9ce42f7 | 1431 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 1432 | return -E2BIG; |
b2303d7b MW |
1433 | newmem = kvzalloc(struct_size(newmem, regions, mem.nregions), |
1434 | GFP_KERNEL); | |
3a4d5c94 MT |
1435 | if (!newmem) |
1436 | return -ENOMEM; | |
1437 | ||
1438 | memcpy(newmem, &mem, size); | |
7ad9c9d2 TY |
1439 | if (copy_from_user(newmem->regions, m->regions, |
1440 | mem.nregions * sizeof *m->regions)) { | |
bcfeacab | 1441 | kvfree(newmem); |
7ad9c9d2 | 1442 | return -EFAULT; |
3a4d5c94 MT |
1443 | } |
1444 | ||
6b1e6cc7 | 1445 | newumem = vhost_umem_alloc(); |
a9709d68 | 1446 | if (!newumem) { |
4de7255f | 1447 | kvfree(newmem); |
a9709d68 JW |
1448 | return -ENOMEM; |
1449 | } | |
1450 | ||
a9709d68 JW |
1451 | for (region = newmem->regions; |
1452 | region < newmem->regions + mem.nregions; | |
1453 | region++) { | |
6b1e6cc7 JW |
1454 | if (vhost_new_umem_range(newumem, |
1455 | region->guest_phys_addr, | |
1456 | region->memory_size, | |
1457 | region->guest_phys_addr + | |
1458 | region->memory_size - 1, | |
1459 | region->userspace_addr, | |
1460 | VHOST_ACCESS_RW)) | |
a9709d68 | 1461 | goto err; |
a02c3789 | 1462 | } |
a9709d68 JW |
1463 | |
1464 | if (!memory_access_ok(d, newumem, 0)) | |
1465 | goto err; | |
1466 | ||
1467 | oldumem = d->umem; | |
1468 | d->umem = newumem; | |
98f9ca0a | 1469 | |
47283bef | 1470 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
1471 | for (i = 0; i < d->nvqs; ++i) { |
1472 | mutex_lock(&d->vqs[i]->mutex); | |
a9709d68 | 1473 | d->vqs[i]->umem = newumem; |
98f9ca0a MT |
1474 | mutex_unlock(&d->vqs[i]->mutex); |
1475 | } | |
a9709d68 JW |
1476 | |
1477 | kvfree(newmem); | |
1478 | vhost_umem_clean(oldumem); | |
3a4d5c94 | 1479 | return 0; |
a9709d68 JW |
1480 | |
1481 | err: | |
1482 | vhost_umem_clean(newumem); | |
1483 | kvfree(newmem); | |
1484 | return -EFAULT; | |
3a4d5c94 MT |
1485 | } |
1486 | ||
feebcaea JW |
1487 | static long vhost_vring_set_num(struct vhost_dev *d, |
1488 | struct vhost_virtqueue *vq, | |
1489 | void __user *argp) | |
1490 | { | |
1491 | struct vhost_vring_state s; | |
1492 | ||
1493 | /* Resizing ring with an active backend? | |
1494 | * You don't want to do that. */ | |
1495 | if (vq->private_data) | |
1496 | return -EBUSY; | |
1497 | ||
1498 | if (copy_from_user(&s, argp, sizeof s)) | |
1499 | return -EFAULT; | |
1500 | ||
1501 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) | |
1502 | return -EINVAL; | |
1503 | vq->num = s.num; | |
1504 | ||
1505 | return 0; | |
1506 | } | |
1507 | ||
1508 | static long vhost_vring_set_addr(struct vhost_dev *d, | |
1509 | struct vhost_virtqueue *vq, | |
1510 | void __user *argp) | |
1511 | { | |
1512 | struct vhost_vring_addr a; | |
1513 | ||
1514 | if (copy_from_user(&a, argp, sizeof a)) | |
1515 | return -EFAULT; | |
1516 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) | |
1517 | return -EOPNOTSUPP; | |
1518 | ||
1519 | /* For 32bit, verify that the top 32bits of the user | |
1520 | data are set to zero. */ | |
1521 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
1522 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
1523 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) | |
1524 | return -EFAULT; | |
1525 | ||
1526 | /* Make sure it's safe to cast pointers to vring types. */ | |
1527 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
1528 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
1529 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
1530 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
1531 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) | |
1532 | return -EINVAL; | |
1533 | ||
1534 | /* We only verify access here if backend is configured. | |
1535 | * If it is not, we don't as size might not have been setup. | |
1536 | * We will verify when backend is configured. */ | |
1537 | if (vq->private_data) { | |
1538 | if (!vq_access_ok(vq, vq->num, | |
1539 | (void __user *)(unsigned long)a.desc_user_addr, | |
1540 | (void __user *)(unsigned long)a.avail_user_addr, | |
1541 | (void __user *)(unsigned long)a.used_user_addr)) | |
1542 | return -EINVAL; | |
1543 | ||
1544 | /* Also validate log access for used ring if enabled. */ | |
1545 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && | |
1546 | !log_access_ok(vq->log_base, a.log_guest_addr, | |
1547 | sizeof *vq->used + | |
1548 | vq->num * sizeof *vq->used->ring)) | |
1549 | return -EINVAL; | |
1550 | } | |
1551 | ||
1552 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); | |
1553 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
1554 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
1555 | vq->log_addr = a.log_guest_addr; | |
1556 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
1557 | ||
1558 | return 0; | |
1559 | } | |
1560 | ||
1561 | static long vhost_vring_set_num_addr(struct vhost_dev *d, | |
1562 | struct vhost_virtqueue *vq, | |
1563 | unsigned int ioctl, | |
1564 | void __user *argp) | |
1565 | { | |
1566 | long r; | |
1567 | ||
1568 | mutex_lock(&vq->mutex); | |
1569 | ||
1570 | switch (ioctl) { | |
1571 | case VHOST_SET_VRING_NUM: | |
1572 | r = vhost_vring_set_num(d, vq, argp); | |
1573 | break; | |
1574 | case VHOST_SET_VRING_ADDR: | |
1575 | r = vhost_vring_set_addr(d, vq, argp); | |
1576 | break; | |
1577 | default: | |
1578 | BUG(); | |
1579 | } | |
1580 | ||
1581 | mutex_unlock(&vq->mutex); | |
1582 | ||
1583 | return r; | |
1584 | } | |
26b36604 | 1585 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1586 | { |
cecb46f1 AV |
1587 | struct file *eventfp, *filep = NULL; |
