Commit | Line | Data |
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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> |
3a4d5c94 | 30 | |
3a4d5c94 MT |
31 | #include "vhost.h" |
32 | ||
c9ce42f7 IM |
33 | static ushort max_mem_regions = 64; |
34 | module_param(max_mem_regions, ushort, 0444); | |
35 | MODULE_PARM_DESC(max_mem_regions, | |
36 | "Maximum number of memory regions in memory map. (default: 64)"); | |
37 | ||
3a4d5c94 | 38 | enum { |
3a4d5c94 MT |
39 | VHOST_MEMORY_F_LOG = 0x1, |
40 | }; | |
41 | ||
3b1bbe89 MT |
42 | #define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num]) |
43 | #define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num]) | |
8ea8cf89 | 44 | |
2751c988 | 45 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
c5072037 | 46 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
47 | { |
48 | vq->user_be = !virtio_legacy_is_little_endian(); | |
49 | } | |
50 | ||
c5072037 GK |
51 | static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq) |
52 | { | |
53 | vq->user_be = true; | |
54 | } | |
55 | ||
56 | static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq) | |
57 | { | |
58 | vq->user_be = false; | |
59 | } | |
60 | ||
2751c988 GK |
61 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) |
62 | { | |
63 | struct vhost_vring_state s; | |
64 | ||
65 | if (vq->private_data) | |
66 | return -EBUSY; | |
67 | ||
68 | if (copy_from_user(&s, argp, sizeof(s))) | |
69 | return -EFAULT; | |
70 | ||
71 | if (s.num != VHOST_VRING_LITTLE_ENDIAN && | |
72 | s.num != VHOST_VRING_BIG_ENDIAN) | |
73 | return -EINVAL; | |
74 | ||
c5072037 GK |
75 | if (s.num == VHOST_VRING_BIG_ENDIAN) |
76 | vhost_enable_cross_endian_big(vq); | |
77 | else | |
78 | vhost_enable_cross_endian_little(vq); | |
2751c988 GK |
79 | |
80 | return 0; | |
81 | } | |
82 | ||
83 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
84 | int __user *argp) | |
85 | { | |
86 | struct vhost_vring_state s = { | |
87 | .index = idx, | |
88 | .num = vq->user_be | |
89 | }; | |
90 | ||
91 | if (copy_to_user(argp, &s, sizeof(s))) | |
92 | return -EFAULT; | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
97 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
98 | { | |
99 | /* Note for legacy virtio: user_be is initialized at reset time | |
100 | * according to the host endianness. If userspace does not set an | |
101 | * explicit endianness, the default behavior is native endian, as | |
102 | * expected by legacy virtio. | |
103 | */ | |
104 | vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) || !vq->user_be; | |
105 | } | |
106 | #else | |
c5072037 | 107 | static void vhost_disable_cross_endian(struct vhost_virtqueue *vq) |
2751c988 GK |
108 | { |
109 | } | |
110 | ||
111 | static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp) | |
112 | { | |
113 | return -ENOIOCTLCMD; | |
114 | } | |
115 | ||
116 | static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, | |
117 | int __user *argp) | |
118 | { | |
119 | return -ENOIOCTLCMD; | |
120 | } | |
121 | ||
122 | static void vhost_init_is_le(struct vhost_virtqueue *vq) | |
123 | { | |
124 | if (vhost_has_feature(vq, VIRTIO_F_VERSION_1)) | |
125 | vq->is_le = true; | |
126 | } | |
127 | #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ | |
128 | ||
c5072037 GK |
129 | static void vhost_reset_is_le(struct vhost_virtqueue *vq) |
130 | { | |
131 | vq->is_le = virtio_legacy_is_little_endian(); | |
132 | } | |
133 | ||
3a4d5c94 MT |
134 | static void vhost_poll_func(struct file *file, wait_queue_head_t *wqh, |
135 | poll_table *pt) | |
136 | { | |
137 | struct vhost_poll *poll; | |
3a4d5c94 | 138 | |
d47effe1 | 139 | poll = container_of(pt, struct vhost_poll, table); |
3a4d5c94 MT |
140 | poll->wqh = wqh; |
141 | add_wait_queue(wqh, &poll->wait); | |
142 | } | |
143 | ||
144 | static int vhost_poll_wakeup(wait_queue_t *wait, unsigned mode, int sync, | |
145 | void *key) | |
146 | { | |
c23f3445 TH |
147 | struct vhost_poll *poll = container_of(wait, struct vhost_poll, wait); |
148 | ||
3a4d5c94 MT |
149 | if (!((unsigned long)key & poll->mask)) |
150 | return 0; | |
151 | ||
c23f3445 | 152 | vhost_poll_queue(poll); |
3a4d5c94 MT |
153 | return 0; |
154 | } | |
155 | ||
163049ae | 156 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn) |
87d6a412 MT |
157 | { |
158 | INIT_LIST_HEAD(&work->node); | |
159 | work->fn = fn; | |
160 | init_waitqueue_head(&work->done); | |
161 | work->flushing = 0; | |
162 | work->queue_seq = work->done_seq = 0; | |
163 | } | |
6ac1afbf | 164 | EXPORT_SYMBOL_GPL(vhost_work_init); |
87d6a412 | 165 | |
3a4d5c94 | 166 | /* Init poll structure */ |
c23f3445 TH |
167 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
168 | unsigned long mask, struct vhost_dev *dev) | |
3a4d5c94 | 169 | { |
3a4d5c94 MT |
170 | init_waitqueue_func_entry(&poll->wait, vhost_poll_wakeup); |
171 | init_poll_funcptr(&poll->table, vhost_poll_func); | |
172 | poll->mask = mask; | |
c23f3445 | 173 | poll->dev = dev; |
2b8b328b | 174 | poll->wqh = NULL; |
c23f3445 | 175 | |
87d6a412 | 176 | vhost_work_init(&poll->work, fn); |
3a4d5c94 | 177 | } |
6ac1afbf | 178 | EXPORT_SYMBOL_GPL(vhost_poll_init); |
3a4d5c94 MT |
179 | |
180 | /* Start polling a file. We add ourselves to file's wait queue. The caller must | |
181 | * keep a reference to a file until after vhost_poll_stop is called. */ | |
2b8b328b | 182 | int vhost_poll_start(struct vhost_poll *poll, struct file *file) |
3a4d5c94 MT |
183 | { |
184 | unsigned long mask; | |
2b8b328b | 185 | int ret = 0; |
d47effe1 | 186 | |
70181d51 JW |
187 | if (poll->wqh) |
188 | return 0; | |
189 | ||
3a4d5c94 MT |
190 | mask = file->f_op->poll(file, &poll->table); |
191 | if (mask) | |
192 | vhost_poll_wakeup(&poll->wait, 0, 0, (void *)mask); | |
2b8b328b JW |
193 | if (mask & POLLERR) { |
194 | if (poll->wqh) | |
195 | remove_wait_queue(poll->wqh, &poll->wait); | |
196 | ret = -EINVAL; | |
197 | } | |
198 | ||
199 | return ret; | |
3a4d5c94 | 200 | } |
6ac1afbf | 201 | EXPORT_SYMBOL_GPL(vhost_poll_start); |
3a4d5c94 MT |
202 | |
203 | /* Stop polling a file. After this function returns, it becomes safe to drop the | |
204 | * file reference. You must also flush afterwards. */ | |
205 | void vhost_poll_stop(struct vhost_poll *poll) | |
206 | { | |
2b8b328b JW |
207 | if (poll->wqh) { |
208 | remove_wait_queue(poll->wqh, &poll->wait); | |
209 | poll->wqh = NULL; | |
210 | } | |
3a4d5c94 | 211 | } |
6ac1afbf | 212 | EXPORT_SYMBOL_GPL(vhost_poll_stop); |
3a4d5c94 | 213 | |
0174b0c3 MT |
214 | static bool vhost_work_seq_done(struct vhost_dev *dev, struct vhost_work *work, |
215 | unsigned seq) | |
216 | { | |
217 | int left; | |
d47effe1 | 218 | |
0174b0c3 MT |
219 | spin_lock_irq(&dev->work_lock); |
220 | left = seq - work->done_seq; | |
221 | spin_unlock_irq(&dev->work_lock); | |
222 | return left <= 0; | |
223 | } | |
224 | ||
6ac1afbf | 225 | void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 226 | { |
c23f3445 | 227 | unsigned seq; |
c23f3445 TH |
228 | int flushing; |
229 | ||
87d6a412 | 230 | spin_lock_irq(&dev->work_lock); |
c23f3445 TH |
231 | seq = work->queue_seq; |
232 | work->flushing++; | |
87d6a412 | 233 | spin_unlock_irq(&dev->work_lock); |
0174b0c3 | 234 | wait_event(work->done, vhost_work_seq_done(dev, work, seq)); |
87d6a412 | 235 | spin_lock_irq(&dev->work_lock); |
c23f3445 | 236 | flushing = --work->flushing; |
87d6a412 | 237 | spin_unlock_irq(&dev->work_lock); |
c23f3445 | 238 | BUG_ON(flushing < 0); |
3a4d5c94 | 239 | } |
6ac1afbf | 240 | EXPORT_SYMBOL_GPL(vhost_work_flush); |
3a4d5c94 | 241 | |
87d6a412 MT |
242 | /* Flush any work that has been scheduled. When calling this, don't hold any |
243 | * locks that are also used by the callback. */ | |
244 | void vhost_poll_flush(struct vhost_poll *poll) | |
245 | { | |
246 | vhost_work_flush(poll->dev, &poll->work); | |
247 | } | |
6ac1afbf | 248 | EXPORT_SYMBOL_GPL(vhost_poll_flush); |
87d6a412 | 249 | |
163049ae | 250 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) |
3a4d5c94 | 251 | { |
c23f3445 TH |
252 | unsigned long flags; |
253 | ||
254 | spin_lock_irqsave(&dev->work_lock, flags); | |
255 | if (list_empty(&work->node)) { | |
256 | list_add_tail(&work->node, &dev->work_list); | |
257 | work->queue_seq++; | |
ac9fde24 | 258 | spin_unlock_irqrestore(&dev->work_lock, flags); |
c23f3445 | 259 | wake_up_process(dev->worker); |
ac9fde24 QC |
260 | } else { |
261 | spin_unlock_irqrestore(&dev->work_lock, flags); | |
c23f3445 | 262 | } |
3a4d5c94 | 263 | } |
6ac1afbf | 264 | EXPORT_SYMBOL_GPL(vhost_work_queue); |
3a4d5c94 | 265 | |
526d3e7f JW |
266 | /* A lockless hint for busy polling code to exit the loop */ |
267 | bool vhost_has_work(struct vhost_dev *dev) | |
268 | { | |
269 | return !list_empty(&dev->work_list); | |
270 | } | |
271 | EXPORT_SYMBOL_GPL(vhost_has_work); | |
272 | ||
87d6a412 MT |
273 | void vhost_poll_queue(struct vhost_poll *poll) |
274 | { | |
275 | vhost_work_queue(poll->dev, &poll->work); | |
276 | } | |
6ac1afbf | 277 | EXPORT_SYMBOL_GPL(vhost_poll_queue); |
87d6a412 | 278 | |
3a4d5c94 MT |
279 | static void vhost_vq_reset(struct vhost_dev *dev, |
280 | struct vhost_virtqueue *vq) | |
281 | { | |
282 | vq->num = 1; | |
283 | vq->desc = NULL; | |
284 | vq->avail = NULL; | |
285 | vq->used = NULL; | |
286 | vq->last_avail_idx = 0; | |
287 | vq->avail_idx = 0; | |
288 | vq->last_used_idx = 0; | |
8ea8cf89 MT |
289 | vq->signalled_used = 0; |
290 | vq->signalled_used_valid = false; | |
3a4d5c94 | 291 | vq->used_flags = 0; |
3a4d5c94 MT |
292 | vq->log_used = false; |
293 | vq->log_addr = -1ull; | |
3a4d5c94 | 294 | vq->private_data = NULL; |
ea16c514 | 295 | vq->acked_features = 0; |
3a4d5c94 MT |
296 | vq->log_base = NULL; |
297 | vq->error_ctx = NULL; | |
298 | vq->error = NULL; | |
299 | vq->kick = NULL; | |
300 | vq->call_ctx = NULL; | |
301 | vq->call = NULL; | |
73a99f08 | 302 | vq->log_ctx = NULL; |
47283bef | 303 | vq->memory = NULL; |
c5072037 GK |
304 | vhost_reset_is_le(vq); |
305 | vhost_disable_cross_endian(vq); | |
03088137 | 306 | vq->busyloop_timeout = 0; |
3a4d5c94 MT |
307 | } |
308 | ||
c23f3445 TH |
309 | static int vhost_worker(void *data) |
310 | { | |
311 | struct vhost_dev *dev = data; | |
312 | struct vhost_work *work = NULL; | |
313 | unsigned uninitialized_var(seq); | |
d7ffde35 | 314 | mm_segment_t oldfs = get_fs(); |
c23f3445 | 315 | |
d7ffde35 | 316 | set_fs(USER_DS); |
64e1c807 MT |
317 | use_mm(dev->mm); |
318 | ||
c23f3445 TH |
319 | for (;;) { |
320 | /* mb paired w/ kthread_stop */ | |
321 | set_current_state(TASK_INTERRUPTIBLE); | |
322 | ||
323 | spin_lock_irq(&dev->work_lock); | |
324 | if (work) { | |
325 | work->done_seq = seq; | |
326 | if (work->flushing) | |
327 | wake_up_all(&work->done); | |
328 | } | |
329 | ||
330 | if (kthread_should_stop()) { | |
331 | spin_unlock_irq(&dev->work_lock); | |
332 | __set_current_state(TASK_RUNNING); | |
64e1c807 | 333 | break; |
c23f3445 TH |
334 | } |
335 | if (!list_empty(&dev->work_list)) { | |
336 | work = list_first_entry(&dev->work_list, | |
337 | struct vhost_work, node); | |
338 | list_del_init(&work->node); | |
339 | seq = work->queue_seq; | |
340 | } else | |
341 | work = NULL; | |
342 | spin_unlock_irq(&dev->work_lock); | |
343 | ||
344 | if (work) { | |
345 | __set_current_state(TASK_RUNNING); | |
346 | work->fn(work); | |
d550dda1 NHE |
347 | if (need_resched()) |
348 | schedule(); | |
c23f3445 TH |
349 | } else |
350 | schedule(); | |
351 | ||
352 | } | |
64e1c807 | 353 | unuse_mm(dev->mm); |
d7ffde35 | 354 | set_fs(oldfs); |
64e1c807 | 355 | return 0; |
c23f3445 TH |
356 | } |
357 | ||
bab632d6 MT |
358 | static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) |
359 | { | |
360 | kfree(vq->indirect); | |
361 | vq->indirect = NULL; | |
362 | kfree(vq->log); | |
363 | vq->log = NULL; | |
364 | kfree(vq->heads); | |
365 | vq->heads = NULL; | |
bab632d6 MT |
366 | } |
367 | ||
e0e9b406 JW |
368 | /* Helper to allocate iovec buffers for all vqs. */ |
369 | static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) | |
370 | { | |
6d5e6aa8 | 371 | struct vhost_virtqueue *vq; |
e0e9b406 | 372 | int i; |
d47effe1 | 373 | |
e0e9b406 | 374 | for (i = 0; i < dev->nvqs; ++i) { |
6d5e6aa8 AH |
375 | vq = dev->vqs[i]; |
376 | vq->indirect = kmalloc(sizeof *vq->indirect * UIO_MAXIOV, | |
377 | GFP_KERNEL); | |
378 | vq->log = kmalloc(sizeof *vq->log * UIO_MAXIOV, GFP_KERNEL); | |
379 | vq->heads = kmalloc(sizeof *vq->heads * UIO_MAXIOV, GFP_KERNEL); | |
380 | if (!vq->indirect || !vq->log || !vq->heads) | |
e0e9b406 JW |
381 | goto err_nomem; |
382 | } | |
383 | return 0; | |
d47effe1 | 384 | |
e0e9b406 | 385 | err_nomem: |
bab632d6 | 386 | for (; i >= 0; --i) |
3ab2e420 | 387 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
388 | return -ENOMEM; |
389 | } | |
390 | ||
391 | static void vhost_dev_free_iovecs(struct vhost_dev *dev) | |
392 | { | |
393 | int i; | |
d47effe1 | 394 | |
bab632d6 | 395 | for (i = 0; i < dev->nvqs; ++i) |
3ab2e420 | 396 | vhost_vq_free_iovecs(dev->vqs[i]); |
e0e9b406 JW |
397 | } |
398 | ||
59566b6e | 399 | void vhost_dev_init(struct vhost_dev *dev, |
3ab2e420 | 400 | struct vhost_virtqueue **vqs, int nvqs) |
3a4d5c94 | 401 | { |
6d5e6aa8 | 402 | struct vhost_virtqueue *vq; |
3a4d5c94 | 403 | int i; |
c23f3445 | 404 | |
3a4d5c94 MT |
405 | dev->vqs = vqs; |
406 | dev->nvqs = nvqs; | |
407 | mutex_init(&dev->mutex); | |
408 | dev->log_ctx = NULL; | |
409 | dev->log_file = NULL; | |
410 | dev->memory = NULL; | |
411 | dev->mm = NULL; | |
c23f3445 TH |
412 | spin_lock_init(&dev->work_lock); |
413 | INIT_LIST_HEAD(&dev->work_list); | |
414 | dev->worker = NULL; | |
3a4d5c94 MT |
415 | |
416 | for (i = 0; i < dev->nvqs; ++i) { | |
6d5e6aa8 AH |
417 | vq = dev->vqs[i]; |
418 | vq->log = NULL; | |
419 | vq->indirect = NULL; | |
420 | vq->heads = NULL; | |
421 | vq->dev = dev; | |
422 | mutex_init(&vq->mutex); | |
423 | vhost_vq_reset(dev, vq); | |
424 | if (vq->handle_kick) | |
425 | vhost_poll_init(&vq->poll, vq->handle_kick, | |
426 | POLLIN, dev); | |
3a4d5c94 | 427 | } |
3a4d5c94 | 428 | } |
6ac1afbf | 429 | EXPORT_SYMBOL_GPL(vhost_dev_init); |
3a4d5c94 MT |
430 | |
431 | /* Caller should have device mutex */ | |
432 | long vhost_dev_check_owner(struct vhost_dev *dev) | |
433 | { | |
434 | /* Are you the owner? If not, I don't think you mean to do that */ | |
435 | return dev->mm == current->mm ? 0 : -EPERM; | |
436 | } | |
6ac1afbf | 437 | EXPORT_SYMBOL_GPL(vhost_dev_check_owner); |
3a4d5c94 | 438 | |
87d6a412 | 439 | struct vhost_attach_cgroups_struct { |
d47effe1 KK |
440 | struct vhost_work work; |
441 | struct task_struct *owner; | |
442 | int ret; | |
87d6a412 MT |
443 | }; |
444 | ||
445 | static void vhost_attach_cgroups_work(struct vhost_work *work) | |
446 | { | |
d47effe1 KK |
447 | struct vhost_attach_cgroups_struct *s; |
448 | ||
449 | s = container_of(work, struct vhost_attach_cgroups_struct, work); | |
450 | s->ret = cgroup_attach_task_all(s->owner, current); | |
87d6a412 MT |
451 | } |
452 | ||
453 | static int vhost_attach_cgroups(struct vhost_dev *dev) | |
454 | { | |
d47effe1 KK |
455 | struct vhost_attach_cgroups_struct attach; |
456 | ||
457 | attach.owner = current; | |
458 | vhost_work_init(&attach.work, vhost_attach_cgroups_work); | |
459 | vhost_work_queue(dev, &attach.work); | |
460 | vhost_work_flush(dev, &attach.work); | |
461 | return attach.ret; | |
87d6a412 MT |
462 | } |
463 | ||
05c05351 MT |
464 | /* Caller should have device mutex */ |
465 | bool vhost_dev_has_owner(struct vhost_dev *dev) | |
466 | { | |
467 | return dev->mm; | |
468 | } | |
6ac1afbf | 469 | EXPORT_SYMBOL_GPL(vhost_dev_has_owner); |
05c05351 | 470 | |
3a4d5c94 | 471 | /* Caller should have device mutex */ |
54db63c2 | 472 | long vhost_dev_set_owner(struct vhost_dev *dev) |
3a4d5c94 | 473 | { |
c23f3445 TH |
474 | struct task_struct *worker; |
475 | int err; | |
d47effe1 | 476 | |
3a4d5c94 | 477 | /* Is there an owner already? */ |
05c05351 | 478 | if (vhost_dev_has_owner(dev)) { |
c23f3445 TH |
479 | err = -EBUSY; |
480 | goto err_mm; | |
481 | } | |
d47effe1 | 482 | |
3a4d5c94 MT |
483 | /* No owner, become one */ |
484 | dev->mm = get_task_mm(current); | |
c23f3445 TH |
485 | worker = kthread_create(vhost_worker, dev, "vhost-%d", current->pid); |
486 | if (IS_ERR(worker)) { | |
487 | err = PTR_ERR(worker); | |
488 | goto err_worker; | |
489 | } | |
490 | ||
491 | dev->worker = worker; | |
87d6a412 MT |
492 | wake_up_process(worker); /* avoid contributing to loadavg */ |
493 | ||
494 | err = vhost_attach_cgroups(dev); | |
9e3d1957 MT |
495 | if (err) |
496 | goto err_cgroup; | |
c23f3445 | 497 | |
e0e9b406 JW |
498 | err = vhost_dev_alloc_iovecs(dev); |
499 | if (err) | |
500 | goto err_cgroup; | |
501 | ||
3a4d5c94 | 502 | return 0; |
9e3d1957 MT |
503 | err_cgroup: |
504 | kthread_stop(worker); | |
615cc221 | 505 | dev->worker = NULL; |
c23f3445 TH |
506 | err_worker: |
507 | if (dev->mm) | |
508 | mmput(dev->mm); | |
509 | dev->mm = NULL; | |
510 | err_mm: | |
511 | return err; | |
3a4d5c94 | 512 | } |
6ac1afbf | 513 | EXPORT_SYMBOL_GPL(vhost_dev_set_owner); |
3a4d5c94 | 514 | |
150b9e51 | 515 | struct vhost_memory *vhost_dev_reset_owner_prepare(void) |
3a4d5c94 | 516 | { |
150b9e51 MT |
517 | return kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL); |
518 | } | |
6ac1afbf | 519 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner_prepare); |
3a4d5c94 | 520 | |
150b9e51 MT |
521 | /* Caller should have device mutex */ |
522 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_memory *memory) | |
523 | { | |
47283bef MT |
524 | int i; |
525 | ||
ea5d4046 | 526 | vhost_dev_cleanup(dev, true); |
3a4d5c94 | 527 | |
150b9e51 | 528 | /* Restore memory to default empty mapping. */ |
3a4d5c94 | 529 | memory->nregions = 0; |
47283bef MT |
530 | dev->memory = memory; |
531 | /* We don't need VQ locks below since vhost_dev_cleanup makes sure | |
532 | * VQs aren't running. | |
533 | */ | |
534 | for (i = 0; i < dev->nvqs; ++i) | |
535 | dev->vqs[i]->memory = memory; | |
3a4d5c94 | 536 | } |
6ac1afbf | 537 | EXPORT_SYMBOL_GPL(vhost_dev_reset_owner); |
3a4d5c94 | 538 | |
b211616d | 539 | void vhost_dev_stop(struct vhost_dev *dev) |
bab632d6 MT |
540 | { |
541 | int i; | |
b211616d MT |
542 | |
543 | for (i = 0; i < dev->nvqs; ++i) { | |
3ab2e420 AH |
544 | if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) { |
545 | vhost_poll_stop(&dev->vqs[i]->poll); | |
546 | vhost_poll_flush(&dev->vqs[i]->poll); | |
b211616d | 547 | } |
bab632d6 | 548 | } |
bab632d6 | 549 | } |
6ac1afbf | 550 | EXPORT_SYMBOL_GPL(vhost_dev_stop); |
bab632d6 | 551 | |
ea5d4046 MT |
552 | /* Caller should have device mutex if and only if locked is set */ |
553 | void vhost_dev_cleanup(struct vhost_dev *dev, bool locked) | |
3a4d5c94 MT |
554 | { |
555 | int i; | |
d47effe1 | 556 | |
3a4d5c94 | 557 | for (i = 0; i < dev->nvqs; ++i) { |
3ab2e420 AH |
558 | if (dev->vqs[i]->error_ctx) |
559 | eventfd_ctx_put(dev->vqs[i]->error_ctx); | |
560 | if (dev->vqs[i]->error) | |
561 | fput(dev->vqs[i]->error); | |
562 | if (dev->vqs[i]->kick) | |
563 | fput(dev->vqs[i]->kick); | |
564 | if (dev->vqs[i]->call_ctx) | |
565 | eventfd_ctx_put(dev->vqs[i]->call_ctx); | |
566 | if (dev->vqs[i]->call) | |
567 | fput(dev->vqs[i]->call); | |
568 | vhost_vq_reset(dev, dev->vqs[i]); | |
3a4d5c94 | 569 | } |
e0e9b406 | 570 | vhost_dev_free_iovecs(dev); |
3a4d5c94 MT |
571 | if (dev->log_ctx) |
572 | eventfd_ctx_put(dev->log_ctx); | |
573 | dev->log_ctx = NULL; | |
574 | if (dev->log_file) | |
575 | fput(dev->log_file); | |
576 | dev->log_file = NULL; | |
577 | /* No one will access memory at this point */ | |
4de7255f | 578 | kvfree(dev->memory); |
47283bef | 579 | dev->memory = NULL; |
c23f3445 | 580 | WARN_ON(!list_empty(&dev->work_list)); |
78b620ce ED |
581 | if (dev->worker) { |
582 | kthread_stop(dev->worker); | |
583 | dev->worker = NULL; | |
584 | } | |
533a19b4 MT |
585 | if (dev->mm) |
586 | mmput(dev->mm); | |
587 | dev->mm = NULL; | |
3a4d5c94 | 588 | } |
6ac1afbf | 589 | EXPORT_SYMBOL_GPL(vhost_dev_cleanup); |
3a4d5c94 MT |
590 | |
591 | static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) | |
592 | { | |
593 | u64 a = addr / VHOST_PAGE_SIZE / 8; | |
d47effe1 | 594 | |
3a4d5c94 MT |
595 | /* Make sure 64 bit math will not overflow. */ |
596 | if (a > ULONG_MAX - (unsigned long)log_base || | |
597 | a + (unsigned long)log_base > ULONG_MAX) | |
6d97e55f | 598 | return 0; |
3a4d5c94 MT |
599 | |
600 | return access_ok(VERIFY_WRITE, log_base + a, | |
601 | (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); | |
602 | } | |
603 | ||
604 | /* Caller should have vq mutex and device mutex. */ | |
605 | static int vq_memory_access_ok(void __user *log_base, struct vhost_memory *mem, | |
606 | int log_all) | |
607 | { | |
608 | int i; | |
179b284e | 609 | |
f8322fbe MT |
610 | if (!mem) |
611 | return 0; | |
179b284e | 612 | |
3a4d5c94 MT |
613 | for (i = 0; i < mem->nregions; ++i) { |
614 | struct vhost_memory_region *m = mem->regions + i; | |
615 | unsigned long a = m->userspace_addr; | |
616 | if (m->memory_size > ULONG_MAX) | |
617 | return 0; | |
618 | else if (!access_ok(VERIFY_WRITE, (void __user *)a, | |
619 | m->memory_size)) | |
620 | return 0; | |
621 | else if (log_all && !log_access_ok(log_base, | |
622 | m->guest_phys_addr, | |
623 | m->memory_size)) | |
624 | return 0; | |
625 | } | |
626 | return 1; | |
627 | } | |
628 | ||
629 | /* Can we switch to this memory table? */ | |
630 | /* Caller should have device mutex but not vq mutex */ | |
631 | static int memory_access_ok(struct vhost_dev *d, struct vhost_memory *mem, | |
632 | int log_all) | |
633 | { | |
634 | int i; | |
d47effe1 | 635 | |
3a4d5c94 MT |
636 | for (i = 0; i < d->nvqs; ++i) { |
637 | int ok; | |
ea16c514 MT |
638 | bool log; |
639 | ||
3ab2e420 | 640 | mutex_lock(&d->vqs[i]->mutex); |
ea16c514 | 641 | log = log_all || vhost_has_feature(d->vqs[i], VHOST_F_LOG_ALL); |
3a4d5c94 | 642 | /* If ring is inactive, will check when it's enabled. */ |
3ab2e420 | 643 | if (d->vqs[i]->private_data) |
ea16c514 | 644 | ok = vq_memory_access_ok(d->vqs[i]->log_base, mem, log); |
3a4d5c94 MT |
645 | else |
646 | ok = 1; | |
3ab2e420 | 647 | mutex_unlock(&d->vqs[i]->mutex); |
3a4d5c94 MT |
648 | if (!ok) |
649 | return 0; | |
650 | } | |
651 | return 1; | |
652 | } | |
653 | ||
ea16c514 | 654 | static int vq_access_ok(struct vhost_virtqueue *vq, unsigned int num, |
3a4d5c94 MT |
655 | struct vring_desc __user *desc, |
656 | struct vring_avail __user *avail, | |
657 | struct vring_used __user *used) | |
658 | { | |
ea16c514 | 659 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
3a4d5c94 MT |
660 | return access_ok(VERIFY_READ, desc, num * sizeof *desc) && |
661 | access_ok(VERIFY_READ, avail, | |
8ea8cf89 | 662 | sizeof *avail + num * sizeof *avail->ring + s) && |
3a4d5c94 | 663 | access_ok(VERIFY_WRITE, used, |
8ea8cf89 | 664 | sizeof *used + num * sizeof *used->ring + s); |
3a4d5c94 MT |
665 | } |
666 | ||
667 | /* Can we log writes? */ | |
668 | /* Caller should have device mutex but not vq mutex */ | |
669 | int vhost_log_access_ok(struct vhost_dev *dev) | |
670 | { | |
47283bef | 671 | return memory_access_ok(dev, dev->memory, 1); |
3a4d5c94 | 672 | } |
6ac1afbf | 673 | EXPORT_SYMBOL_GPL(vhost_log_access_ok); |
3a4d5c94 MT |
674 | |
675 | /* Verify access for write logging. */ | |
676 | /* Caller should have vq mutex and device mutex */ | |
ea16c514 | 677 | static int vq_log_access_ok(struct vhost_virtqueue *vq, |
8ea8cf89 | 678 | void __user *log_base) |
3a4d5c94 | 679 | { |
ea16c514 | 680 | size_t s = vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0; |
28457ee6 | 681 | |
47283bef | 682 | return vq_memory_access_ok(log_base, vq->memory, |
ea16c514 | 683 | vhost_has_feature(vq, VHOST_F_LOG_ALL)) && |
3a4d5c94 MT |
684 | (!vq->log_used || log_access_ok(log_base, vq->log_addr, |
685 | sizeof *vq->used + | |
8ea8cf89 | 686 | vq->num * sizeof *vq->used->ring + s)); |
3a4d5c94 MT |
687 | } |
688 | ||
689 | /* Can we start vq? */ | |
690 | /* Caller should have vq mutex and device mutex */ | |
691 | int vhost_vq_access_ok(struct vhost_virtqueue *vq) | |
692 | { | |
ea16c514 MT |
693 | return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) && |
694 | vq_log_access_ok(vq, vq->log_base); | |
3a4d5c94 | 695 | } |
6ac1afbf | 696 | EXPORT_SYMBOL_GPL(vhost_vq_access_ok); |
3a4d5c94 | 697 | |
bcfeacab IM |
698 | static int vhost_memory_reg_sort_cmp(const void *p1, const void *p2) |
699 | { | |
700 | const struct vhost_memory_region *r1 = p1, *r2 = p2; | |
701 | if (r1->guest_phys_addr < r2->guest_phys_addr) | |
702 | return 1; | |
703 | if (r1->guest_phys_addr > r2->guest_phys_addr) | |
704 | return -1; | |
705 | return 0; | |
706 | } | |
707 | ||
4de7255f IM |
708 | static void *vhost_kvzalloc(unsigned long size) |
709 | { | |
710 | void *n = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT); | |
711 | ||
1e099473 | 712 | if (!n) |
4de7255f | 713 | n = vzalloc(size); |
4de7255f IM |
714 | return n; |
715 | } | |
716 | ||
3a4d5c94 MT |
717 | static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m) |
718 | { | |
719 | struct vhost_memory mem, *newmem, *oldmem; | |
720 | unsigned long size = offsetof(struct vhost_memory, regions); | |
98f9ca0a | 721 | int i; |
d47effe1 | 722 | |
7ad9c9d2 TY |
723 | if (copy_from_user(&mem, m, size)) |
724 | return -EFAULT; | |
3a4d5c94 MT |
725 | if (mem.padding) |
726 | return -EOPNOTSUPP; | |
c9ce42f7 | 727 | if (mem.nregions > max_mem_regions) |
3a4d5c94 | 728 | return -E2BIG; |
4de7255f | 729 | newmem = vhost_kvzalloc(size + mem.nregions * sizeof(*m->regions)); |
3a4d5c94 MT |
730 | if (!newmem) |
731 | return -ENOMEM; | |
732 | ||
733 | memcpy(newmem, &mem, size); | |
7ad9c9d2 TY |
734 | if (copy_from_user(newmem->regions, m->regions, |
735 | mem.nregions * sizeof *m->regions)) { | |
bcfeacab | 736 | kvfree(newmem); |
7ad9c9d2 | 737 | return -EFAULT; |
3a4d5c94 | 738 | } |
bcfeacab IM |
739 | sort(newmem->regions, newmem->nregions, sizeof(*newmem->regions), |
740 | vhost_memory_reg_sort_cmp, NULL); | |
3a4d5c94 | 741 | |
ea16c514 | 742 | if (!memory_access_ok(d, newmem, 0)) { |
4de7255f | 743 | kvfree(newmem); |
3a4d5c94 | 744 | return -EFAULT; |
a02c3789 | 745 | } |
47283bef MT |
746 | oldmem = d->memory; |
747 | d->memory = newmem; | |
98f9ca0a | 748 | |
47283bef | 749 | /* All memory accesses are done under some VQ mutex. */ |
98f9ca0a MT |
750 | for (i = 0; i < d->nvqs; ++i) { |
751 | mutex_lock(&d->vqs[i]->mutex); | |
47283bef | 752 | d->vqs[i]->memory = newmem; |
98f9ca0a MT |
753 | mutex_unlock(&d->vqs[i]->mutex); |
754 | } | |
4de7255f | 755 | kvfree(oldmem); |
3a4d5c94 MT |
756 | return 0; |
757 | } | |
758 | ||
935cdee7 | 759 | long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp) |
3a4d5c94 | 760 | { |
cecb46f1 AV |
761 | struct file *eventfp, *filep = NULL; |
762 | bool pollstart = false, pollstop = false; | |
3a4d5c94 MT |
763 | struct eventfd_ctx *ctx = NULL; |
764 | u32 __user *idxp = argp; | |
765 | struct vhost_virtqueue *vq; | |
766 | struct vhost_vring_state s; | |
767 | struct vhost_vring_file f; | |
768 | struct vhost_vring_addr a; | |
769 | u32 idx; | |
770 | long r; | |
771 | ||
772 | r = get_user(idx, idxp); | |
773 | if (r < 0) | |
774 | return r; | |
0f3d9a17 | 775 | if (idx >= d->nvqs) |
3a4d5c94 MT |
776 | return -ENOBUFS; |
777 | ||
3ab2e420 | 778 | vq = d->vqs[idx]; |
3a4d5c94 MT |
779 | |
780 | mutex_lock(&vq->mutex); | |
781 | ||
782 | switch (ioctl) { | |
783 | case VHOST_SET_VRING_NUM: | |
784 | /* Resizing ring with an active backend? | |
785 | * You don't want to do that. */ | |
786 | if (vq->private_data) { | |
787 | r = -EBUSY; | |
788 | break; | |
789 | } | |
7ad9c9d2 TY |
790 | if (copy_from_user(&s, argp, sizeof s)) { |
791 | r = -EFAULT; | |
3a4d5c94 | 792 | break; |
7ad9c9d2 | 793 | } |
3a4d5c94 MT |
794 | if (!s.num || s.num > 0xffff || (s.num & (s.num - 1))) { |
795 | r = -EINVAL; | |
796 | break; | |
797 | } | |
798 | vq->num = s.num; | |
799 | break; | |
800 | case VHOST_SET_VRING_BASE: | |
801 | /* Moving base with an active backend? | |
802 | * You don't want to do that. */ | |
803 | if (vq->private_data) { | |
804 | r = -EBUSY; | |
805 | break; | |
806 | } | |
7ad9c9d2 TY |
807 | if (copy_from_user(&s, argp, sizeof s)) { |
808 | r = -EFAULT; | |
3a4d5c94 | 809 | break; |
7ad9c9d2 | 810 | } |
3a4d5c94 MT |
811 | if (s.num > 0xffff) { |
812 | r = -EINVAL; | |
813 | break; | |
814 | } | |
815 | vq->last_avail_idx = s.num; | |
816 | /* Forget the cached index value. */ | |
817 | vq->avail_idx = vq->last_avail_idx; | |
818 | break; | |
819 | case VHOST_GET_VRING_BASE: | |
820 | s.index = idx; | |
821 | s.num = vq->last_avail_idx; | |
7ad9c9d2 TY |
822 | if (copy_to_user(argp, &s, sizeof s)) |
823 | r = -EFAULT; | |
3a4d5c94 MT |
824 | break; |
825 | case VHOST_SET_VRING_ADDR: | |
7ad9c9d2 TY |
826 | if (copy_from_user(&a, argp, sizeof a)) { |
827 | r = -EFAULT; | |
3a4d5c94 | 828 | break; |
7ad9c9d2 | 829 | } |
3a4d5c94 MT |
830 | if (a.flags & ~(0x1 << VHOST_VRING_F_LOG)) { |
831 | r = -EOPNOTSUPP; | |
832 | break; | |
833 | } | |
834 | /* For 32bit, verify that the top 32bits of the user | |
835 | data are set to zero. */ | |
836 | if ((u64)(unsigned long)a.desc_user_addr != a.desc_user_addr || | |
837 | (u64)(unsigned long)a.used_user_addr != a.used_user_addr || | |
838 | (u64)(unsigned long)a.avail_user_addr != a.avail_user_addr) { | |
839 | r = -EFAULT; | |
840 | break; | |
841 | } | |
5d9a07b0 MT |
842 | |
843 | /* Make sure it's safe to cast pointers to vring types. */ | |
844 | BUILD_BUG_ON(__alignof__ *vq->avail > VRING_AVAIL_ALIGN_SIZE); | |
845 | BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE); | |
846 | if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) || | |
847 | (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) || | |
d5424838 | 848 | (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) { |
3a4d5c94 MT |
849 | r = -EINVAL; |
850 | break; | |
851 | } | |
852 | ||
853 | /* We only verify access here if backend is configured. | |
854 | * If it is not, we don't as size might not have been setup. | |
855 | * We will verify when backend is configured. */ | |
856 | if (vq->private_data) { | |
ea16c514 | 857 | if (!vq_access_ok(vq, vq->num, |
3a4d5c94 MT |
858 | (void __user *)(unsigned long)a.desc_user_addr, |
859 | (void __user *)(unsigned long)a.avail_user_addr, | |
860 | (void __user *)(unsigned long)a.used_user_addr)) { | |
861 | r = -EINVAL; | |
862 | break; | |
863 | } | |
864 | ||
865 | /* Also validate log access for used ring if enabled. */ | |
866 | if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && | |
867 | !log_access_ok(vq->log_base, a.log_guest_addr, | |
868 | sizeof *vq->used + | |
869 | vq->num * sizeof *vq->used->ring)) { | |
870 | r = -EINVAL; | |
871 | break; | |
872 | } | |
873 | } | |
874 | ||
3a4d5c94 MT |
875 | vq->log_used = !!(a.flags & (0x1 << VHOST_VRING_F_LOG)); |
876 | vq->desc = (void __user *)(unsigned long)a.desc_user_addr; | |
877 | vq->avail = (void __user *)(unsigned long)a.avail_user_addr; | |
878 | vq->log_addr = a.log_guest_addr; | |
879 | vq->used = (void __user *)(unsigned long)a.used_user_addr; | |
880 | break; | |
881 | case VHOST_SET_VRING_KICK: | |
7ad9c9d2 TY |
882 | if (copy_from_user(&f, argp, sizeof f)) { |
883 | r = -EFAULT; | |
3a4d5c94 | 884 | break; |
7ad9c9d2 | 885 | } |
3a4d5c94 | 886 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
887 | if (IS_ERR(eventfp)) { |
888 | r = PTR_ERR(eventfp); | |
889 | break; | |
890 | } | |
3a4d5c94 | 891 | if (eventfp != vq->kick) { |
cecb46f1 AV |
892 | pollstop = (filep = vq->kick) != NULL; |
893 | pollstart = (vq->kick = eventfp) != NULL; | |
3a4d5c94 MT |
894 | } else |
895 | filep = eventfp; | |
896 | break; | |
897 | case VHOST_SET_VRING_CALL: | |
7ad9c9d2 TY |
898 | if (copy_from_user(&f, argp, sizeof f)) { |
899 | r = -EFAULT; | |
3a4d5c94 | 900 | break; |
7ad9c9d2 | 901 | } |
3a4d5c94 | 902 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
903 | if (IS_ERR(eventfp)) { |
904 | r = PTR_ERR(eventfp); | |
905 | break; | |
906 | } | |
3a4d5c94 MT |
907 | if (eventfp != vq->call) { |
908 | filep = vq->call; | |
909 | ctx = vq->call_ctx; | |
910 | vq->call = eventfp; | |
911 | vq->call_ctx = eventfp ? | |
912 | eventfd_ctx_fileget(eventfp) : NULL; | |
913 | } else | |
914 | filep = eventfp; | |
915 | break; | |
916 | case VHOST_SET_VRING_ERR: | |
7ad9c9d2 TY |
917 | if (copy_from_user(&f, argp, sizeof f)) { |
918 | r = -EFAULT; | |
3a4d5c94 | 919 | break; |
7ad9c9d2 | 920 | } |
3a4d5c94 | 921 | eventfp = f.fd == -1 ? NULL : eventfd_fget(f.fd); |
535297a6 MT |
922 | if (IS_ERR(eventfp)) { |
923 | r = PTR_ERR(eventfp); | |
924 | break; | |
925 | } | |
3a4d5c94 MT |
926 | if (eventfp != vq->error) { |
927 | filep = vq->error; | |
928 | vq->error = eventfp; | |
929 | ctx = vq->error_ctx; | |
930 | vq->error_ctx = eventfp ? | |
931 | eventfd_ctx_fileget(eventfp) : NULL; | |
932 | } else | |
933 | filep = eventfp; | |
934 | break; | |
2751c988 GK |
935 | case VHOST_SET_VRING_ENDIAN: |
936 | r = vhost_set_vring_endian(vq, argp); | |
937 | break; | |
938 | case VHOST_GET_VRING_ENDIAN: | |
939 | r = vhost_get_vring_endian(vq, idx, argp); | |
940 | break; | |
03088137 JW |
941 | case VHOST_SET_VRING_BUSYLOOP_TIMEOUT: |
942 | if (copy_from_user(&s, argp, sizeof(s))) { | |
943 | r = -EFAULT; | |
944 | break; | |
945 | } | |
946 | vq->busyloop_timeout = s.num; | |
947 | break; | |
948 | case VHOST_GET_VRING_BUSYLOOP_TIMEOUT: | |
949 | s.index = idx; | |
950 | s.num = vq->busyloop_timeout; | |
951 | if (copy_to_user(argp, &s, sizeof(s))) | |
952 | r = -EFAULT; | |
953 | break; | |
3a4d5c94 MT |
954 | default: |
955 | r = -ENOIOCTLCMD; | |
956 | } | |
957 | ||
958 | if (pollstop && vq->handle_kick) | |
959 | vhost_poll_stop(&vq->poll); | |
960 | ||
961 | if (ctx) | |
962 | eventfd_ctx_put(ctx); | |
963 | if (filep) | |
964 | fput(filep); | |
965 | ||
966 | if (pollstart && vq->handle_kick) | |
2b8b328b | 967 | r = vhost_poll_start(&vq->poll, vq->kick); |
3a4d5c94 MT |
968 | |
969 | mutex_unlock(&vq->mutex); | |
970 | ||
971 | if (pollstop && vq->handle_kick) | |
972 | vhost_poll_flush(&vq->poll); | |
973 | return r; | |
974 | } | |
6ac1afbf | 975 | EXPORT_SYMBOL_GPL(vhost_vring_ioctl); |
3a4d5c94 MT |
976 | |
977 | /* Caller must have device mutex */ | |
935cdee7 | 978 | long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp) |
3a4d5c94 | 979 | { |
3a4d5c94 MT |
980 | struct file *eventfp, *filep = NULL; |
981 | struct eventfd_ctx *ctx = NULL; | |
982 | u64 p; | |
983 | long r; | |
984 | int i, fd; | |
985 | ||
986 | /* If you are not the owner, you can become one */ | |
987 | if (ioctl == VHOST_SET_OWNER) { | |
988 | r = vhost_dev_set_owner(d); | |
989 | goto done; | |
990 | } | |
991 | ||
992 | /* You must be the owner to do anything else */ | |
993 | r = vhost_dev_check_owner(d); | |
994 | if (r) | |
995 | goto done; | |
996 | ||
997 | switch (ioctl) { | |
998 | case VHOST_SET_MEM_TABLE: | |
999 | r = vhost_set_memory(d, argp); | |
1000 | break; | |
1001 | case VHOST_SET_LOG_BASE: | |
7ad9c9d2 TY |
1002 | if (copy_from_user(&p, argp, sizeof p)) { |
1003 | r = -EFAULT; | |
3a4d5c94 | 1004 | break; |
7ad9c9d2 | 1005 | } |
3a4d5c94 MT |
1006 | if ((u64)(unsigned long)p != p) { |
1007 | r = -EFAULT; | |
1008 | break; | |
1009 | } | |
1010 | for (i = 0; i < d->nvqs; ++i) { | |
1011 | struct vhost_virtqueue *vq; | |
1012 | void __user *base = (void __user *)(unsigned long)p; | |
3ab2e420 | 1013 | vq = d->vqs[i]; |
3a4d5c94 MT |
1014 | mutex_lock(&vq->mutex); |
1015 | /* If ring is inactive, will check when it's enabled. */ | |
ea16c514 | 1016 | if (vq->private_data && !vq_log_access_ok(vq, base)) |
3a4d5c94 MT |
1017 | r = -EFAULT; |
1018 | else | |
1019 | vq->log_base = base; | |
1020 | mutex_unlock(&vq->mutex); | |
1021 | } | |
1022 | break; | |
1023 | case VHOST_SET_LOG_FD: | |
1024 | r = get_user(fd, (int __user *)argp); | |
1025 | if (r < 0) | |
1026 | break; | |
1027 | eventfp = fd == -1 ? NULL : eventfd_fget(fd); | |
1028 | if (IS_ERR(eventfp)) { | |
1029 | r = PTR_ERR(eventfp); | |
1030 | break; | |
1031 | } | |
1032 | if (eventfp != d->log_file) { | |
1033 | filep = d->log_file; | |
7932c0bd | 1034 | d->log_file = eventfp; |
3a4d5c94 MT |
1035 | ctx = d->log_ctx; |
1036 | d->log_ctx = eventfp ? | |
1037 | eventfd_ctx_fileget(eventfp) : NULL; | |
1038 | } else | |
1039 | filep = eventfp; | |
1040 | for (i = 0; i < d->nvqs; ++i) { | |
3ab2e420 AH |
1041 | mutex_lock(&d->vqs[i]->mutex); |
1042 | d->vqs[i]->log_ctx = d->log_ctx; | |
1043 | mutex_unlock(&d->vqs[i]->mutex); | |
3a4d5c94 MT |
1044 | } |
1045 | if (ctx) | |
1046 | eventfd_ctx_put(ctx); | |
1047 | if (filep) | |
1048 | fput(filep); | |
1049 | break; | |
1050 | default: | |
935cdee7 | 1051 | r = -ENOIOCTLCMD; |
3a4d5c94 MT |
1052 | break; |
1053 | } | |
1054 | done: | |
1055 | return r; | |
1056 | } | |
6ac1afbf | 1057 | EXPORT_SYMBOL_GPL(vhost_dev_ioctl); |
3a4d5c94 MT |
1058 | |
1059 | static const struct vhost_memory_region *find_region(struct vhost_memory *mem, | |
1060 | __u64 addr, __u32 len) | |
1061 | { | |
bcfeacab IM |
1062 | const struct vhost_memory_region *reg; |
1063 | int start = 0, end = mem->nregions; | |
1064 | ||
1065 | while (start < end) { | |
1066 | int slot = start + (end - start) / 2; | |
1067 | reg = mem->regions + slot; | |
1068 | if (addr >= reg->guest_phys_addr) | |
1069 | end = slot; | |
1070 | else | |
1071 | start = slot + 1; | |
3a4d5c94 | 1072 | } |
bcfeacab IM |
1073 | |
1074 | reg = mem->regions + start; | |
1075 | if (addr >= reg->guest_phys_addr && | |
1076 | reg->guest_phys_addr + reg->memory_size > addr) | |
1077 | return reg; | |
3a4d5c94 MT |
1078 | return NULL; |
1079 | } | |
1080 | ||
1081 | /* TODO: This is really inefficient. We need something like get_user() | |
1082 | * (instruction directly accesses the data, with an exception table entry | |
1083 | * returning -EFAULT). See Documentation/x86/exception-tables.txt. | |
1084 | */ | |
1085 | static int set_bit_to_user(int nr, void __user *addr) | |
1086 | { | |
1087 | unsigned long log = (unsigned long)addr; | |
1088 | struct page *page; | |
1089 | void *base; | |
1090 | int bit = nr + (log % PAGE_SIZE) * 8; | |
1091 | int r; | |
d47effe1 | 1092 | |
3a4d5c94 | 1093 | r = get_user_pages_fast(log, 1, 1, &page); |
d6db3f5c | 1094 | if (r < 0) |
3a4d5c94 | 1095 | return r; |
d6db3f5c | 1096 | BUG_ON(r != 1); |
c6daa7ff | 1097 | base = kmap_atomic(page); |
3a4d5c94 | 1098 | set_bit(bit, base); |
c6daa7ff | 1099 | kunmap_atomic(base); |
3a4d5c94 MT |
1100 | set_page_dirty_lock(page); |
1101 | put_page(page); | |
1102 | return 0; | |
1103 | } | |
1104 | ||
1105 | static int log_write(void __user *log_base, | |
1106 | u64 write_address, u64 write_length) | |
1107 | { | |
28831ee6 | 1108 | u64 write_page = write_address / VHOST_PAGE_SIZE; |
3a4d5c94 | 1109 | int r; |
d47effe1 | 1110 | |
3a4d5c94 MT |
1111 | if (!write_length) |
1112 | return 0; | |
3bf9be40 | 1113 | write_length += write_address % VHOST_PAGE_SIZE; |
3a4d5c94 MT |
1114 | for (;;) { |
1115 | u64 base = (u64)(unsigned long)log_base; | |
28831ee6 MT |
1116 | u64 log = base + write_page / 8; |
1117 | int bit = write_page % 8; | |
3a4d5c94 MT |
1118 | if ((u64)(unsigned long)log != log) |
1119 | return -EFAULT; | |
1120 | r = set_bit_to_user(bit, (void __user *)(unsigned long)log); | |
1121 | if (r < 0) | |
1122 | return r; | |
1123 | if (write_length <= VHOST_PAGE_SIZE) | |
1124 | break; | |
1125 | write_length -= VHOST_PAGE_SIZE; | |
28831ee6 | 1126 | write_page += 1; |
3a4d5c94 MT |
1127 | } |
1128 | return r; | |
1129 | } | |
1130 | ||
1131 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, | |
1132 | unsigned int log_num, u64 len) | |
1133 | { | |
1134 | int i, r; | |
1135 | ||
1136 | /* Make sure data written is seen before log. */ | |
5659338c | 1137 | smp_wmb(); |
3a4d5c94 MT |
1138 | for (i = 0; i < log_num; ++i) { |
1139 | u64 l = min(log[i].len, len); | |
1140 | r = log_write(vq->log_base, log[i].addr, l); | |
1141 | if (r < 0) | |
1142 | return r; | |
1143 | len -= l; | |
5786aee8 MT |
1144 | if (!len) { |
1145 | if (vq->log_ctx) | |
1146 | eventfd_signal(vq->log_ctx, 1); | |
3a4d5c94 | 1147 | return 0; |
5786aee8 | 1148 | } |
3a4d5c94 | 1149 | } |
3a4d5c94 MT |
1150 | /* Length written exceeds what we have stored. This is a bug. */ |
1151 | BUG(); | |
1152 | return 0; | |
1153 | } | |
6ac1afbf | 1154 | EXPORT_SYMBOL_GPL(vhost_log_write); |
3a4d5c94 | 1155 | |
2723feaa JW |
1156 | static int vhost_update_used_flags(struct vhost_virtqueue *vq) |
1157 | { | |
1158 | void __user *used; | |
3b1bbe89 | 1159 | if (__put_user(cpu_to_vhost16(vq, vq->used_flags), &vq->used->flags) < 0) |
2723feaa JW |
1160 | return -EFAULT; |
1161 | if (unlikely(vq->log_used)) { | |
1162 | /* Make sure the flag is seen before log. */ | |
1163 | smp_wmb(); | |
1164 | /* Log used flag write. */ | |
1165 | used = &vq->used->flags; | |
1166 | log_write(vq->log_base, vq->log_addr + | |
1167 | (used - (void __user *)vq->used), | |
1168 | sizeof vq->used->flags); | |
1169 | if (vq->log_ctx) | |
1170 | eventfd_signal(vq->log_ctx, 1); | |
1171 | } | |
1172 | return 0; | |
1173 | } | |
1174 | ||
1175 | static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event) | |
1176 | { | |
3b1bbe89 | 1177 | if (__put_user(cpu_to_vhost16(vq, vq->avail_idx), vhost_avail_event(vq))) |
2723feaa JW |
1178 | return -EFAULT; |
1179 | if (unlikely(vq->log_used)) { | |
1180 | void __user *used; | |
1181 | /* Make sure the event is seen before log. */ | |
1182 | smp_wmb(); | |
1183 | /* Log avail event write */ | |
1184 | used = vhost_avail_event(vq); | |
1185 | log_write(vq->log_base, vq->log_addr + | |
1186 | (used - (void __user *)vq->used), | |
1187 | sizeof *vhost_avail_event(vq)); | |
1188 | if (vq->log_ctx) | |
1189 | eventfd_signal(vq->log_ctx, 1); | |
1190 | } | |
1191 | return 0; | |
1192 | } | |
1193 | ||
80f7d030 | 1194 | int vhost_vq_init_access(struct vhost_virtqueue *vq) |
2723feaa | 1195 | { |
3b1bbe89 | 1196 | __virtio16 last_used_idx; |
2723feaa | 1197 | int r; |
e1f33be9 GK |
1198 | bool is_le = vq->is_le; |
1199 | ||
2751c988 | 1200 | if (!vq->private_data) { |
c5072037 | 1201 | vhost_reset_is_le(vq); |
2723feaa | 1202 | return 0; |
2751c988 GK |
1203 | } |
1204 | ||
1205 | vhost_init_is_le(vq); | |
2723feaa JW |
1206 | |
1207 | r = vhost_update_used_flags(vq); | |
1208 | if (r) | |
e1f33be9 | 1209 | goto err; |
2723feaa | 1210 | vq->signalled_used_valid = false; |
e1f33be9 GK |
1211 | if (!access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) { |
1212 | r = -EFAULT; | |
1213 | goto err; | |
1214 | } | |
64f7f051 MT |
1215 | r = __get_user(last_used_idx, &vq->used->idx); |
1216 | if (r) | |
e1f33be9 | 1217 | goto err; |
3b1bbe89 | 1218 | vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx); |
64f7f051 | 1219 | return 0; |
e1f33be9 GK |
1220 | err: |
1221 | vq->is_le = is_le; | |
1222 | return r; | |
2723feaa | 1223 | } |
80f7d030 | 1224 | EXPORT_SYMBOL_GPL(vhost_vq_init_access); |
2723feaa | 1225 | |
47283bef | 1226 | static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len, |
a8d3782f | 1227 | struct iovec iov[], int iov_size) |
3a4d5c94 MT |
1228 | { |
1229 | const struct vhost_memory_region *reg; | |
1230 | struct vhost_memory *mem; | |
1231 | struct iovec *_iov; | |
1232 | u64 s = 0; | |
1233 | int ret = 0; | |
1234 | ||
47283bef | 1235 | mem = vq->memory; |
3a4d5c94 MT |
1236 | while ((u64)len > s) { |
1237 | u64 size; | |
7b3384fc | 1238 | if (unlikely(ret >= iov_size)) { |
3a4d5c94 MT |
1239 | ret = -ENOBUFS; |
1240 | break; | |
1241 | } | |
1242 | reg = find_region(mem, addr, len); | |
7b3384fc | 1243 | if (unlikely(!reg)) { |
3a4d5c94 MT |
1244 | ret = -EFAULT; |
1245 | break; | |
1246 | } | |
1247 | _iov = iov + ret; | |
1248 | size = reg->memory_size - addr + reg->guest_phys_addr; | |
bd97120f | 1249 | _iov->iov_len = min((u64)len - s, size); |
a8d3782f | 1250 | _iov->iov_base = (void __user *)(unsigned long) |
3a4d5c94 MT |
1251 | (reg->userspace_addr + addr - reg->guest_phys_addr); |
1252 | s += size; | |
1253 | addr += size; | |
1254 | ++ret; | |
1255 | } | |
1256 | ||
3a4d5c94 MT |
1257 | return ret; |
1258 | } | |
1259 | ||
1260 | /* Each buffer in the virtqueues is actually a chain of descriptors. This | |
1261 | * function returns the next descriptor in the chain, | |
1262 | * or -1U if we're at the end. */ | |
3b1bbe89 | 1263 | static unsigned next_desc(struct vhost_virtqueue *vq, struct vring_desc *desc) |
3a4d5c94 MT |
1264 | { |
1265 | unsigned int next; | |
1266 | ||
1267 | /* If this descriptor says it doesn't chain, we're done. */ | |
3b1bbe89 | 1268 | if (!(desc->flags & cpu_to_vhost16(vq, VRING_DESC_F_NEXT))) |
3a4d5c94 MT |
1269 | return -1U; |
1270 | ||
1271 | /* Check they're not leading us off end of descriptors. */ | |
3b1bbe89 | 1272 | next = vhost16_to_cpu(vq, desc->next); |
3a4d5c94 MT |
1273 | /* Make sure compiler knows to grab that: we don't want it changing! */ |
1274 | /* We will use the result as an index in an array, so most | |
1275 | * architectures only need a compiler barrier here. */ | |
1276 | read_barrier_depends(); | |
1277 | ||
1278 | return next; | |
1279 | } | |
1280 | ||
47283bef | 1281 | static int get_indirect(struct vhost_virtqueue *vq, |
7b3384fc MT |
1282 | struct iovec iov[], unsigned int iov_size, |
1283 | unsigned int *out_num, unsigned int *in_num, | |
1284 | struct vhost_log *log, unsigned int *log_num, | |
1285 | struct vring_desc *indirect) | |
3a4d5c94 MT |
1286 | { |
1287 | struct vring_desc desc; | |
1288 | unsigned int i = 0, count, found = 0; | |
3b1bbe89 | 1289 | u32 len = vhost32_to_cpu(vq, indirect->len); |
aad9a1ce | 1290 | struct iov_iter from; |
3a4d5c94 MT |
1291 | int ret; |
1292 | ||
1293 | /* Sanity check */ | |
3b1bbe89 | 1294 | if (unlikely(len % sizeof desc)) { |
3a4d5c94 MT |
1295 | vq_err(vq, "Invalid length in indirect descriptor: " |
1296 | "len 0x%llx not multiple of 0x%zx\n", | |
3b1bbe89 | 1297 | (unsigned long long)len, |
3a4d5c94 MT |
1298 | sizeof desc); |
1299 | return -EINVAL; | |
1300 | } | |
1301 | ||
3b1bbe89 | 1302 | ret = translate_desc(vq, vhost64_to_cpu(vq, indirect->addr), len, vq->indirect, |
e0e9b406 | 1303 | UIO_MAXIOV); |
7b3384fc | 1304 | if (unlikely(ret < 0)) { |
3a4d5c94 MT |
1305 | vq_err(vq, "Translation failure %d in indirect.\n", ret); |
1306 | return ret; | |
1307 | } | |
aad9a1ce | 1308 | iov_iter_init(&from, READ, vq->indirect, ret, len); |
3a4d5c94 MT |
1309 | |
1310 | /* We will use the result as an address to read from, so most | |
1311 | * architectures only need a compiler barrier here. */ | |
1312 | read_barrier_depends(); | |
1313 | ||
3b1bbe89 | 1314 | count = len / sizeof desc; |
3a4d5c94 MT |
1315 | /* Buffers are chained via a 16 bit next field, so |
1316 | * we can have at most 2^16 of these. */ | |
7b3384fc | 1317 | if (unlikely(count > USHRT_MAX + 1)) { |
3a4d5c94 MT |
1318 | vq_err(vq, "Indirect buffer length too big: %d\n", |
1319 | indirect->len); | |
1320 | return -E2BIG; | |
1321 | } | |
1322 | ||
1323 | do { | |
1324 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 1325 | if (unlikely(++found > count)) { |
3a4d5c94 MT |
1326 | vq_err(vq, "Loop detected: last one at %u " |
1327 | "indirect size %u\n", | |
1328 | i, count); | |
1329 | return -EINVAL; | |
1330 | } | |
aad9a1ce AV |
1331 | if (unlikely(copy_from_iter(&desc, sizeof(desc), &from) != |
1332 | sizeof(desc))) { | |
3a4d5c94 | 1333 | vq_err(vq, "Failed indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 1334 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
1335 | return -EINVAL; |
1336 | } | |
3b1bbe89 | 1337 | if (unlikely(desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT))) { |
3a4d5c94 | 1338 | vq_err(vq, "Nested indirect descriptor: idx %d, %zx\n", |
3b1bbe89 | 1339 | i, (size_t)vhost64_to_cpu(vq, indirect->addr) + i * sizeof desc); |
3a4d5c94 MT |
1340 | return -EINVAL; |
1341 | } | |
1342 | ||
3b1bbe89 MT |
1343 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
1344 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
3a4d5c94 | 1345 | iov_size - iov_count); |
7b3384fc | 1346 | if (unlikely(ret < 0)) { |
3a4d5c94 MT |
1347 | vq_err(vq, "Translation failure %d indirect idx %d\n", |
1348 | ret, i); | |
1349 | return ret; | |
1350 | } | |
1351 | /* If this is an input descriptor, increment that count. */ | |
3b1bbe89 | 1352 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) { |
3a4d5c94 MT |
1353 | *in_num += ret; |
1354 | if (unlikely(log)) { | |
3b1bbe89 MT |
1355 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
1356 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
1357 | ++*log_num; |
1358 | } | |
1359 | } else { | |
1360 | /* If it's an output descriptor, they're all supposed | |
1361 | * to come before any input descriptors. */ | |
7b3384fc | 1362 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
1363 | vq_err(vq, "Indirect descriptor " |
1364 | "has out after in: idx %d\n", i); | |
1365 | return -EINVAL; | |
1366 | } | |
1367 | *out_num += ret; | |
1368 | } | |
3b1bbe89 | 1369 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
1370 | return 0; |
1371 | } | |
1372 | ||
1373 | /* This looks in the virtqueue and for the first available buffer, and converts | |
1374 | * it to an iovec for convenient access. Since descriptors consist of some | |
1375 | * number of output then some number of input descriptors, it's actually two | |
1376 | * iovecs, but we pack them into one and note how many of each there were. | |
1377 | * | |
d5675bd2 MT |
1378 | * This function returns the descriptor number found, or vq->num (which is |
1379 | * never a valid descriptor number) if none was found. A negative code is | |
1380 | * returned on error. */ | |
47283bef | 1381 | int vhost_get_vq_desc(struct vhost_virtqueue *vq, |
d5675bd2 MT |
1382 | struct iovec iov[], unsigned int iov_size, |
1383 | unsigned int *out_num, unsigned int *in_num, | |
1384 | struct vhost_log *log, unsigned int *log_num) | |
3a4d5c94 MT |
1385 | { |
1386 | struct vring_desc desc; | |
1387 | unsigned int i, head, found = 0; | |
1388 | u16 last_avail_idx; | |
3b1bbe89 MT |
1389 | __virtio16 avail_idx; |
1390 | __virtio16 ring_head; | |
3a4d5c94 MT |
1391 | int ret; |
1392 | ||
1393 | /* Check it isn't doing very strange things with descriptor numbers. */ | |
1394 | last_avail_idx = vq->last_avail_idx; | |
3b1bbe89 | 1395 | if (unlikely(__get_user(avail_idx, &vq->avail->idx))) { |
3a4d5c94 MT |
1396 | vq_err(vq, "Failed to access avail idx at %p\n", |
1397 | &vq->avail->idx); | |
d5675bd2 | 1398 | return -EFAULT; |
3a4d5c94 | 1399 | } |
3b1bbe89 | 1400 | vq->avail_idx = vhost16_to_cpu(vq, avail_idx); |
3a4d5c94 | 1401 | |
7b3384fc | 1402 | if (unlikely((u16)(vq->avail_idx - last_avail_idx) > vq->num)) { |
3a4d5c94 MT |
1403 | vq_err(vq, "Guest moved used index from %u to %u", |
1404 | last_avail_idx, vq->avail_idx); | |
d5675bd2 | 1405 | return -EFAULT; |
3a4d5c94 MT |
1406 | } |
1407 | ||
1408 | /* If there's nothing new since last we looked, return invalid. */ | |
1409 | if (vq->avail_idx == last_avail_idx) | |
1410 | return vq->num; | |
1411 | ||
1412 | /* Only get avail ring entries after they have been exposed by guest. */ | |
5659338c | 1413 | smp_rmb(); |
3a4d5c94 MT |
1414 | |
1415 | /* Grab the next descriptor number they're advertising, and increment | |
1416 | * the index we've seen. */ | |
3b1bbe89 | 1417 | if (unlikely(__get_user(ring_head, |
5fba13b5 | 1418 | &vq->avail->ring[last_avail_idx & (vq->num - 1)]))) { |
3a4d5c94 MT |
1419 | vq_err(vq, "Failed to read head: idx %d address %p\n", |
1420 | last_avail_idx, | |
1421 | &vq->avail->ring[last_avail_idx % vq->num]); | |
d5675bd2 | 1422 | return -EFAULT; |
3a4d5c94 MT |
1423 | } |
1424 | ||
3b1bbe89 MT |
1425 | head = vhost16_to_cpu(vq, ring_head); |
1426 | ||
3a4d5c94 | 1427 | /* If their number is silly, that's an error. */ |
7b3384fc | 1428 | if (unlikely(head >= vq->num)) { |
3a4d5c94 MT |
1429 | vq_err(vq, "Guest says index %u > %u is available", |
1430 | head, vq->num); | |
d5675bd2 | 1431 | return -EINVAL; |
3a4d5c94 MT |
1432 | } |
1433 | ||
1434 | /* When we start there are none of either input nor output. */ | |
1435 | *out_num = *in_num = 0; | |
1436 | if (unlikely(log)) | |
1437 | *log_num = 0; | |
1438 | ||
1439 | i = head; | |
1440 | do { | |
1441 | unsigned iov_count = *in_num + *out_num; | |
7b3384fc | 1442 | if (unlikely(i >= vq->num)) { |
3a4d5c94 MT |
1443 | vq_err(vq, "Desc index is %u > %u, head = %u", |
1444 | i, vq->num, head); | |
d5675bd2 | 1445 | return -EINVAL; |
3a4d5c94 | 1446 | } |
7b3384fc | 1447 | if (unlikely(++found > vq->num)) { |
3a4d5c94 MT |
1448 | vq_err(vq, "Loop detected: last one at %u " |
1449 | "vq size %u head %u\n", | |
1450 | i, vq->num, head); | |
d5675bd2 | 1451 | return -EINVAL; |
3a4d5c94 | 1452 | } |
fcc042a2 | 1453 | ret = __copy_from_user(&desc, vq->desc + i, sizeof desc); |
7b3384fc | 1454 | if (unlikely(ret)) { |
3a4d5c94 MT |
1455 | vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", |
1456 | i, vq->desc + i); | |
d5675bd2 | 1457 | return -EFAULT; |
3a4d5c94 | 1458 | } |
3b1bbe89 | 1459 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_INDIRECT)) { |
47283bef | 1460 | ret = get_indirect(vq, iov, iov_size, |
3a4d5c94 MT |
1461 | out_num, in_num, |
1462 | log, log_num, &desc); | |
7b3384fc | 1463 | if (unlikely(ret < 0)) { |
3a4d5c94 MT |
1464 | vq_err(vq, "Failure detected " |
1465 | "in indirect descriptor at idx %d\n", i); | |
d5675bd2 | 1466 | return ret; |
3a4d5c94 MT |
1467 | } |
1468 | continue; | |
1469 | } | |
1470 | ||
3b1bbe89 MT |
1471 | ret = translate_desc(vq, vhost64_to_cpu(vq, desc.addr), |
1472 | vhost32_to_cpu(vq, desc.len), iov + iov_count, | |
3a4d5c94 | 1473 | iov_size - iov_count); |
7b3384fc | 1474 | if (unlikely(ret < 0)) { |
3a4d5c94 MT |
1475 | vq_err(vq, "Translation failure %d descriptor idx %d\n", |
1476 | ret, i); | |
d5675bd2 | 1477 | return ret; |
3a4d5c94 | 1478 | } |
3b1bbe89 | 1479 | if (desc.flags & cpu_to_vhost16(vq, VRING_DESC_F_WRITE)) { |
3a4d5c94 MT |
1480 | /* If this is an input descriptor, |
1481 | * increment that count. */ | |
1482 | *in_num += ret; | |
1483 | if (unlikely(log)) { | |
3b1bbe89 MT |
1484 | log[*log_num].addr = vhost64_to_cpu(vq, desc.addr); |
1485 | log[*log_num].len = vhost32_to_cpu(vq, desc.len); | |
3a4d5c94 MT |
1486 | ++*log_num; |
1487 | } | |
1488 | } else { | |
1489 | /* If it's an output descriptor, they're all supposed | |
1490 | * to come before any input descriptors. */ | |
7b3384fc | 1491 | if (unlikely(*in_num)) { |
3a4d5c94 MT |
1492 | vq_err(vq, "Descriptor has out after in: " |
1493 | "idx %d\n", i); | |
d5675bd2 | 1494 | return -EINVAL; |
3a4d5c94 MT |
1495 | } |
1496 | *out_num += ret; | |
1497 | } | |
3b1bbe89 | 1498 | } while ((i = next_desc(vq, &desc)) != -1); |
3a4d5c94 MT |
1499 | |
1500 | /* On success, increment avail index. */ | |
1501 | vq->last_avail_idx++; | |
8ea8cf89 MT |
1502 | |
1503 | /* Assume notifications from guest are disabled at this point, | |
1504 | * if they aren't we would need to update avail_event index. */ | |
1505 | BUG_ON(!(vq->used_flags & VRING_USED_F_NO_NOTIFY)); | |
3a4d5c94 MT |
1506 | return head; |
1507 | } | |
6ac1afbf | 1508 | EXPORT_SYMBOL_GPL(vhost_get_vq_desc); |
3a4d5c94 MT |
1509 | |
1510 | /* Reverse the effect of vhost_get_vq_desc. Useful for error handling. */ | |
8dd014ad | 1511 | void vhost_discard_vq_desc(struct vhost_virtqueue *vq, int n) |
3a4d5c94 | 1512 | { |
8dd014ad | 1513 | vq->last_avail_idx -= n; |
3a4d5c94 | 1514 | } |
6ac1afbf | 1515 | EXPORT_SYMBOL_GPL(vhost_discard_vq_desc); |
3a4d5c94 MT |
1516 | |
1517 | /* After we've used one of their buffers, we tell them about it. We'll then | |
1518 | * want to notify the guest, using eventfd. */ | |
1519 | int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len) | |
1520 | { | |
3b1bbe89 MT |
1521 | struct vring_used_elem heads = { |
1522 | cpu_to_vhost32(vq, head), | |
1523 | cpu_to_vhost32(vq, len) | |
1524 | }; | |
3a4d5c94 | 1525 | |
c49e4e57 | 1526 | return vhost_add_used_n(vq, &heads, 1); |
3a4d5c94 | 1527 | } |
6ac1afbf | 1528 | EXPORT_SYMBOL_GPL(vhost_add_used); |
3a4d5c94 | 1529 | |
8dd014ad DS |
1530 | static int __vhost_add_used_n(struct vhost_virtqueue *vq, |
1531 | struct vring_used_elem *heads, | |
1532 | unsigned count) | |
1533 | { | |
1534 | struct vring_used_elem __user *used; | |
8ea8cf89 | 1535 | u16 old, new; |
8dd014ad DS |
1536 | int start; |
1537 | ||
5fba13b5 | 1538 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad | 1539 | used = vq->used->ring + start; |
c49e4e57 JW |
1540 | if (count == 1) { |
1541 | if (__put_user(heads[0].id, &used->id)) { | |
1542 | vq_err(vq, "Failed to write used id"); | |
1543 | return -EFAULT; | |
1544 | } | |
1545 | if (__put_user(heads[0].len, &used->len)) { | |
1546 | vq_err(vq, "Failed to write used len"); | |
1547 | return -EFAULT; | |
1548 | } | |
1549 | } else if (__copy_to_user(used, heads, count * sizeof *used)) { | |
8dd014ad DS |
1550 | vq_err(vq, "Failed to write used"); |
1551 | return -EFAULT; | |
1552 | } | |
1553 | if (unlikely(vq->log_used)) { | |
1554 | /* Make sure data is seen before log. */ | |
1555 | smp_wmb(); | |
1556 | /* Log used ring entry write. */ | |
1557 | log_write(vq->log_base, | |
1558 | vq->log_addr + | |
1559 | ((void __user *)used - (void __user *)vq->used), | |
1560 | count * sizeof *used); | |
1561 | } | |
8ea8cf89 MT |
1562 | old = vq->last_used_idx; |
1563 | new = (vq->last_used_idx += count); | |
1564 | /* If the driver never bothers to signal in a very long while, | |
1565 | * used index might wrap around. If that happens, invalidate | |
1566 | * signalled_used index we stored. TODO: make sure driver | |
1567 | * signals at least once in 2^16 and remove this. */ | |
1568 | if (unlikely((u16)(new - vq->signalled_used) < (u16)(new - old))) | |
1569 | vq->signalled_used_valid = false; | |
8dd014ad DS |
1570 | return 0; |
1571 | } | |
1572 | ||
1573 | /* After we've used one of their buffers, we tell them about it. We'll then | |
1574 | * want to notify the guest, using eventfd. */ | |
1575 | int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads, | |
1576 | unsigned count) | |
1577 | { | |
1578 | int start, n, r; | |
1579 | ||
5fba13b5 | 1580 | start = vq->last_used_idx & (vq->num - 1); |
8dd014ad DS |
1581 | n = vq->num - start; |
1582 | if (n < count) { | |
1583 | r = __vhost_add_used_n(vq, heads, n); | |
1584 | if (r < 0) | |
1585 | return r; | |
1586 | heads += n; | |
1587 | count -= n; | |
1588 | } | |
1589 | r = __vhost_add_used_n(vq, heads, count); | |
1590 | ||
1591 | /* Make sure buffer is written before we update index. */ | |
1592 | smp_wmb(); | |
3b1bbe89 | 1593 | if (__put_user(cpu_to_vhost16(vq, vq->last_used_idx), &vq->used->idx)) { |
8dd014ad DS |
1594 | vq_err(vq, "Failed to increment used idx"); |
1595 | return -EFAULT; | |
1596 | } | |
1597 | if (unlikely(vq->log_used)) { | |
1598 | /* Log used index update. */ | |
1599 | log_write(vq->log_base, | |
1600 | vq->log_addr + offsetof(struct vring_used, idx), | |
1601 | sizeof vq->used->idx); | |
1602 | if (vq->log_ctx) | |
1603 | eventfd_signal(vq->log_ctx, 1); | |
1604 | } | |
1605 | return r; | |
1606 | } | |
6ac1afbf | 1607 | EXPORT_SYMBOL_GPL(vhost_add_used_n); |
8dd014ad | 1608 | |
8ea8cf89 | 1609 | static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 1610 | { |
3b1bbe89 MT |
1611 | __u16 old, new; |
1612 | __virtio16 event; | |
8ea8cf89 | 1613 | bool v; |
0d499356 MT |
1614 | /* Flush out used index updates. This is paired |
1615 | * with the barrier that the Guest executes when enabling | |
1616 | * interrupts. */ | |
1617 | smp_mb(); | |
1618 | ||
ea16c514 | 1619 | if (vhost_has_feature(vq, VIRTIO_F_NOTIFY_ON_EMPTY) && |
8ea8cf89 MT |
1620 | unlikely(vq->avail_idx == vq->last_avail_idx)) |
1621 | return true; | |
1622 | ||
ea16c514 | 1623 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
3b1bbe89 | 1624 | __virtio16 flags; |
8ea8cf89 MT |
1625 | if (__get_user(flags, &vq->avail->flags)) { |
1626 | vq_err(vq, "Failed to get flags"); | |
1627 | return true; | |
1628 | } | |
3b1bbe89 | 1629 | return !(flags & cpu_to_vhost16(vq, VRING_AVAIL_F_NO_INTERRUPT)); |
3a4d5c94 | 1630 | } |
8ea8cf89 MT |
1631 | old = vq->signalled_used; |
1632 | v = vq->signalled_used_valid; | |
1633 | new = vq->signalled_used = vq->last_used_idx; | |
1634 | vq->signalled_used_valid = true; | |
3a4d5c94 | 1635 | |
8ea8cf89 MT |
1636 | if (unlikely(!v)) |
1637 | return true; | |
3a4d5c94 | 1638 | |
64f7f051 | 1639 | if (__get_user(event, vhost_used_event(vq))) { |
8ea8cf89 MT |
1640 | vq_err(vq, "Failed to get used event idx"); |
1641 | return true; | |
1642 | } | |
3b1bbe89 | 1643 | return vring_need_event(vhost16_to_cpu(vq, event), new, old); |
8ea8cf89 MT |
1644 | } |
1645 | ||
1646 | /* This actually signals the guest, using eventfd. */ | |
1647 | void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
1648 | { | |
3a4d5c94 | 1649 | /* Signal the Guest tell them we used something up. */ |
8ea8cf89 | 1650 | if (vq->call_ctx && vhost_notify(dev, vq)) |
3a4d5c94 MT |
1651 | eventfd_signal(vq->call_ctx, 1); |
1652 | } | |
6ac1afbf | 1653 | EXPORT_SYMBOL_GPL(vhost_signal); |
3a4d5c94 MT |
1654 | |
1655 | /* And here's the combo meal deal. Supersize me! */ | |
1656 | void vhost_add_used_and_signal(struct vhost_dev *dev, | |
1657 | struct vhost_virtqueue *vq, | |
1658 | unsigned int head, int len) | |
1659 | { | |
1660 | vhost_add_used(vq, head, len); | |
1661 | vhost_signal(dev, vq); | |
1662 | } | |
6ac1afbf | 1663 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal); |
3a4d5c94 | 1664 | |
8dd014ad DS |
1665 | /* multi-buffer version of vhost_add_used_and_signal */ |
1666 | void vhost_add_used_and_signal_n(struct vhost_dev *dev, | |
1667 | struct vhost_virtqueue *vq, | |
1668 | struct vring_used_elem *heads, unsigned count) | |
1669 | { | |
1670 | vhost_add_used_n(vq, heads, count); | |
1671 | vhost_signal(dev, vq); | |
1672 | } | |
6ac1afbf | 1673 | EXPORT_SYMBOL_GPL(vhost_add_used_and_signal_n); |
8dd014ad | 1674 | |
d4a60603 JW |
1675 | /* return true if we're sure that avaiable ring is empty */ |
1676 | bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq) | |
1677 | { | |
1678 | __virtio16 avail_idx; | |
1679 | int r; | |
1680 | ||
1681 | r = __get_user(avail_idx, &vq->avail->idx); | |
1682 | if (r) | |
1683 | return false; | |
1684 | ||
1685 | return vhost16_to_cpu(vq, avail_idx) == vq->avail_idx; | |
1686 | } | |
1687 | EXPORT_SYMBOL_GPL(vhost_vq_avail_empty); | |
1688 | ||
3a4d5c94 | 1689 | /* OK, now we need to know about added descriptors. */ |
8ea8cf89 | 1690 | bool vhost_enable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 | 1691 | { |
3b1bbe89 | 1692 | __virtio16 avail_idx; |
3a4d5c94 | 1693 | int r; |
d47effe1 | 1694 | |
3a4d5c94 MT |
1695 | if (!(vq->used_flags & VRING_USED_F_NO_NOTIFY)) |
1696 | return false; | |
1697 | vq->used_flags &= ~VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 1698 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 1699 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
1700 | if (r) { |
1701 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
1702 | &vq->used->flags, r); | |
1703 | return false; | |
1704 | } | |
1705 | } else { | |
2723feaa | 1706 | r = vhost_update_avail_event(vq, vq->avail_idx); |
8ea8cf89 MT |
1707 | if (r) { |
1708 | vq_err(vq, "Failed to update avail event index at %p: %d\n", | |
1709 | vhost_avail_event(vq), r); | |
1710 | return false; | |
1711 | } | |
1712 | } | |
3a4d5c94 MT |
1713 | /* They could have slipped one in as we were doing that: make |
1714 | * sure it's written, then check again. */ | |
5659338c | 1715 | smp_mb(); |
8b7347aa | 1716 | r = __get_user(avail_idx, &vq->avail->idx); |
3a4d5c94 MT |
1717 | if (r) { |
1718 | vq_err(vq, "Failed to check avail idx at %p: %d\n", | |
1719 | &vq->avail->idx, r); | |
1720 | return false; | |
1721 | } | |
1722 | ||
3b1bbe89 | 1723 | return vhost16_to_cpu(vq, avail_idx) != vq->avail_idx; |
3a4d5c94 | 1724 | } |
6ac1afbf | 1725 | EXPORT_SYMBOL_GPL(vhost_enable_notify); |
3a4d5c94 MT |
1726 | |
1727 | /* We don't need to be notified again. */ | |
8ea8cf89 | 1728 | void vhost_disable_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) |
3a4d5c94 MT |
1729 | { |
1730 | int r; | |
d47effe1 | 1731 | |
3a4d5c94 MT |
1732 | if (vq->used_flags & VRING_USED_F_NO_NOTIFY) |
1733 | return; | |
1734 | vq->used_flags |= VRING_USED_F_NO_NOTIFY; | |
ea16c514 | 1735 | if (!vhost_has_feature(vq, VIRTIO_RING_F_EVENT_IDX)) { |
2723feaa | 1736 | r = vhost_update_used_flags(vq); |
8ea8cf89 MT |
1737 | if (r) |
1738 | vq_err(vq, "Failed to enable notification at %p: %d\n", | |
1739 | &vq->used->flags, r); | |
1740 | } | |
3a4d5c94 | 1741 | } |
6ac1afbf AH |
1742 | EXPORT_SYMBOL_GPL(vhost_disable_notify); |
1743 | ||
1744 | static int __init vhost_init(void) | |
1745 | { | |
1746 | return 0; | |
1747 | } | |
1748 | ||
1749 | static void __exit vhost_exit(void) | |
1750 | { | |
1751 | } | |
1752 | ||
1753 | module_init(vhost_init); | |
1754 | module_exit(vhost_exit); | |
1755 | ||
1756 | MODULE_VERSION("0.0.1"); | |
1757 | MODULE_LICENSE("GPL v2"); | |
1758 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
1759 | MODULE_DESCRIPTION("Host kernel accelerator for virtio"); |