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3a4d5c94 MT |
1 | /* Copyright (C) 2009 Red Hat, Inc. |
2 | * Copyright (C) 2006 Rusty Russell IBM Corporation | |
3 | * | |
4 | * Author: Michael S. Tsirkin <mst@redhat.com> | |
5 | * | |
6 | * Inspiration, some code, and most witty comments come from | |
61516587 | 7 | * Documentation/virtual/lguest/lguest.c, by Rusty Russell |
3a4d5c94 MT |
8 | * |
9 | * This work is licensed under the terms of the GNU GPL, version 2. | |
10 | * | |
11 | * Generic code for virtio server in host kernel. | |
12 | */ | |
13 | ||
14 | #include <linux/eventfd.h> | |
15 | #include <linux/vhost.h> | |
35596b27 | 16 | #include <linux/uio.h> |
3a4d5c94 | 17 | #include <linux/mm.h> |
64e1c807 | 18 | #include <linux/mmu_context.h> |
3a4d5c94 MT |
19 | #include <linux/miscdevice.h> |
20 | #include <linux/mutex.h> | |
3a4d5c94 MT |
21 | #include <linux/poll.h> |
22 | #include <linux/file.h> | |
23 | #include <linux/highmem.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
4de7255f | 25 | #include <linux/vmalloc.h> |
c23f3445 | 26 | #include <linux/kthread.h> |
9e3d1957 | 27 | #include <linux/cgroup.h> |
6ac1afbf | 28 | #include <linux/module.h> |
bcfeacab | 29 | #include <linux/sort.h> |
a9709d68 | 30 | #include <linux/interval_tree_generic.h> |
3a4d5c94 | 31 | |
3a4d5c94 MT |
32 | #include "vhost.h" |
33 | ||
c9ce42f7 IM |
34 | static ushort max_mem_regions = 64; |
35 | module_param(max_mem_regions, ushort, 0444); | |
36 | MODULE_PARM_DESC(max_mem_regions, | |
37 | "Maximum number of memory regions in memory map. (default: 64)"); | |
6b1e6cc7 JW |
38 | static int max_iotlb_entries = 2048; |
39 | module_param(max_iotlb_entries, int, 0444); | |
40 | MODULE_PARM_DESC(max_iotlb_entries, | |
41 | "Maximum number of iotlb entries. (default: 2048)"); | |
c9ce42f7 | 42 | |
3a4d5c94 | 43 | enum { |
3a4d5c94 MT |
44 | VHOST_MEMORY_F_LOG = 0x1, |
45 | }; | |
46 | ||
3b1bbe89 MT |
47 | #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) |
48 | #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) | |
8ea8cf89 | 49 | |
a9709d68 JW |
50 | INTERVAL_TREE_DEFINE(struct vhost_umem_node, |
51 | rb, __u64, __subtree_last, | |
52 | START, LAST, , vhost_umem_interval_tree); | |
53 | ||
2751c988 | 54 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
c5072037 | 55 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
56 | { |
57 | vq->user_be = !virtio_legacy_is_little_endian(); | |
58 | } | |
59 | ||
c5072037 GK |
60 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
61 | { | |
62 | vq->user_be = true; | |
63 | } | |
64 | ||
65 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) | |
66 | { | |
67 | vq->user_be = false; | |
68 | } | |
69 | ||
2751c988 GK |
70 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
71 | { | |
72 | struct vhost_vring_state s; | |
73 | ||
74 | if (vq->private_data) | |
75 | return -EBUSY; | |
76 | ||
77 | if (copy_from_user(&s, argp, sizeof(s))) | |
78 | return -EFAULT; | |
79 | ||
80 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && | |
81 | s.num != VHOST_VRING_BIG_ENDIAN) | |
82 | return -EINVAL; | |
83 | ||
c5072037 GK |
84 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
85 | vhost_enable_cross_endian_big(vq); | |
86 | else | |
87 | vhost_enable_cross_endian_little(vq); | |
2751c988 GK |
88 | |
89 | return 0; | |
90 | } | |
91 | ||
92 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
93 | int __user *argp) | |
94 | { | |
95 | struct vhost_vring_state s = { | |
96 | .index = idx, | |
97 | .num = vq->user_be | |
98 | }; | |
99 | ||
100 | if (copy_to_user(argp, &s, sizeof(s))) | |
101 | return -EFAULT; | |
102 | ||
103 | return 0; | |
104 | } | |
105 | ||
106 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
107 | { | |
108 | /* Note for legacy virtio: user_be is initialized at reset time | |
109 | * according to the host endianness. If userspace does not set an | |
110 | * explicit endianness, the default behavior is native endian, as | |
111 | * expected by legacy virtio. | |
112 | */ | |
113 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; | |
114 | } | |
115 | #else | |
c5072037 | 116 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
117 | { |
118 | } | |
119 | ||
120 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) | |
121 | { | |
122 | return -ENOIOCTLCMD; | |
123 | } | |
124 | ||
125 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
126 | int __user *argp) | |
127 | { | |
128 | return -ENOIOCTLCMD; | |
129 | } | |
130 | ||
131 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
132 | { | |
133 | if (vhost_has_feature(vq, VIRTIO_F_VERSION_1)) | |
134 | vq->is_le = true; | |
135 | } | |
136 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ | |
137 | ||
c5072037 GK |
138 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
139 | { | |
140 | vq->is_le = virtio_legacy_is_little_endian(); | |
141 | } | |
142 | ||
7235acdb JW |
143 | struct vhost_flush_struct { |
144 | struct vhost_work work; | |
145 | struct completion wait_event; | |
146 | }; | |
147 | ||
148 | static void vhost_flush_work(struct vhost_work *work) | |
149 | { | |
150 | struct vhost_flush_struct *s; | |
151 | ||
152 | s = container_of(work, struct vhost_flush_struct, work); | |
153 | complete(&s->wait_event); | |
154 | } | |
155 | ||
3a4d5c94 MT |
156 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
157 | poll_table *pt) | |
158 | { | |
159 | struct vhost_poll *poll; | |
3a4d5c94 | 160 | |
d47effe1 | 161 | poll = container_of(pt, struct vhost_poll, table); |
3a4d5c94 MT |
162 | poll->wqh = wqh; |
163 | add_wait_queue(wqh, &poll->wait); | |
164 | } | |
165 | ||
166 | static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync, | |
167 | void *key) | |
168 | { | |
c23f3445 TH |
169 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
170 | ||
3a4d5c94 MT |
171 | if (!((unsigned long)key & poll->mask)) |
172 | return 0; | |
173 | ||
c23f3445 | 174 | vhost_poll_queue(poll); |
3a4d5c94 MT |
175 | return 0; |
176 | } | |
177 | ||
163049ae | 178 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
87d6a412 | 179 | { |
04b96e55 | 180 | clear_bit(VHOST_WORK_QUEUED, &work->flags); |
87d6a412 MT |
181 | work->fn = fn; |
182 | init_waitqueue_head(&work->done); | |
87d6a412 | 183 | } |
6ac1afbf | 184 | EXPORT_SYMBOL_GPL(vhost_work_init); |
87d6a412 | 185 | |
3a4d5c94 | 186 | /* Init poll structure */ |
c23f3445 TH |
187 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
188 | unsigned long mask, struct vhost_dev *dev) | |
3a4d5c94 | 189 | { |
3a4d5c94 MT |
190 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
191 | init_poll_funcptr(&poll->table, vhost_poll_func); | |
192 | poll->mask = mask; | |
c23f3445 | 193 | poll->dev = dev; |
2b8b328b | 194 | poll->wqh = NULL; |
c23f3445 | 195 | |
87d6a412 | 196 | vhost_work_init(&poll->work, fn); |
3a4d5c94 | 197 | } |
6ac1afbf | 198 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
3a4d5c94 MT |
199 | |
200 | /* Start polling a file. We add ourselves to file's wait queue. The caller must | |
201 | * keep a reference to a file until after vhost_poll_stop is called. */ | |
2b8b328b | 202 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
3a4d5c94 MT |
203 | { |
204 | unsigned long mask; | |
2b8b328b | 205 | int ret = 0; |
d47effe1 | 206 | |
70181d51 JW |
207 | if (poll->wqh) |
208 | return 0; | |
209 | ||
3a4d5c94 MT |
210 | mask = file->f_op->poll(file, &poll->table); |
211 | if (mask) | |
212 | vhost_poll_wakeup(&poll->wait, 0, 0, (void *)mask); | |
2b8b328b JW |
213 | if (mask & POLLERR) { |
214 | if (poll->wqh) | |
215 | remove_wait_queue(poll->wqh, &poll->wait); | |
216 | ret = -EINVAL; | |
217 | } | |
218 | ||
219 | return ret; | |
3a4d5c94 | 220 | } |
6ac1afbf | 221 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
222 | |
223 | /* Stop polling a file. After this function returns, it becomes safe to drop the | |
224 | * file reference. You must also flush afterwards. */ | |
225 | void vhost_poll_stop(struct vhost_poll *poll) | |
226 | { | |
2b8b328b JW |
227 | if (poll->wqh) { |
228 | remove_wait_queue(poll->wqh, &poll->wait); | |
229 | poll->wqh = NULL; | |
230 | } | |
3a4d5c94 | 231 | } |
6ac1afbf | 232 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 233 | |
7235acdb | 234 | void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
0174b0c3 | 235 | { |
7235acdb | 236 | struct vhost_flush_struct flush; |
d47effe1 | 237 | |
7235acdb JW |
238 | if (dev->worker) { |
239 | init_completion(&flush.wait_event); | |
240 | vhost_work_init(&flush.work, vhost_flush_work); | |
0174b0c3 | 241 | |
7235acdb JW |
242 | vhost_work_queue(dev, &flush.work); |
243 | wait_for_completion(&flush.wait_event); | |
244 | } | |
3a4d5c94 | 245 | } |
6ac1afbf | 246 | EXPORT_SYMBOL_GPL(vhost_work_flush); |
3a4d5c94 | 247 | |
87d6a412 MT |
248 | /* Flush any work that has been scheduled. When calling this, don't hold any |
249 | * locks that are also used by the callback. */ | |
250 | void vhost_poll_flush(struct vhost_poll *poll) | |
251 | { | |
252 | vhost_work_flush(poll->dev, &poll->work); | |
253 | } | |
6ac1afbf | 254 | EXPORT_SYMBOL_GPL(vhost_poll_flush); |
87d6a412 | 255 | |
163049ae | 256 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 257 | { |
04b96e55 JW |
258 | if (!dev->worker) |
259 | return; | |
c23f3445 | 260 | |
04b96e55 JW |
261 | if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { |
262 | /* We can only add the work to the list after we're | |
263 | * sure it was not in the list. | |
264 | */ | |
265 | smp_mb(); | |
266 | llist_add(&work->node, &dev->work_list); | |
c23f3445 TH |
267 | wake_up_process(dev->worker); |
268 | } | |
3a4d5c94 | 269 | } |
6ac1afbf | 270 | EXPORT_SYMBOL_GPL(vhost_work_queue); |
3a4d5c94 | 271 | |
526d3e7f JW |
272 | /* A lockless hint for busy polling code to exit the loop */ |
273 | bool vhost_has_work(struct vhost_dev *dev) | |
274 | { | |
04b96e55 | 275 | return !llist_empty(&dev->work_list); |
526d3e7f JW |
276 | } |
277 | EXPORT_SYMBOL_GPL(vhost_has_work); | |
278 | ||
87d6a412 MT |
279 | void vhost_poll_queue(struct vhost_poll *poll) |
280 | { | |
281 | vhost_work_queue(poll->dev, &poll->work); | |
282 | } | |
6ac1afbf | 283 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 284 | |
3a4d5c94 MT |
285 | static void vhost_vq_reset(struct vhost_dev *dev, |
286 | struct vhost_virtqueue *vq) | |
287 | { | |
288 | vq->num = 1; | |
289 | vq->desc = NULL; | |
290 | vq->avail = NULL; | |
291 | vq->used = NULL; | |