1588 | bool pollstart = false, pollstop = false; | |
3a4d5c94 MT |
1589 | struct eventfd_ctx *ctx = NULL; |
1590 | u32 __user *idxp = argp; | |
1591 | struct vhost_virtqueue *vq; | |
1592 | struct vhost_vring_state s; | |
1593 | struct vhost_vring_file f; | |
3a4d5c94 MT |
1594 | u32 idx; |
1595 | long r; | |
1596 | ||
1597 | r = get_user(idx, idxp); | |
1598 | if (r < 0) | |
1599 | return r; | |
0f3d9a17 | 1600 | if (idx >= d->nvqs) |
3a4d5c94 MT |
1601 | return -ENOBUFS; |
1602 | ||
ff002269 | 1603 | idx = array_index_nospec(idx, d->nvqs); |
3ab2e420 | 1604 | vq = d->vqs[idx]; |
3a4d5c94 | 1605 | |
feebcaea JW |
1606 | if (ioctl == VHOST_SET_VRING_NUM || |
1607 | ioctl == VHOST_SET_VRING_ADDR) { | |
1608 | return vhost_vring_set_num_addr(d, vq, ioctl, argp); | |
1609 | } | |
1610 | ||
3a4d5c94 MT |
1611 | mutex_lock(&vq->mutex); |
1612 | ||
1613 | switch (ioctl) { | |
3a4d5c94 MT |
1614 | case VHOST_SET_VRING_BASE: |
1615 | /* Moving base with an active backend? | |
1616 | * You don't want to do that. */ | |
1617 | if (vq->private_data) { | |
1618 | r = -EBUSY; | |
1619 | break; | |
1620 | } | |
7ad9c9d2 TY |
1621 | if (copy_from_user(&s, argp, sizeof s)) { |
1622 | r = -EFAULT; | |
3a4d5c94 | 1623 | break; |
7ad9c9d2 | 1624 | } |
3a4d5c94 MT |
1625 | if (s.num > 0xffff) { |
1626 | r = -EINVAL; | |
1627 | break; | |
1628 | } | |
8d65843c | 1629 | vq->last_avail_idx = s.num; |
3a4d5c94 MT |
1630 | /* Forget the cached index value. */ |
1631 | vq->avail_idx = vq->last_avail_idx; | |
1632 | break; | |
1633 | case VHOST_GET_VRING_BASE: | |
1634 | s.index = idx; | |
1635 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
1636 | if (copy_to_user(argp, &s, sizeof s)) |
1637 | r = -EFAULT; | |
3a4d5c94 | 1638 | break; |
3a4d5c94 | 1639 | case VHOST_SET_VRING_KICK: |
7ad9c9d2 TY |
1640 | if (copy_from_user(&f, argp, sizeof f)) { |
1641 | r = -EFAULT; | |
3a4d5c94 | 1642 | break; |
7ad9c9d2 | 1643 | } |
3a4d5c94 | 1644 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1645 | if (IS_ERR(eventfp)) { |
1646 | r = PTR_ERR(eventfp); | |
1647 | break; | |
1648 | } | |
3a4d5c94 | 1649 | if (eventfp != vq->kick) { |
cecb46f1 AV |
1650 | pollstop = (filep = vq->kick) != NULL; |
1651 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
1652 | } else |
1653 | filep = eventfp; | |
1654 | break; | |
1655 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
1656 | if (copy_from_user(&f, argp, sizeof f)) { |
1657 | r = -EFAULT; | |
3a4d5c94 | 1658 | break; |
7ad9c9d2 | 1659 | } |
e050c7d9 EB |
1660 | ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); |
1661 | if (IS_ERR(ctx)) { | |
1662 | r = PTR_ERR(ctx); | |
535297a6 MT |
1663 | break; |
1664 | } | |
e050c7d9 | 1665 | swap(ctx, vq->call_ctx); |
3a4d5c94 MT |
1666 | break; |
1667 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
1668 | if (copy_from_user(&f, argp, sizeof f)) { |
1669 | r = -EFAULT; | |
3a4d5c94 | 1670 | break; |
7ad9c9d2 | 1671 | } |
09f332a5 EB |
1672 | ctx = f.fd == -1 ? NULL : eventfd_ctx_fdget(f.fd); |
1673 | if (IS_ERR(ctx)) { | |
1674 | r = PTR_ERR(ctx); | |
535297a6 MT |
1675 | break; |
1676 | } | |
09f332a5 | 1677 | swap(ctx, vq->error_ctx); |
3a4d5c94 | 1678 | break; |
2751c988 GK |
1679 | case VHOST_SET_VRING_ENDIAN: |
1680 | r = vhost_set_vring_endian(vq, argp); | |
1681 | break; | |
1682 | case VHOST_GET_VRING_ENDIAN: | |
1683 | r = vhost_get_vring_endian(vq, idx, argp); | |
1684 | break; | |
03088137 JW |
1685 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1686 | if (copy_from_user(&s, argp, sizeof(s))) { | |
1687 | r = -EFAULT; | |
1688 | break; | |
1689 | } | |
1690 | vq->busyloop_timeout = s.num; | |
1691 | break; | |
1692 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
1693 | s.index = idx; | |
1694 | s.num = vq->busyloop_timeout; | |
1695 | if (copy_to_user(argp, &s, sizeof(s))) | |
1696 | r = -EFAULT; | |
1697 | break; | |
3a4d5c94 MT |
1698 | default: |
1699 | r = -ENOIOCTLCMD; | |
1700 | } | |
1701 | ||
1702 | if (pollstop && vq->handle_kick) | |
1703 | vhost_poll_stop(&vq->poll); | |
1704 | ||
e050c7d9 | 1705 | if (!IS_ERR_OR_NULL(ctx)) |
3a4d5c94 MT |
1706 | eventfd_ctx_put(ctx); |
1707 | if (filep) | |
1708 | fput(filep); | |
1709 | ||
1710 | if (pollstart && vq->handle_kick) | |
2b8b328b | 1711 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
1712 | |
1713 | mutex_unlock(&vq->mutex); | |
1714 | ||
1715 | if (pollstop && vq->handle_kick) | |
1716 | vhost_poll_flush(&vq->poll); | |
1717 | return r; | |
1718 | } | |
6ac1afbf | 1719 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 | 1720 | |
6b1e6cc7 JW |
1721 | int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled) |
1722 | { | |
1723 | struct vhost_umem *niotlb, *oiotlb; | |
1724 | int i; | |
1725 | ||
1726 | niotlb = vhost_umem_alloc(); | |
1727 | if (!niotlb) | |
1728 | return -ENOMEM; | |
1729 | ||
1730 | oiotlb = d->iotlb; | |
1731 | d->iotlb = niotlb; | |
1732 | ||
1733 | for (i = 0; i < d->nvqs; ++i) { | |
b13f9c63 JW |
1734 | struct vhost_virtqueue *vq = d->vqs[i]; |
1735 | ||
1736 | mutex_lock(&vq->mutex); | |
1737 | vq->iotlb = niotlb; | |
1738 | __vhost_vq_meta_reset(vq); | |
1739 | mutex_unlock(&vq->mutex); | |
6b1e6cc7 JW |
1740 | } |
1741 | ||
1742 | vhost_umem_clean(oiotlb); | |
1743 | ||
1744 | return 0; | |
1745 | } | |
1746 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); | |
1747 | ||
3a4d5c94 | 1748 | /* Caller must have device mutex */ |
935cdee7 | 1749 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1750 | { |
