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1 | /* |
2 | * VMware VMCI Driver | |
3 | * | |
4 | * Copyright (C) 2012 VMware, Inc. All rights reserved. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation version 2 and no later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
12 | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
13 | * for more details. | |
14 | */ | |
15 | ||
16 | #include <linux/vmw_vmci_defs.h> | |
17 | #include <linux/vmw_vmci_api.h> | |
18 | #include <linux/highmem.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/slab.h> | |
23 | ||
24 | #include "vmci_queue_pair.h" | |
25 | #include "vmci_datagram.h" | |
26 | #include "vmci_doorbell.h" | |
27 | #include "vmci_context.h" | |
28 | #include "vmci_driver.h" | |
29 | #include "vmci_event.h" | |
30 | ||
31 | /* | |
32 | * List of current VMCI contexts. Contexts can be added by | |
33 | * vmci_ctx_create() and removed via vmci_ctx_destroy(). | |
34 | * These, along with context lookup, are protected by the | |
35 | * list structure's lock. | |
36 | */ | |
37 | static struct { | |
38 | struct list_head head; | |
39 | spinlock_t lock; /* Spinlock for context list operations */ | |
40 | } ctx_list = { | |
41 | .head = LIST_HEAD_INIT(ctx_list.head), | |
42 | .lock = __SPIN_LOCK_UNLOCKED(ctx_list.lock), | |
43 | }; | |
44 | ||
45 | /* Used by contexts that did not set up notify flag pointers */ | |
46 | static bool ctx_dummy_notify; | |
47 | ||
48 | static void ctx_signal_notify(struct vmci_ctx *context) | |
49 | { | |
50 | *context->notify = true; | |
51 | } | |
52 | ||
53 | static void ctx_clear_notify(struct vmci_ctx *context) | |
54 | { | |
55 | *context->notify = false; | |
56 | } | |
57 | ||
58 | /* | |
59 | * If nothing requires the attention of the guest, clears both | |
60 | * notify flag and call. | |
61 | */ | |
62 | static void ctx_clear_notify_call(struct vmci_ctx *context) | |
63 | { | |
64 | if (context->pending_datagrams == 0 && | |
65 | vmci_handle_arr_get_size(context->pending_doorbell_array) == 0) | |
66 | ctx_clear_notify(context); | |
67 | } | |
68 | ||
69 | /* | |
70 | * Sets the context's notify flag iff datagrams are pending for this | |
71 | * context. Called from vmci_setup_notify(). | |
72 | */ | |
73 | void vmci_ctx_check_signal_notify(struct vmci_ctx *context) | |
74 | { | |
75 | spin_lock(&context->lock); | |
76 | if (context->pending_datagrams) | |
77 | ctx_signal_notify(context); | |
78 | spin_unlock(&context->lock); | |
79 | } | |
80 | ||
81 | /* | |
82 | * Allocates and initializes a VMCI context. | |
83 | */ | |
84 | struct vmci_ctx *vmci_ctx_create(u32 cid, u32 priv_flags, | |
85 | uintptr_t event_hnd, | |
86 | int user_version, | |
87 | const struct cred *cred) | |
88 | { | |
89 | struct vmci_ctx *context; | |
90 | int error; | |
91 | ||
92 | if (cid == VMCI_INVALID_ID) { | |
93 | pr_devel("Invalid context ID for VMCI context\n"); | |
94 | error = -EINVAL; | |
95 | goto err_out; | |
96 | } | |
97 | ||
98 | if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS) { | |
99 | pr_devel("Invalid flag (flags=0x%x) for VMCI context\n", | |
100 | priv_flags); | |
101 | error = -EINVAL; | |
102 | goto err_out; | |
103 | } | |
104 | ||
105 | if (user_version == 0) { | |
106 | pr_devel("Invalid suer_version %d\n", user_version); | |
107 | error = -EINVAL; | |
108 | goto err_out; | |
109 | } | |
110 | ||
111 | context = kzalloc(sizeof(*context), GFP_KERNEL); | |
112 | if (!context) { | |
113 | pr_warn("Failed to allocate memory for VMCI context\n"); | |
114 | error = -EINVAL; | |
115 | goto err_out; | |
116 | } | |
117 | ||
118 | kref_init(&context->kref); | |
119 | spin_lock_init(&context->lock); | |
120 | INIT_LIST_HEAD(&context->list_item); | |
121 | INIT_LIST_HEAD(&context->datagram_queue); | |
122 | INIT_LIST_HEAD(&context->notifier_list); | |
123 | ||
124 | /* Initialize host-specific VMCI context. */ | |
125 | init_waitqueue_head(&context->host_context.wait_queue); | |
126 | ||
127 | context->queue_pair_array = vmci_handle_arr_create(0); | |
128 | if (!context->queue_pair_array) { | |
129 | error = -ENOMEM; | |
130 | goto err_free_ctx; | |
131 | } | |
132 | ||
133 | context->doorbell_array = vmci_handle_arr_create(0); | |
134 | if (!context->doorbell_array) { | |
135 | error = -ENOMEM; | |
136 | goto err_free_qp_array; | |
137 | } | |
138 | ||
139 | context->pending_doorbell_array = vmci_handle_arr_create(0); | |
140 | if (!context->pending_doorbell_array) { | |
141 | error = -ENOMEM; | |
142 | goto err_free_db_array; | |
143 | } | |
144 | ||
145 | context->user_version = user_version; | |
146 | ||
147 | context->priv_flags = priv_flags; | |
148 | ||
149 | if (cred) | |
150 | context->cred = get_cred(cred); | |
151 | ||
152 | context->notify = &ctx_dummy_notify; | |
153 | context->notify_page = NULL; | |
154 | ||
155 | /* | |
156 | * If we collide with an existing context we generate a new | |
157 | * and use it instead. The VMX will determine if regeneration | |
158 | * is okay. Since there isn't 4B - 16 VMs running on a given | |
159 | * host, the below loop will terminate. | |
160 | */ | |
161 | spin_lock(&ctx_list.lock); | |
162 | ||
163 | while (vmci_ctx_exists(cid)) { | |