292 | vq->last_avail_idx = 0; | |
293 | vq->avail_idx = 0; | |
294 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
295 | vq->signalled_used = 0; |
296 | vq->signalled_used_valid = false; | |
3a4d5c94 | 297 | vq->used_flags = 0; |
3a4d5c94 MT |
298 | vq->log_used = false; |
299 | vq->log_addr = -1ull; | |
3a4d5c94 | 300 | vq->private_data = NULL; |
ea16c514 | 301 | vq->acked_features = 0; |
3a4d5c94 MT |
302 | vq->log_base = NULL; |
303 | vq->error_ctx = NULL; | |
304 | vq->error = NULL; | |
305 | vq->kick = NULL; | |
306 | vq->call_ctx = NULL; | |
307 | vq->call = NULL; | |
73a99f08 | 308 | vq->log_ctx = NULL; |
c5072037 GK |
309 | vhost_reset_is_le(vq); |
310 | vhost_disable_cross_endian(vq); | |
03088137 | 311 | vq->busyloop_timeout = 0; |
a9709d68 | 312 | vq->umem = NULL; |
6b1e6cc7 | 313 | vq->iotlb = NULL; |
3a4d5c94 MT |
314 | } |
315 | ||
c23f3445 TH |
316 | static int vhost_worker(void *data) |
317 | { | |
318 | struct vhost_dev *dev = data; | |
04b96e55 JW |
319 | struct vhost_work *work, *work_next; |
320 | struct llist_node *node; | |
d7ffde35 | 321 | mm_segment_t oldfs = get_fs(); |
c23f3445 | 322 | |
d7ffde35 | 323 | set_fs(USER_DS); |
64e1c807 MT |
324 | use_mm(dev->mm); |
325 | ||
c23f3445 TH |
326 | for (;;) { |
327 | /* mb paired w/ kthread_stop */ | |
328 | set_current_state(TASK_INTERRUPTIBLE); | |
329 | ||
c23f3445 | 330 | if (kthread_should_stop()) { |
c23f3445 | 331 | __set_current_state(TASK_RUNNING); |
64e1c807 | 332 | break; |
c23f3445 | 333 | } |
04b96e55 JW |
334 | |
335 | node = llist_del_all(&dev->work_list); | |
336 | if (!node) | |
337 | schedule(); | |
338 | ||
339 | node = llist_reverse_order(node); | |
340 | /* make sure flag is seen after deletion */ | |
341 | smp_wmb(); | |
342 | llist_for_each_entry_safe(work, work_next, node, node) { | |
343 | clear_bit(VHOST_WORK_QUEUED, &work->flags); | |
c23f3445 TH |
344 | __set_current_state(TASK_RUNNING); |
345 | work->fn(work); | |
d550dda1 NHE |
346 | if (need_resched()) |
347 | schedule(); | |
04b96e55 | 348 | } |
c23f3445 | 349 | } |
64e1c807 | 350 | unuse_mm(dev->mm); |
d7ffde35 | 351 | set_fs(oldfs); |
64e1c807 | 352 | return 0; |
c23f3445 TH |
353 | } |
354 | ||
bab632d6 MT |
355 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
356 | { | |
357 | kfree(vq->indirect); | |
358 | vq->indirect = NULL; | |
359 | kfree(vq->log); | |
360 | vq->log = NULL; | |
361 | kfree(vq->heads); | |
362 | vq->heads = NULL; | |
bab632d6 MT |
363 | } |
364 | ||
e0e9b406 JW |
365 | /* Helper to allocate iovec buffers for all vqs. */ |
366 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
367 | { | |
6d5e6aa8 | 368 | struct vhost_virtqueue *vq; |
e0e9b406 | 369 | int i; |
d47effe1 | 370 | |
e0e9b406 | 371 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 AH |
372 | vq = dev->vqs[i]; |
373 | vq->indirect = kmalloc(sizeof *vq->indirect * UIO_MAXIOV, | |
374 | GFP_KERNEL); | |
375 | vq->log = kmalloc(sizeof *vq->log * UIO_MAXIOV, GFP_KERNEL); | |
376 | vq->heads = kmalloc(sizeof *vq->heads * UIO_MAXIOV, GFP_KERNEL); | |
377 | if (!vq->indirect || !vq->log || !vq->heads) | |
e0e9b406 JW |
378 | goto err_nomem; |
379 | } | |
380 | return 0; | |
d47effe1 | 381 | |
e0e9b406 | 382 | err_nomem: |
bab632d6 | 383 | for (; i >= 0; --i) |
3ab2e420 | 384 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
385 | return -ENOMEM; |
386 | } | |
387 | ||
388 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
389 | { | |
390 | int i; | |
d47effe1 | 391 | |
bab632d6 | 392 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 393 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
394 | } |
395 | ||
59566b6e | 396 | void vhost_dev_init(struct vhost_dev *dev, |
3ab2e420 | 397 | struct vhost_virtqueue **vqs, int nvqs) |
3a4d5c94 | 398 | { |
6d5e6aa8 | 399 | struct vhost_virtqueue *vq; |
3a4d5c94 | 400 | int i; |
c23f3445 | 401 | |
3a4d5c94 MT |
402 | dev->vqs = vqs; |
403 | dev->nvqs = nvqs; | |
404 | mutex_init(&dev->mutex); | |
405 | dev->log_ctx = NULL; | |
406 | dev->log_file = NULL; | |
a9709d68 | 407 | dev->umem = NULL; |
6b1e6cc7 | 408 | dev->iotlb = NULL; |
3a4d5c94 | 409 | dev->mm = NULL; |
c23f3445 | 410 | dev->worker = NULL; |
04b96e55 | 411 | init_llist_head(&dev->work_list); |
6b1e6cc7 JW |
412 | init_waitqueue_head(&dev->wait); |
413 | INIT_LIST_HEAD(&dev->read_list); | |
414 | INIT_LIST_HEAD(&dev->pending_list); | |
415 | spin_lock_init(&dev->iotlb_lock); | |
04b96e55 | 416 | |
3a4d5c94 MT |
417 | |
418 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
419 | vq = dev->vqs[i]; |
420 | vq->log = NULL; | |
421 | vq->indirect = NULL; | |
422 | vq->heads = NULL; | |
423 | vq->dev = dev; | |
424 | mutex_init(&vq->mutex); | |
425 | vhost_vq_reset(dev, vq); | |
426 | if (vq->handle_kick) | |
427 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
428 | POLLIN, dev); | |
3a4d5c94 | 429 | } |
3a4d5c94 | 430 | } |
6ac1afbf | 431 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
432 | |
433 | /* Caller should have device mutex */ | |
434 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
435 | { | |
436 | /* Are you the owner? If not, I don't think you mean to do that */ | |
437 | return dev->mm == current->mm ? 0 : -EPERM; | |
438 | } | |
6ac1afbf | 439 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 440 | |
87d6a412 | 441 | struct vhost_attach_cgroups_struct { |
d47effe1 KK |
442 | struct vhost_work work; |
443 | struct task_struct *owner; | |
444 | int ret; | |
87d6a412 MT |
445 | }; |
446 | ||
447 | static void vhost_attach_cgroups_work(struct vhost_work *work) | |
448 | { | |
d47effe1 KK |
449 | struct vhost_attach_cgroups_struct *s; |
450 | ||
451 | s = container_of(work, struct vhost_attach_cgroups_struct, work); | |
452 | s->ret = cgroup_attach_task_all(s->owner, current); | |
87d6a412 MT |
453 | } |
454 | ||
455 | static int vhost_attach_cgroups(struct vhost_dev *dev) | |
456 | { | |
d47effe1 KK |
457 | struct vhost_attach_cgroups_struct attach; |
458 | ||
459 | attach.owner = current; | |
460 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); | |
461 | vhost_work_queue(dev, &attach.work); | |
462 | vhost_work_flush(dev, &attach.work); | |
463 | return attach.ret; | |
87d6a412 MT |
464 | } |
465 | ||
05c05351 MT |
466 | /* Caller should have device mutex */ |
467 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
468 | { | |
469 | return dev->mm; | |
470 | } | |
6ac1afbf | 471 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 472 | |
3a4d5c94 | 473 | /* Caller should have device mutex */ |
54db63c2 | 474 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 475 | { |
c23f3445 TH |
476 | struct task_struct *worker; |
477 | int err; | |
d47effe1 | 478 | |
3a4d5c94 | 479 | /* Is there an owner already? */ |
05c05351 | 480 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
481 | err = -EBUSY; |
482 | goto err_mm; | |
483 | } | |
d47effe1 | 484 | |
3a4d5c94 MT |
485 | /* No owner, become one */ |
486 | dev->mm = get_task_mm(current); | |
c23f3445 TH |
487 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
488 | if (IS_ERR(worker)) { | |
489 | err = PTR_ERR(worker); | |
490 | goto err_worker; | |
491 | } | |
492 | ||
493 | dev->worker = worker; | |
87d6a412 MT |
494 | wake_up_process(worker); /* avoid contributing to loadavg */ |
495 | ||
496 | err = vhost_attach_cgroups(dev); | |
9e3d1957 MT |
497 | if (err) |
498 | goto err_cgroup; | |
c23f3445 | 499 | |
e0e9b406 JW |
500 | err = vhost_dev_alloc_iovecs(dev); |
501 | if (err) | |
502 | goto err_cgroup; | |
503 | ||
3a4d5c94 | 504 | return 0; |
9e3d1957 MT |
505 | err_cgroup: |
506 | kthread_stop(worker); | |
615cc221 | 507 | dev->worker = NULL; |
c23f3445 TH |
508 | err_worker: |
509 | if (dev->mm) | |
510 | mmput(dev->mm); | |
511 | dev->mm = NULL; | |
512 | err_mm: | |
513 | return err; | |
3a4d5c94 | 514 | } |
6ac1afbf | 515 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 516 | |
a9709d68 | 517 | static void *vhost_kvzalloc(unsigned long size) |
3a4d5c94 | 518 | { |
a9709d68 JW |
519 | void *n = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); |
520 | ||
521 | if (!n) | |
522 | n = vzalloc(size); | |
523 | return n; | |
524 | } | |
525 | ||
526 | struct vhost_umem *vhost_dev_reset_owner_prepare(void) | |
527 | { | |
528 | return vhost_kvzalloc(sizeof(struct vhost_umem)); | |
150b9e51 | 529 | } |
6ac1afbf | 530 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 531 | |
150b9e51 | 532 | /* Caller should have device mutex */ |
a9709d68 | 533 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_umem *umem) |
150b9e51 | 534 | { |
47283bef MT |
535 | int i; |
536 | ||
ea5d4046 | 537 | vhost_dev_cleanup(dev, true); |
3a4d5c94 | 538 | |
150b9e51 | 539 | /* Restore memory to default empty mapping. */ |
a9709d68 JW |
540 | INIT_LIST_HEAD(&umem->umem_list); |
541 | dev->umem = umem; | |
47283bef MT |
542 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure |
543 | * VQs aren't running. | |
544 | */ | |
545 | for (i = 0; i < dev->nvqs; ++i) | |
a9709d68 | 546 | dev->vqs[i]->umem = umem; |
3a4d5c94 | 547 | } |
6ac1afbf | 548 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 549 | |
b211616d | 550 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
551 | { |
552 | int i; | |
b211616d MT |
553 | |
554 | for (i = 0; i < dev->nvqs; ++i) { | |
3ab2e420 AH |
555 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) { |
556 | vhost_poll_stop(&dev->vqs[i]->poll); | |
557 | vhost_poll_flush(&dev->vqs[i]->poll); | |
b211616d | 558 | } |
bab632d6 | 559 | } |
bab632d6 | 560 | } |
6ac1afbf | 561 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 562 | |
6b1e6cc7 JW |
563 | static void vhost_umem_free(struct vhost_umem *umem, |
564 | struct vhost_umem_node *node) | |
565 | { | |
566 | vhost_umem_interval_tree_remove(node, &umem->umem_tree); | |
567 | list_del(&node->link); | |
568 | kfree(node); | |
569 | umem->numem--; | |
570 | } | |
571 | ||
a9709d68 JW |
572 | static void vhost_umem_clean(struct vhost_umem *umem) |
573 | { | |
574 | struct vhost_umem_node *node, *tmp; | |
575 | ||
576 | if (!umem) | |
577 | return; | |
578 | ||
6b1e6cc7 JW |
579 | list_for_each_entry_safe(node, tmp, &umem->umem_list, link) |
580 | vhost_umem_free(umem, node); | |
581 | ||
a9709d68 JW |
582 | kvfree(umem); |
583 | } | |
584 | ||
6b1e6cc7 JW |
585 | static void vhost_clear_msg(struct vhost_dev *dev) |
586 | { | |
587 | struct vhost_msg_node *node, *n; | |
588 | ||
589 | spin_lock(&dev->iotlb_lock); | |
590 | ||