d25cc43c | 1751 | struct eventfd_ctx *ctx; |
3a4d5c94 MT |
1752 | u64 p; |
1753 | long r; | |
1754 | int i, fd; | |
1755 | ||
1756 | /* If you are not the owner, you can become one */ | |
1757 | if (ioctl == VHOST_SET_OWNER) { | |
1758 | r = vhost_dev_set_owner(d); | |
1759 | goto done; | |
1760 | } | |
1761 | ||
1762 | /* You must be the owner to do anything else */ | |
1763 | r = vhost_dev_check_owner(d); | |
1764 | if (r) | |
1765 | goto done; | |
1766 | ||
1767 | switch (ioctl) { | |
1768 | case VHOST_SET_MEM_TABLE: | |
1769 | r = vhost_set_memory(d, argp); | |
1770 | break; | |
1771 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
1772 | if (copy_from_user(&p, argp, sizeof p)) { |
1773 | r = -EFAULT; | |
3a4d5c94 | 1774 | break; |
7ad9c9d2 | 1775 | } |
3a4d5c94 MT |
1776 | if ((u64)(unsigned long)p != p) { |
1777 | r = -EFAULT; | |
1778 | break; | |
1779 | } | |
1780 | for (i = 0; i < d->nvqs; ++i) { | |
1781 | struct vhost_virtqueue *vq; | |
1782 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 1783 | vq = d->vqs[i]; |
3a4d5c94 MT |
1784 | mutex_lock(&vq->mutex); |
1785 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 1786 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
1787 | r = -EFAULT; |
1788 | else | |
1789 | vq->log_base = base; | |
1790 | mutex_unlock(&vq->mutex); | |
1791 | } | |
1792 | break; | |
1793 | case VHOST_SET_LOG_FD: | |
1794 | r = get_user(fd, (int __user *)argp); | |
1795 | if (r < 0) | |
1796 | break; | |
d25cc43c EB |
1797 | ctx = fd == -1 ? NULL : eventfd_ctx_fdget(fd); |
1798 | if (IS_ERR(ctx)) { | |
1799 | r = PTR_ERR(ctx); | |
3a4d5c94 MT |
1800 | break; |
1801 | } | |
d25cc43c | 1802 | swap(ctx, d->log_ctx); |
3a4d5c94 | 1803 | for (i = 0; i < d->nvqs; ++i) { |
3ab2e420 AH |
1804 | mutex_lock(&d->vqs[i]->mutex); |
1805 | d->vqs[i]->log_ctx = d->log_ctx; | |
1806 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
1807 | } |
1808 | if (ctx) | |
1809 | eventfd_ctx_put(ctx); | |
3a4d5c94 MT |
1810 | break; |
1811 | default: | |
935cdee7 | 1812 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
1813 | break; |
1814 | } | |
1815 | done: | |
1816 | return r; | |
1817 | } | |
6ac1afbf | 1818 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 | 1819 | |
3a4d5c94 MT |
1820 | /* TODO: This is really inefficient. We need something like get_user() |
1821 | * (instruction directly accesses the data, with an exception table entry | |
cb1aaebe | 1822 | * returning -EFAULT). See Documentation/x86/exception-tables.rst. |
3a4d5c94 MT |
1823 | */ |
1824 | static int set_bit_to_user(int nr, void __user *addr) | |
1825 | { | |
1826 | unsigned long log = (unsigned long)addr; | |
1827 | struct page *page; | |
1828 | void *base; | |
1829 | int bit = nr + (log % PAGE_SIZE) * 8; | |
1830 | int r; | |
d47effe1 | 1831 | |
73b0140b | 1832 | r = get_user_pages_fast(log, 1, FOLL_WRITE, &page); |
d6db3f5c | 1833 | if (r < 0) |
3a4d5c94 | 1834 | return r; |
d6db3f5c | 1835 | BUG_ON(r != 1); |
c6daa7ff | 1836 | base = kmap_atomic(page); |
3a4d5c94 | 1837 | set_bit(bit, base); |
c6daa7ff | 1838 | kunmap_atomic(base); |
3a4d5c94 MT |
1839 | set_page_dirty_lock(page); |
1840 | put_page(page); | |
1841 | return 0; | |
1842 | } | |
1843 | ||
1844 | static int log_write(void __user *log_base, | |
1845 | u64 write_address, u64 write_length) | |
1846 | { | |
28831ee6 | 1847 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 1848 | int r; |
d47effe1 | 1849 | |
3a4d5c94 MT |
1850 | if (!write_length) |
1851 | return 0; | |
3bf9be40 | 1852 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
1853 | for (;;) { |
1854 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
1855 | u64 log = base + write_page / 8; |
1856 | int bit = write_page % 8; | |
3a4d5c94 MT |
1857 | if ((u64)(unsigned long)log != log) |
1858 | return -EFAULT; | |
1859 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
1860 | if (r < 0) | |
1861 | return r; | |
1862 | if (write_length <= VHOST_PAGE_SIZE) | |
1863 | break; | |
1864 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 1865 | write_page += 1; |
3a4d5c94 MT |
1866 | } |
1867 | return r; | |
1868 | } | |
1869 | ||
cc5e7107 JW |
1870 | static int log_write_hva(struct vhost_virtqueue *vq, u64 hva, u64 len) |
1871 | { | |
1872 | struct vhost_umem *umem = vq->umem; | |
1873 | struct vhost_umem_node *u; | |
1874 | u64 start, end, l, min; | |
1875 | int r; | |
1876 | bool hit = false; | |
1877 | ||
1878 | while (len) { | |
1879 | min = len; | |
1880 | /* More than one GPAs can be mapped into a single HVA. So | |
1881 | * iterate all possible umems here to be safe. | |
1882 | */ | |
1883 | list_for_each_entry(u, &umem->umem_list, link) { | |
1884 | if (u->userspace_addr > hva - 1 + len || | |
1885 | u->userspace_addr - 1 + u->size < hva) | |
1886 | continue; | |
1887 | start = max(u->userspace_addr, hva); | |
1888 | end = min(u->userspace_addr - 1 + u->size, | |
1889 | hva - 1 + len); | |
1890 | l = end - start + 1; | |
1891 | r = log_write(vq->log_base, | |
1892 | u->start + start - u->userspace_addr, | |
1893 | l); | |
1894 | if (r < 0) | |
1895 | return r; | |
1896 | hit = true; | |
1897 | min = min(l, min); | |
1898 | } | |
1899 | ||
1900 | if (!hit) | |
1901 | return -EFAULT; | |
1902 | ||
1903 | len -= min; | |
1904 | hva += min; | |
1905 | } | |
1906 | ||
1907 | return 0; | |
1908 | } | |
1909 | ||
1910 | static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len) | |
1911 | { | |
1912 | struct iovec iov[64]; | |
1913 | int i, ret; | |
1914 | ||
1915 | if (!vq->iotlb) | |