164 | /* We reserve the lowest 16 ids for fixed contexts. */ | |
165 | cid = max(cid, VMCI_RESERVED_CID_LIMIT - 1) + 1; | |
166 | if (cid == VMCI_INVALID_ID) | |
167 | cid = VMCI_RESERVED_CID_LIMIT; | |
168 | } | |
169 | context->cid = cid; | |
170 | ||
171 | list_add_tail_rcu(&context->list_item, &ctx_list.head); | |
172 | spin_unlock(&ctx_list.lock); | |
173 | ||
174 | return context; | |
175 | ||
176 | err_free_db_array: | |
177 | vmci_handle_arr_destroy(context->doorbell_array); | |
178 | err_free_qp_array: | |
179 | vmci_handle_arr_destroy(context->queue_pair_array); | |
180 | err_free_ctx: | |
181 | kfree(context); | |
182 | err_out: | |
183 | return ERR_PTR(error); | |
184 | } | |
185 | ||
186 | /* | |
187 | * Destroy VMCI context. | |
188 | */ | |
189 | void vmci_ctx_destroy(struct vmci_ctx *context) | |
190 | { | |
191 | spin_lock(&ctx_list.lock); | |
192 | list_del_rcu(&context->list_item); | |
193 | spin_unlock(&ctx_list.lock); | |
194 | synchronize_rcu(); | |
195 | ||
196 | vmci_ctx_put(context); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Fire notification for all contexts interested in given cid. | |
201 | */ | |
202 | static int ctx_fire_notification(u32 context_id, u32 priv_flags) | |
203 | { | |
204 | u32 i, array_size; | |
205 | struct vmci_ctx *sub_ctx; | |
206 | struct vmci_handle_arr *subscriber_array; | |
207 | struct vmci_handle context_handle = | |
208 | vmci_make_handle(context_id, VMCI_EVENT_HANDLER); | |
209 | ||
210 | /* | |
211 | * We create an array to hold the subscribers we find when | |
212 | * scanning through all contexts. | |
213 | */ | |
214 | subscriber_array = vmci_handle_arr_create(0); | |
215 | if (subscriber_array == NULL) | |
216 | return VMCI_ERROR_NO_MEM; | |
217 | ||
218 | /* | |
219 | * Scan all contexts to find who is interested in being | |
220 | * notified about given contextID. | |
221 | */ | |
222 | rcu_read_lock(); | |
223 | list_for_each_entry_rcu(sub_ctx, &ctx_list.head, list_item) { | |
224 | struct vmci_handle_list *node; | |
225 | ||
226 | /* | |
227 | * We only deliver notifications of the removal of | |
228 | * contexts, if the two contexts are allowed to | |
229 | * interact. | |
230 | */ | |
231 | if (vmci_deny_interaction(priv_flags, sub_ctx->priv_flags)) | |
232 | continue; | |
233 | ||
234 | list_for_each_entry_rcu(node, &sub_ctx->notifier_list, node) { | |
235 | if (!vmci_handle_is_equal(node->handle, context_handle)) | |
236 | continue; | |
237 | ||
238 | vmci_handle_arr_append_entry(&subscriber_array, | |
239 | vmci_make_handle(sub_ctx->cid, | |
240 | VMCI_EVENT_HANDLER)); | |
241 | } | |
242 | } | |
243 | rcu_read_unlock(); | |
244 | ||
245 | /* Fire event to all subscribers. */ | |
246 | array_size = vmci_handle_arr_get_size(subscriber_array); | |
247 | for (i = 0; i < array_size; i++) { | |
248 | int result; | |
249 | struct vmci_event_ctx ev; | |
250 | ||
251 | ev.msg.hdr.dst = vmci_handle_arr_get_entry(subscriber_array, i); | |
252 | ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, | |
253 | VMCI_CONTEXT_RESOURCE_ID); | |
254 | ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr); | |
255 | ev.msg.event_data.event = VMCI_EVENT_CTX_REMOVED; | |
256 | ev.payload.context_id = context_id; | |
257 | ||
258 | result = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID, | |
259 | &ev.msg.hdr, false); | |
260 | if (result < VMCI_SUCCESS) { | |
261 | pr_devel("Failed to enqueue event datagram (type=%d) for context (ID=0x%x)\n", | |
262 | ev.msg.event_data.event, | |
263 | ev.msg.hdr.dst.context); | |
264 | /* We continue to enqueue on next subscriber. */ | |
265 | } | |
266 | } | |
267 | vmci_handle_arr_destroy(subscriber_array); | |
268 | ||
269 | return VMCI_SUCCESS; | |
270 | } | |
271 | ||
272 | /* | |
273 | * Returns the current number of pending datagrams. The call may | |
274 | * also serve as a synchronization point for the datagram queue, | |
275 | * as no enqueue operations can occur concurrently. | |
276 | */ | |
277 | int vmci_ctx_pending_datagrams(u32 cid, u32 *pending) | |
278 | { | |
279 | struct vmci_ctx *context; | |
280 | ||
281 | context = vmci_ctx_get(cid); | |
282 | if (context == NULL) | |
283 | return VMCI_ERROR_INVALID_ARGS; | |
284 | ||
285 | spin_lock(&context->lock); | |
286 | if (pending) | |
287 | *pending = context->pending_datagrams; | |
288 | spin_unlock(&context->lock); | |
289 | vmci_ctx_put(context); | |
290 | ||
291 | return VMCI_SUCCESS; | |
292 | } | |
293 | ||
294 | /* | |
295 | * Queues a VMCI datagram for the appropriate target VM context. | |
296 | */ | |
297 | int vmci_ctx_enqueue_datagram(u32 cid, struct vmci_datagram *dg) | |
298 | { | |
299 | struct vmci_datagram_queue_entry *dq_entry; | |
300 | struct vmci_ctx *context; | |
301 | struct vmci_handle dg_src; | |
302 | size_t vmci_dg_size; | |
303 | ||
304 | vmci_dg_size = VMCI_DG_SIZE(dg); | |
305 | if (vmci_dg_size > VMCI_MAX_DG_SIZE) { | |
306 | pr_devel("Datagram too large (bytes=%Zu)\n", vmci_dg_size); | |
307 | return VMCI_ERROR_INVALID_ARGS; | |
308 | } | |
309 | ||
310 | /* Get the target VM's VMCI context. */ | |
311 | context = vmci_ctx_get(cid); | |
312 | if (!context) { | |
313 | pr_devel("Invalid context (ID=0x%x)\n", cid); | |
314 | return VMCI_ERROR_INVALID_ARGS; | |
315 | } | |
316 | ||
317 | /* Allocate guest call entry and add it to the target VM's queue. */ | |
318 | dq_entry = kmalloc(sizeof(*dq_entry), GFP_KERNEL); | |
319 | if (dq_entry == NULL) { | |
320 | pr_warn("Failed to allocate memory for datagram\n"); | |
321 | vmci_ctx_put(context); | |
322 | return VMCI_ERROR_NO_MEM; | |
323 | } | |
324 | dq_entry->dg = dg; | |
325 | dq_entry->dg_size = vmci_dg_size; | |
326 | dg_src = dg->src; | |
327 | INIT_LIST_HEAD(&dq_entry->list_item); | |
328 | ||
329 | spin_lock(&context->lock); | |
330 | ||
331 | /* | |
332 | * We put a higher limit on datagrams from the hypervisor. If | |
333 | * the pending datagram is not from hypervisor, then we check | |
334 | * if enqueueing it would exceed the | |
335 | * VMCI_MAX_DATAGRAM_QUEUE_SIZE limit on the destination. If | |
336 | * the pending datagram is from hypervisor, we allow it to be | |
337 | * queued at the destination side provided we don't reach the | |
338 | * VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE limit. | |
339 | */ | |
340 | if (context->datagram_queue_size + vmci_dg_size >= | |
341 | VMCI_MAX_DATAGRAM_QUEUE_SIZE && | |
342 | (!vmci_handle_is_equal(dg_src, | |
343 | vmci_make_handle | |
344 | (VMCI_HYPERVISOR_CONTEXT_ID, | |
345 | VMCI_CONTEXT_RESOURCE_ID)) || | |
346 | context->datagram_queue_size + vmci_dg_size >= | |
347 | VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE)) { | |
348 | spin_unlock(&context->lock); | |
349 | vmci_ctx_put(context); | |
350 | kfree(dq_entry); | |
351 | pr_devel("Context (ID=0x%x) receive queue is full\n", cid); | |
352 | return VMCI_ERROR_NO_RESOURCES; | |
353 | } | |
354 | ||
355 | list_add(&dq_entry->list_item, &context->datagram_queue); | |
356 | context->pending_datagrams++; | |
357 | context->datagram_queue_size += vmci_dg_size; | |
358 | ctx_signal_notify(context); | |
359 | wake_up(&context->host_context.wait_queue); | |
360 | spin_unlock(&context->lock); | |
361 | vmci_ctx_put(context); | |
362 | ||
363 | return vmci_dg_size; | |
364 | } | |
365 | ||
366 | /* | |
367 | * Verifies whether a context with the specified context ID exists. | |
368 | * FIXME: utility is dubious as no decisions can be reliably made | |
369 | * using this data as context can appear and disappear at any time. | |
370 | */ | |
371 | bool vmci_ctx_exists(u32 cid) | |
372 | { | |
373 | struct vmci_ctx *context; | |
374 | bool exists = false; | |
375 | ||
376 | rcu_read_lock(); | |
377 | ||
378 | list_for_each_entry_rcu(context, &ctx_list.head, list_item) { | |
379 | if (context->cid == cid) { | |
380 | exists = true; | |
381 | break; | |
382 | } | |
383 | } | |
384 | ||
385 | rcu_read_unlock(); | |
386 | return exists; | |
387 | } | |
388 | ||
389 | /* | |
390 | * Retrieves VMCI context corresponding to the given cid. | |
391 | */ | |
392 | struct vmci_ctx *vmci_ctx_get(u32 cid) | |
393 | { | |
394 | struct vmci_ctx *c, *context = NULL; | |
395 | ||
396 | if (cid == VMCI_INVALID_ID) | |
397 | return NULL; | |
398 | ||
399 | rcu_read_lock(); | |
400 | list_for_each_entry_rcu(c, &ctx_list.head, list_item) { | |
401 | if (c->cid == cid) { | |
402 | /* | |
403 | * The context owner drops its own reference to the | |
404 | * context only after removing it from the list and | |
405 | * waiting for RCU grace period to expire. This | |
406 | * means that we are not about to increase the | |
407 | * reference count of something that is in the | |
408 | * process of being destroyed. | |
409 | */ | |
410 | context = c; | |
411 | kref_get(&context->kref); | |
412 | break; | |
413 | } | |
414 | } | |
415 | rcu_read_unlock(); | |
416 | ||
417 | return context; | |
418 | } | |
419 | ||
420 | /* | |
421 | * Deallocates all parts of a context data structure. This | |
422 | * function doesn't lock the context, because it assumes that | |
423 | * the caller was holding the last reference to context. | |
424 | */ | |
425 | static void ctx_free_ctx(struct kref *kref) | |
426 | { | |
427 | struct vmci_ctx *context = container_of(kref, struct vmci_ctx, kref); | |
428 | struct vmci_datagram_queue_entry *dq_entry, *dq_entry_tmp; | |
429 | struct vmci_handle temp_handle; | |
430 | struct vmci_handle_list *notifier, *tmp; | |
431 | ||
432 | /* | |
433 | * Fire event to all contexts interested in knowing this | |
434 | * context is dying. | |
435 | */ | |
436 | ctx_fire_notification(context->cid, context->priv_flags); | |
437 | ||
438 | /* | |
439 | * Cleanup all queue pair resources attached to context. If | |
440 | * the VM dies without cleaning up, this code will make sure | |
441 | * that no resources are leaked. | |
442 | */ | |
443 | temp_handle = vmci_handle_arr_get_entry(context->queue_pair_array, 0); | |
444 | while (!vmci_handle_is_equal(temp_handle, VMCI_INVALID_HANDLE)) { | |
445 | if (vmci_qp_broker_detach(temp_handle, | |
446 | context) < VMCI_SUCCESS) { | |
447 | /* | |
448 | * When vmci_qp_broker_detach() succeeds it | |
449 | * removes the handle from the array. If | |
450 | * detach fails, we must remove the handle | |
451 | * ourselves. | |
452 | */ | |
