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 */ 37static 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 */ 46static bool ctx_dummy_notify; 47 48static void ctx_signal_notify(struct vmci_ctx *context) 49{ 50 *context->notify = true; 51} 52 53static 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 */ 62static 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 */ 73void 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 */ 84struct 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 */ 189void 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 */ 202static 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 */ 277int 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 */ 297int 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 */ 371bool 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 */ 392struct 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 */ 425static 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 */ 496void 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 */ 509int 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 */ 577void 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 */ 599int 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 */ 660int 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 695static 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 727static 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 */ 763int 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 */ 812int 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 */ 856int 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 */ 890void 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 */ 939int 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 */ 969int 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 */ 997int 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 */ 1035int 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 1112bool 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 */ 1121int 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 */ 1143int 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 */ 1160bool 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 */ 1174u32 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} 1190EXPORT_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 */ 1199bool 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} 1214EXPORT_SYMBOL_GPL(vmci_is_context_owner); 1215