1916 | return log_write(vq->log_base, vq->log_addr + used_offset, len); | |
1917 | ||
1918 | ret = translate_desc(vq, (uintptr_t)vq->used + used_offset, | |
1919 | len, iov, 64, VHOST_ACCESS_WO); | |
816db766 | 1920 | if (ret < 0) |
cc5e7107 JW |
1921 | return ret; |
1922 | ||
1923 | for (i = 0; i < ret; i++) { | |
1924 | ret = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
1925 | iov[i].iov_len); | |
1926 | if (ret) | |
1927 | return ret; | |
1928 | } | |
1929 | ||
1930 | return 0; | |
1931 | } | |
1932 | ||
3a4d5c94 | 1933 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
cc5e7107 | 1934 | unsigned int log_num, u64 len, struct iovec *iov, int count) |
3a4d5c94 MT |
1935 | { |
1936 | int i, r; | |
1937 | ||
1938 | /* Make sure data written is seen before log. */ | |
5659338c | 1939 | smp_wmb(); |
cc5e7107 JW |
1940 | |
1941 | if (vq->iotlb) { | |
1942 | for (i = 0; i < count; i++) { | |
1943 | r = log_write_hva(vq, (uintptr_t)iov[i].iov_base, | |
1944 | iov[i].iov_len); | |
1945 | if (r < 0) | |
1946 | return r; | |
1947 | } | |
1948 | return 0; | |
1949 | } | |
1950 | ||
3a4d5c94 MT |
1951 | for (i = 0; i < log_num; ++i) { |
1952 | u64 l = min(log[i].len, len); | |
1953 | r = log_write(vq->log_base, log[i].addr, l); | |
1954 | if (r < 0) | |
1955 | return r; | |
1956 | len -= l; | |
5786aee8 MT |
1957 | if (!len) { |
1958 | if (vq->log_ctx) | |
1959 | eventfd_signal(vq->log_ctx, 1); | |
3a4d5c94 | 1960 | return 0; |
5786aee8 | 1961 | } |
3a4d5c94 | 1962 | } |
3a4d5c94 MT |
1963 | /* Length written exceeds what we have stored. This is a bug. */ |
1964 | BUG(); | |
1965 | return 0; | |
1966 | } | |
6ac1afbf | 1967 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 1968 | |
2723feaa JW |
1969 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
1970 | { | |
1971 | void __user *used; | |
7b5d753e | 1972 | if (vhost_put_used_flags(vq)) |
2723feaa JW |
1973 | return -EFAULT; |
1974 | if (unlikely(vq->log_used)) { | |
1975 | /* Make sure the flag is seen before log. */ | |
1976 | smp_wmb(); | |
1977 | /* Log used flag write. */ | |
1978 | used = &vq->used->flags; | |
cc5e7107 JW |
1979 | log_used(vq, (used - (void __user *)vq->used), |
1980 | sizeof vq->used->flags); | |
2723feaa JW |
1981 | if (vq->log_ctx) |
1982 | eventfd_signal(vq->log_ctx, 1); | |
1983 | } | |
1984 | return 0; | |
1985 | } | |
1986 | ||
1987 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) | |
1988 | { | |
7b5d753e | 1989 | if (vhost_put_avail_event(vq)) |
2723feaa JW |
1990 | return -EFAULT; |
1991 | if (unlikely(vq->log_used)) { | |
1992 | void __user *used; | |
1993 | /* Make sure the event is seen before log. */ | |
1994 | smp_wmb(); | |
1995 | /* Log avail event write */ | |
1996 | used = vhost_avail_event(vq); | |
cc5e7107 JW |
1997 | log_used(vq, (used - (void __user *)vq->used), |
1998 | sizeof *vhost_avail_event(vq)); | |
2723feaa JW |
1999 | if (vq->log_ctx) |
2000 | eventfd_signal(vq->log_ctx, 1); | |
2001 | } | |
2002 | return 0; | |
2003 | } | |
2004 | ||
80f7d030 | 2005 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 2006 | { |
3b1bbe89 | 2007 | __virtio16 last_used_idx; |
2723feaa | 2008 | int r; |
e1f33be9 GK |
2009 | bool is_le = vq->is_le; |
2010 | ||
cda8bba0 | 2011 | if (!vq->private_data) |
2723feaa | 2012 | return 0; |
2751c988 GK |
2013 | |
2014 | vhost_init_is_le(vq); | |
2723feaa JW |
2015 | |
2016 | r = vhost_update_used_flags(vq); | |
2017 | if (r) | |
e1f33be9 | 2018 | goto err; |
2723feaa | 2019 | vq->signalled_used_valid = false; |
6b1e6cc7 | 2020 | if (!vq->iotlb && |
96d4f267 | 2021 | !access_ok(&vq->used->idx, sizeof vq->used->idx)) { |
e1f33be9 GK |
2022 | r = -EFAULT; |
2023 | goto err; | |
2024 | } | |
7b5d753e | 2025 | r = vhost_get_used_idx(vq, &last_used_idx); |
6b1e6cc7 JW |
2026 | if (r) { |
2027 | vq_err(vq, "Can't access used idx at %p\n", | |
2028 | &vq->used->idx); | |
e1f33be9 | 2029 | goto err; |
6b1e6cc7 | 2030 | } |
3b1bbe89 | 2031 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 2032 | return 0; |
6b1e6cc7 | 2033 | |
e1f33be9 GK |
2034 | err: |
2035 | vq->is_le = is_le; | |
2036 | return r; | |
2723feaa | 2037 | } |
80f7d030 | 2038 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 2039 | |
47283bef | 2040 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
6b1e6cc7 | 2041 | struct iovec iov[], int iov_size, int access) |
3a4d5c94 | 2042 | { |
a9709d68 | 2043 | const struct vhost_umem_node *node; |
6b1e6cc7 JW |
2044 | struct vhost_dev *dev = vq->dev; |
2045 | struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem; | |
3a4d5c94 MT |
2046 | struct iovec *_iov; |
2047 | u64 s = 0; | |
2048 | int ret = 0; | |
2049 | ||
3a4d5c94 MT |
2050 | while ((u64)len > s) { |
2051 | u64 size; | |
7b3384fc | 2052 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
2053 | ret = -ENOBUFS; |
2054 | break; | |
2055 | } | |
6b1e6cc7 | 2056 | |
a9709d68 JW |
2057 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, |
2058 | addr, addr + len - 1); | |
2059 | if (node == NULL || node->start > addr) { | |
6b1e6cc7 JW |
2060 | if (umem != dev->iotlb) { |
2061 | ret = -EFAULT; | |
2062 | break; | |
2063 | } | |
2064 | ret = -EAGAIN; | |
2065 | break; | |
2066 | } else if (!(node->perm & access)) { | |
2067 | ret = -EPERM; | |
3a4d5c94 MT |
2068 | break; |
2069 | } | |
6b1e6cc7 | 2070 | |
3a4d5c94 | 2071 | _iov = iov + ret; |
a9709d68 | 2072 | size = node->size - addr + node->start; |
bd97120f | 2073 | _iov->iov_len = min((u64)len - s, size); |
a8d3782f | 2074 | _iov->iov_base = (void __user *)(unsigned long) |
a9709d68 | 2075 | (node->userspace_addr + addr - node->start); |
3a4d5c94 MT |
2076 | s += size; |
2077 | addr += size; | |
2078 | ++ret; | |
2079 | } | |
2080 | ||
6b1e6cc7 JW |
2081 | if (ret == -EAGAIN) |
2082 | vhost_iotlb_miss(vq, addr, access); | |
3a4d5c94 MT |
2083 | return ret; |
2084 | } | |
2085 | ||
2086 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
2087 | * function returns the next descriptor in the chain, | |
2088 | * or -1U if we're at the end. */ | |
3b1bbe89 | 2089 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
2090 | { |
2091 | unsigned int next; | |
2092 | ||
2093 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 2094 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
2095 | return -1U; |
2096 | ||
2097 | /* Check they're not leading us off end of descriptors. */ | |
3a5db0b1 | 2098 | next = vhost16_to_cpu(vq, READ_ONCE(desc->next)); |
3a4d5c94 MT |
2099 | return next; |
2100 | } | |
2101 | ||
47283bef | 2102 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc 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, | |
2106 | struct vring_desc *indirect) | |
3a4d5c94 MT |
2107 | { |
2108 | struct vring_desc desc; | |
2109 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 2110 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 2111 | struct iov_iter from; |
6b1e6cc7 | 2112 | int ret, access; |
3a4d5c94 MT |
2113 | |
2114 | /* Sanity check */ | |
3b1bbe89 | 2115 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
2116 | vq_err(vq, "Invalid length in indirect descriptor: " |
2117 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 2118 | (unsigned long long)len, |
3a4d5c94 MT |
2119 | sizeof desc); |
2120 | return -EINVAL; | |
2121 | } | |
2122 | ||
3b1bbe89 | 2123 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
6b1e6cc7 | 2124 | UIO_MAXIOV, VHOST_ACCESS_RO); |
7b3384fc | 2125 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2126 | if (ret != -EAGAIN) |
2127 | vq_err(vq, "Translation failure %d in indirect.\n", ret); | |
3a4d5c94 MT |
2128 | return ret; |
2129 | } | |
aad9a1ce | 2130 | iov_iter_init(&from, READ, vq->indirect, ret, len); |
3a4d5c94 MT |
2131 | |
2132 | /* We will use the result as an address to read from, so most | |
2133 | * architectures only need a compiler barrier here. */ | |
2134 | read_barrier_depends(); | |
2135 | ||
3b1bbe89 | 2136 | count = len / sizeof desc; |
3a4d5c94 MT |
2137 | /* Buffers are chained via a 16 bit next field, so |
2138 | * we can have at most 2^16 of these. */ | |
7b3384fc | 2139 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
2140 | vq_err(vq, "Indirect buffer length too big: %d\n", |
2141 | indirect->len); | |
2142 | return -E2BIG; | |
2143 | } | |
2144 | ||
2145 | do { | |
2146 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2147 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
2148 | vq_err(vq, "Loop detected: last one at %u " |
2149 | "indirect size %u\n", | |
2150 | i, count); | |
2151 | return -EINVAL; | |
2152 | } | |
cbbd26b8 | 2153 | if (unlikely(!copy_from_iter_full(&desc, sizeof(desc), &from))) { |
3a4d5c94 | 2154 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2155 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2156 | return -EINVAL; |
2157 | } | |
3b1bbe89 | 2158 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 2159 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 2160 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
2161 | return -EINVAL; |
2162 | } | |
2163 | ||
6b1e6cc7 JW |
2164 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2165 | access = VHOST_ACCESS_WO; | |
2166 | else | |
2167 | access = VHOST_ACCESS_RO; | |
2168 | ||
3b1bbe89 MT |
2169 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2170 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2171 | iov_size - iov_count, access); |
7b3384fc | 2172 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2173 | if (ret != -EAGAIN) |
2174 | vq_err(vq, "Translation failure %d indirect idx %d\n", | |
2175 | ret, i); | |
3a4d5c94 MT |
2176 | return ret; |
2177 | } | |
2178 | /* If this is an input descriptor, increment that count. */ | |
6b1e6cc7 | 2179 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2180 | *in_num += ret; |
2181 | if (unlikely(log)) { | |
3b1bbe89 MT |
2182 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2183 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2184 | ++*log_num; |
2185 | } | |
2186 | } else { | |
2187 | /* If it's an output descriptor, they're all supposed | |
2188 | * to come before any input descriptors. */ | |
7b3384fc | 2189 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2190 | vq_err(vq, "Indirect descriptor " |
2191 | "has out after in: idx %d\n", i); | |
2192 | return -EINVAL; | |
2193 | } | |
2194 | *out_num += ret; | |
2195 | } | |
3b1bbe89 | 2196 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2197 | return 0; |
2198 | } | |
2199 | ||
2200 | /* This looks in the virtqueue and for the first available buffer, and converts | |
2201 | * it to an iovec for convenient access. Since descriptors consist of some | |
2202 | * number of output then some number of input descriptors, it's actually two | |
2203 | * iovecs, but we pack them into one and note how many of each there were. | |
2204 | * | |
d5675bd2 MT |
2205 | * This function returns the descriptor number found, or vq->num (which is |
2206 | * never a valid descriptor number) if none was found. A negative code is | |
2207 | * returned on error. */ | |
47283bef | 2208 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
2209 | struct iovec iov[], unsigned int iov_size, |
2210 | unsigned int *out_num, unsigned int *in_num, | |
2211 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
2212 | { |
2213 | struct vring_desc desc; | |
2214 | unsigned int i, head, found = 0; | |
2215 | u16 last_avail_idx; | |
3b1bbe89 MT |
2216 | __virtio16 avail_idx; |
2217 | __virtio16 ring_head; | |
6b1e6cc7 | 2218 | int ret, access; |
3a4d5c94 MT |
2219 | |
2220 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
2221 | last_avail_idx = vq->last_avail_idx; | |
3a4d5c94 | 2222 | |
e3b56cdd | 2223 | if (vq->avail_idx == vq->last_avail_idx) { |
7b5d753e | 2224 | if (unlikely(vhost_get_avail_idx(vq, &avail_idx))) { |
e3b56cdd JW |
2225 | vq_err(vq, "Failed to access avail idx at %p\n", |
2226 | &vq->avail->idx); | |
2227 | return -EFAULT; | |
2228 | } | |
2229 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); | |
3a4d5c94 | 2230 | |
e3b56cdd JW |
2231 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
2232 | vq_err(vq, "Guest moved used index from %u to %u", | |
2233 | last_avail_idx, vq->avail_idx); | |
2234 | return -EFAULT; | |
2235 | } | |
2236 | ||
2237 | /* If there's nothing new since last we looked, return | |
2238 | * invalid. | |
2239 | */ | |
2240 | if (vq->avail_idx == last_avail_idx) | |
2241 | return vq->num; | |
3a4d5c94 | 2242 | |
e3b56cdd JW |
2243 | /* Only get avail ring entries after they have been |
2244 | * exposed by guest. | |
2245 | */ | |
2246 | smp_rmb(); | |
2247 | } | |
3a4d5c94 MT |
2248 | |
2249 | /* Grab the next descriptor number they're advertising, and increment | |
2250 | * the index we've seen. */ | |
7b5d753e | 2251 | if (unlikely(vhost_get_avail_head(vq, &ring_head, last_avail_idx))) { |
3a4d5c94 MT |
2252 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
2253 | last_avail_idx, | |
2254 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 2255 | return -EFAULT; |
3a4d5c94 MT |
2256 | } |
2257 | ||
3b1bbe89 MT |
2258 | head = vhost16_to_cpu(vq, ring_head); |
2259 | ||
3a4d5c94 | 2260 | /* If their number is silly, that's an error. */ |
7b3384fc | 2261 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
2262 | vq_err(vq, "Guest says index %u > %u is available", |
2263 | head, vq->num); | |
d5675bd2 | 2264 | return -EINVAL; |
3a4d5c94 MT |
2265 | } |
2266 | ||
2267 | /* When we start there are none of either input nor output. */ | |
2268 | *out_num = *in_num = 0; | |
2269 | if (unlikely(log)) | |
2270 | *log_num = 0; | |
2271 | ||
2272 | i = head; | |
2273 | do { | |
2274 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 2275 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
2276 | vq_err(vq, "Desc index is %u > %u, head = %u", |
2277 | i, vq->num, head); | |
d5675bd2 | 2278 | return -EINVAL; |
3a4d5c94 | 2279 | } |
7b3384fc | 2280 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
2281 | vq_err(vq, "Loop detected: last one at %u " |
2282 | "vq size %u head %u\n", | |
2283 | i, vq->num, head); | |
d5675bd2 | 2284 | return -EINVAL; |
3a4d5c94 | 2285 | } |
7b5d753e | 2286 | ret = vhost_get_desc(vq, &desc, i); |
7b3384fc | 2287 | if (unlikely(ret)) { |
3a4d5c94 MT |
2288 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
2289 | i, vq->desc + i); | |
d5675bd2 | 2290 | return -EFAULT; |
3a4d5c94 | 2291 | } |
3b1bbe89 | 2292 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 2293 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
2294 | out_num, in_num, |
2295 | log, log_num, &desc); | |
7b3384fc | 2296 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2297 | if (ret != -EAGAIN) |
2298 | vq_err(vq, "Failure detected " | |
2299 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 2300 | return ret; |
3a4d5c94 MT |
2301 | } |
2302 | continue; | |
2303 | } | |
2304 | ||
6b1e6cc7 JW |
2305 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2306 | access = VHOST_ACCESS_WO; | |
2307 | else | |
2308 | access = VHOST_ACCESS_RO; | |
3b1bbe89 MT |
2309 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2310 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2311 | iov_size - iov_count, access); |
7b3384fc | 2312 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2313 | if (ret != -EAGAIN) |
2314 | vq_err(vq, "Translation failure %d descriptor idx %d\n", | |
2315 | ret, i); | |
d5675bd2 | 2316 | return ret; |
3a4d5c94 | 2317 | } |
6b1e6cc7 | 2318 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2319 | /* If this is an input descriptor, |
2320 | * increment that count. */ | |
2321 | *in_num += ret; | |
2322 | if (unlikely(log)) { | |
3b1bbe89 MT |
2323 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2324 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2325 | ++*log_num; |
2326 | } | |
2327 | } else { | |
2328 | /* If it's an output descriptor, they're all supposed | |
2329 | * to come before any input descriptors. */ | |
7b3384fc | 2330 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2331 | vq_err(vq, "Descriptor has out after in: " |
2332 | "idx %d\n", i); | |
d5675bd2 | 2333 | return -EINVAL; |
3a4d5c94 MT |
2334 | } |
2335 | *out_num += ret; | |
2336 | } | |
3b1bbe89 | 2337 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2338 | |
2339 | /* On success, increment avail index. */ | |
2340 | vq->last_avail_idx++; | |
8ea8cf89 MT |
2341 | |
2342 | /* Assume notifications from guest are disabled at this point, | |
2343 | * if they aren't we would need to update avail_event index. */ | |
2344 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
2345 | return head; |
2346 | } | |
6ac1afbf | 2347 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
2348 | |
2349 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 2350 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 2351 | { |
8dd014ad | 2352 | vq->last_avail_idx -= n; |
3a4d5c94 | 2353 | } |
6ac1afbf | 2354 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
2355 | |
2356 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2357 | * want to notify the guest, using eventfd. */ | |
2358 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
2359 | { | |
3b1bbe89 MT |
2360 | struct vring_used_elem heads = { |
2361 | cpu_to_vhost32(vq, head), | |
2362 | cpu_to_vhost32(vq, len) | |
2363 | }; | |
3a4d5c94 | 2364 | |
c49e4e57 | 2365 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 2366 | } |
6ac1afbf | 2367 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 2368 | |
8dd014ad DS |
2369 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2370 | struct vring_used_elem *heads, | |
2371 | unsigned count) | |
2372 | { | |
2373 | struct vring_used_elem __user *used; | |
8ea8cf89 | 2374 | u16 old, new; |
8dd014ad DS |
2375 | int start; |
2376 | ||
5fba13b5 | 2377 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 2378 | used = vq->used->ring + start; |
7b5d753e | 2379 | if (vhost_put_used(vq, heads, start, count)) { |
8dd014ad DS |
2380 | vq_err(vq, "Failed to write used"); |
2381 | return -EFAULT; | |
2382 | } | |
2383 | if (unlikely(vq->log_used)) { | |
2384 | /* Make sure data is seen before log. */ | |
2385 | smp_wmb(); | |
2386 | /* Log used ring entry write. */ | |
cc5e7107 JW |
2387 | log_used(vq, ((void __user *)used - (void __user *)vq->used), |
2388 | count * sizeof *used); | |
8dd014ad | 2389 | } |
8ea8cf89 MT |
2390 | old = vq->last_used_idx; |
2391 | new = (vq->last_used_idx += count); | |
2392 | /* If the driver never bothers to signal in a very long while, | |
2393 | * used index might wrap around. If that happens, invalidate | |
2394 | * signalled_used index we stored. TODO: make sure driver | |
2395 | * signals at least once in 2^16 and remove this. */ | |
2396 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
2397 | vq->signalled_used_valid = false; | |
8dd014ad DS |
2398 | return 0; |
2399 | } | |
2400 | ||
2401 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2402 | * want to notify the guest, using eventfd. */ | |
2403 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
2404 | unsigned count) | |
2405 | { | |
2406 | int start, n, r; | |
2407 | ||
5fba13b5 | 2408 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
2409 | n = vq->num - start; |
2410 | if (n < count) { | |
2411 | r = __vhost_add_used_n(vq, heads, n); | |
2412 | if (r < 0) | |
2413 | return r; | |
2414 | heads += n; | |
2415 | count -= n; | |
2416 | } | |
2417 | r = __vhost_add_used_n(vq, heads, count); | |
2418 | ||
2419 | /* Make sure buffer is written before we update index. */ | |
2420 | smp_wmb(); | |
7b5d753e | 2421 | if (vhost_put_used_idx(vq)) { |
8dd014ad DS |
2422 | vq_err(vq, "Failed to increment used idx"); |
2423 | return -EFAULT; | |
2424 | } | |
2425 | if (unlikely(vq->log_used)) { | |
841df922 JW |
2426 | /* Make sure used idx is seen before log. */ |
2427 | smp_wmb(); | |
8dd014ad | 2428 | /* Log used index update. */ |
cc5e7107 JW |
2429 | log_used(vq, offsetof(struct vring_used, idx), |
2430 | sizeof vq->used->idx); | |
8dd014ad DS |
2431 | if (vq->log_ctx) |
2432 | eventfd_signal(vq->log_ctx, 1); | |
2433 | } | |
2434 | return r; | |
2435 | } | |
6ac1afbf | 2436 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 2437 | |
8ea8cf89 | 2438 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2439 | { |
3b1bbe89 MT |
2440 | __u16 old, new; |
2441 | __virtio16 event; | |
8ea8cf89 | 2442 | bool v; |
8d65843c JW |
2443 | /* Flush out used index updates. This is paired |
2444 | * with the barrier that the Guest executes when enabling | |
2445 | * interrupts. */ | |
2446 | smp_mb(); | |
0d499356 | 2447 | |
ea16c514 | 2448 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
2449 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2450 | return true; | |
2451 | ||
ea16c514 | 2452 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 2453 | __virtio16 flags; |
7b5d753e | 2454 | if (vhost_get_avail_flags(vq, &flags)) { |
8ea8cf89 MT |
2455 | vq_err(vq, "Failed to get flags"); |
2456 | return true; | |
2457 | } | |
3b1bbe89 | 2458 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 2459 | } |
8ea8cf89 MT |
2460 | old = vq->signalled_used; |
2461 | v = vq->signalled_used_valid; | |
2462 | new = vq->signalled_used = vq->last_used_idx; | |
2463 | vq->signalled_used_valid = true; | |
3a4d5c94 | 2464 | |
8ea8cf89 MT |
2465 | if (unlikely(!v)) |
2466 | return true; | |
3a4d5c94 | 2467 | |
7b5d753e | 2468 | if (vhost_get_used_event(vq, &event)) { |
8ea8cf89 MT |
2469 | vq_err(vq, "Failed to get used event idx"); |
2470 | return true; | |
2471 | } | |
8d65843c | 2472 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
2473 | } |
2474 | ||
2475 | /* This actually signals the guest, using eventfd. */ | |
2476 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2477 | { | |
3a4d5c94 | 2478 | /* Signal the Guest tell them we used something up. */ |
8ea8cf89 | 2479 | if (vq->call_ctx && vhost_notify(dev, vq)) |
3a4d5c94 MT |
2480 | eventfd_signal(vq->call_ctx, 1); |
2481 | } | |
6ac1afbf | 2482 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
2483 | |
2484 | /* And here's the combo meal deal. Supersize me! */ | |
2485 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
2486 | struct vhost_virtqueue *vq, | |
2487 | unsigned int head, int len) | |
2488 | { | |
2489 | vhost_add_used(vq, head, len); | |
2490 | vhost_signal(dev, vq); | |
2491 | } | |
6ac1afbf | 2492 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 2493 | |
8dd014ad DS |
2494 | /* multi-buffer version of vhost_add_used_and_signal */ |
2495 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
2496 | struct vhost_virtqueue *vq, | |
2497 | struct vring_used_elem *heads, unsigned count) | |
2498 | { | |
2499 | vhost_add_used_n(vq, heads, count); | |
2500 | vhost_signal(dev, vq); | |
2501 | } | |
6ac1afbf | 2502 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 2503 | |
d4a60603 JW |
2504 | /* return true if we're sure that avaiable ring is empty */ |
2505 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2506 | { | |
2507 | __virtio16 avail_idx; | |
2508 | int r; | |
2509 | ||
275bf960 JW |
2510 | if (vq->avail_idx != vq->last_avail_idx) |
2511 | return false; | |
2512 | ||
7b5d753e | 2513 | r = vhost_get_avail_idx(vq, &avail_idx); |
275bf960 | 2514 | if (unlikely(r)) |
d4a60603 | 2515 | return false; |
275bf960 | 2516 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
d4a60603 | 2517 | |
275bf960 | 2518 | return vq->avail_idx == vq->last_avail_idx; |
d4a60603 JW |
2519 | } |
2520 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
2521 | ||
3a4d5c94 | 2522 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 2523 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2524 | { |
3b1bbe89 | 2525 | __virtio16 avail_idx; |
3a4d5c94 | 2526 | int r; |
d47effe1 | 2527 | |
3a4d5c94 MT |
2528 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2529 | return false; | |
2530 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2531 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2532 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2533 | if (r) { |
2534 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2535 | &vq->used->flags, r); | |
2536 | return false; | |
2537 | } | |
2538 | } else { | |
2723feaa | 2539 | r = vhost_update_avail_event(vq, vq->avail_idx); |
8ea8cf89 MT |
2540 | if (r) { |
2541 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
2542 | vhost_avail_event(vq), r); | |
2543 | return false; | |
2544 | } | |
2545 | } | |
3a4d5c94 MT |
2546 | /* They could have slipped one in as we were doing that: make |
2547 | * sure it's written, then check again. */ | |
5659338c | 2548 | smp_mb(); |
7b5d753e | 2549 | r = vhost_get_avail_idx(vq, &avail_idx); |
3a4d5c94 MT |
2550 | if (r) { |
2551 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
2552 | &vq->avail->idx, r); | |
2553 | return false; | |
2554 | } | |
2555 | ||
3b1bbe89 | 2556 | return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx; |
3a4d5c94 | 2557 | } |
6ac1afbf | 2558 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
2559 | |
2560 | /* We don't need to be notified again. */ | |
8ea8cf89 | 2561 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
2562 | { |
2563 | int r; | |
d47effe1 | 2564 | |
3a4d5c94 MT |
2565 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2566 | return; | |
2567 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2568 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2569 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2570 | if (r) |
2571 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2572 | &vq->used->flags, r); | |
2573 | } | |
3a4d5c94 | 2574 | } |
6ac1afbf AH |
2575 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2576 | ||
6b1e6cc7 JW |
2577 | /* Create a new message. */ |
2578 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) | |
2579 | { | |
2580 | struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL); | |
2581 | if (!node) | |
2582 | return NULL; | |
670ae9ca MT |
2583 | |
2584 | /* Make sure all padding within the structure is initialized. */ | |
2585 | memset(&node->msg, 0, sizeof node->msg); | |
6b1e6cc7 JW |
2586 | node->vq = vq; |
2587 | node->msg.type = type; | |
2588 | return node; | |
2589 | } | |
2590 | EXPORT_SYMBOL_GPL(vhost_new_msg); | |
2591 | ||
2592 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, | |
2593 | struct vhost_msg_node *node) | |
2594 | { | |
2595 | spin_lock(&dev->iotlb_lock); | |
2596 | list_add_tail(&node->node, head); | |
2597 | spin_unlock(&dev->iotlb_lock); | |
2598 | ||
a9a08845 | 2599 | wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); |
6b1e6cc7 JW |
2600 | } |
2601 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); | |
2602 | ||
2603 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, | |
2604 | struct list_head *head) | |
2605 | { | |
2606 | struct vhost_msg_node *node = NULL; | |
2607 | ||
2608 | spin_lock(&dev->iotlb_lock); | |
2609 | if (!list_empty(head)) { | |
2610 | node = list_first_entry(head, struct vhost_msg_node, | |
2611 | node); | |
2612 | list_del(&node->node); | |
2613 | } | |
2614 | spin_unlock(&dev->iotlb_lock); | |
2615 | ||
2616 | return node; | |
2617 | } | |
2618 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); | |
2619 | ||
2620 | ||
6ac1afbf AH |
2621 | static int __init vhost_init(void) |
2622 | { | |
2623 | return 0; | |
2624 | } | |
2625 | ||
2626 | static void __exit vhost_exit(void) | |
2627 | { | |
2628 | } | |
2629 | ||
2630 | module_init(vhost_init); | |
2631 | module_exit(vhost_exit); | |
2632 | ||
2633 | MODULE_VERSION("0.0.1"); | |
2634 | MODULE_LICENSE("GPL v2"); | |
2635 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
2636 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |