George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 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 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 31 | /* Use a wide upper bound for the maximum contexts. */ |
| 32 | #define VMCI_MAX_CONTEXTS 2000 |
| 33 | |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 34 | /* |
| 35 | * List of current VMCI contexts. Contexts can be added by |
| 36 | * vmci_ctx_create() and removed via vmci_ctx_destroy(). |
| 37 | * These, along with context lookup, are protected by the |
| 38 | * list structure's lock. |
| 39 | */ |
| 40 | static struct { |
| 41 | struct list_head head; |
| 42 | spinlock_t lock; /* Spinlock for context list operations */ |
| 43 | } ctx_list = { |
| 44 | .head = LIST_HEAD_INIT(ctx_list.head), |
| 45 | .lock = __SPIN_LOCK_UNLOCKED(ctx_list.lock), |
| 46 | }; |
| 47 | |
| 48 | /* Used by contexts that did not set up notify flag pointers */ |
| 49 | static bool ctx_dummy_notify; |
| 50 | |
| 51 | static void ctx_signal_notify(struct vmci_ctx *context) |
| 52 | { |
| 53 | *context->notify = true; |
| 54 | } |
| 55 | |
| 56 | static void ctx_clear_notify(struct vmci_ctx *context) |
| 57 | { |
| 58 | *context->notify = false; |
| 59 | } |
| 60 | |
| 61 | /* |
| 62 | * If nothing requires the attention of the guest, clears both |
| 63 | * notify flag and call. |
| 64 | */ |
| 65 | static void ctx_clear_notify_call(struct vmci_ctx *context) |
| 66 | { |
| 67 | if (context->pending_datagrams == 0 && |
| 68 | vmci_handle_arr_get_size(context->pending_doorbell_array) == 0) |
| 69 | ctx_clear_notify(context); |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * Sets the context's notify flag iff datagrams are pending for this |
| 74 | * context. Called from vmci_setup_notify(). |
| 75 | */ |
| 76 | void vmci_ctx_check_signal_notify(struct vmci_ctx *context) |
| 77 | { |
| 78 | spin_lock(&context->lock); |
| 79 | if (context->pending_datagrams) |
| 80 | ctx_signal_notify(context); |
| 81 | spin_unlock(&context->lock); |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * Allocates and initializes a VMCI context. |
| 86 | */ |
| 87 | struct vmci_ctx *vmci_ctx_create(u32 cid, u32 priv_flags, |
| 88 | uintptr_t event_hnd, |
| 89 | int user_version, |
| 90 | const struct cred *cred) |
| 91 | { |
| 92 | struct vmci_ctx *context; |
| 93 | int error; |
| 94 | |
| 95 | if (cid == VMCI_INVALID_ID) { |
| 96 | pr_devel("Invalid context ID for VMCI context\n"); |
| 97 | error = -EINVAL; |
| 98 | goto err_out; |
| 99 | } |
| 100 | |
| 101 | if (priv_flags & ~VMCI_PRIVILEGE_ALL_FLAGS) { |
| 102 | pr_devel("Invalid flag (flags=0x%x) for VMCI context\n", |
| 103 | priv_flags); |
| 104 | error = -EINVAL; |
| 105 | goto err_out; |
| 106 | } |
| 107 | |
| 108 | if (user_version == 0) { |
| 109 | pr_devel("Invalid suer_version %d\n", user_version); |
| 110 | error = -EINVAL; |
| 111 | goto err_out; |
| 112 | } |
| 113 | |
| 114 | context = kzalloc(sizeof(*context), GFP_KERNEL); |
| 115 | if (!context) { |
| 116 | pr_warn("Failed to allocate memory for VMCI context\n"); |
| 117 | error = -EINVAL; |
| 118 | goto err_out; |
| 119 | } |
| 120 | |
| 121 | kref_init(&context->kref); |
| 122 | spin_lock_init(&context->lock); |
| 123 | INIT_LIST_HEAD(&context->list_item); |
| 124 | INIT_LIST_HEAD(&context->datagram_queue); |
| 125 | INIT_LIST_HEAD(&context->notifier_list); |
| 126 | |
| 127 | /* Initialize host-specific VMCI context. */ |
| 128 | init_waitqueue_head(&context->host_context.wait_queue); |
| 129 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 130 | context->queue_pair_array = |
| 131 | vmci_handle_arr_create(0, VMCI_MAX_GUEST_QP_COUNT); |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 132 | if (!context->queue_pair_array) { |
| 133 | error = -ENOMEM; |
| 134 | goto err_free_ctx; |
| 135 | } |
| 136 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 137 | context->doorbell_array = |
| 138 | vmci_handle_arr_create(0, VMCI_MAX_GUEST_DOORBELL_COUNT); |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 139 | if (!context->doorbell_array) { |
| 140 | error = -ENOMEM; |
| 141 | goto err_free_qp_array; |
| 142 | } |
| 143 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 144 | context->pending_doorbell_array = |
| 145 | vmci_handle_arr_create(0, VMCI_MAX_GUEST_DOORBELL_COUNT); |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 146 | if (!context->pending_doorbell_array) { |
| 147 | error = -ENOMEM; |
| 148 | goto err_free_db_array; |
| 149 | } |
| 150 | |
| 151 | context->user_version = user_version; |
| 152 | |
| 153 | context->priv_flags = priv_flags; |
| 154 | |
| 155 | if (cred) |
| 156 | context->cred = get_cred(cred); |
| 157 | |
| 158 | context->notify = &ctx_dummy_notify; |
| 159 | context->notify_page = NULL; |
| 160 | |
| 161 | /* |
| 162 | * If we collide with an existing context we generate a new |
| 163 | * and use it instead. The VMX will determine if regeneration |
| 164 | * is okay. Since there isn't 4B - 16 VMs running on a given |
| 165 | * host, the below loop will terminate. |
| 166 | */ |
| 167 | spin_lock(&ctx_list.lock); |
| 168 | |
| 169 | while (vmci_ctx_exists(cid)) { |
| 170 | /* We reserve the lowest 16 ids for fixed contexts. */ |
| 171 | cid = max(cid, VMCI_RESERVED_CID_LIMIT - 1) + 1; |
| 172 | if (cid == VMCI_INVALID_ID) |
| 173 | cid = VMCI_RESERVED_CID_LIMIT; |
| 174 | } |
| 175 | context->cid = cid; |
| 176 | |
| 177 | list_add_tail_rcu(&context->list_item, &ctx_list.head); |
| 178 | spin_unlock(&ctx_list.lock); |
| 179 | |
| 180 | return context; |
| 181 | |
| 182 | err_free_db_array: |
| 183 | vmci_handle_arr_destroy(context->doorbell_array); |
| 184 | err_free_qp_array: |
| 185 | vmci_handle_arr_destroy(context->queue_pair_array); |
| 186 | err_free_ctx: |
| 187 | kfree(context); |
| 188 | err_out: |
| 189 | return ERR_PTR(error); |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Destroy VMCI context. |
| 194 | */ |
| 195 | void vmci_ctx_destroy(struct vmci_ctx *context) |
| 196 | { |
| 197 | spin_lock(&ctx_list.lock); |
| 198 | list_del_rcu(&context->list_item); |
| 199 | spin_unlock(&ctx_list.lock); |
| 200 | synchronize_rcu(); |
| 201 | |
| 202 | vmci_ctx_put(context); |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * Fire notification for all contexts interested in given cid. |
| 207 | */ |
| 208 | static int ctx_fire_notification(u32 context_id, u32 priv_flags) |
| 209 | { |
| 210 | u32 i, array_size; |
| 211 | struct vmci_ctx *sub_ctx; |
| 212 | struct vmci_handle_arr *subscriber_array; |
| 213 | struct vmci_handle context_handle = |
| 214 | vmci_make_handle(context_id, VMCI_EVENT_HANDLER); |
| 215 | |
| 216 | /* |
| 217 | * We create an array to hold the subscribers we find when |
| 218 | * scanning through all contexts. |
| 219 | */ |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 220 | subscriber_array = vmci_handle_arr_create(0, VMCI_MAX_CONTEXTS); |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 221 | if (subscriber_array == NULL) |
| 222 | return VMCI_ERROR_NO_MEM; |
| 223 | |
| 224 | /* |
| 225 | * Scan all contexts to find who is interested in being |
| 226 | * notified about given contextID. |
| 227 | */ |
| 228 | rcu_read_lock(); |
| 229 | list_for_each_entry_rcu(sub_ctx, &ctx_list.head, list_item) { |
| 230 | struct vmci_handle_list *node; |
| 231 | |
| 232 | /* |
| 233 | * We only deliver notifications of the removal of |
| 234 | * contexts, if the two contexts are allowed to |
| 235 | * interact. |
| 236 | */ |
| 237 | if (vmci_deny_interaction(priv_flags, sub_ctx->priv_flags)) |
| 238 | continue; |
| 239 | |
| 240 | list_for_each_entry_rcu(node, &sub_ctx->notifier_list, node) { |
| 241 | if (!vmci_handle_is_equal(node->handle, context_handle)) |
| 242 | continue; |
| 243 | |
| 244 | vmci_handle_arr_append_entry(&subscriber_array, |
| 245 | vmci_make_handle(sub_ctx->cid, |
| 246 | VMCI_EVENT_HANDLER)); |
| 247 | } |
| 248 | } |
| 249 | rcu_read_unlock(); |
| 250 | |
| 251 | /* Fire event to all subscribers. */ |
| 252 | array_size = vmci_handle_arr_get_size(subscriber_array); |
| 253 | for (i = 0; i < array_size; i++) { |
| 254 | int result; |
| 255 | struct vmci_event_ctx ev; |
| 256 | |
| 257 | ev.msg.hdr.dst = vmci_handle_arr_get_entry(subscriber_array, i); |
| 258 | ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, |
| 259 | VMCI_CONTEXT_RESOURCE_ID); |
| 260 | ev.msg.hdr.payload_size = sizeof(ev) - sizeof(ev.msg.hdr); |
| 261 | ev.msg.event_data.event = VMCI_EVENT_CTX_REMOVED; |
| 262 | ev.payload.context_id = context_id; |
| 263 | |
| 264 | result = vmci_datagram_dispatch(VMCI_HYPERVISOR_CONTEXT_ID, |
| 265 | &ev.msg.hdr, false); |
| 266 | if (result < VMCI_SUCCESS) { |
| 267 | pr_devel("Failed to enqueue event datagram (type=%d) for context (ID=0x%x)\n", |
| 268 | ev.msg.event_data.event, |
| 269 | ev.msg.hdr.dst.context); |
| 270 | /* We continue to enqueue on next subscriber. */ |
| 271 | } |
| 272 | } |
| 273 | vmci_handle_arr_destroy(subscriber_array); |
| 274 | |
| 275 | return VMCI_SUCCESS; |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * Returns the current number of pending datagrams. The call may |
| 280 | * also serve as a synchronization point for the datagram queue, |
| 281 | * as no enqueue operations can occur concurrently. |
| 282 | */ |
| 283 | int vmci_ctx_pending_datagrams(u32 cid, u32 *pending) |
| 284 | { |
| 285 | struct vmci_ctx *context; |
| 286 | |
| 287 | context = vmci_ctx_get(cid); |
| 288 | if (context == NULL) |
| 289 | return VMCI_ERROR_INVALID_ARGS; |
| 290 | |
| 291 | spin_lock(&context->lock); |
| 292 | if (pending) |
| 293 | *pending = context->pending_datagrams; |
| 294 | spin_unlock(&context->lock); |
| 295 | vmci_ctx_put(context); |
| 296 | |
| 297 | return VMCI_SUCCESS; |
| 298 | } |
| 299 | |
| 300 | /* |
| 301 | * Queues a VMCI datagram for the appropriate target VM context. |
| 302 | */ |
| 303 | int vmci_ctx_enqueue_datagram(u32 cid, struct vmci_datagram *dg) |
| 304 | { |
| 305 | struct vmci_datagram_queue_entry *dq_entry; |
| 306 | struct vmci_ctx *context; |
| 307 | struct vmci_handle dg_src; |
| 308 | size_t vmci_dg_size; |
| 309 | |
| 310 | vmci_dg_size = VMCI_DG_SIZE(dg); |
| 311 | if (vmci_dg_size > VMCI_MAX_DG_SIZE) { |
| 312 | pr_devel("Datagram too large (bytes=%Zu)\n", vmci_dg_size); |
| 313 | return VMCI_ERROR_INVALID_ARGS; |
| 314 | } |
| 315 | |
| 316 | /* Get the target VM's VMCI context. */ |
| 317 | context = vmci_ctx_get(cid); |
| 318 | if (!context) { |
| 319 | pr_devel("Invalid context (ID=0x%x)\n", cid); |
| 320 | return VMCI_ERROR_INVALID_ARGS; |
| 321 | } |
| 322 | |
| 323 | /* Allocate guest call entry and add it to the target VM's queue. */ |
| 324 | dq_entry = kmalloc(sizeof(*dq_entry), GFP_KERNEL); |
| 325 | if (dq_entry == NULL) { |
| 326 | pr_warn("Failed to allocate memory for datagram\n"); |
| 327 | vmci_ctx_put(context); |
| 328 | return VMCI_ERROR_NO_MEM; |
| 329 | } |
| 330 | dq_entry->dg = dg; |
| 331 | dq_entry->dg_size = vmci_dg_size; |
| 332 | dg_src = dg->src; |
| 333 | INIT_LIST_HEAD(&dq_entry->list_item); |
| 334 | |
| 335 | spin_lock(&context->lock); |
| 336 | |
| 337 | /* |
| 338 | * We put a higher limit on datagrams from the hypervisor. If |
| 339 | * the pending datagram is not from hypervisor, then we check |
| 340 | * if enqueueing it would exceed the |
| 341 | * VMCI_MAX_DATAGRAM_QUEUE_SIZE limit on the destination. If |
| 342 | * the pending datagram is from hypervisor, we allow it to be |
| 343 | * queued at the destination side provided we don't reach the |
| 344 | * VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE limit. |
| 345 | */ |
| 346 | if (context->datagram_queue_size + vmci_dg_size >= |
| 347 | VMCI_MAX_DATAGRAM_QUEUE_SIZE && |
| 348 | (!vmci_handle_is_equal(dg_src, |
| 349 | vmci_make_handle |
| 350 | (VMCI_HYPERVISOR_CONTEXT_ID, |
| 351 | VMCI_CONTEXT_RESOURCE_ID)) || |
| 352 | context->datagram_queue_size + vmci_dg_size >= |
| 353 | VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE)) { |
| 354 | spin_unlock(&context->lock); |
| 355 | vmci_ctx_put(context); |
| 356 | kfree(dq_entry); |
| 357 | pr_devel("Context (ID=0x%x) receive queue is full\n", cid); |
| 358 | return VMCI_ERROR_NO_RESOURCES; |
| 359 | } |
| 360 | |
| 361 | list_add(&dq_entry->list_item, &context->datagram_queue); |
| 362 | context->pending_datagrams++; |
| 363 | context->datagram_queue_size += vmci_dg_size; |
| 364 | ctx_signal_notify(context); |
| 365 | wake_up(&context->host_context.wait_queue); |
| 366 | spin_unlock(&context->lock); |
| 367 | vmci_ctx_put(context); |
| 368 | |
| 369 | return vmci_dg_size; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * Verifies whether a context with the specified context ID exists. |
| 374 | * FIXME: utility is dubious as no decisions can be reliably made |
| 375 | * using this data as context can appear and disappear at any time. |
| 376 | */ |
| 377 | bool vmci_ctx_exists(u32 cid) |
| 378 | { |
| 379 | struct vmci_ctx *context; |
| 380 | bool exists = false; |
| 381 | |
| 382 | rcu_read_lock(); |
| 383 | |
| 384 | list_for_each_entry_rcu(context, &ctx_list.head, list_item) { |
| 385 | if (context->cid == cid) { |
| 386 | exists = true; |
| 387 | break; |
| 388 | } |
| 389 | } |
| 390 | |
| 391 | rcu_read_unlock(); |
| 392 | return exists; |
| 393 | } |
| 394 | |
| 395 | /* |
| 396 | * Retrieves VMCI context corresponding to the given cid. |
| 397 | */ |
| 398 | struct vmci_ctx *vmci_ctx_get(u32 cid) |
| 399 | { |
| 400 | struct vmci_ctx *c, *context = NULL; |
| 401 | |
| 402 | if (cid == VMCI_INVALID_ID) |
| 403 | return NULL; |
| 404 | |
| 405 | rcu_read_lock(); |
| 406 | list_for_each_entry_rcu(c, &ctx_list.head, list_item) { |
| 407 | if (c->cid == cid) { |
| 408 | /* |
| 409 | * The context owner drops its own reference to the |
| 410 | * context only after removing it from the list and |
| 411 | * waiting for RCU grace period to expire. This |
| 412 | * means that we are not about to increase the |
| 413 | * reference count of something that is in the |
| 414 | * process of being destroyed. |
| 415 | */ |
| 416 | context = c; |
| 417 | kref_get(&context->kref); |
| 418 | break; |
| 419 | } |
| 420 | } |
| 421 | rcu_read_unlock(); |
| 422 | |
| 423 | return context; |
| 424 | } |
| 425 | |
| 426 | /* |
| 427 | * Deallocates all parts of a context data structure. This |
| 428 | * function doesn't lock the context, because it assumes that |
| 429 | * the caller was holding the last reference to context. |
| 430 | */ |
| 431 | static void ctx_free_ctx(struct kref *kref) |
| 432 | { |
| 433 | struct vmci_ctx *context = container_of(kref, struct vmci_ctx, kref); |
| 434 | struct vmci_datagram_queue_entry *dq_entry, *dq_entry_tmp; |
| 435 | struct vmci_handle temp_handle; |
| 436 | struct vmci_handle_list *notifier, *tmp; |
| 437 | |
| 438 | /* |
| 439 | * Fire event to all contexts interested in knowing this |
| 440 | * context is dying. |
| 441 | */ |
| 442 | ctx_fire_notification(context->cid, context->priv_flags); |
| 443 | |
| 444 | /* |
| 445 | * Cleanup all queue pair resources attached to context. If |
| 446 | * the VM dies without cleaning up, this code will make sure |
| 447 | * that no resources are leaked. |
| 448 | */ |
| 449 | temp_handle = vmci_handle_arr_get_entry(context->queue_pair_array, 0); |
| 450 | while (!vmci_handle_is_equal(temp_handle, VMCI_INVALID_HANDLE)) { |
| 451 | if (vmci_qp_broker_detach(temp_handle, |
| 452 | context) < VMCI_SUCCESS) { |
| 453 | /* |
| 454 | * When vmci_qp_broker_detach() succeeds it |
| 455 | * removes the handle from the array. If |
| 456 | * detach fails, we must remove the handle |
| 457 | * ourselves. |
| 458 | */ |
| 459 | vmci_handle_arr_remove_entry(context->queue_pair_array, |
| 460 | temp_handle); |
| 461 | } |
| 462 | temp_handle = |
| 463 | vmci_handle_arr_get_entry(context->queue_pair_array, 0); |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | * It is fine to destroy this without locking the callQueue, as |
| 468 | * this is the only thread having a reference to the context. |
| 469 | */ |
| 470 | list_for_each_entry_safe(dq_entry, dq_entry_tmp, |
| 471 | &context->datagram_queue, list_item) { |
| 472 | WARN_ON(dq_entry->dg_size != VMCI_DG_SIZE(dq_entry->dg)); |
| 473 | list_del(&dq_entry->list_item); |
| 474 | kfree(dq_entry->dg); |
| 475 | kfree(dq_entry); |
| 476 | } |
| 477 | |
| 478 | list_for_each_entry_safe(notifier, tmp, |
| 479 | &context->notifier_list, node) { |
| 480 | list_del(¬ifier->node); |
| 481 | kfree(notifier); |
| 482 | } |
| 483 | |
| 484 | vmci_handle_arr_destroy(context->queue_pair_array); |
| 485 | vmci_handle_arr_destroy(context->doorbell_array); |
| 486 | vmci_handle_arr_destroy(context->pending_doorbell_array); |
| 487 | vmci_ctx_unset_notify(context); |
| 488 | if (context->cred) |
| 489 | put_cred(context->cred); |
| 490 | kfree(context); |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Drops reference to VMCI context. If this is the last reference to |
| 495 | * the context it will be deallocated. A context is created with |
| 496 | * a reference count of one, and on destroy, it is removed from |
| 497 | * the context list before its reference count is decremented. Thus, |
| 498 | * if we reach zero, we are sure that nobody else are about to increment |
| 499 | * it (they need the entry in the context list for that), and so there |
| 500 | * is no need for locking. |
| 501 | */ |
| 502 | void vmci_ctx_put(struct vmci_ctx *context) |
| 503 | { |
| 504 | kref_put(&context->kref, ctx_free_ctx); |
| 505 | } |
| 506 | |
| 507 | /* |
| 508 | * Dequeues the next datagram and returns it to caller. |
| 509 | * The caller passes in a pointer to the max size datagram |
| 510 | * it can handle and the datagram is only unqueued if the |
| 511 | * size is less than max_size. If larger max_size is set to |
| 512 | * the size of the datagram to give the caller a chance to |
| 513 | * set up a larger buffer for the guestcall. |
| 514 | */ |
| 515 | int vmci_ctx_dequeue_datagram(struct vmci_ctx *context, |
| 516 | size_t *max_size, |
| 517 | struct vmci_datagram **dg) |
| 518 | { |
| 519 | struct vmci_datagram_queue_entry *dq_entry; |
| 520 | struct list_head *list_item; |
| 521 | int rv; |
| 522 | |
| 523 | /* Dequeue the next datagram entry. */ |
| 524 | spin_lock(&context->lock); |
| 525 | if (context->pending_datagrams == 0) { |
| 526 | ctx_clear_notify_call(context); |
| 527 | spin_unlock(&context->lock); |
| 528 | pr_devel("No datagrams pending\n"); |
| 529 | return VMCI_ERROR_NO_MORE_DATAGRAMS; |
| 530 | } |
| 531 | |
| 532 | list_item = context->datagram_queue.next; |
| 533 | |
| 534 | dq_entry = |
| 535 | list_entry(list_item, struct vmci_datagram_queue_entry, list_item); |
| 536 | |
| 537 | /* Check size of caller's buffer. */ |
| 538 | if (*max_size < dq_entry->dg_size) { |
| 539 | *max_size = dq_entry->dg_size; |
| 540 | spin_unlock(&context->lock); |
| 541 | pr_devel("Caller's buffer should be at least (size=%u bytes)\n", |
| 542 | (u32) *max_size); |
| 543 | return VMCI_ERROR_NO_MEM; |
| 544 | } |
| 545 | |
| 546 | list_del(list_item); |
| 547 | context->pending_datagrams--; |
| 548 | context->datagram_queue_size -= dq_entry->dg_size; |
| 549 | if (context->pending_datagrams == 0) { |
| 550 | ctx_clear_notify_call(context); |
| 551 | rv = VMCI_SUCCESS; |
| 552 | } else { |
| 553 | /* |
| 554 | * Return the size of the next datagram. |
| 555 | */ |
| 556 | struct vmci_datagram_queue_entry *next_entry; |
| 557 | |
| 558 | list_item = context->datagram_queue.next; |
| 559 | next_entry = |
| 560 | list_entry(list_item, struct vmci_datagram_queue_entry, |
| 561 | list_item); |
| 562 | |
| 563 | /* |
| 564 | * The following size_t -> int truncation is fine as |
| 565 | * the maximum size of a (routable) datagram is 68KB. |
| 566 | */ |
| 567 | rv = (int)next_entry->dg_size; |
| 568 | } |
| 569 | spin_unlock(&context->lock); |
| 570 | |
| 571 | /* Caller must free datagram. */ |
| 572 | *dg = dq_entry->dg; |
| 573 | dq_entry->dg = NULL; |
| 574 | kfree(dq_entry); |
| 575 | |
| 576 | return rv; |
| 577 | } |
| 578 | |
| 579 | /* |
| 580 | * Reverts actions set up by vmci_setup_notify(). Unmaps and unlocks the |
| 581 | * page mapped/locked by vmci_setup_notify(). |
| 582 | */ |
| 583 | void vmci_ctx_unset_notify(struct vmci_ctx *context) |
| 584 | { |
| 585 | struct page *notify_page; |
| 586 | |
| 587 | spin_lock(&context->lock); |
| 588 | |
| 589 | notify_page = context->notify_page; |
| 590 | context->notify = &ctx_dummy_notify; |
| 591 | context->notify_page = NULL; |
| 592 | |
| 593 | spin_unlock(&context->lock); |
| 594 | |
| 595 | if (notify_page) { |
| 596 | kunmap(notify_page); |
| 597 | put_page(notify_page); |
| 598 | } |
| 599 | } |
| 600 | |
| 601 | /* |
| 602 | * Add remote_cid to list of contexts current contexts wants |
| 603 | * notifications from/about. |
| 604 | */ |
| 605 | int vmci_ctx_add_notification(u32 context_id, u32 remote_cid) |
| 606 | { |
| 607 | struct vmci_ctx *context; |
| 608 | struct vmci_handle_list *notifier, *n; |
| 609 | int result; |
| 610 | bool exists = false; |
| 611 | |
| 612 | context = vmci_ctx_get(context_id); |
| 613 | if (!context) |
| 614 | return VMCI_ERROR_NOT_FOUND; |
| 615 | |
| 616 | if (VMCI_CONTEXT_IS_VM(context_id) && VMCI_CONTEXT_IS_VM(remote_cid)) { |
| 617 | pr_devel("Context removed notifications for other VMs not supported (src=0x%x, remote=0x%x)\n", |
| 618 | context_id, remote_cid); |
| 619 | result = VMCI_ERROR_DST_UNREACHABLE; |
| 620 | goto out; |
| 621 | } |
| 622 | |
| 623 | if (context->priv_flags & VMCI_PRIVILEGE_FLAG_RESTRICTED) { |
| 624 | result = VMCI_ERROR_NO_ACCESS; |
| 625 | goto out; |
| 626 | } |
| 627 | |
| 628 | notifier = kmalloc(sizeof(struct vmci_handle_list), GFP_KERNEL); |
| 629 | if (!notifier) { |
| 630 | result = VMCI_ERROR_NO_MEM; |
| 631 | goto out; |
| 632 | } |
| 633 | |
| 634 | INIT_LIST_HEAD(¬ifier->node); |
| 635 | notifier->handle = vmci_make_handle(remote_cid, VMCI_EVENT_HANDLER); |
| 636 | |
| 637 | spin_lock(&context->lock); |
| 638 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 639 | if (context->n_notifiers < VMCI_MAX_CONTEXTS) { |
| 640 | list_for_each_entry(n, &context->notifier_list, node) { |
| 641 | if (vmci_handle_is_equal(n->handle, notifier->handle)) { |
| 642 | exists = true; |
| 643 | break; |
| 644 | } |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 645 | } |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 646 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 647 | if (exists) { |
| 648 | kfree(notifier); |
| 649 | result = VMCI_ERROR_ALREADY_EXISTS; |
| 650 | } else { |
| 651 | list_add_tail_rcu(¬ifier->node, |
| 652 | &context->notifier_list); |
| 653 | context->n_notifiers++; |
| 654 | result = VMCI_SUCCESS; |
| 655 | } |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 656 | } else { |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 657 | kfree(notifier); |
| 658 | result = VMCI_ERROR_NO_MEM; |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 659 | } |
| 660 | |
| 661 | spin_unlock(&context->lock); |
| 662 | |
| 663 | out: |
| 664 | vmci_ctx_put(context); |
| 665 | return result; |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Remove remote_cid from current context's list of contexts it is |
| 670 | * interested in getting notifications from/about. |
| 671 | */ |
| 672 | int vmci_ctx_remove_notification(u32 context_id, u32 remote_cid) |
| 673 | { |
| 674 | struct vmci_ctx *context; |
| 675 | struct vmci_handle_list *notifier, *tmp; |
| 676 | struct vmci_handle handle; |
| 677 | bool found = false; |
| 678 | |
| 679 | context = vmci_ctx_get(context_id); |
| 680 | if (!context) |
| 681 | return VMCI_ERROR_NOT_FOUND; |
| 682 | |
| 683 | handle = vmci_make_handle(remote_cid, VMCI_EVENT_HANDLER); |
| 684 | |
| 685 | spin_lock(&context->lock); |
| 686 | list_for_each_entry_safe(notifier, tmp, |
| 687 | &context->notifier_list, node) { |
| 688 | if (vmci_handle_is_equal(notifier->handle, handle)) { |
| 689 | list_del_rcu(¬ifier->node); |
| 690 | context->n_notifiers--; |
| 691 | found = true; |
| 692 | break; |
| 693 | } |
| 694 | } |
| 695 | spin_unlock(&context->lock); |
| 696 | |
| 697 | if (found) { |
| 698 | synchronize_rcu(); |
| 699 | kfree(notifier); |
| 700 | } |
| 701 | |
| 702 | vmci_ctx_put(context); |
| 703 | |
| 704 | return found ? VMCI_SUCCESS : VMCI_ERROR_NOT_FOUND; |
| 705 | } |
| 706 | |
| 707 | static int vmci_ctx_get_chkpt_notifiers(struct vmci_ctx *context, |
| 708 | u32 *buf_size, void **pbuf) |
| 709 | { |
| 710 | u32 *notifiers; |
| 711 | size_t data_size; |
| 712 | struct vmci_handle_list *entry; |
| 713 | int i = 0; |
| 714 | |
| 715 | if (context->n_notifiers == 0) { |
| 716 | *buf_size = 0; |
| 717 | *pbuf = NULL; |
| 718 | return VMCI_SUCCESS; |
| 719 | } |
| 720 | |
| 721 | data_size = context->n_notifiers * sizeof(*notifiers); |
| 722 | if (*buf_size < data_size) { |
| 723 | *buf_size = data_size; |
| 724 | return VMCI_ERROR_MORE_DATA; |
| 725 | } |
| 726 | |
| 727 | notifiers = kmalloc(data_size, GFP_ATOMIC); /* FIXME: want GFP_KERNEL */ |
| 728 | if (!notifiers) |
| 729 | return VMCI_ERROR_NO_MEM; |
| 730 | |
| 731 | list_for_each_entry(entry, &context->notifier_list, node) |
| 732 | notifiers[i++] = entry->handle.context; |
| 733 | |
| 734 | *buf_size = data_size; |
| 735 | *pbuf = notifiers; |
| 736 | return VMCI_SUCCESS; |
| 737 | } |
| 738 | |
| 739 | static int vmci_ctx_get_chkpt_doorbells(struct vmci_ctx *context, |
| 740 | u32 *buf_size, void **pbuf) |
| 741 | { |
| 742 | struct dbell_cpt_state *dbells; |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 743 | u32 i, n_doorbells; |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 744 | |
| 745 | n_doorbells = vmci_handle_arr_get_size(context->doorbell_array); |
| 746 | if (n_doorbells > 0) { |
| 747 | size_t data_size = n_doorbells * sizeof(*dbells); |
| 748 | if (*buf_size < data_size) { |
| 749 | *buf_size = data_size; |
| 750 | return VMCI_ERROR_MORE_DATA; |
| 751 | } |
| 752 | |
| 753 | dbells = kmalloc(data_size, GFP_ATOMIC); |
| 754 | if (!dbells) |
| 755 | return VMCI_ERROR_NO_MEM; |
| 756 | |
| 757 | for (i = 0; i < n_doorbells; i++) |
| 758 | dbells[i].handle = vmci_handle_arr_get_entry( |
| 759 | context->doorbell_array, i); |
| 760 | |
| 761 | *buf_size = data_size; |
| 762 | *pbuf = dbells; |
| 763 | } else { |
| 764 | *buf_size = 0; |
| 765 | *pbuf = NULL; |
| 766 | } |
| 767 | |
| 768 | return VMCI_SUCCESS; |
| 769 | } |
| 770 | |
| 771 | /* |
| 772 | * Get current context's checkpoint state of given type. |
| 773 | */ |
| 774 | int vmci_ctx_get_chkpt_state(u32 context_id, |
| 775 | u32 cpt_type, |
| 776 | u32 *buf_size, |
| 777 | void **pbuf) |
| 778 | { |
| 779 | struct vmci_ctx *context; |
| 780 | int result; |
| 781 | |
| 782 | context = vmci_ctx_get(context_id); |
| 783 | if (!context) |
| 784 | return VMCI_ERROR_NOT_FOUND; |
| 785 | |
| 786 | spin_lock(&context->lock); |
| 787 | |
| 788 | switch (cpt_type) { |
| 789 | case VMCI_NOTIFICATION_CPT_STATE: |
| 790 | result = vmci_ctx_get_chkpt_notifiers(context, buf_size, pbuf); |
| 791 | break; |
| 792 | |
| 793 | case VMCI_WELLKNOWN_CPT_STATE: |
| 794 | /* |
| 795 | * For compatibility with VMX'en with VM to VM communication, we |
| 796 | * always return zero wellknown handles. |
| 797 | */ |
| 798 | |
| 799 | *buf_size = 0; |
| 800 | *pbuf = NULL; |
| 801 | result = VMCI_SUCCESS; |
| 802 | break; |
| 803 | |
| 804 | case VMCI_DOORBELL_CPT_STATE: |
| 805 | result = vmci_ctx_get_chkpt_doorbells(context, buf_size, pbuf); |
| 806 | break; |
| 807 | |
| 808 | default: |
| 809 | pr_devel("Invalid cpt state (type=%d)\n", cpt_type); |
| 810 | result = VMCI_ERROR_INVALID_ARGS; |
| 811 | break; |
| 812 | } |
| 813 | |
| 814 | spin_unlock(&context->lock); |
| 815 | vmci_ctx_put(context); |
| 816 | |
| 817 | return result; |
| 818 | } |
| 819 | |
| 820 | /* |
| 821 | * Set current context's checkpoint state of given type. |
| 822 | */ |
| 823 | int vmci_ctx_set_chkpt_state(u32 context_id, |
| 824 | u32 cpt_type, |
| 825 | u32 buf_size, |
| 826 | void *cpt_buf) |
| 827 | { |
| 828 | u32 i; |
| 829 | u32 current_id; |
| 830 | int result = VMCI_SUCCESS; |
| 831 | u32 num_ids = buf_size / sizeof(u32); |
| 832 | |
| 833 | if (cpt_type == VMCI_WELLKNOWN_CPT_STATE && num_ids > 0) { |
| 834 | /* |
| 835 | * We would end up here if VMX with VM to VM communication |
| 836 | * attempts to restore a checkpoint with wellknown handles. |
| 837 | */ |
| 838 | pr_warn("Attempt to restore checkpoint with obsolete wellknown handles\n"); |
| 839 | return VMCI_ERROR_OBSOLETE; |
| 840 | } |
| 841 | |
| 842 | if (cpt_type != VMCI_NOTIFICATION_CPT_STATE) { |
| 843 | pr_devel("Invalid cpt state (type=%d)\n", cpt_type); |
| 844 | return VMCI_ERROR_INVALID_ARGS; |
| 845 | } |
| 846 | |
| 847 | for (i = 0; i < num_ids && result == VMCI_SUCCESS; i++) { |
| 848 | current_id = ((u32 *)cpt_buf)[i]; |
| 849 | result = vmci_ctx_add_notification(context_id, current_id); |
| 850 | if (result != VMCI_SUCCESS) |
| 851 | break; |
| 852 | } |
| 853 | if (result != VMCI_SUCCESS) |
| 854 | pr_devel("Failed to set cpt state (type=%d) (error=%d)\n", |
| 855 | cpt_type, result); |
| 856 | |
| 857 | return result; |
| 858 | } |
| 859 | |
| 860 | /* |
| 861 | * Retrieves the specified context's pending notifications in the |
| 862 | * form of a handle array. The handle arrays returned are the |
| 863 | * actual data - not a copy and should not be modified by the |
| 864 | * caller. They must be released using |
| 865 | * vmci_ctx_rcv_notifications_release. |
| 866 | */ |
| 867 | int vmci_ctx_rcv_notifications_get(u32 context_id, |
| 868 | struct vmci_handle_arr **db_handle_array, |
| 869 | struct vmci_handle_arr **qp_handle_array) |
| 870 | { |
| 871 | struct vmci_ctx *context; |
| 872 | int result = VMCI_SUCCESS; |
| 873 | |
| 874 | context = vmci_ctx_get(context_id); |
| 875 | if (context == NULL) |
| 876 | return VMCI_ERROR_NOT_FOUND; |
| 877 | |
| 878 | spin_lock(&context->lock); |
| 879 | |
| 880 | *db_handle_array = context->pending_doorbell_array; |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 881 | context->pending_doorbell_array = |
| 882 | vmci_handle_arr_create(0, VMCI_MAX_GUEST_DOORBELL_COUNT); |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 883 | if (!context->pending_doorbell_array) { |
| 884 | context->pending_doorbell_array = *db_handle_array; |
| 885 | *db_handle_array = NULL; |
| 886 | result = VMCI_ERROR_NO_MEM; |
| 887 | } |
| 888 | *qp_handle_array = NULL; |
| 889 | |
| 890 | spin_unlock(&context->lock); |
| 891 | vmci_ctx_put(context); |
| 892 | |
| 893 | return result; |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * Releases handle arrays with pending notifications previously |
| 898 | * retrieved using vmci_ctx_rcv_notifications_get. If the |
| 899 | * notifications were not successfully handed over to the guest, |
| 900 | * success must be false. |
| 901 | */ |
| 902 | void vmci_ctx_rcv_notifications_release(u32 context_id, |
| 903 | struct vmci_handle_arr *db_handle_array, |
| 904 | struct vmci_handle_arr *qp_handle_array, |
| 905 | bool success) |
| 906 | { |
| 907 | struct vmci_ctx *context = vmci_ctx_get(context_id); |
| 908 | |
| 909 | spin_lock(&context->lock); |
| 910 | if (!success) { |
| 911 | struct vmci_handle handle; |
| 912 | |
| 913 | /* |
| 914 | * New notifications may have been added while we were not |
| 915 | * holding the context lock, so we transfer any new pending |
| 916 | * doorbell notifications to the old array, and reinstate the |
| 917 | * old array. |
| 918 | */ |
| 919 | |
| 920 | handle = vmci_handle_arr_remove_tail( |
| 921 | context->pending_doorbell_array); |
| 922 | while (!vmci_handle_is_invalid(handle)) { |
| 923 | if (!vmci_handle_arr_has_entry(db_handle_array, |
| 924 | handle)) { |
| 925 | vmci_handle_arr_append_entry( |
| 926 | &db_handle_array, handle); |
| 927 | } |
| 928 | handle = vmci_handle_arr_remove_tail( |
| 929 | context->pending_doorbell_array); |
| 930 | } |
| 931 | vmci_handle_arr_destroy(context->pending_doorbell_array); |
| 932 | context->pending_doorbell_array = db_handle_array; |
| 933 | db_handle_array = NULL; |
| 934 | } else { |
| 935 | ctx_clear_notify_call(context); |
| 936 | } |
| 937 | spin_unlock(&context->lock); |
| 938 | vmci_ctx_put(context); |
| 939 | |
| 940 | if (db_handle_array) |
| 941 | vmci_handle_arr_destroy(db_handle_array); |
| 942 | |
| 943 | if (qp_handle_array) |
| 944 | vmci_handle_arr_destroy(qp_handle_array); |
| 945 | } |
| 946 | |
| 947 | /* |
| 948 | * Registers that a new doorbell handle has been allocated by the |
| 949 | * context. Only doorbell handles registered can be notified. |
| 950 | */ |
| 951 | int vmci_ctx_dbell_create(u32 context_id, struct vmci_handle handle) |
| 952 | { |
| 953 | struct vmci_ctx *context; |
| 954 | int result; |
| 955 | |
| 956 | if (context_id == VMCI_INVALID_ID || vmci_handle_is_invalid(handle)) |
| 957 | return VMCI_ERROR_INVALID_ARGS; |
| 958 | |
| 959 | context = vmci_ctx_get(context_id); |
| 960 | if (context == NULL) |
| 961 | return VMCI_ERROR_NOT_FOUND; |
| 962 | |
| 963 | spin_lock(&context->lock); |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 964 | if (!vmci_handle_arr_has_entry(context->doorbell_array, handle)) |
| 965 | result = vmci_handle_arr_append_entry(&context->doorbell_array, |
| 966 | handle); |
| 967 | else |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 968 | result = VMCI_ERROR_DUPLICATE_ENTRY; |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 969 | |
| 970 | spin_unlock(&context->lock); |
| 971 | vmci_ctx_put(context); |
| 972 | |
| 973 | return result; |
| 974 | } |
| 975 | |
| 976 | /* |
| 977 | * Unregisters a doorbell handle that was previously registered |
| 978 | * with vmci_ctx_dbell_create. |
| 979 | */ |
| 980 | int vmci_ctx_dbell_destroy(u32 context_id, struct vmci_handle handle) |
| 981 | { |
| 982 | struct vmci_ctx *context; |
| 983 | struct vmci_handle removed_handle; |
| 984 | |
| 985 | if (context_id == VMCI_INVALID_ID || vmci_handle_is_invalid(handle)) |
| 986 | return VMCI_ERROR_INVALID_ARGS; |
| 987 | |
| 988 | context = vmci_ctx_get(context_id); |
| 989 | if (context == NULL) |
| 990 | return VMCI_ERROR_NOT_FOUND; |
| 991 | |
| 992 | spin_lock(&context->lock); |
| 993 | removed_handle = |
| 994 | vmci_handle_arr_remove_entry(context->doorbell_array, handle); |
| 995 | vmci_handle_arr_remove_entry(context->pending_doorbell_array, handle); |
| 996 | spin_unlock(&context->lock); |
| 997 | |
| 998 | vmci_ctx_put(context); |
| 999 | |
| 1000 | return vmci_handle_is_invalid(removed_handle) ? |
| 1001 | VMCI_ERROR_NOT_FOUND : VMCI_SUCCESS; |
| 1002 | } |
| 1003 | |
| 1004 | /* |
| 1005 | * Unregisters all doorbell handles that were previously |
| 1006 | * registered with vmci_ctx_dbell_create. |
| 1007 | */ |
| 1008 | int vmci_ctx_dbell_destroy_all(u32 context_id) |
| 1009 | { |
| 1010 | struct vmci_ctx *context; |
| 1011 | struct vmci_handle handle; |
| 1012 | |
| 1013 | if (context_id == VMCI_INVALID_ID) |
| 1014 | return VMCI_ERROR_INVALID_ARGS; |
| 1015 | |
| 1016 | context = vmci_ctx_get(context_id); |
| 1017 | if (context == NULL) |
| 1018 | return VMCI_ERROR_NOT_FOUND; |
| 1019 | |
| 1020 | spin_lock(&context->lock); |
| 1021 | do { |
| 1022 | struct vmci_handle_arr *arr = context->doorbell_array; |
| 1023 | handle = vmci_handle_arr_remove_tail(arr); |
| 1024 | } while (!vmci_handle_is_invalid(handle)); |
| 1025 | do { |
| 1026 | struct vmci_handle_arr *arr = context->pending_doorbell_array; |
| 1027 | handle = vmci_handle_arr_remove_tail(arr); |
| 1028 | } while (!vmci_handle_is_invalid(handle)); |
| 1029 | spin_unlock(&context->lock); |
| 1030 | |
| 1031 | vmci_ctx_put(context); |
| 1032 | |
| 1033 | return VMCI_SUCCESS; |
| 1034 | } |
| 1035 | |
| 1036 | /* |
| 1037 | * Registers a notification of a doorbell handle initiated by the |
| 1038 | * specified source context. The notification of doorbells are |
| 1039 | * subject to the same isolation rules as datagram delivery. To |
| 1040 | * allow host side senders of notifications a finer granularity |
| 1041 | * of sender rights than those assigned to the sending context |
| 1042 | * itself, the host context is required to specify a different |
| 1043 | * set of privilege flags that will override the privileges of |
| 1044 | * the source context. |
| 1045 | */ |
| 1046 | int vmci_ctx_notify_dbell(u32 src_cid, |
| 1047 | struct vmci_handle handle, |
| 1048 | u32 src_priv_flags) |
| 1049 | { |
| 1050 | struct vmci_ctx *dst_context; |
| 1051 | int result; |
| 1052 | |
| 1053 | if (vmci_handle_is_invalid(handle)) |
| 1054 | return VMCI_ERROR_INVALID_ARGS; |
| 1055 | |
| 1056 | /* Get the target VM's VMCI context. */ |
| 1057 | dst_context = vmci_ctx_get(handle.context); |
| 1058 | if (!dst_context) { |
| 1059 | pr_devel("Invalid context (ID=0x%x)\n", handle.context); |
| 1060 | return VMCI_ERROR_NOT_FOUND; |
| 1061 | } |
| 1062 | |
| 1063 | if (src_cid != handle.context) { |
| 1064 | u32 dst_priv_flags; |
| 1065 | |
| 1066 | if (VMCI_CONTEXT_IS_VM(src_cid) && |
| 1067 | VMCI_CONTEXT_IS_VM(handle.context)) { |
| 1068 | pr_devel("Doorbell notification from VM to VM not supported (src=0x%x, dst=0x%x)\n", |
| 1069 | src_cid, handle.context); |
| 1070 | result = VMCI_ERROR_DST_UNREACHABLE; |
| 1071 | goto out; |
| 1072 | } |
| 1073 | |
| 1074 | result = vmci_dbell_get_priv_flags(handle, &dst_priv_flags); |
| 1075 | if (result < VMCI_SUCCESS) { |
| 1076 | pr_warn("Failed to get privilege flags for destination (handle=0x%x:0x%x)\n", |
| 1077 | handle.context, handle.resource); |
| 1078 | goto out; |
| 1079 | } |
| 1080 | |
| 1081 | if (src_cid != VMCI_HOST_CONTEXT_ID || |
| 1082 | src_priv_flags == VMCI_NO_PRIVILEGE_FLAGS) { |
| 1083 | src_priv_flags = vmci_context_get_priv_flags(src_cid); |
| 1084 | } |
| 1085 | |
| 1086 | if (vmci_deny_interaction(src_priv_flags, dst_priv_flags)) { |
| 1087 | result = VMCI_ERROR_NO_ACCESS; |
| 1088 | goto out; |
| 1089 | } |
| 1090 | } |
| 1091 | |
| 1092 | if (handle.context == VMCI_HOST_CONTEXT_ID) { |
| 1093 | result = vmci_dbell_host_context_notify(src_cid, handle); |
| 1094 | } else { |
| 1095 | spin_lock(&dst_context->lock); |
| 1096 | |
| 1097 | if (!vmci_handle_arr_has_entry(dst_context->doorbell_array, |
| 1098 | handle)) { |
| 1099 | result = VMCI_ERROR_NOT_FOUND; |
| 1100 | } else { |
| 1101 | if (!vmci_handle_arr_has_entry( |
| 1102 | dst_context->pending_doorbell_array, |
| 1103 | handle)) { |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 1104 | result = vmci_handle_arr_append_entry( |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 1105 | &dst_context->pending_doorbell_array, |
| 1106 | handle); |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 1107 | if (result == VMCI_SUCCESS) { |
| 1108 | ctx_signal_notify(dst_context); |
| 1109 | wake_up(&dst_context->host_context.wait_queue); |
| 1110 | } |
| 1111 | } else { |
| 1112 | result = VMCI_SUCCESS; |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 1113 | } |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 1114 | } |
| 1115 | spin_unlock(&dst_context->lock); |
| 1116 | } |
| 1117 | |
| 1118 | out: |
| 1119 | vmci_ctx_put(dst_context); |
| 1120 | |
| 1121 | return result; |
| 1122 | } |
| 1123 | |
| 1124 | bool vmci_ctx_supports_host_qp(struct vmci_ctx *context) |
| 1125 | { |
| 1126 | return context && context->user_version >= VMCI_VERSION_HOSTQP; |
| 1127 | } |
| 1128 | |
| 1129 | /* |
| 1130 | * Registers that a new queue pair handle has been allocated by |
| 1131 | * the context. |
| 1132 | */ |
| 1133 | int vmci_ctx_qp_create(struct vmci_ctx *context, struct vmci_handle handle) |
| 1134 | { |
| 1135 | int result; |
| 1136 | |
| 1137 | if (context == NULL || vmci_handle_is_invalid(handle)) |
| 1138 | return VMCI_ERROR_INVALID_ARGS; |
| 1139 | |
Vishnu DASA | 6f56992 | 2019-05-24 15:13:10 +0000 | [diff] [blame] | 1140 | if (!vmci_handle_arr_has_entry(context->queue_pair_array, handle)) |
| 1141 | result = vmci_handle_arr_append_entry( |
| 1142 | &context->queue_pair_array, handle); |
| 1143 | else |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 1144 | result = VMCI_ERROR_DUPLICATE_ENTRY; |
George Zhang | 28d6692 | 2013-01-08 15:52:59 -0800 | [diff] [blame] | 1145 | |
| 1146 | return result; |
| 1147 | } |
| 1148 | |
| 1149 | /* |
| 1150 | * Unregisters a queue pair handle that was previously registered |
| 1151 | * with vmci_ctx_qp_create. |
| 1152 | */ |
| 1153 | int vmci_ctx_qp_destroy(struct vmci_ctx *context, struct vmci_handle handle) |
| 1154 | { |
| 1155 | struct vmci_handle hndl; |
| 1156 | |
| 1157 | if (context == NULL || vmci_handle_is_invalid(handle)) |
| 1158 | return VMCI_ERROR_INVALID_ARGS; |
| 1159 | |
| 1160 | hndl = vmci_handle_arr_remove_entry(context->queue_pair_array, handle); |
| 1161 | |
| 1162 | return vmci_handle_is_invalid(hndl) ? |
| 1163 | VMCI_ERROR_NOT_FOUND : VMCI_SUCCESS; |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * Determines whether a given queue pair handle is registered |
| 1168 | * with the given context. |
| 1169 | */ |
| 1170 | bool vmci_ctx_qp_exists(struct vmci_ctx *context, struct vmci_handle handle) |
| 1171 | { |
| 1172 | if (context == NULL || vmci_handle_is_invalid(handle)) |
| 1173 | return false; |
| 1174 | |
| 1175 | return vmci_handle_arr_has_entry(context->queue_pair_array, handle); |
| 1176 | } |
| 1177 | |
| 1178 | /* |
| 1179 | * vmci_context_get_priv_flags() - Retrieve privilege flags. |
| 1180 | * @context_id: The context ID of the VMCI context. |
| 1181 | * |
| 1182 | * Retrieves privilege flags of the given VMCI context ID. |
| 1183 | */ |
| 1184 | u32 vmci_context_get_priv_flags(u32 context_id) |
| 1185 | { |
| 1186 | if (vmci_host_code_active()) { |
| 1187 | u32 flags; |
| 1188 | struct vmci_ctx *context; |
| 1189 | |
| 1190 | context = vmci_ctx_get(context_id); |
| 1191 | if (!context) |
| 1192 | return VMCI_LEAST_PRIVILEGE_FLAGS; |
| 1193 | |
| 1194 | flags = context->priv_flags; |
| 1195 | vmci_ctx_put(context); |
| 1196 | return flags; |
| 1197 | } |
| 1198 | return VMCI_NO_PRIVILEGE_FLAGS; |
| 1199 | } |
| 1200 | EXPORT_SYMBOL_GPL(vmci_context_get_priv_flags); |
| 1201 | |
| 1202 | /* |
| 1203 | * vmci_is_context_owner() - Determimnes if user is the context owner |
| 1204 | * @context_id: The context ID of the VMCI context. |
| 1205 | * @uid: The host user id (real kernel value). |
| 1206 | * |
| 1207 | * Determines whether a given UID is the owner of given VMCI context. |
| 1208 | */ |
| 1209 | bool vmci_is_context_owner(u32 context_id, kuid_t uid) |
| 1210 | { |
| 1211 | bool is_owner = false; |
| 1212 | |
| 1213 | if (vmci_host_code_active()) { |
| 1214 | struct vmci_ctx *context = vmci_ctx_get(context_id); |
| 1215 | if (context) { |
| 1216 | if (context->cred) |
| 1217 | is_owner = uid_eq(context->cred->uid, uid); |
| 1218 | vmci_ctx_put(context); |
| 1219 | } |
| 1220 | } |
| 1221 | |
| 1222 | return is_owner; |
| 1223 | } |
| 1224 | EXPORT_SYMBOL_GPL(vmci_is_context_owner); |