453 | vmci_handle_arr_remove_entry(context->queue_pair_array, | |
454 | temp_handle); | |
455 | } | |
456 | temp_handle = | |
457 | vmci_handle_arr_get_entry(context->queue_pair_array, 0); | |
458 | } | |
459 | ||
460 | /* | |
461 | * It is fine to destroy this without locking the callQueue, as | |
462 | * this is the only thread having a reference to the context. | |
463 | */ | |
464 | list_for_each_entry_safe(dq_entry, dq_entry_tmp, | |
465 | &context->datagram_queue, list_item) { | |
466 | WARN_ON(dq_entry->dg_size != VMCI_DG_SIZE(dq_entry->dg)); | |
467 | list_del(&dq_entry->list_item); | |
468 | kfree(dq_entry->dg); | |
469 | kfree(dq_entry); | |
470 | } | |
471 | ||
472 | list_for_each_entry_safe(notifier, tmp, | |
473 | &context->notifier_list, node) { | |
474 | list_del(¬ifier->node); | |
475 | kfree(notifier); | |
476 | } | |
477 | ||
478 | vmci_handle_arr_destroy(context->queue_pair_array); | |
479 | vmci_handle_arr_destroy(context->doorbell_array); | |
480 | vmci_handle_arr_destroy(context->pending_doorbell_array); | |
481 | vmci_ctx_unset_notify(context); | |
482 | if (context->cred) | |
483 | put_cred(context->cred); | |
484 | kfree(context); | |
485 | } | |
486 | ||
487 | /* | |
488 | * Drops reference to VMCI context. If this is the last reference to | |
489 | * the context it will be deallocated. A context is created with | |
490 | * a reference count of one, and on destroy, it is removed from | |
491 | * the context list before its reference count is decremented. Thus, | |
492 | * if we reach zero, we are sure that nobody else are about to increment | |
493 | * it (they need the entry in the context list for that), and so there | |
494 | * is no need for locking. | |
495 | */ | |
496 | void vmci_ctx_put(struct vmci_ctx *context) | |
497 | { | |
498 | kref_put(&context->kref, ctx_free_ctx); | |
499 | } | |
500 | ||
501 | /* | |
502 | * Dequeues the next datagram and returns it to caller. | |
503 | * The caller passes in a pointer to the max size datagram | |
504 | * it can handle and the datagram is only unqueued if the | |
505 | * size is less than max_size. If larger max_size is set to | |
506 | * the size of the datagram to give the caller a chance to | |
507 | * set up a larger buffer for the guestcall. | |
508 | */ | |
509 | int vmci_ctx_dequeue_datagram(struct vmci_ctx *context, | |
510 | size_t *max_size, | |
511 | struct vmci_datagram **dg) | |
512 | { | |
513 | struct vmci_datagram_queue_entry *dq_entry; | |
514 | struct list_head *list_item; | |
515 | int rv; | |
516 | ||
517 | /* Dequeue the next datagram entry. */ | |
518 | spin_lock(&context->lock); | |
519 | if (context->pending_datagrams == 0) { | |
520 | ctx_clear_notify_call(context); | |
521 | spin_unlock(&context->lock); | |
522 | pr_devel("No datagrams pending\n"); | |
523 | return VMCI_ERROR_NO_MORE_DATAGRAMS; | |
524 | } | |
525 | ||
526 | list_item = context->datagram_queue.next; | |
527 | ||
528 | dq_entry = | |
529 | list_entry(list_item, struct vmci_datagram_queue_entry, list_item); | |
530 | ||
531 | /* Check size of caller's buffer. */ | |
532 | if (*max_size < dq_entry->dg_size) { | |
533 | *max_size = dq_entry->dg_size; | |
534 | spin_unlock(&context->lock); | |
535 | pr_devel("Caller's buffer should be at least (size=%u bytes)\n", | |
536 | (u32) *max_size); | |
537 | return VMCI_ERROR_NO_MEM; | |
538 | } | |
539 | ||
540 | list_del(list_item); | |
541 | context->pending_datagrams--; | |
542 | context->datagram_queue_size -= dq_entry->dg_size; | |
543 | if (context->pending_datagrams == 0) { | |
544 | ctx_clear_notify_call(context); | |
545 | rv = VMCI_SUCCESS; | |
546 | } else { | |
547 | /* | |
548 | * Return the size of the next datagram. | |
549 | */ | |
550 | struct vmci_datagram_queue_entry *next_entry; | |
551 | ||
552 | list_item = context->datagram_queue.next; | |
553 | next_entry = | |
554 | list_entry(list_item, struct vmci_datagram_queue_entry, | |
555 | list_item); | |
556 | ||
557 | /* | |
558 | * The following size_t -> int truncation is fine as | |
559 | * the maximum size of a (routable) datagram is 68KB. | |
560 | */ | |
561 | rv = (int)next_entry->dg_size; | |
562 | } | |
563 | spin_unlock(&context->lock); | |
564 | ||
565 | /* Caller must free datagram. */ | |
566 | *dg = dq_entry->dg; | |
567 | dq_entry->dg = NULL; | |
568 | kfree(dq_entry); | |
569 | ||
570 | return rv; | |
571 | } | |
572 | ||
573 | /* | |
574 | * Reverts actions set up by vmci_setup_notify(). Unmaps and unlocks the | |
575 | * page mapped/locked by vmci_setup_notify(). | |
576 | */ | |
577 | void vmci_ctx_unset_notify(struct vmci_ctx *context) | |
578 | { | |
579 | struct page *notify_page; | |
580 | ||
581 | spin_lock(&context->lock); | |
582 | ||
583 | notify_page = context->notify_page; | |
584 | context->notify = &ctx_dummy_notify; | |
585 | context->notify_page = NULL; | |
586 | ||
587 | spin_unlock(&context->lock); | |
588 | ||
589 | if (notify_page) { | |
590 | kunmap(notify_page); | |
591 | put_page(notify_page); | |
592 | } | |
593 | } | |
594 | ||
595 | /* | |
596 | * Add remote_cid to list of contexts current contexts wants | |
597 | * notifications from/about. | |
598 | */ | |
599 | int vmci_ctx_add_notification(u32 context_id, u32 remote_cid) | |
600 | { | |
601 | struct vmci_ctx *context; | |
602 | struct vmci_handle_list *notifier, *n; | |
603 | int result; | |
604 | bool exists = false; | |
605 | ||
606 | context = vmci_ctx_get(context_id); | |
607 | if (!context) | |
608 | return VMCI_ERROR_NOT_FOUND; | |
609 | ||
610 | if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(remote_cid)) { | |
611 | pr_devel("Context removed notifications for other VMs not supported (src=0x%x, remote=0x%x)\n", | |
612 | context_id, remote_cid); | |
613 | result = VMCI_ERROR_DST_UNREACHABLE; | |
614 | goto out; | |
615 | } | |
616 | ||
617 | if (context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED) { | |
618 | result = VMCI_ERROR_NO_ACCESS; | |
619 | goto out; | |
620 | } | |
621 | ||
622 | notifier = kmalloc(sizeof(struct vmci_handle_list), GFP_KERNEL); | |
623 | if (!notifier) { | |
624 | result = VMCI_ERROR_NO_MEM; | |
625 | goto out; | |
626 | } | |
627 | ||
628 | INIT_LIST_HEAD(¬ifier->node); | |
629 | notifier->handle = vmci_make_handle(remote_cid, VMCI_EVENT_HANDLER); | |
630 | ||
631 | spin_lock(&context->lock); | |
632 | ||
633 | list_for_each_entry(n, &context->notifier_list, node) { | |
634 | if (vmci_handle_is_equal(n->handle, notifier->handle)) { | |
635 | exists = true; | |
636 | break; | |
637 | } | |
638 | } | |
639 | ||
640 | if (exists) { | |
641 | kfree(notifier); | |
642 | result = VMCI_ERROR_ALREADY_EXISTS; | |
643 | } else { | |
644 | list_add_tail_rcu(¬ifier->node, &context->notifier_list); | |
645 | context->n_notifiers++; | |
646 | result = VMCI_SUCCESS; | |
647 | } | |
648 | ||
649 | spin_unlock(&context->lock); | |
650 | ||
651 | out: | |
652 | vmci_ctx_put(context); | |
653 | return result; | |
654 | } | |
655 | ||
656 | /* | |
657 | * Remove remote_cid from current context's list of contexts it is | |
658 | * interested in getting notifications from/about. | |
659 | */ | |
660 | int vmci_ctx_remove_notification(u32 context_id, u32 remote_cid) | |
661 | { | |
662 | struct vmci_ctx *context; | |
663 | struct vmci_handle_list *notifier, *tmp; | |
664 | struct vmci_handle handle; | |
665 | bool found = false; | |
666 | ||
667 | context = vmci_ctx_get(context_id); | |
668 | if (!context) | |
669 | return VMCI_ERROR_NOT_FOUND; | |
670 | ||
671 | handle = vmci_make_handle(remote_cid, VMCI_EVENT_HANDLER); | |
672 | ||
673 | spin_lock(&context->lock); | |
674 | list_for_each_entry_safe(notifier, tmp, | |
675 | &context->notifier_list, node) { | |
676 | if (vmci_handle_is_equal(notifier->handle, handle)) { | |
677 | list_del_rcu(¬ifier->node); | |
678 | context->n_notifiers--; | |
679 | found = true; | |
680 | break; | |
681 | } | |
682 | } | |
683 | spin_unlock(&context->lock); | |
684 | ||
685 | if (found) { | |
686 | synchronize_rcu(); | |
687 | kfree(notifier); | |
688 | } | |
689 | ||
690 | vmci_ctx_put(context); | |
691 | ||
692 | return found ? VMCI_SUCCESS : VMCI_ERROR_NOT_FOUND; | |
693 | } | |
694 | ||
695 | static int vmci_ctx_get_chkpt_notifiers(struct vmci_ctx *context, | |
696 | u32 *buf_size, void **pbuf) | |
697 | { | |
698 | u32 *notifiers; | |
699 | size_t data_size; | |
700 | struct vmci_handle_list *entry; | |
701 | int i = 0; | |
702 | ||
703 | if (context->n_notifiers == 0) { | |
704 | *buf_size = 0; | |
705 | *pbuf = NULL; | |
706 | return VMCI_SUCCESS; | |
707 | } | |
708 | ||
709 | data_size = context->n_notifiers * sizeof(*notifiers); | |
710 | if (*buf_size < data_size) { | |
711 | *buf_size = data_size; | |
712 | return VMCI_ERROR_MORE_DATA; | |
713 | } | |
714 | ||
715 | notifiers = kmalloc(data_size, GFP_ATOMIC); /* FIXME: want GFP_KERNEL */ | |
716 | if (!notifiers) | |
717 | return VMCI_ERROR_NO_MEM; | |
718 | ||
719 | list_for_each_entry(entry, &context->notifier_list, node) | |
720 | notifiers[i++] = entry->handle.context; | |
721 | ||
722 | *buf_size = data_size; | |
723 | *pbuf = notifiers; | |
724 | return VMCI_SUCCESS; | |
725 | } | |
726 | ||
727 | static int vmci_ctx_get_chkpt_doorbells(struct vmci_ctx *context, | |
728 | u32 *buf_size, void **pbuf) | |
729 | { | |
730 | struct dbell_cpt_state *dbells; | |
731 | size_t n_doorbells; | |
732 | int i; | |
733 | ||
734 | n_doorbells = vmci_handle_arr_get_size(context->doorbell_array); | |
735 | if (n_doorbells > 0) { | |
736 | size_t data_size = n_doorbells * sizeof(*dbells); | |
737 | if (*buf_size < data_size) { | |
738 | *buf_size = data_size; | |
739 | return VMCI_ERROR_MORE_DATA; | |
740 | } | |
741 | ||
742 | dbells = kmalloc(data_size, GFP_ATOMIC); | |
743 | if (!dbells) | |
744 | return VMCI_ERROR_NO_MEM; | |
745 | ||
746 | for (i = 0; i < n_doorbells; i++) | |
747 | dbells[i].handle = vmci_handle_arr_get_entry( | |
748 | context->doorbell_array, i); | |
749 | ||
750 | *buf_size = data_size; | |
751 | *pbuf = dbells; | |
752 | } else { | |
753 | *buf_size = 0; | |
754 | *pbuf = NULL; | |
755 | } | |
756 | ||
757 | return VMCI_SUCCESS; | |
758 | } | |
759 | ||
760 | /* | |
761 | * Get current context's checkpoint state of given type. | |
762 | */ | |
763 | int vmci_ctx_get_chkpt_state(u32 context_id, | |
764 | u32 cpt_type, | |
765 | u32 *buf_size, | |
766 | void **pbuf) | |
767 | { | |
768 | struct vmci_ctx *context; | |
769 | int result; | |
770 | ||
771 | context = vmci_ctx_get(context_id); | |
772 | if (!context) | |
773 | return VMCI_ERROR_NOT_FOUND; | |
774 | ||
775 | spin_lock(&context->lock); | |
776 | ||
777 | switch (cpt_type) { | |
778 | case VMCI_NOTIFICATION_CPT_STATE: | |
779 | result = vmci_ctx_get_chkpt_notifiers(context, buf_size, pbuf); | |
780 | break; | |
781 | ||
782 | case VMCI_WELLKNOWN_CPT_STATE: | |
783 | /* | |
784 | * For compatibility with VMX'en with VM to VM communication, we | |
785 | * always return zero wellknown handles. | |
786 | */ | |
787 | ||
788 | *buf_size = 0; | |
789 | *pbuf = NULL; | |
790 | result = VMCI_SUCCESS; | |
791 | break; | |
792 | ||
793 | case VMCI_DOORBELL_CPT_STATE: | |
794 | result = vmci_ctx_get_chkpt_doorbells(context, buf_size, pbuf); | |
795 | break; | |
796 | ||
797 | default: | |
798 | pr_devel("Invalid cpt state (type=%d)\n", cpt_type); | |
799 | result = VMCI_ERROR_INVALID_ARGS; | |
800 | break; | |
801 | } | |
802 | ||
803 | spin_unlock(&context->lock); | |
804 | vmci_ctx_put(context); | |
805 | ||
806 | return result; | |
807 | } | |
808 | ||
809 | /* | |
810 | * Set current context's checkpoint state of given type. | |
811 | */ | |
812 | int vmci_ctx_set_chkpt_state(u32 context_id, | |
813 | u32 cpt_type, | |
814 | u32 buf_size, | |
815 | void *cpt_buf) | |
816 | { | |
817 | u32 i; | |
818 | u32 current_id; | |
819 | int result = VMCI_SUCCESS; | |
820 | u32 num_ids = buf_size / sizeof(u32); | |
821 | ||
822 | if (cpt_type == VMCI_WELLKNOWN_CPT_STATE && num_ids > 0) { | |
823 | /* | |
824 | * We would end up here if VMX with VM to VM communication | |
825 | * attempts to restore a checkpoint with wellknown handles. | |
826 | */ | |
827 | pr_warn("Attempt to restore checkpoint with obsolete wellknown handles\n"); | |
828 | return VMCI_ERROR_OBSOLETE; | |
829 | } | |
830 | ||
831 | if (cpt_type != VMCI_NOTIFICATION_CPT_STATE) { | |
832 | pr_devel("Invalid cpt state (type=%d)\n", cpt_type); | |
833 | return VMCI_ERROR_INVALID_ARGS; | |
834 | } | |
835 | ||
836 | for (i = 0; i < num_ids && result == VMCI_SUCCESS; i++) { | |
837 | current_id = ((u32 *)cpt_buf)[i]; | |
838 | result = vmci_ctx_add_notification(context_id, current_id); | |
839 | if (result != VMCI_SUCCESS) | |
840 | break; | |
841 | } | |
842 | if (result != VMCI_SUCCESS) | |
843 | pr_devel("Failed to set cpt state (type=%d) (error=%d)\n", | |
844 | cpt_type, result); | |
845 | ||
846 | return result; | |
847 | } | |
848 | ||
849 | /* | |
850 | * Retrieves the specified context's pending notifications in the | |
851 | * form of a handle array. The handle arrays returned are the | |
852 | * actual data - not a copy and should not be modified by the | |
853 | * caller. They must be released using | |
854 | * vmci_ctx_rcv_notifications_release. | |
855 | */ | |
856 | int vmci_ctx_rcv_notifications_get(u32 context_id, | |
857 | struct vmci_handle_arr **db_handle_array, | |
858 | struct vmci_handle_arr **qp_handle_array) | |
859 | { | |
860 | struct vmci_ctx *context; | |
861 | int result = VMCI_SUCCESS; | |
862 | ||
863 | context = vmci_ctx_get(context_id); | |
864 | if (context == NULL) | |
865 | return VMCI_ERROR_NOT_FOUND; | |
866 | ||
867 | spin_lock(&context->lock); | |
868 | ||
869 | *db_handle_array = context->pending_doorbell_array; | |
870 | context->pending_doorbell_array = vmci_handle_arr_create(0); | |
871 | if (!context->pending_doorbell_array) { | |
872 | context->pending_doorbell_array = *db_handle_array; | |
873 | *db_handle_array = NULL; | |
874 | result = VMCI_ERROR_NO_MEM; | |
875 | } | |
876 | *qp_handle_array = NULL; | |
877 | ||
878 | spin_unlock(&context->lock); | |
879 | vmci_ctx_put(context); | |
880 | ||
881 | return result; | |
882 | } | |
883 | ||
884 | /* | |
885 | * Releases handle arrays with pending notifications previously | |
886 | * retrieved using vmci_ctx_rcv_notifications_get. If the | |
887 | * notifications were not successfully handed over to the guest, | |
888 | * success must be false. | |
889 | */ | |
890 | void vmci_ctx_rcv_notifications_release(u32 context_id, | |
891 | struct vmci_handle_arr *db_handle_array, | |
892 | struct vmci_handle_arr *qp_handle_array, | |
893 | bool success) | |
894 | { | |
895 | struct vmci_ctx *context = vmci_ctx_get(context_id); | |
896 | ||
897 | spin_lock(&context->lock); | |
898 | if (!success) { | |
899 | struct vmci_handle handle; | |
900 | ||
901 | /* | |
902 | * New notifications may have been added while we were not | |
903 | * holding the context lock, so we transfer any new pending | |
904 | * doorbell notifications to the old array, and reinstate the | |
905 | * old array. | |
906 | */ | |
907 | ||
908 | handle = vmci_handle_arr_remove_tail( | |
909 | context->pending_doorbell_array); | |
910 | while (!vmci_handle_is_invalid(handle)) { | |
911 | if (!vmci_handle_arr_has_entry(db_handle_array, | |
912 | handle)) { | |
913 | vmci_handle_arr_append_entry( | |
914 | &db_handle_array, handle); | |
915 | } | |
916 | handle = vmci_handle_arr_remove_tail( | |
917 | context->pending_doorbell_array); | |
918 | } | |
919 | vmci_handle_arr_destroy(context->pending_doorbell_array); | |
920 | context->pending_doorbell_array = db_handle_array; | |
921 | db_handle_array = NULL; | |
922 | } else { | |
923 | ctx_clear_notify_call(context); | |
924 | } | |
925 | spin_unlock(&context->lock); | |
926 | vmci_ctx_put(context); | |
927 | ||
928 | if (db_handle_array) | |
929 | vmci_handle_arr_destroy(db_handle_array); | |
930 | ||
931 | if (qp_handle_array) | |
932 | vmci_handle_arr_destroy(qp_handle_array); | |
933 | } | |
934 | ||
935 | /* | |
936 | * Registers that a new doorbell handle has been allocated by the | |
937 | * context. Only doorbell handles registered can be notified. | |
938 | */ | |
939 | int vmci_ctx_dbell_create(u32 context_id, struct vmci_handle handle) | |
940 | { | |
941 | struct vmci_ctx *context; | |
942 | int result; | |
943 | ||
944 | if (context_id == VMCI_INVALID_ID || vmci_handle_is_invalid(handle)) | |
945 | return VMCI_ERROR_INVALID_ARGS; | |
946 | ||
947 | context = vmci_ctx_get(context_id); | |
948 | if (context == NULL) | |
949 | return VMCI_ERROR_NOT_FOUND; | |
950 | ||
951 | spin_lock(&context->lock); | |
952 | if (!vmci_handle_arr_has_entry(context->doorbell_array, handle)) { | |
953 | vmci_handle_arr_append_entry(&context->doorbell_array, handle); | |
954 | result = VMCI_SUCCESS; | |
955 | } else { | |
956 | result = VMCI_ERROR_DUPLICATE_ENTRY; | |
957 | } | |
958 | ||
959 | spin_unlock(&context->lock); | |
960 | vmci_ctx_put(context); | |
961 | ||
962 | return result; | |
963 | } | |
964 | ||
965 | /* | |
966 | * Unregisters a doorbell handle that was previously registered | |
967 | * with vmci_ctx_dbell_create. | |
968 | */ | |
969 | int vmci_ctx_dbell_destroy(u32 context_id, struct vmci_handle handle) | |
970 | { | |
971 | struct vmci_ctx *context; | |
972 | struct vmci_handle removed_handle; | |
973 | ||
974 | if (context_id == VMCI_INVALID_ID || vmci_handle_is_invalid(handle)) | |
975 | return VMCI_ERROR_INVALID_ARGS; | |
976 | ||
977 | context = vmci_ctx_get(context_id); | |
978 | if (context == NULL) | |
979 | return VMCI_ERROR_NOT_FOUND; | |
980 | ||
981 | spin_lock(&context->lock); | |
982 | removed_handle = | |
983 | vmci_handle_arr_remove_entry(context->doorbell_array, handle); | |
984 | vmci_handle_arr_remove_entry(context->pending_doorbell_array, handle); | |
985 | spin_unlock(&context->lock); | |
986 | ||
987 | vmci_ctx_put(context); | |
988 | ||
989 | return vmci_handle_is_invalid(removed_handle) ? | |
990 | VMCI_ERROR_NOT_FOUND : VMCI_SUCCESS; | |
991 | } | |
992 | ||
993 | /* | |
994 | * Unregisters all doorbell handles that were previously | |
995 | * registered with vmci_ctx_dbell_create. | |
996 | */ | |
997 | int vmci_ctx_dbell_destroy_all(u32 context_id) | |
998 | { | |
999 | struct vmci_ctx *context; | |
1000 | struct vmci_handle handle; | |
1001 | ||
1002 | if (context_id == VMCI_INVALID_ID) | |
1003 | return VMCI_ERROR_INVALID_ARGS; | |
1004 | ||
1005 | context = vmci_ctx_get(context_id); | |
1006 | if (context == NULL) | |
1007 | return VMCI_ERROR_NOT_FOUND; | |
1008 | ||
1009 | spin_lock(&context->lock); | |
1010 | do { | |
1011 | struct vmci_handle_arr *arr = context->doorbell_array; | |
1012 | handle = vmci_handle_arr_remove_tail(arr); | |
1013 | } while (!vmci_handle_is_invalid(handle)); | |
1014 | do { | |
1015 | struct vmci_handle_arr *arr = context->pending_doorbell_array; | |
1016 | handle = vmci_handle_arr_remove_tail(arr); | |
1017 | } while (!vmci_handle_is_invalid(handle)); | |
1018 | spin_unlock(&context->lock); | |
1019 | ||
1020 | vmci_ctx_put(context); | |
1021 | ||
1022 | return VMCI_SUCCESS; | |
1023 | } | |
1024 | ||
1025 | /* | |
1026 | * Registers a notification of a doorbell handle initiated by the | |
1027 | * specified source context. The notification of doorbells are | |
1028 | * subject to the same isolation rules as datagram delivery. To | |
1029 | * allow host side senders of notifications a finer granularity | |
1030 | * of sender rights than those assigned to the sending context | |
1031 | * itself, the host context is required to specify a different | |
1032 | * set of privilege flags that will override the privileges of | |
1033 | * the source context. | |
1034 | */ | |
1035 | int vmci_ctx_notify_dbell(u32 src_cid, | |
1036 | struct vmci_handle handle, | |
1037 | u32 src_priv_flags) | |
1038 | { | |
1039 | struct vmci_ctx *dst_context; | |
1040 | int result; | |
1041 | ||
1042 | if (vmci_handle_is_invalid(handle)) | |
1043 | return VMCI_ERROR_INVALID_ARGS; | |
1044 | ||
1045 | /* Get the target VM's VMCI context. */ | |
1046 | dst_context = vmci_ctx_get(handle.context); | |
1047 | if (!dst_context) { | |
1048 | pr_devel("Invalid context (ID=0x%x)\n", handle.context); | |
1049 | return VMCI_ERROR_NOT_FOUND; | |
1050 | } | |
1051 | ||
1052 | if (src_cid != handle.context) { | |
1053 | u32 dst_priv_flags; | |
1054 | ||
1055 | if (VMCI_CONTEXT_IS_VM(src_cid) && | |
1056 | VMCI_CONTEXT_IS_VM(handle.context)) { | |
1057 | pr_devel("Doorbell notification from VM to VM not supported (src=0x%x, dst=0x%x)\n", | |
1058 | src_cid, handle.context); | |
1059 | result = VMCI_ERROR_DST_UNREACHABLE; | |
1060 | goto out; | |
1061 | } | |
1062 | ||
1063 | result = vmci_dbell_get_priv_flags(handle, &dst_priv_flags); | |
1064 | if (result < VMCI_SUCCESS) { | |
1065 | pr_warn("Failed to get privilege flags for destination (handle=0x%x:0x%x)\n", | |
1066 | handle.context, handle.resource); | |
1067 | goto out; | |
1068 | } | |
1069 | ||
1070 | if (src_cid != VMCI_HOST_CONTEXT_ID || | |
1071 | src_priv_flags == VMCI_NO_PRIVILEGE_FLAGS) { | |
1072 | src_priv_flags = vmci_context_get_priv_flags(src_cid); | |
1073 | } | |
1074 | ||
1075 | if (vmci_deny_interaction(src_priv_flags, dst_priv_flags)) { | |
1076 | result = VMCI_ERROR_NO_ACCESS; | |
1077 | goto out; | |
1078 | } | |
1079 | } | |
1080 | ||
1081 | if (handle.context == VMCI_HOST_CONTEXT_ID) { | |
1082 | result = vmci_dbell_host_context_notify(src_cid, handle); | |
1083 | } else { | |
1084 | spin_lock(&dst_context->lock); | |
1085 | ||
1086 | if (!vmci_handle_arr_has_entry(dst_context->doorbell_array, | |
1087 | handle)) { | |
1088 | result = VMCI_ERROR_NOT_FOUND; | |
1089 | } else { | |
1090 | if (!vmci_handle_arr_has_entry( | |
1091 | dst_context->pending_doorbell_array, | |
1092 | handle)) { | |
1093 | vmci_handle_arr_append_entry( | |
1094 | &dst_context->pending_doorbell_array, | |
1095 | handle); | |
1096 | ||
1097 | ctx_signal_notify(dst_context); | |
1098 | wake_up(&dst_context->host_context.wait_queue); | |
1099 | ||
1100 | } | |
1101 | result = VMCI_SUCCESS; | |
1102 | } | |
1103 | spin_unlock(&dst_context->lock); | |
1104 | } | |
1105 | ||
1106 | out: | |
1107 | vmci_ctx_put(dst_context); | |
1108 | ||
1109 | return result; | |
1110 | } | |
1111 | ||
1112 | bool vmci_ctx_supports_host_qp(struct vmci_ctx *context) | |
1113 | { | |
1114 | return context && context->user_version >= VMCI_VERSION_HOSTQP; | |
1115 | } | |
1116 | ||
1117 | /* | |
1118 | * Registers that a new queue pair handle has been allocated by | |
1119 | * the context. | |
1120 | */ | |
1121 | int vmci_ctx_qp_create(struct vmci_ctx *context, struct vmci_handle handle) | |
1122 | { | |
1123 | int result; | |
1124 | ||
1125 | if (context == NULL || vmci_handle_is_invalid(handle)) | |
1126 | return VMCI_ERROR_INVALID_ARGS; | |
1127 | ||
1128 | if (!vmci_handle_arr_has_entry(context->queue_pair_array, handle)) { | |
1129 | vmci_handle_arr_append_entry(&context->queue_pair_array, | |
1130 | handle); | |
1131 | result = VMCI_SUCCESS; | |
1132 | } else { | |
1133 | result = VMCI_ERROR_DUPLICATE_ENTRY; | |
1134 | } | |
1135 | ||
1136 | return result; | |
1137 | } | |
1138 | ||
1139 | /* | |
1140 | * Unregisters a queue pair handle that was previously registered | |
1141 | * with vmci_ctx_qp_create. | |
1142 | */ | |
1143 | int vmci_ctx_qp_destroy(struct vmci_ctx *context, struct vmci_handle handle) | |
1144 | { | |
1145 | struct vmci_handle hndl; | |
1146 | ||
1147 | if (context == NULL || vmci_handle_is_invalid(handle)) | |
1148 | return VMCI_ERROR_INVALID_ARGS; | |
1149 | ||
1150 | hndl = vmci_handle_arr_remove_entry(context->queue_pair_array, handle); | |
1151 | ||
1152 | return vmci_handle_is_invalid(hndl) ? | |
1153 | VMCI_ERROR_NOT_FOUND : VMCI_SUCCESS; | |
1154 | } | |
1155 | ||
1156 | /* | |
1157 | * Determines whether a given queue pair handle is registered | |
1158 | * with the given context. | |
1159 | */ | |
1160 | bool vmci_ctx_qp_exists(struct vmci_ctx *context, struct vmci_handle handle) | |
1161 | { | |
1162 | if (context == NULL || vmci_handle_is_invalid(handle)) | |
1163 | return false; | |
1164 | ||
1165 | return vmci_handle_arr_has_entry(context->queue_pair_array, handle); | |
1166 | } | |
1167 | ||
1168 | /* | |
1169 | * vmci_context_get_priv_flags() - Retrieve privilege flags. | |
1170 | * @context_id: The context ID of the VMCI context. | |
1171 | * | |
1172 | * Retrieves privilege flags of the given VMCI context ID. | |
1173 | */ | |
1174 | u32 vmci_context_get_priv_flags(u32 context_id) | |
1175 | { | |
1176 | if (vmci_host_code_active()) { | |
1177 | u32 flags; | |
1178 | struct vmci_ctx *context; | |
1179 | ||
1180 | context = vmci_ctx_get(context_id); | |
1181 | if (!context) | |
1182 | return VMCI_LEAST_PRIVILEGE_FLAGS; | |
1183 | ||
1184 | flags = context->priv_flags; | |
1185 | vmci_ctx_put(context); | |
1186 | return flags; | |
1187 | } | |
1188 | return VMCI_NO_PRIVILEGE_FLAGS; | |
1189 | } | |
1190 | EXPORT_SYMBOL_GPL(vmci_context_get_priv_flags); | |
1191 | ||
1192 | /* | |
1193 | * vmci_is_context_owner() - Determimnes if user is the context owner | |
1194 | * @context_id: The context ID of the VMCI context. | |
1195 | * @uid: The host user id (real kernel value). | |
1196 | * | |
1197 | * Determines whether a given UID is the owner of given VMCI context. | |
1198 | */ | |
1199 | bool vmci_is_context_owner(u32 context_id, kuid_t uid) | |
1200 | { | |
1201 | bool is_owner = false; | |
1202 | ||
1203 | if (vmci_host_code_active()) { | |
1204 | struct vmci_ctx *context = vmci_ctx_get(context_id); | |
1205 | if (context) { | |
1206 | if (context->cred) | |
1207 | is_owner = uid_eq(context->cred->uid, uid); | |
1208 | vmci_ctx_put(context); | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | return is_owner; | |
1213 | } | |
1214 | EXPORT_SYMBOL_GPL(vmci_is_context_owner); |