591 | list_for_each_entry_safe(node, n, &dev->read_list, node) { | |
592 | list_del(&node->node); | |
593 | kfree(node); | |
594 | } | |
595 | ||
596 | list_for_each_entry_safe(node, n, &dev->pending_list, node) { | |
597 | list_del(&node->node); | |
598 | kfree(node); | |
599 | } | |
600 | ||
601 | spin_unlock(&dev->iotlb_lock); | |
602 | } | |
603 | ||
ea5d4046 MT |
604 | /* Caller should have device mutex if and only if locked is set */ |
605 | void vhost_dev_cleanup(struct vhost_dev *dev, bool locked) | |
3a4d5c94 MT |
606 | { |
607 | int i; | |
d47effe1 | 608 | |
3a4d5c94 | 609 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
610 | if (dev->vqs[i]->error_ctx) |
611 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
612 | if (dev->vqs[i]->error) | |
613 | fput(dev->vqs[i]->error); | |
614 | if (dev->vqs[i]->kick) | |
615 | fput(dev->vqs[i]->kick); | |
616 | if (dev->vqs[i]->call_ctx) | |
617 | eventfd_ctx_put(dev->vqs[i]->call_ctx); | |
618 | if (dev->vqs[i]->call) | |
619 | fput(dev->vqs[i]->call); | |
620 | vhost_vq_reset(dev, dev->vqs[i]); | |
3a4d5c94 | 621 | } |
e0e9b406 | 622 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
623 | if (dev->log_ctx) |
624 | eventfd_ctx_put(dev->log_ctx); | |
625 | dev->log_ctx = NULL; | |
626 | if (dev->log_file) | |
627 | fput(dev->log_file); | |
628 | dev->log_file = NULL; | |
629 | /* No one will access memory at this point */ | |
a9709d68 JW |
630 | vhost_umem_clean(dev->umem); |
631 | dev->umem = NULL; | |
6b1e6cc7 JW |
632 | vhost_umem_clean(dev->iotlb); |
633 | dev->iotlb = NULL; | |
634 | vhost_clear_msg(dev); | |
635 | wake_up_interruptible_poll(&dev->wait, POLLIN | POLLRDNORM); | |
04b96e55 | 636 | WARN_ON(!llist_empty(&dev->work_list)); |
78b620ce ED |
637 | if (dev->worker) { |
638 | kthread_stop(dev->worker); | |
639 | dev->worker = NULL; | |
640 | } | |
533a19b4 MT |
641 | if (dev->mm) |
642 | mmput(dev->mm); | |
643 | dev->mm = NULL; | |
3a4d5c94 | 644 | } |
6ac1afbf | 645 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 MT |
646 | |
647 | static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) | |
648 | { | |
649 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 650 | |
3a4d5c94 MT |
651 | /* Make sure 64 bit math will not overflow. */ |
652 | if (a > ULONG_MAX - (unsigned long)log_base || | |
653 | a + (unsigned long)log_base > ULONG_MAX) | |
6d97e55f | 654 | return 0; |
3a4d5c94 MT |
655 | |
656 | return access_ok(VERIFY_WRITE, log_base + a, | |
657 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); | |
658 | } | |
659 | ||
660 | /* Caller should have vq mutex and device mutex. */ | |
a9709d68 | 661 | static int vq_memory_access_ok(void __user *log_base, struct vhost_umem *umem, |
3a4d5c94 MT |
662 | int log_all) |
663 | { | |
a9709d68 | 664 | struct vhost_umem_node *node; |
179b284e | 665 | |
a9709d68 | 666 | if (!umem) |
f8322fbe | 667 | return 0; |
179b284e | 668 | |
a9709d68 JW |
669 | list_for_each_entry(node, &umem->umem_list, link) { |
670 | unsigned long a = node->userspace_addr; | |
671 | ||
672 | if (node->size > ULONG_MAX) | |
3a4d5c94 MT |
673 | return 0; |
674 | else if (!access_ok(VERIFY_WRITE, (void __user *)a, | |
a9709d68 | 675 | node->size)) |
3a4d5c94 MT |
676 | return 0; |
677 | else if (log_all && !log_access_ok(log_base, | |
a9709d68 JW |
678 | node->start, |
679 | node->size)) | |
3a4d5c94 MT |
680 | return 0; |
681 | } | |
682 | return 1; | |
683 | } | |
684 | ||
685 | /* Can we switch to this memory table? */ | |
686 | /* Caller should have device mutex but not vq mutex */ | |
a9709d68 | 687 | static int memory_access_ok(struct vhost_dev *d, struct vhost_umem *umem, |
3a4d5c94 MT |
688 | int log_all) |
689 | { | |
690 | int i; | |
d47effe1 | 691 | |
3a4d5c94 MT |
692 | for (i = 0; i < d->nvqs; ++i) { |
693 | int ok; | |
ea16c514 MT |
694 | bool log; |
695 | ||
3ab2e420 | 696 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 697 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 698 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 699 | if (d->vqs[i]->private_data) |
a9709d68 JW |
700 | ok = vq_memory_access_ok(d->vqs[i]->log_base, |
701 | umem, log); | |
3a4d5c94 MT |
702 | else |
703 | ok = 1; | |
3ab2e420 | 704 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 MT |
705 | if (!ok) |
706 | return 0; | |
707 | } | |
708 | return 1; | |
709 | } | |
710 | ||
6b1e6cc7 JW |
711 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
712 | struct iovec iov[], int iov_size, int access); | |
bfe2bc51 JW |
713 | |
714 | static int vhost_copy_to_user(struct vhost_virtqueue *vq, void *to, | |
715 | const void *from, unsigned size) | |
716 | { | |
6b1e6cc7 | 717 | int ret; |
bfe2bc51 | 718 | |
6b1e6cc7 JW |
719 | if (!vq->iotlb) |
720 | return __copy_to_user(to, from, size); | |
721 | else { | |
722 | /* This function should be called after iotlb | |
723 | * prefetch, which means we're sure that all vq | |
724 | * could be access through iotlb. So -EAGAIN should | |
725 | * not happen in this case. | |
726 | */ | |
727 | /* TODO: more fast path */ | |
728 | struct iov_iter t; | |
729 | ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, | |
730 | ARRAY_SIZE(vq->iotlb_iov), | |
731 | VHOST_ACCESS_WO); | |
732 | if (ret < 0) | |
733 | goto out; | |
734 | iov_iter_init(&t, WRITE, vq->iotlb_iov, ret, size); | |
735 | ret = copy_to_iter(from, size, &t); | |
736 | if (ret == size) | |
737 | ret = 0; | |
738 | } | |
739 | out: | |
740 | return ret; | |
741 | } | |
bfe2bc51 JW |
742 | |
743 | static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, | |
744 | void *from, unsigned size) | |
745 | { | |
6b1e6cc7 JW |
746 | int ret; |
747 | ||
748 | if (!vq->iotlb) | |
749 | return __copy_from_user(to, from, size); | |
750 | else { | |
751 | /* This function should be called after iotlb | |
752 | * prefetch, which means we're sure that vq | |
753 | * could be access through iotlb. So -EAGAIN should | |
754 | * not happen in this case. | |
755 | */ | |
756 | /* TODO: more fast path */ | |
757 | struct iov_iter f; | |
758 | ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, | |
759 | ARRAY_SIZE(vq->iotlb_iov), | |
760 | VHOST_ACCESS_RO); | |
761 | if (ret < 0) { | |
762 | vq_err(vq, "IOTLB translation failure: uaddr " | |
763 | "%p size 0x%llx\n", from, | |
764 | (unsigned long long) size); | |
765 | goto out; | |
766 | } | |
767 | iov_iter_init(&f, READ, vq->iotlb_iov, ret, size); | |
768 | ret = copy_from_iter(to, size, &f); | |
769 | if (ret == size) | |
770 | ret = 0; | |
771 | } | |
772 | ||
773 | out: | |
774 | return ret; | |
775 | } | |
776 | ||
777 | static void __user *__vhost_get_user(struct vhost_virtqueue *vq, | |
778 | void *addr, unsigned size) | |
779 | { | |
780 | int ret; | |
781 | ||
782 | /* This function should be called after iotlb | |
783 | * prefetch, which means we're sure that vq | |
784 | * could be access through iotlb. So -EAGAIN should | |
785 | * not happen in this case. | |
786 | */ | |
787 | /* TODO: more fast path */ | |
788 | ret = translate_desc(vq, (u64)(uintptr_t)addr, size, vq->iotlb_iov, | |
789 | ARRAY_SIZE(vq->iotlb_iov), | |
790 | VHOST_ACCESS_RO); | |
791 | if (ret < 0) { | |
792 | vq_err(vq, "IOTLB translation failure: uaddr " | |
793 | "%p size 0x%llx\n", addr, | |
794 | (unsigned long long) size); | |
795 | return NULL; | |
796 | } | |
797 | ||
798 | if (ret != 1 || vq->iotlb_iov[0].iov_len != size) { | |
799 | vq_err(vq, "Non atomic userspace memory access: uaddr " | |
800 | "%p size 0x%llx\n", addr, | |
801 | (unsigned long long) size); | |
802 | return NULL; | |
803 | } | |
804 | ||
805 | return vq->iotlb_iov[0].iov_base; | |
806 | } | |
807 | ||
808 | #define vhost_put_user(vq, x, ptr) \ | |
809 | ({ \ | |
810 | int ret = -EFAULT; \ | |
811 | if (!vq->iotlb) { \ | |
812 | ret = __put_user(x, ptr); \ | |
813 | } else { \ | |
814 | __typeof__(ptr) to = \ | |
815 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, sizeof(*ptr)); \ | |
816 | if (to != NULL) \ | |
817 | ret = __put_user(x, to); \ | |
818 | else \ | |
819 | ret = -EFAULT; \ | |
820 | } \ | |
821 | ret; \ | |
822 | }) | |
823 | ||
824 | #define vhost_get_user(vq, x, ptr) \ | |
825 | ({ \ | |
826 | int ret; \ | |
827 | if (!vq->iotlb) { \ | |
828 | ret = __get_user(x, ptr); \ | |
829 | } else { \ | |
830 | __typeof__(ptr) from = \ | |
831 | (__typeof__(ptr)) __vhost_get_user(vq, ptr, sizeof(*ptr)); \ | |
832 | if (from != NULL) \ | |
833 | ret = __get_user(x, from); \ | |
834 | else \ | |
835 | ret = -EFAULT; \ | |
836 | } \ | |
837 | ret; \ | |
838 | }) | |
839 | ||
840 | static void vhost_dev_lock_vqs(struct vhost_dev *d) | |
841 | { | |
842 | int i = 0; | |
843 | for (i = 0; i < d->nvqs; ++i) | |
844 | mutex_lock(&d->vqs[i]->mutex); | |
845 | } | |
846 | ||
847 | static void vhost_dev_unlock_vqs(struct vhost_dev *d) | |
848 | { | |
849 | int i = 0; | |
850 | for (i = 0; i < d->nvqs; ++i) | |
851 | mutex_unlock(&d->vqs[i]->mutex); | |
852 | } | |
853 | ||
854 | static int vhost_new_umem_range(struct vhost_umem *umem, | |
855 | u64 start, u64 size, u64 end, | |
856 | u64 userspace_addr, int perm) | |
857 | { | |
858 | struct vhost_umem_node *tmp, *node = kmalloc(sizeof(*node), GFP_ATOMIC); | |
859 | ||
860 | if (!node) | |
861 | return -ENOMEM; | |
862 | ||
863 | if (umem->numem == max_iotlb_entries) { | |
864 | tmp = list_first_entry(&umem->umem_list, typeof(*tmp), link); | |
865 | vhost_umem_free(umem, tmp); | |
866 | } | |
867 | ||
868 | node->start = start; | |
869 | node->size = size; | |
870 | node->last = end; | |
871 | node->userspace_addr = userspace_addr; | |
872 | node->perm = perm; | |
873 | INIT_LIST_HEAD(&node->link); | |
874 | list_add_tail(&node->link, &umem->umem_list); | |
875 | vhost_umem_interval_tree_insert(node, &umem->umem_tree); | |
876 | umem->numem++; | |
877 | ||
878 | return 0; | |
879 | } | |
880 | ||
881 | static void vhost_del_umem_range(struct vhost_umem *umem, | |
882 | u64 start, u64 end) | |
883 | { | |
884 | struct vhost_umem_node *node; | |
885 | ||
886 | while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
887 | start, end))) | |
888 | vhost_umem_free(umem, node); | |
889 | } | |
890 | ||
891 | static void vhost_iotlb_notify_vq(struct vhost_dev *d, | |
892 | struct vhost_iotlb_msg *msg) | |
893 | { | |
894 | struct vhost_msg_node *node, *n; | |
895 | ||
896 | spin_lock(&d->iotlb_lock); | |
897 | ||
898 | list_for_each_entry_safe(node, n, &d->pending_list, node) { | |
899 | struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb; | |
900 | if (msg->iova <= vq_msg->iova && | |
901 | msg->iova + msg->size - 1 > vq_msg->iova && | |
902 | vq_msg->type == VHOST_IOTLB_MISS) { | |
903 | vhost_poll_queue(&node->vq->poll); | |
904 | list_del(&node->node); | |
905 | kfree(node); | |
906 | } | |
907 | } | |
908 | ||
909 | spin_unlock(&d->iotlb_lock); | |
910 | } | |
911 | ||
912 | static int umem_access_ok(u64 uaddr, u64 size, int access) | |
913 | { | |
914 | unsigned long a = uaddr; | |
915 | ||
916 | if ((access & VHOST_ACCESS_RO) && | |
917 | !access_ok(VERIFY_READ, (void __user *)a, size)) | |
918 | return -EFAULT; | |
919 | if ((access & VHOST_ACCESS_WO) && | |
920 | !access_ok(VERIFY_WRITE, (void __user *)a, size)) | |
921 | return -EFAULT; | |
922 | return 0; | |
923 | } | |
924 | ||
925 | int vhost_process_iotlb_msg(struct vhost_dev *dev, | |
926 | struct vhost_iotlb_msg *msg) | |
927 | { | |
928 | int ret = 0; | |
929 | ||
930 | vhost_dev_lock_vqs(dev); | |
931 | switch (msg->type) { | |
932 | case VHOST_IOTLB_UPDATE: | |
933 | if (!dev->iotlb) { | |
934 | ret = -EFAULT; | |
935 | break; | |
936 | } | |
937 | if (umem_access_ok(msg->uaddr, msg->size, msg->perm)) { | |
938 | ret = -EFAULT; | |
939 | break; | |
940 | } | |
941 | if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size, | |
942 | msg->iova + msg->size - 1, | |
943 | msg->uaddr, msg->perm)) { | |
944 | ret = -ENOMEM; | |
945 | break; | |
946 | } | |
947 | vhost_iotlb_notify_vq(dev, msg); | |
948 | break; | |
949 | case VHOST_IOTLB_INVALIDATE: | |
950 | vhost_del_umem_range(dev->iotlb, msg->iova, | |
951 | msg->iova + msg->size - 1); | |
952 | break; | |
953 | default: | |
954 | ret = -EINVAL; | |
955 | break; | |
956 | } | |
957 | ||
958 | vhost_dev_unlock_vqs(dev); | |
959 | return ret; | |
960 | } | |
961 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, | |
962 | struct iov_iter *from) | |
963 | { | |
964 | struct vhost_msg_node node; | |
965 | unsigned size = sizeof(struct vhost_msg); | |
966 | size_t ret; | |
967 | int err; | |
968 | ||
969 | if (iov_iter_count(from) < size) | |
970 | return 0; | |
971 | ret = copy_from_iter(&node.msg, size, from); | |
972 | if (ret != size) | |
973 | goto done; | |
974 | ||
975 | switch (node.msg.type) { | |
976 | case VHOST_IOTLB_MSG: | |
977 | err = vhost_process_iotlb_msg(dev, &node.msg.iotlb); | |
978 | if (err) | |
979 | ret = err; | |
980 | break; | |
981 | default: | |
982 | ret = -EINVAL; | |
983 | break; | |
984 | } | |
985 | ||
986 | done: | |
987 | return ret; | |
988 | } | |
989 | EXPORT_SYMBOL(vhost_chr_write_iter); | |
990 | ||
991 | unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev, | |
992 | poll_table *wait) | |
993 | { | |
994 | unsigned int mask = 0; | |
995 | ||
996 | poll_wait(file, &dev->wait, wait); | |
997 | ||
998 | if (!list_empty(&dev->read_list)) | |
999 | mask |= POLLIN | POLLRDNORM; | |
1000 | ||
1001 | return mask; | |
1002 | } | |
1003 | EXPORT_SYMBOL(vhost_chr_poll); | |
1004 | ||
1005 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, | |
1006 | int noblock) | |
1007 | { | |
1008 | DEFINE_WAIT(wait); | |
1009 | struct vhost_msg_node *node; | |
1010 | ssize_t ret = 0; | |
1011 | unsigned size = sizeof(struct vhost_msg); | |
1012 | ||
1013 | if (iov_iter_count(to) < size) | |
1014 | return 0; | |
1015 | ||
1016 | while (1) { | |
1017 | if (!noblock) | |
1018 | prepare_to_wait(&dev->wait, &wait, | |
1019 | TASK_INTERRUPTIBLE); | |
1020 | ||
1021 | node = vhost_dequeue_msg(dev, &dev->read_list); | |
1022 | if (node) | |
1023 | break; | |
1024 | if (noblock) { | |
1025 | ret = -EAGAIN; | |
1026 | break; | |
1027 | } | |
1028 | if (signal_pending(current)) { | |
1029 | ret = -ERESTARTSYS; | |
1030 | break; | |
1031 | } | |
1032 | if (!dev->iotlb) { | |
1033 | ret = -EBADFD; | |
1034 | break; | |
1035 | } | |
1036 | ||
1037 | schedule(); | |
1038 | } | |
1039 | ||
1040 | if (!noblock) | |
1041 | finish_wait(&dev->wait, &wait); | |
1042 | ||
1043 | if (node) { | |
1044 | ret = copy_to_iter(&node->msg, size, to); | |
1045 | ||
1046 | if (ret != size || node->msg.type != VHOST_IOTLB_MISS) { | |
1047 | kfree(node); | |
1048 | return ret; | |
1049 | } | |
1050 | ||
1051 | vhost_enqueue_msg(dev, &dev->pending_list, node); | |
1052 | } | |
1053 | ||
1054 | return ret; | |
1055 | } | |
1056 | EXPORT_SYMBOL_GPL(vhost_chr_read_iter); | |
1057 | ||
1058 | static int vhost_iotlb_miss(struct vhost_virtqueue *vq, u64 iova, int access) | |
1059 | { | |
1060 | struct vhost_dev *dev = vq->dev; | |
1061 | struct vhost_msg_node *node; | |
1062 | struct vhost_iotlb_msg *msg; | |
1063 | ||
1064 | node = vhost_new_msg(vq, VHOST_IOTLB_MISS); | |
1065 | if (!node) | |
1066 | return -ENOMEM; | |
1067 | ||
1068 | msg = &node->msg.iotlb; | |
1069 | msg->type = VHOST_IOTLB_MISS; | |
1070 | msg->iova = iova; | |
1071 | msg->perm = access; | |
1072 | ||
1073 | vhost_enqueue_msg(dev, &dev->read_list, node); | |
1074 | ||
1075 | return 0; | |
bfe2bc51 JW |
1076 | } |
1077 | ||
ea16c514 | 1078 | static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
3a4d5c94 MT |
1079 | struct vring_desc __user *desc, |
1080 | struct vring_avail __user *avail, | |
1081 | struct vring_used __user *used) | |
6b1e6cc7 | 1082 | |
3a4d5c94 | 1083 | { |
ea16c514 | 1084 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
6b1e6cc7 | 1085 | |
3a4d5c94 MT |
1086 | return access_ok(VERIFY_READ, desc, num * sizeof *desc) && |
1087 | access_ok(VERIFY_READ, avail, | |
8ea8cf89 | 1088 | sizeof *avail + num * sizeof *avail->ring + s) && |
3a4d5c94 | 1089 | access_ok(VERIFY_WRITE, used, |
8ea8cf89 | 1090 | sizeof *used + num * sizeof *used->ring + s); |
3a4d5c94 MT |
1091 | } |
1092 | ||
6b1e6cc7 JW |
1093 | static int iotlb_access_ok(struct vhost_virtqueue *vq, |
1094 | int access, u64 addr, u64 len) | |
1095 | { | |
1096 | const struct vhost_umem_node *node; | |
1097 | struct vhost_umem *umem = vq->iotlb; | |
1098 | u64 s = 0, size; | |
1099 | ||
1100 | while (len > s) { | |
1101 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, | |
1102 | addr, | |
1103 | addr + len - 1); | |
1104 | if (node == NULL || node->start > addr) { | |
1105 | vhost_iotlb_miss(vq, addr, access); | |
1106 | return false; | |
1107 | } else if (!(node->perm & access)) { | |
1108 | /* Report the possible access violation by | |
1109 | * request another translation from userspace. | |
1110 | */ | |
1111 | return false; | |
1112 | } | |
1113 | ||
1114 | size = node->size - addr + node->start; | |
1115 | s += size; | |
1116 | addr += size; | |
1117 | } | |
1118 | ||
1119 | return true; | |
1120 | } | |
1121 | ||
1122 | int vq_iotlb_prefetch(struct vhost_virtqueue *vq) | |
1123 | { | |
1124 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; | |
1125 | unsigned int num = vq->num; | |
1126 | ||
1127 | if (!vq->iotlb) | |
1128 | return 1; | |
1129 | ||
1130 | return iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->desc, | |
1131 | num * sizeof *vq->desc) && | |
1132 | iotlb_access_ok(vq, VHOST_ACCESS_RO, (u64)(uintptr_t)vq->avail, | |
1133 | sizeof *vq->avail + | |
1134 | num * sizeof *vq->avail->ring + s) && | |
1135 | iotlb_access_ok(vq, VHOST_ACCESS_WO, (u64)(uintptr_t)vq->used, | |
1136 | sizeof *vq->used + | |
1137 | num * sizeof *vq->used->ring + s); | |
1138 | } | |
1139 | EXPORT_SYMBOL_GPL(vq_iotlb_prefetch); | |
1140 | ||
3a4d5c94 MT |
1141 | /* Can we log writes? */ |
1142 | /* Caller should have device mutex but not vq mutex */ | |
1143 | int vhost_log_access_ok(struct vhost_dev *dev) | |
1144 | { | |
a9709d68 | 1145 | return memory_access_ok(dev, dev->umem, 1); |
3a4d5c94 | 1146 | } |
6ac1afbf | 1147 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 MT |
1148 | |
1149 | /* Verify access for write logging. */ | |
1150 | /* Caller should have vq mutex and device mutex */ | |
ea16c514 | 1151 | static int vq_log_access_ok(struct vhost_virtqueue *vq, |
8ea8cf89 | 1152 | void __user *log_base) |
3a4d5c94 | 1153 | { |
ea16c514 | 1154 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
28457ee6 | 1155 | |
a9709d68 | 1156 | return vq_memory_access_ok(log_base, vq->umem, |
ea16c514 | 1157 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
3a4d5c94 MT |
1158 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
1159 | sizeof *vq->used + | |
8ea8cf89 | 1160 | vq->num * sizeof *vq->used->ring + s)); |
3a4d5c94 MT |
1161 | } |
1162 | ||
1163 | /* Can we start vq? */ | |
1164 | /* Caller should have vq mutex and device mutex */ | |
1165 | int vhost_vq_access_ok(struct vhost_virtqueue *vq) | |
1166 | { | |
6b1e6cc7 JW |
1167 | if (vq->iotlb) { |
1168 | /* When device IOTLB was used, the access validation | |
1169 | * will be validated during prefetching. | |
1170 | */ | |
1171 | return 1; | |
1172 | } | |
ea16c514 MT |
1173 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) && |
1174 | vq_log_access_ok(vq, vq->log_base); | |
3a4d5c94 | 1175 | } |
6ac1afbf | 1176 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 | 1177 | |
6b1e6cc7 JW |
1178 | static struct vhost_umem *vhost_umem_alloc(void) |
1179 | { | |
1180 | struct vhost_umem *umem = vhost_kvzalloc(sizeof(*umem)); | |
1181 | ||
1182 | if (!umem) | |
1183 | return NULL; | |
1184 | ||
1185 | umem->umem_tree = RB_ROOT; | |
1186 | umem->numem = 0; | |
1187 | INIT_LIST_HEAD(&umem->umem_list); | |
1188 | ||
1189 | return umem; | |
1190 | } | |
1191 | ||
3a4d5c94 MT |
1192 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
1193 | { | |
a9709d68 JW |
1194 | struct vhost_memory mem, *newmem; |
1195 | struct vhost_memory_region *region; | |
a9709d68 | 1196 | struct vhost_umem *newumem, *oldumem; |
3a4d5c94 | 1197 | unsigned long size = offsetof(struct vhost_memory, regions); |
98f9ca0a | 1198 | int i; |
d47effe1 | 1199 | |
7ad9c9d2 TY |
1200 | if (copy_from_user(&mem, m, size)) |
1201 | return -EFAULT; | |
3a4d5c94 MT |
1202 | if (mem.padding) |
1203 | return -EOPNOTSUPP; | |
c9ce42f7 | 1204 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 1205 | return -E2BIG; |
4de7255f | 1206 | newmem = vhost_kvzalloc(size + mem.nregions * sizeof(*m->regions)); |
3a4d5c94 MT |
1207 | if (!newmem) |
1208 | return -ENOMEM; | |
1209 | ||
1210 | memcpy(newmem, &mem, size); | |
7ad9c9d2 TY |
1211 | if (copy_from_user(newmem->regions, m->regions, |
1212 | mem.nregions * sizeof *m->regions)) { | |
bcfeacab | 1213 | kvfree(newmem); |
7ad9c9d2 | 1214 | return -EFAULT; |
3a4d5c94 MT |
1215 | } |
1216 | ||
6b1e6cc7 | 1217 | newumem = vhost_umem_alloc(); |
a9709d68 | 1218 | if (!newumem) { |
4de7255f | 1219 | kvfree(newmem); |
a9709d68 JW |
1220 | return -ENOMEM; |
1221 | } | |
1222 | ||
a9709d68 JW |
1223 | for (region = newmem->regions; |
1224 | region < newmem->regions + mem.nregions; | |
1225 | region++) { | |
6b1e6cc7 JW |
1226 | if (vhost_new_umem_range(newumem, |
1227 | region->guest_phys_addr, | |
1228 | region->memory_size, | |
1229 | region->guest_phys_addr + | |
1230 | region->memory_size - 1, | |
1231 | region->userspace_addr, | |
1232 | VHOST_ACCESS_RW)) | |
a9709d68 | 1233 | goto err; |
a02c3789 | 1234 | } |
a9709d68 JW |
1235 | |
1236 | if (!memory_access_ok(d, newumem, 0)) | |
1237 | goto err; | |
1238 | ||
1239 | oldumem = d->umem; | |
1240 | d->umem = newumem; | |
98f9ca0a | 1241 | |
47283bef | 1242 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
1243 | for (i = 0; i < d->nvqs; ++i) { |
1244 | mutex_lock(&d->vqs[i]->mutex); | |
a9709d68 | 1245 | d->vqs[i]->umem = newumem; |
98f9ca0a MT |
1246 | mutex_unlock(&d->vqs[i]->mutex); |
1247 | } | |
a9709d68 JW |
1248 | |
1249 | kvfree(newmem); | |
1250 | vhost_umem_clean(oldumem); | |
3a4d5c94 | 1251 | return 0; |
a9709d68 JW |
1252 | |
1253 | err: | |
1254 | vhost_umem_clean(newumem); | |
1255 | kvfree(newmem); | |
1256 | return -EFAULT; | |
3a4d5c94 MT |
1257 | } |
1258 | ||
935cdee7 | 1259 | long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) |
3a4d5c94 | 1260 | { |
cecb46f1 AV |
1261 | struct file *eventfp, *filep = NULL; |
1262 | bool pollstart = false, pollstop = false; | |
3a4d5c94 MT |
1263 | struct eventfd_ctx *ctx = NULL; |
1264 | u32 __user *idxp = argp; | |
1265 | struct vhost_virtqueue *vq; | |
1266 | struct vhost_vring_state s; | |
1267 | struct vhost_vring_file f; | |
1268 | struct vhost_vring_addr a; | |
1269 | u32 idx; | |
1270 | long r; | |
1271 | ||
1272 | r = get_user(idx, idxp); | |
1273 | if (r < 0) | |
1274 | return r; | |
0f3d9a17 | 1275 | if (idx >= d->nvqs) |
3a4d5c94 MT |
1276 | return -ENOBUFS; |
1277 | ||
3ab2e420 | 1278 | vq = d->vqs[idx]; |
3a4d5c94 MT |
1279 | |
1280 | mutex_lock(&vq->mutex); | |
1281 | ||
1282 | switch (ioctl) { | |
1283 | case VHOST_SET_VRING_NUM: | |
1284 | /* Resizing ring with an active backend? | |
1285 | * You don't want to do that. */ | |
1286 | if (vq->private_data) { | |
1287 | r = -EBUSY; | |
1288 | break; | |
1289 | } | |
7ad9c9d2 TY |
1290 | if (copy_from_user(&s, argp, sizeof s)) { |
1291 | r = -EFAULT; | |
3a4d5c94 | 1292 | break; |
7ad9c9d2 | 1293 | } |
3a4d5c94 MT |
1294 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) { |
1295 | r = -EINVAL; | |
1296 | break; | |
1297 | } | |
1298 | vq->num = s.num; | |
1299 | break; | |
1300 | case VHOST_SET_VRING_BASE: | |
1301 | /* Moving base with an active backend? | |
1302 | * You don't want to do that. */ | |
1303 | if (vq->private_data) { | |
1304 | r = -EBUSY; | |
1305 | break; | |
1306 | } | |
7ad9c9d2 TY |
1307 | if (copy_from_user(&s, argp, sizeof s)) { |
1308 | r = -EFAULT; | |
3a4d5c94 | 1309 | break; |
7ad9c9d2 | 1310 | } |
3a4d5c94 MT |
1311 | if (s.num > 0xffff) { |
1312 | r = -EINVAL; | |
1313 | break; | |
1314 | } | |
1315 | vq->last_avail_idx = s.num; | |
1316 | /* Forget the cached index value. */ | |
1317 | vq->avail_idx = vq->last_avail_idx; | |
1318 | break; | |
1319 | case VHOST_GET_VRING_BASE: | |
1320 | s.index = idx; | |
1321 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
1322 | if (copy_to_user(argp, &s, sizeof s)) |
1323 | r = -EFAULT; | |
3a4d5c94 MT |
1324 | break; |
1325 | case VHOST_SET_VRING_ADDR: | |
7ad9c9d2 TY |
1326 | if (copy_from_user(&a, argp, sizeof a)) { |
1327 | r = -EFAULT; | |
3a4d5c94 | 1328 | break; |
7ad9c9d2 | 1329 | } |
3a4d5c94 MT |
1330 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) { |
1331 | r = -EOPNOTSUPP; | |
1332 | break; | |
1333 | } | |
1334 | /* For 32bit, verify that the top 32bits of the user | |
1335 | data are set to zero. */ | |
1336 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
1337 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
1338 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { | |
1339 | r = -EFAULT; | |
1340 | break; | |
1341 | } | |
5d9a07b0 MT |
1342 | |
1343 | /* Make sure it's safe to cast pointers to vring types. */ | |
1344 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
1345 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
1346 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
1347 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
d5424838 | 1348 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) { |
3a4d5c94 MT |
1349 | r = -EINVAL; |
1350 | break; | |
1351 | } | |
1352 | ||
1353 | /* We only verify access here if backend is configured. | |
1354 | * If it is not, we don't as size might not have been setup. | |
1355 | * We will verify when backend is configured. */ | |
1356 | if (vq->private_data) { | |
ea16c514 | 1357 | if (!vq_access_ok(vq, vq->num, |
3a4d5c94 MT |
1358 | (void __user *)(unsigned long)a.desc_user_addr, |
1359 | (void __user *)(unsigned long)a.avail_user_addr, | |
1360 | (void __user *)(unsigned long)a.used_user_addr)) { | |
1361 | r = -EINVAL; | |
1362 | break; | |
1363 | } | |
1364 | ||
1365 | /* Also validate log access for used ring if enabled. */ | |
1366 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && | |
1367 | !log_access_ok(vq->log_base, a.log_guest_addr, | |
1368 | sizeof *vq->used + | |
1369 | vq->num * sizeof *vq->used->ring)) { | |
1370 | r = -EINVAL; | |
1371 | break; | |
1372 | } | |
1373 | } | |
1374 | ||
3a4d5c94 MT |
1375 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); |
1376 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
1377 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
1378 | vq->log_addr = a.log_guest_addr; | |
1379 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
1380 | break; | |
1381 | case VHOST_SET_VRING_KICK: | |
7ad9c9d2 TY |
1382 | if (copy_from_user(&f, argp, sizeof f)) { |
1383 | r = -EFAULT; | |
3a4d5c94 | 1384 | break; |
7ad9c9d2 | 1385 | } |
3a4d5c94 | 1386 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1387 | if (IS_ERR(eventfp)) { |
1388 | r = PTR_ERR(eventfp); | |
1389 | break; | |
1390 | } | |
3a4d5c94 | 1391 | if (eventfp != vq->kick) { |
cecb46f1 AV |
1392 | pollstop = (filep = vq->kick) != NULL; |
1393 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
1394 | } else |
1395 | filep = eventfp; | |
1396 | break; | |
1397 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
1398 | if (copy_from_user(&f, argp, sizeof f)) { |
1399 | r = -EFAULT; | |
3a4d5c94 | 1400 | break; |
7ad9c9d2 | 1401 | } |
3a4d5c94 | 1402 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1403 | if (IS_ERR(eventfp)) { |
1404 | r = PTR_ERR(eventfp); | |
1405 | break; | |
1406 | } | |
3a4d5c94 MT |
1407 | if (eventfp != vq->call) { |
1408 | filep = vq->call; | |
1409 | ctx = vq->call_ctx; | |
1410 | vq->call = eventfp; | |
1411 | vq->call_ctx = eventfp ? | |
1412 | eventfd_ctx_fileget(eventfp) : NULL; | |
1413 | } else | |
1414 | filep = eventfp; | |
1415 | break; | |
1416 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
1417 | if (copy_from_user(&f, argp, sizeof f)) { |
1418 | r = -EFAULT; | |
3a4d5c94 | 1419 | break; |
7ad9c9d2 | 1420 | } |
3a4d5c94 | 1421 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
1422 | if (IS_ERR(eventfp)) { |
1423 | r = PTR_ERR(eventfp); | |
1424 | break; | |
1425 | } | |
3a4d5c94 MT |
1426 | if (eventfp != vq->error) { |
1427 | filep = vq->error; | |
1428 | vq->error = eventfp; | |
1429 | ctx = vq->error_ctx; | |
1430 | vq->error_ctx = eventfp ? | |
1431 | eventfd_ctx_fileget(eventfp) : NULL; | |
1432 | } else | |
1433 | filep = eventfp; | |
1434 | break; | |
2751c988 GK |
1435 | case VHOST_SET_VRING_ENDIAN: |
1436 | r = vhost_set_vring_endian(vq, argp); | |
1437 | break; | |
1438 | case VHOST_GET_VRING_ENDIAN: | |
1439 | r = vhost_get_vring_endian(vq, idx, argp); | |
1440 | break; | |
03088137 JW |
1441 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
1442 | if (copy_from_user(&s, argp, sizeof(s))) { | |
1443 | r = -EFAULT; | |
1444 | break; | |
1445 | } | |
1446 | vq->busyloop_timeout = s.num; | |
1447 | break; | |
1448 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
1449 | s.index = idx; | |
1450 | s.num = vq->busyloop_timeout; | |
1451 | if (copy_to_user(argp, &s, sizeof(s))) | |
1452 | r = -EFAULT; | |
1453 | break; | |
3a4d5c94 MT |
1454 | default: |
1455 | r = -ENOIOCTLCMD; | |
1456 | } | |
1457 | ||
1458 | if (pollstop && vq->handle_kick) | |
1459 | vhost_poll_stop(&vq->poll); | |
1460 | ||
1461 | if (ctx) | |
1462 | eventfd_ctx_put(ctx); | |
1463 | if (filep) | |
1464 | fput(filep); | |
1465 | ||
1466 | if (pollstart && vq->handle_kick) | |
2b8b328b | 1467 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
1468 | |
1469 | mutex_unlock(&vq->mutex); | |
1470 | ||
1471 | if (pollstop && vq->handle_kick) | |
1472 | vhost_poll_flush(&vq->poll); | |
1473 | return r; | |
1474 | } | |
6ac1afbf | 1475 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 | 1476 | |
6b1e6cc7 JW |
1477 | int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled) |
1478 | { | |
1479 | struct vhost_umem *niotlb, *oiotlb; | |
1480 | int i; | |
1481 | ||
1482 | niotlb = vhost_umem_alloc(); | |
1483 | if (!niotlb) | |
1484 | return -ENOMEM; | |
1485 | ||
1486 | oiotlb = d->iotlb; | |
1487 | d->iotlb = niotlb; | |
1488 | ||
1489 | for (i = 0; i < d->nvqs; ++i) { | |
1490 | mutex_lock(&d->vqs[i]->mutex); | |
1491 | d->vqs[i]->iotlb = niotlb; | |
1492 | mutex_unlock(&d->vqs[i]->mutex); | |
1493 | } | |
1494 | ||
1495 | vhost_umem_clean(oiotlb); | |
1496 | ||
1497 | return 0; | |
1498 | } | |
1499 | EXPORT_SYMBOL_GPL(vhost_init_device_iotlb); | |
1500 | ||
3a4d5c94 | 1501 | /* Caller must have device mutex */ |
935cdee7 | 1502 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 1503 | { |
3a4d5c94 MT |
1504 | struct file *eventfp, *filep = NULL; |
1505 | struct eventfd_ctx *ctx = NULL; | |
1506 | u64 p; | |
1507 | long r; | |
1508 | int i, fd; | |
1509 | ||
1510 | /* If you are not the owner, you can become one */ | |
1511 | if (ioctl == VHOST_SET_OWNER) { | |
1512 | r = vhost_dev_set_owner(d); | |
1513 | goto done; | |
1514 | } | |
1515 | ||
1516 | /* You must be the owner to do anything else */ | |
1517 | r = vhost_dev_check_owner(d); | |
1518 | if (r) | |
1519 | goto done; | |
1520 | ||
1521 | switch (ioctl) { | |
1522 | case VHOST_SET_MEM_TABLE: | |
1523 | r = vhost_set_memory(d, argp); | |
1524 | break; | |
1525 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
1526 | if (copy_from_user(&p, argp, sizeof p)) { |
1527 | r = -EFAULT; | |
3a4d5c94 | 1528 | break; |
7ad9c9d2 | 1529 | } |
3a4d5c94 MT |
1530 | if ((u64)(unsigned long)p != p) { |
1531 | r = -EFAULT; | |
1532 | break; | |
1533 | } | |
1534 | for (i = 0; i < d->nvqs; ++i) { | |
1535 | struct vhost_virtqueue *vq; | |
1536 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 1537 | vq = d->vqs[i]; |
3a4d5c94 MT |
1538 | mutex_lock(&vq->mutex); |
1539 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 1540 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
1541 | r = -EFAULT; |
1542 | else | |
1543 | vq->log_base = base; | |
1544 | mutex_unlock(&vq->mutex); | |
1545 | } | |
1546 | break; | |
1547 | case VHOST_SET_LOG_FD: | |
1548 | r = get_user(fd, (int __user *)argp); | |
1549 | if (r < 0) | |
1550 | break; | |
1551 | eventfp = fd == -1 ? NULL : eventfd_fget(fd); | |
1552 | if (IS_ERR(eventfp)) { | |
1553 | r = PTR_ERR(eventfp); | |
1554 | break; | |
1555 | } | |
1556 | if (eventfp != d->log_file) { | |
1557 | filep = d->log_file; | |
7932c0bd | 1558 | d->log_file = eventfp; |
3a4d5c94 MT |
1559 | ctx = d->log_ctx; |
1560 | d->log_ctx = eventfp ? | |
1561 | eventfd_ctx_fileget(eventfp) : NULL; | |
1562 | } else | |
1563 | filep = eventfp; | |
1564 | for (i = 0; i < d->nvqs; ++i) { | |
3ab2e420 AH |
1565 | mutex_lock(&d->vqs[i]->mutex); |
1566 | d->vqs[i]->log_ctx = d->log_ctx; | |
1567 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
1568 | } |
1569 | if (ctx) | |
1570 | eventfd_ctx_put(ctx); | |
1571 | if (filep) | |
1572 | fput(filep); | |
1573 | break; | |
1574 | default: | |
935cdee7 | 1575 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
1576 | break; |
1577 | } | |
1578 | done: | |
1579 | return r; | |
1580 | } | |
6ac1afbf | 1581 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 | 1582 | |
3a4d5c94 MT |
1583 | /* TODO: This is really inefficient. We need something like get_user() |
1584 | * (instruction directly accesses the data, with an exception table entry | |
1585 | * returning -EFAULT). See Documentation/x86/exception-tables.txt. | |
1586 | */ | |
1587 | static int set_bit_to_user(int nr, void __user *addr) | |
1588 | { | |
1589 | unsigned long log = (unsigned long)addr; | |
1590 | struct page *page; | |
1591 | void *base; | |
1592 | int bit = nr + (log % PAGE_SIZE) * 8; | |
1593 | int r; | |
d47effe1 | 1594 | |
3a4d5c94 | 1595 | r = get_user_pages_fast(log, 1, 1, &page); |
d6db3f5c | 1596 | if (r < 0) |
3a4d5c94 | 1597 | return r; |
d6db3f5c | 1598 | BUG_ON(r != 1); |
c6daa7ff | 1599 | base = kmap_atomic(page); |
3a4d5c94 | 1600 | set_bit(bit, base); |
c6daa7ff | 1601 | kunmap_atomic(base); |
3a4d5c94 MT |
1602 | set_page_dirty_lock(page); |
1603 | put_page(page); | |
1604 | return 0; | |
1605 | } | |
1606 | ||
1607 | static int log_write(void __user *log_base, | |
1608 | u64 write_address, u64 write_length) | |
1609 | { | |
28831ee6 | 1610 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 1611 | int r; |
d47effe1 | 1612 | |
3a4d5c94 MT |
1613 | if (!write_length) |
1614 | return 0; | |
3bf9be40 | 1615 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
1616 | for (;;) { |
1617 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
1618 | u64 log = base + write_page / 8; |
1619 | int bit = write_page % 8; | |
3a4d5c94 MT |
1620 | if ((u64)(unsigned long)log != log) |
1621 | return -EFAULT; | |
1622 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
1623 | if (r < 0) | |
1624 | return r; | |
1625 | if (write_length <= VHOST_PAGE_SIZE) | |
1626 | break; | |
1627 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 1628 | write_page += 1; |
3a4d5c94 MT |
1629 | } |
1630 | return r; | |
1631 | } | |
1632 | ||
1633 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
1634 | unsigned int log_num, u64 len) | |
1635 | { | |
1636 | int i, r; | |
1637 | ||
1638 | /* Make sure data written is seen before log. */ | |
5659338c | 1639 | smp_wmb(); |
3a4d5c94 MT |
1640 | for (i = 0; i < log_num; ++i) { |
1641 | u64 l = min(log[i].len, len); | |
1642 | r = log_write(vq->log_base, log[i].addr, l); | |
1643 | if (r < 0) | |
1644 | return r; | |
1645 | len -= l; | |
5786aee8 MT |
1646 | if (!len) { |
1647 | if (vq->log_ctx) | |
1648 | eventfd_signal(vq->log_ctx, 1); | |
3a4d5c94 | 1649 | return 0; |
5786aee8 | 1650 | } |
3a4d5c94 | 1651 | } |
3a4d5c94 MT |
1652 | /* Length written exceeds what we have stored. This is a bug. */ |
1653 | BUG(); | |
1654 | return 0; | |
1655 | } | |
6ac1afbf | 1656 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 1657 | |
2723feaa JW |
1658 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
1659 | { | |
1660 | void __user *used; | |
bfe2bc51 JW |
1661 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->used_flags), |
1662 | &vq->used->flags) < 0) | |
2723feaa JW |
1663 | return -EFAULT; |
1664 | if (unlikely(vq->log_used)) { | |
1665 | /* Make sure the flag is seen before log. */ | |
1666 | smp_wmb(); | |
1667 | /* Log used flag write. */ | |
1668 | used = &vq->used->flags; | |
1669 | log_write(vq->log_base, vq->log_addr + | |
1670 | (used - (void __user *)vq->used), | |
1671 | sizeof vq->used->flags); | |
1672 | if (vq->log_ctx) | |
1673 | eventfd_signal(vq->log_ctx, 1); | |
1674 | } | |
1675 | return 0; | |
1676 | } | |
1677 | ||
1678 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) | |
1679 | { | |
bfe2bc51 JW |
1680 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->avail_idx), |
1681 | vhost_avail_event(vq))) | |
2723feaa JW |
1682 | return -EFAULT; |
1683 | if (unlikely(vq->log_used)) { | |
1684 | void __user *used; | |
1685 | /* Make sure the event is seen before log. */ | |
1686 | smp_wmb(); | |
1687 | /* Log avail event write */ | |
1688 | used = vhost_avail_event(vq); | |
1689 | log_write(vq->log_base, vq->log_addr + | |
1690 | (used - (void __user *)vq->used), | |
1691 | sizeof *vhost_avail_event(vq)); | |
1692 | if (vq->log_ctx) | |
1693 | eventfd_signal(vq->log_ctx, 1); | |
1694 | } | |
1695 | return 0; | |
1696 | } | |
1697 | ||
80f7d030 | 1698 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 1699 | { |
3b1bbe89 | 1700 | __virtio16 last_used_idx; |
2723feaa | 1701 | int r; |
e1f33be9 GK |
1702 | bool is_le = vq->is_le; |
1703 | ||
2751c988 | 1704 | if (!vq->private_data) { |
c5072037 | 1705 | vhost_reset_is_le(vq); |
2723feaa | 1706 | return 0; |
2751c988 GK |
1707 | } |
1708 | ||
1709 | vhost_init_is_le(vq); | |
2723feaa JW |
1710 | |
1711 | r = vhost_update_used_flags(vq); | |
1712 | if (r) | |
e1f33be9 | 1713 | goto err; |
2723feaa | 1714 | vq->signalled_used_valid = false; |
6b1e6cc7 JW |
1715 | if (!vq->iotlb && |
1716 | !access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) { | |
e1f33be9 GK |
1717 | r = -EFAULT; |
1718 | goto err; | |
1719 | } | |
bfe2bc51 | 1720 | r = vhost_get_user(vq, last_used_idx, &vq->used->idx); |
6b1e6cc7 JW |
1721 | if (r) { |
1722 | vq_err(vq, "Can't access used idx at %p\n", | |
1723 | &vq->used->idx); | |
e1f33be9 | 1724 | goto err; |
6b1e6cc7 | 1725 | } |
3b1bbe89 | 1726 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 1727 | return 0; |
6b1e6cc7 | 1728 | |
e1f33be9 GK |
1729 | err: |
1730 | vq->is_le = is_le; | |
1731 | return r; | |
2723feaa | 1732 | } |
80f7d030 | 1733 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 1734 | |
47283bef | 1735 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
6b1e6cc7 | 1736 | struct iovec iov[], int iov_size, int access) |
3a4d5c94 | 1737 | { |
a9709d68 | 1738 | const struct vhost_umem_node *node; |
6b1e6cc7 JW |
1739 | struct vhost_dev *dev = vq->dev; |
1740 | struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem; | |
3a4d5c94 MT |
1741 | struct iovec *_iov; |
1742 | u64 s = 0; | |
1743 | int ret = 0; | |
1744 | ||
3a4d5c94 MT |
1745 | while ((u64)len > s) { |
1746 | u64 size; | |
7b3384fc | 1747 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
1748 | ret = -ENOBUFS; |
1749 | break; | |
1750 | } | |
6b1e6cc7 | 1751 | |
a9709d68 JW |
1752 | node = vhost_umem_interval_tree_iter_first(&umem->umem_tree, |
1753 | addr, addr + len - 1); | |
1754 | if (node == NULL || node->start > addr) { | |
6b1e6cc7 JW |
1755 | if (umem != dev->iotlb) { |
1756 | ret = -EFAULT; | |
1757 | break; | |
1758 | } | |
1759 | ret = -EAGAIN; | |
1760 | break; | |
1761 | } else if (!(node->perm & access)) { | |
1762 | ret = -EPERM; | |
3a4d5c94 MT |
1763 | break; |
1764 | } | |
6b1e6cc7 | 1765 | |
3a4d5c94 | 1766 | _iov = iov + ret; |
a9709d68 | 1767 | size = node->size - addr + node->start; |
bd97120f | 1768 | _iov->iov_len = min((u64)len - s, size); |
a8d3782f | 1769 | _iov->iov_base = (void __user *)(unsigned long) |
a9709d68 | 1770 | (node->userspace_addr + addr - node->start); |
3a4d5c94 MT |
1771 | s += size; |
1772 | addr += size; | |
1773 | ++ret; | |
1774 | } | |
1775 | ||
6b1e6cc7 JW |
1776 | if (ret == -EAGAIN) |
1777 | vhost_iotlb_miss(vq, addr, access); | |
3a4d5c94 MT |
1778 | return ret; |
1779 | } | |
1780 | ||
1781 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
1782 | * function returns the next descriptor in the chain, | |
1783 | * or -1U if we're at the end. */ | |
3b1bbe89 | 1784 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
1785 | { |
1786 | unsigned int next; | |
1787 | ||
1788 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 1789 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
1790 | return -1U; |
1791 | ||
1792 | /* Check they're not leading us off end of descriptors. */ | |
3b1bbe89 | 1793 | next = vhost16_to_cpu(vq, desc->next); |
3a4d5c94 MT |
1794 | /* Make sure compiler knows to grab that: we don't want it changing! */ |
1795 | /* We will use the result as an index in an array, so most | |
1796 | * architectures only need a compiler barrier here. */ | |
1797 | read_barrier_depends(); | |
1798 | ||
1799 | return next; | |
1800 | } | |
1801 | ||
47283bef | 1802 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc MT |
1803 | struct iovec iov[], unsigned int iov_size, |
1804 | unsigned int *out_num, unsigned int *in_num, | |
1805 | struct vhost_log *log, unsigned int *log_num, | |
1806 | struct vring_desc *indirect) | |
3a4d5c94 MT |
1807 | { |
1808 | struct vring_desc desc; | |
1809 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 1810 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 1811 | struct iov_iter from; |
6b1e6cc7 | 1812 | int ret, access; |
3a4d5c94 MT |
1813 | |
1814 | /* Sanity check */ | |
3b1bbe89 | 1815 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
1816 | vq_err(vq, "Invalid length in indirect descriptor: " |
1817 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 1818 | (unsigned long long)len, |
3a4d5c94 MT |
1819 | sizeof desc); |
1820 | return -EINVAL; | |
1821 | } | |
1822 | ||
3b1bbe89 | 1823 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
6b1e6cc7 | 1824 | UIO_MAXIOV, VHOST_ACCESS_RO); |
7b3384fc | 1825 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
1826 | if (ret != -EAGAIN) |
1827 | vq_err(vq, "Translation failure %d in indirect.\n", ret); | |
3a4d5c94 MT |
1828 | return ret; |
1829 | } | |
aad9a1ce | 1830 | iov_iter_init(&from, READ, vq->indirect, ret, len); |
3a4d5c94 MT |
1831 | |
1832 | /* We will use the result as an address to read from, so most | |
1833 | * architectures only need a compiler barrier here. */ | |
1834 | read_barrier_depends(); | |
1835 | ||
3b1bbe89 | 1836 | count = len / sizeof desc; |
3a4d5c94 MT |
1837 | /* Buffers are chained via a 16 bit next field, so |
1838 | * we can have at most 2^16 of these. */ | |
7b3384fc | 1839 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
1840 | vq_err(vq, "Indirect buffer length too big: %d\n", |
1841 | indirect->len); | |
1842 | return -E2BIG; | |
1843 | } | |
1844 | ||
1845 | do { | |
1846 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 1847 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
1848 | vq_err(vq, "Loop detected: last one at %u " |
1849 | "indirect size %u\n", | |
1850 | i, count); | |
1851 | return -EINVAL; | |
1852 | } | |
aad9a1ce AV |
1853 | if (unlikely(copy_from_iter(&desc, sizeof(desc), &from) != |
1854 | sizeof(desc))) { | |
3a4d5c94 | 1855 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 1856 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
1857 | return -EINVAL; |
1858 | } | |
3b1bbe89 | 1859 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 1860 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 1861 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
1862 | return -EINVAL; |
1863 | } | |
1864 | ||
6b1e6cc7 JW |
1865 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
1866 | access = VHOST_ACCESS_WO; | |
1867 | else | |
1868 | access = VHOST_ACCESS_RO; | |
1869 | ||
3b1bbe89 MT |
1870 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
1871 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 1872 | iov_size - iov_count, access); |
7b3384fc | 1873 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
1874 | if (ret != -EAGAIN) |
1875 | vq_err(vq, "Translation failure %d indirect idx %d\n", | |
1876 | ret, i); | |
3a4d5c94 MT |
1877 | return ret; |
1878 | } | |
1879 | /* If this is an input descriptor, increment that count. */ | |
6b1e6cc7 | 1880 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
1881 | *in_num += ret; |
1882 | if (unlikely(log)) { | |
3b1bbe89 MT |
1883 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
1884 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
1885 | ++*log_num; |
1886 | } | |
1887 | } else { | |
1888 | /* If it's an output descriptor, they're all supposed | |
1889 | * to come before any input descriptors. */ | |
7b3384fc | 1890 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
1891 | vq_err(vq, "Indirect descriptor " |
1892 | "has out after in: idx %d\n", i); | |
1893 | return -EINVAL; | |
1894 | } | |
1895 | *out_num += ret; | |
1896 | } | |
3b1bbe89 | 1897 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
1898 | return 0; |
1899 | } | |
1900 | ||
1901 | /* This looks in the virtqueue and for the first available buffer, and converts | |
1902 | * it to an iovec for convenient access. Since descriptors consist of some | |
1903 | * number of output then some number of input descriptors, it's actually two | |
1904 | * iovecs, but we pack them into one and note how many of each there were. | |
1905 | * | |
d5675bd2 MT |
1906 | * This function returns the descriptor number found, or vq->num (which is |
1907 | * never a valid descriptor number) if none was found. A negative code is | |
1908 | * returned on error. */ | |
47283bef | 1909 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
1910 | struct iovec iov[], unsigned int iov_size, |
1911 | unsigned int *out_num, unsigned int *in_num, | |
1912 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
1913 | { |
1914 | struct vring_desc desc; | |
1915 | unsigned int i, head, found = 0; | |
1916 | u16 last_avail_idx; | |
3b1bbe89 MT |
1917 | __virtio16 avail_idx; |
1918 | __virtio16 ring_head; | |
6b1e6cc7 | 1919 | int ret, access; |
3a4d5c94 MT |
1920 | |
1921 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
1922 | last_avail_idx = vq->last_avail_idx; | |
bfe2bc51 | 1923 | if (unlikely(vhost_get_user(vq, avail_idx, &vq->avail->idx))) { |
3a4d5c94 MT |
1924 | vq_err(vq, "Failed to access avail idx at %p\n", |
1925 | &vq->avail->idx); | |
d5675bd2 | 1926 | return -EFAULT; |
3a4d5c94 | 1927 | } |
3b1bbe89 | 1928 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
3a4d5c94 | 1929 | |
7b3384fc | 1930 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
3a4d5c94 MT |
1931 | vq_err(vq, "Guest moved used index from %u to %u", |
1932 | last_avail_idx, vq->avail_idx); | |
d5675bd2 | 1933 | return -EFAULT; |
3a4d5c94 MT |
1934 | } |
1935 | ||
1936 | /* If there's nothing new since last we looked, return invalid. */ | |
1937 | if (vq->avail_idx == last_avail_idx) | |
1938 | return vq->num; | |
1939 | ||
1940 | /* Only get avail ring entries after they have been exposed by guest. */ | |
5659338c | 1941 | smp_rmb(); |
3a4d5c94 MT |
1942 | |
1943 | /* Grab the next descriptor number they're advertising, and increment | |
1944 | * the index we've seen. */ | |
bfe2bc51 JW |
1945 | if (unlikely(vhost_get_user(vq, ring_head, |
1946 | &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) { | |
3a4d5c94 MT |
1947 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
1948 | last_avail_idx, | |
1949 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 1950 | return -EFAULT; |
3a4d5c94 MT |
1951 | } |
1952 | ||
3b1bbe89 MT |
1953 | head = vhost16_to_cpu(vq, ring_head); |
1954 | ||
3a4d5c94 | 1955 | /* If their number is silly, that's an error. */ |
7b3384fc | 1956 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
1957 | vq_err(vq, "Guest says index %u > %u is available", |
1958 | head, vq->num); | |
d5675bd2 | 1959 | return -EINVAL; |
3a4d5c94 MT |
1960 | } |
1961 | ||
1962 | /* When we start there are none of either input nor output. */ | |
1963 | *out_num = *in_num = 0; | |
1964 | if (unlikely(log)) | |
1965 | *log_num = 0; | |
1966 | ||
1967 | i = head; | |
1968 | do { | |
1969 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 1970 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
1971 | vq_err(vq, "Desc index is %u > %u, head = %u", |
1972 | i, vq->num, head); | |
d5675bd2 | 1973 | return -EINVAL; |
3a4d5c94 | 1974 | } |
7b3384fc | 1975 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
1976 | vq_err(vq, "Loop detected: last one at %u " |
1977 | "vq size %u head %u\n", | |
1978 | i, vq->num, head); | |
d5675bd2 | 1979 | return -EINVAL; |
3a4d5c94 | 1980 | } |
bfe2bc51 JW |
1981 | ret = vhost_copy_from_user(vq, &desc, vq->desc + i, |
1982 | sizeof desc); | |
7b3384fc | 1983 | if (unlikely(ret)) { |
3a4d5c94 MT |
1984 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
1985 | i, vq->desc + i); | |
d5675bd2 | 1986 | return -EFAULT; |
3a4d5c94 | 1987 | } |
3b1bbe89 | 1988 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 1989 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
1990 | out_num, in_num, |
1991 | log, log_num, &desc); | |
7b3384fc | 1992 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
1993 | if (ret != -EAGAIN) |
1994 | vq_err(vq, "Failure detected " | |
1995 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 1996 | return ret; |
3a4d5c94 MT |
1997 | } |
1998 | continue; | |
1999 | } | |
2000 | ||
6b1e6cc7 JW |
2001 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) |
2002 | access = VHOST_ACCESS_WO; | |
2003 | else | |
2004 | access = VHOST_ACCESS_RO; | |
3b1bbe89 MT |
2005 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
2006 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
6b1e6cc7 | 2007 | iov_size - iov_count, access); |
7b3384fc | 2008 | if (unlikely(ret < 0)) { |
6b1e6cc7 JW |
2009 | if (ret != -EAGAIN) |
2010 | vq_err(vq, "Translation failure %d descriptor idx %d\n", | |
2011 | ret, i); | |
d5675bd2 | 2012 | return ret; |
3a4d5c94 | 2013 | } |
6b1e6cc7 | 2014 | if (access == VHOST_ACCESS_WO) { |
3a4d5c94 MT |
2015 | /* If this is an input descriptor, |
2016 | * increment that count. */ | |
2017 | *in_num += ret; | |
2018 | if (unlikely(log)) { | |
3b1bbe89 MT |
2019 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
2020 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
2021 | ++*log_num; |
2022 | } | |
2023 | } else { | |
2024 | /* If it's an output descriptor, they're all supposed | |
2025 | * to come before any input descriptors. */ | |
7b3384fc | 2026 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
2027 | vq_err(vq, "Descriptor has out after in: " |
2028 | "idx %d\n", i); | |
d5675bd2 | 2029 | return -EINVAL; |
3a4d5c94 MT |
2030 | } |
2031 | *out_num += ret; | |
2032 | } | |
3b1bbe89 | 2033 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
2034 | |
2035 | /* On success, increment avail index. */ | |
2036 | vq->last_avail_idx++; | |
8ea8cf89 MT |
2037 | |
2038 | /* Assume notifications from guest are disabled at this point, | |
2039 | * if they aren't we would need to update avail_event index. */ | |
2040 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
2041 | return head; |
2042 | } | |
6ac1afbf | 2043 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
2044 | |
2045 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 2046 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 2047 | { |
8dd014ad | 2048 | vq->last_avail_idx -= n; |
3a4d5c94 | 2049 | } |
6ac1afbf | 2050 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
2051 | |
2052 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2053 | * want to notify the guest, using eventfd. */ | |
2054 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
2055 | { | |
3b1bbe89 MT |
2056 | struct vring_used_elem heads = { |
2057 | cpu_to_vhost32(vq, head), | |
2058 | cpu_to_vhost32(vq, len) | |
2059 | }; | |
3a4d5c94 | 2060 | |
c49e4e57 | 2061 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 2062 | } |
6ac1afbf | 2063 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 2064 | |
8dd014ad DS |
2065 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
2066 | struct vring_used_elem *heads, | |
2067 | unsigned count) | |
2068 | { | |
2069 | struct vring_used_elem __user *used; | |
8ea8cf89 | 2070 | u16 old, new; |
8dd014ad DS |
2071 | int start; |
2072 | ||
5fba13b5 | 2073 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 2074 | used = vq->used->ring + start; |
c49e4e57 | 2075 | if (count == 1) { |
bfe2bc51 | 2076 | if (vhost_put_user(vq, heads[0].id, &used->id)) { |
c49e4e57 JW |
2077 | vq_err(vq, "Failed to write used id"); |
2078 | return -EFAULT; | |
2079 | } | |
bfe2bc51 | 2080 | if (vhost_put_user(vq, heads[0].len, &used->len)) { |
c49e4e57 JW |
2081 | vq_err(vq, "Failed to write used len"); |
2082 | return -EFAULT; | |
2083 | } | |
bfe2bc51 | 2084 | } else if (vhost_copy_to_user(vq, used, heads, count * sizeof *used)) { |
8dd014ad DS |
2085 | vq_err(vq, "Failed to write used"); |
2086 | return -EFAULT; | |
2087 | } | |
2088 | if (unlikely(vq->log_used)) { | |
2089 | /* Make sure data is seen before log. */ | |
2090 | smp_wmb(); | |
2091 | /* Log used ring entry write. */ | |
2092 | log_write(vq->log_base, | |
2093 | vq->log_addr + | |
2094 | ((void __user *)used - (void __user *)vq->used), | |
2095 | count * sizeof *used); | |
2096 | } | |
8ea8cf89 MT |
2097 | old = vq->last_used_idx; |
2098 | new = (vq->last_used_idx += count); | |
2099 | /* If the driver never bothers to signal in a very long while, | |
2100 | * used index might wrap around. If that happens, invalidate | |
2101 | * signalled_used index we stored. TODO: make sure driver | |
2102 | * signals at least once in 2^16 and remove this. */ | |
2103 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
2104 | vq->signalled_used_valid = false; | |
8dd014ad DS |
2105 | return 0; |
2106 | } | |
2107 | ||
2108 | /* After we've used one of their buffers, we tell them about it. We'll then | |
2109 | * want to notify the guest, using eventfd. */ | |
2110 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
2111 | unsigned count) | |
2112 | { | |
2113 | int start, n, r; | |
2114 | ||
5fba13b5 | 2115 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
2116 | n = vq->num - start; |
2117 | if (n < count) { | |
2118 | r = __vhost_add_used_n(vq, heads, n); | |
2119 | if (r < 0) | |
2120 | return r; | |
2121 | heads += n; | |
2122 | count -= n; | |
2123 | } | |
2124 | r = __vhost_add_used_n(vq, heads, count); | |
2125 | ||
2126 | /* Make sure buffer is written before we update index. */ | |
2127 | smp_wmb(); | |
bfe2bc51 JW |
2128 | if (vhost_put_user(vq, cpu_to_vhost16(vq, vq->last_used_idx), |
2129 | &vq->used->idx)) { | |
8dd014ad DS |
2130 | vq_err(vq, "Failed to increment used idx"); |
2131 | return -EFAULT; | |
2132 | } | |
2133 | if (unlikely(vq->log_used)) { | |
2134 | /* Log used index update. */ | |
2135 | log_write(vq->log_base, | |
2136 | vq->log_addr + offsetof(struct vring_used, idx), | |
2137 | sizeof vq->used->idx); | |
2138 | if (vq->log_ctx) | |
2139 | eventfd_signal(vq->log_ctx, 1); | |
2140 | } | |
2141 | return r; | |
2142 | } | |
6ac1afbf | 2143 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 2144 | |
8ea8cf89 | 2145 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2146 | { |
3b1bbe89 MT |
2147 | __u16 old, new; |
2148 | __virtio16 event; | |
8ea8cf89 | 2149 | bool v; |
0d499356 MT |
2150 | /* Flush out used index updates. This is paired |
2151 | * with the barrier that the Guest executes when enabling | |
2152 | * interrupts. */ | |
2153 | smp_mb(); | |
2154 | ||
ea16c514 | 2155 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
2156 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
2157 | return true; | |
2158 | ||
ea16c514 | 2159 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 2160 | __virtio16 flags; |
bfe2bc51 | 2161 | if (vhost_get_user(vq, flags, &vq->avail->flags)) { |
8ea8cf89 MT |
2162 | vq_err(vq, "Failed to get flags"); |
2163 | return true; | |
2164 | } | |
3b1bbe89 | 2165 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 2166 | } |
8ea8cf89 MT |
2167 | old = vq->signalled_used; |
2168 | v = vq->signalled_used_valid; | |
2169 | new = vq->signalled_used = vq->last_used_idx; | |
2170 | vq->signalled_used_valid = true; | |
3a4d5c94 | 2171 | |
8ea8cf89 MT |
2172 | if (unlikely(!v)) |
2173 | return true; | |
3a4d5c94 | 2174 | |
bfe2bc51 | 2175 | if (vhost_get_user(vq, event, vhost_used_event(vq))) { |
8ea8cf89 MT |
2176 | vq_err(vq, "Failed to get used event idx"); |
2177 | return true; | |
2178 | } | |
3b1bbe89 | 2179 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
2180 | } |
2181 | ||
2182 | /* This actually signals the guest, using eventfd. */ | |
2183 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2184 | { | |
3a4d5c94 | 2185 | /* Signal the Guest tell them we used something up. */ |
8ea8cf89 | 2186 | if (vq->call_ctx && vhost_notify(dev, vq)) |
3a4d5c94 MT |
2187 | eventfd_signal(vq->call_ctx, 1); |
2188 | } | |
6ac1afbf | 2189 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
2190 | |
2191 | /* And here's the combo meal deal. Supersize me! */ | |
2192 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
2193 | struct vhost_virtqueue *vq, | |
2194 | unsigned int head, int len) | |
2195 | { | |
2196 | vhost_add_used(vq, head, len); | |
2197 | vhost_signal(dev, vq); | |
2198 | } | |
6ac1afbf | 2199 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 2200 | |
8dd014ad DS |
2201 | /* multi-buffer version of vhost_add_used_and_signal */ |
2202 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
2203 | struct vhost_virtqueue *vq, | |
2204 | struct vring_used_elem *heads, unsigned count) | |
2205 | { | |
2206 | vhost_add_used_n(vq, heads, count); | |
2207 | vhost_signal(dev, vq); | |
2208 | } | |
6ac1afbf | 2209 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 2210 | |
d4a60603 JW |
2211 | /* return true if we're sure that avaiable ring is empty */ |
2212 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
2213 | { | |
2214 | __virtio16 avail_idx; | |
2215 | int r; | |
2216 | ||
bfe2bc51 | 2217 | r = vhost_get_user(vq, avail_idx, &vq->avail->idx); |
d4a60603 JW |
2218 | if (r) |
2219 | return false; | |
2220 | ||
2221 | return vhost16_to_cpu(vq, avail_idx) == vq->avail_idx; | |
2222 | } | |
2223 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
2224 | ||
3a4d5c94 | 2225 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 2226 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 2227 | { |
3b1bbe89 | 2228 | __virtio16 avail_idx; |
3a4d5c94 | 2229 | int r; |
d47effe1 | 2230 | |
3a4d5c94 MT |
2231 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
2232 | return false; | |
2233 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2234 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2235 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2236 | if (r) { |
2237 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2238 | &vq->used->flags, r); | |
2239 | return false; | |
2240 | } | |
2241 | } else { | |
2723feaa | 2242 | r = vhost_update_avail_event(vq, vq->avail_idx); |
8ea8cf89 MT |
2243 | if (r) { |
2244 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
2245 | vhost_avail_event(vq), r); | |
2246 | return false; | |
2247 | } | |
2248 | } | |
3a4d5c94 MT |
2249 | /* They could have slipped one in as we were doing that: make |
2250 | * sure it's written, then check again. */ | |
5659338c | 2251 | smp_mb(); |
bfe2bc51 | 2252 | r = vhost_get_user(vq, avail_idx, &vq->avail->idx); |
3a4d5c94 MT |
2253 | if (r) { |
2254 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
2255 | &vq->avail->idx, r); | |
2256 | return false; | |
2257 | } | |
2258 | ||
3b1bbe89 | 2259 | return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx; |
3a4d5c94 | 2260 | } |
6ac1afbf | 2261 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
2262 | |
2263 | /* We don't need to be notified again. */ | |
8ea8cf89 | 2264 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
2265 | { |
2266 | int r; | |
d47effe1 | 2267 | |
3a4d5c94 MT |
2268 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
2269 | return; | |
2270 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 2271 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 2272 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
2273 | if (r) |
2274 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
2275 | &vq->used->flags, r); | |
2276 | } | |
3a4d5c94 | 2277 | } |
6ac1afbf AH |
2278 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
2279 | ||
6b1e6cc7 JW |
2280 | /* Create a new message. */ |
2281 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type) | |
2282 | { | |
2283 | struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL); | |
2284 | if (!node) | |
2285 | return NULL; | |
2286 | node->vq = vq; | |
2287 | node->msg.type = type; | |
2288 | return node; | |
2289 | } | |
2290 | EXPORT_SYMBOL_GPL(vhost_new_msg); | |
2291 | ||
2292 | void vhost_enqueue_msg(struct vhost_dev *dev, struct list_head *head, | |
2293 | struct vhost_msg_node *node) | |
2294 | { | |
2295 | spin_lock(&dev->iotlb_lock); | |
2296 | list_add_tail(&node->node, head); | |
2297 | spin_unlock(&dev->iotlb_lock); | |
2298 | ||
2299 | wake_up_interruptible_poll(&dev->wait, POLLIN | POLLRDNORM); | |
2300 | } | |
2301 | EXPORT_SYMBOL_GPL(vhost_enqueue_msg); | |
2302 | ||
2303 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, | |
2304 | struct list_head *head) | |
2305 | { | |
2306 | struct vhost_msg_node *node = NULL; | |
2307 | ||
2308 | spin_lock(&dev->iotlb_lock); | |
2309 | if (!list_empty(head)) { | |
2310 | node = list_first_entry(head, struct vhost_msg_node, | |
2311 | node); | |
2312 | list_del(&node->node); | |
2313 | } | |
2314 | spin_unlock(&dev->iotlb_lock); | |
2315 | ||
2316 | return node; | |
2317 | } | |
2318 | EXPORT_SYMBOL_GPL(vhost_dequeue_msg); | |
2319 | ||
2320 | ||
6ac1afbf AH |
2321 | static int __init vhost_init(void) |
2322 | { | |
2323 | return 0; | |
2324 | } | |
2325 | ||
2326 | static void __exit vhost_exit(void) | |
2327 | { | |
2328 | } | |
2329 | ||
2330 | module_init(vhost_init); | |
2331 | module_exit(vhost_exit); | |
2332 | ||
2333 | MODULE_VERSION("0.0.1"); | |
2334 | MODULE_LICENSE("GPL v2"); | |
2335 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
2336 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |