1 /* 2 * Copyright (c) 2009, Microsoft Corporation. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms and conditions of the GNU General Public License, 6 * version 2, as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 11 * more details. 12 * 13 * You should have received a copy of the GNU General Public License along with 14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 15 * Place - Suite 330, Boston, MA 02111-1307 USA. 16 * 17 * Authors: 18 * Haiyang Zhang <haiyangz@microsoft.com> 19 * Hank Janssen <hjanssen@microsoft.com> 20 */ 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/kernel.h> 24 #include <linux/sched.h> 25 #include <linux/wait.h> 26 #include <linux/mm.h> 27 #include <linux/slab.h> 28 #include <linux/list.h> 29 #include <linux/module.h> 30 #include <linux/completion.h> 31 #include <linux/hyperv.h> 32 33 #include "hyperv_vmbus.h" 34 35 struct vmbus_channel_message_table_entry { 36 enum vmbus_channel_message_type message_type; 37 void (*message_handler)(struct vmbus_channel_message_header *msg); 38 }; 39 40 41 /** 42 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message 43 * @icmsghdrp: Pointer to msg header structure 44 * @icmsg_negotiate: Pointer to negotiate message structure 45 * @buf: Raw buffer channel data 46 * 47 * @icmsghdrp is of type &struct icmsg_hdr. 48 * @negop is of type &struct icmsg_negotiate. 49 * Set up and fill in default negotiate response message. 50 * 51 * The fw_version specifies the framework version that 52 * we can support and srv_version specifies the service 53 * version we can support. 54 * 55 * Mainly used by Hyper-V drivers. 56 */ 57 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, 58 struct icmsg_negotiate *negop, u8 *buf, 59 int fw_version, int srv_version) 60 { 61 int icframe_major, icframe_minor; 62 int icmsg_major, icmsg_minor; 63 int fw_major, fw_minor; 64 int srv_major, srv_minor; 65 int i; 66 bool found_match = false; 67 68 icmsghdrp->icmsgsize = 0x10; 69 fw_major = (fw_version >> 16); 70 fw_minor = (fw_version & 0xFFFF); 71 72 srv_major = (srv_version >> 16); 73 srv_minor = (srv_version & 0xFFFF); 74 75 negop = (struct icmsg_negotiate *)&buf[ 76 sizeof(struct vmbuspipe_hdr) + 77 sizeof(struct icmsg_hdr)]; 78 79 icframe_major = negop->icframe_vercnt; 80 icframe_minor = 0; 81 82 icmsg_major = negop->icmsg_vercnt; 83 icmsg_minor = 0; 84 85 /* 86 * Select the framework version number we will 87 * support. 88 */ 89 90 for (i = 0; i < negop->icframe_vercnt; i++) { 91 if ((negop->icversion_data[i].major == fw_major) && 92 (negop->icversion_data[i].minor == fw_minor)) { 93 icframe_major = negop->icversion_data[i].major; 94 icframe_minor = negop->icversion_data[i].minor; 95 found_match = true; 96 } 97 } 98 99 if (!found_match) 100 goto fw_error; 101 102 found_match = false; 103 104 for (i = negop->icframe_vercnt; 105 (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) { 106 if ((negop->icversion_data[i].major == srv_major) && 107 (negop->icversion_data[i].minor == srv_minor)) { 108 icmsg_major = negop->icversion_data[i].major; 109 icmsg_minor = negop->icversion_data[i].minor; 110 found_match = true; 111 } 112 } 113 114 /* 115 * Respond with the framework and service 116 * version numbers we can support. 117 */ 118 119 fw_error: 120 if (!found_match) { 121 negop->icframe_vercnt = 0; 122 negop->icmsg_vercnt = 0; 123 } else { 124 negop->icframe_vercnt = 1; 125 negop->icmsg_vercnt = 1; 126 } 127 128 negop->icversion_data[0].major = icframe_major; 129 negop->icversion_data[0].minor = icframe_minor; 130 negop->icversion_data[1].major = icmsg_major; 131 negop->icversion_data[1].minor = icmsg_minor; 132 return found_match; 133 } 134 135 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp); 136 137 /* 138 * alloc_channel - Allocate and initialize a vmbus channel object 139 */ 140 static struct vmbus_channel *alloc_channel(void) 141 { 142 struct vmbus_channel *channel; 143 144 channel = kzalloc(sizeof(*channel), GFP_ATOMIC); 145 if (!channel) 146 return NULL; 147 148 spin_lock_init(&channel->inbound_lock); 149 spin_lock_init(&channel->sc_lock); 150 151 INIT_LIST_HEAD(&channel->sc_list); 152 153 channel->controlwq = create_workqueue("hv_vmbus_ctl"); 154 if (!channel->controlwq) { 155 kfree(channel); 156 return NULL; 157 } 158 159 return channel; 160 } 161 162 /* 163 * release_hannel - Release the vmbus channel object itself 164 */ 165 static void release_channel(struct work_struct *work) 166 { 167 struct vmbus_channel *channel = container_of(work, 168 struct vmbus_channel, 169 work); 170 171 destroy_workqueue(channel->controlwq); 172 173 kfree(channel); 174 } 175 176 /* 177 * free_channel - Release the resources used by the vmbus channel object 178 */ 179 static void free_channel(struct vmbus_channel *channel) 180 { 181 182 /* 183 * We have to release the channel's workqueue/thread in the vmbus's 184 * workqueue/thread context 185 * ie we can't destroy ourselves. 186 */ 187 INIT_WORK(&channel->work, release_channel); 188 queue_work(vmbus_connection.work_queue, &channel->work); 189 } 190 191 192 193 /* 194 * vmbus_process_rescind_offer - 195 * Rescind the offer by initiating a device removal 196 */ 197 static void vmbus_process_rescind_offer(struct work_struct *work) 198 { 199 struct vmbus_channel *channel = container_of(work, 200 struct vmbus_channel, 201 work); 202 unsigned long flags; 203 struct vmbus_channel *primary_channel; 204 struct vmbus_channel_relid_released msg; 205 206 if (channel->device_obj) 207 vmbus_device_unregister(channel->device_obj); 208 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 209 msg.child_relid = channel->offermsg.child_relid; 210 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 211 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released)); 212 213 if (channel->primary_channel == NULL) { 214 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 215 list_del(&channel->listentry); 216 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 217 } else { 218 primary_channel = channel->primary_channel; 219 spin_lock_irqsave(&primary_channel->sc_lock, flags); 220 list_del(&channel->sc_list); 221 spin_unlock_irqrestore(&primary_channel->sc_lock, flags); 222 } 223 free_channel(channel); 224 } 225 226 void vmbus_free_channels(void) 227 { 228 struct vmbus_channel *channel; 229 230 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 231 vmbus_device_unregister(channel->device_obj); 232 kfree(channel->device_obj); 233 free_channel(channel); 234 } 235 } 236 237 /* 238 * vmbus_process_offer - Process the offer by creating a channel/device 239 * associated with this offer 240 */ 241 static void vmbus_process_offer(struct work_struct *work) 242 { 243 struct vmbus_channel *newchannel = container_of(work, 244 struct vmbus_channel, 245 work); 246 struct vmbus_channel *channel; 247 bool fnew = true; 248 int ret; 249 unsigned long flags; 250 251 /* The next possible work is rescind handling */ 252 INIT_WORK(&newchannel->work, vmbus_process_rescind_offer); 253 254 /* Make sure this is a new offer */ 255 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 256 257 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 258 if (!uuid_le_cmp(channel->offermsg.offer.if_type, 259 newchannel->offermsg.offer.if_type) && 260 !uuid_le_cmp(channel->offermsg.offer.if_instance, 261 newchannel->offermsg.offer.if_instance)) { 262 fnew = false; 263 break; 264 } 265 } 266 267 if (fnew) 268 list_add_tail(&newchannel->listentry, 269 &vmbus_connection.chn_list); 270 271 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 272 273 if (!fnew) { 274 /* 275 * Check to see if this is a sub-channel. 276 */ 277 if (newchannel->offermsg.offer.sub_channel_index != 0) { 278 /* 279 * Process the sub-channel. 280 */ 281 newchannel->primary_channel = channel; 282 spin_lock_irqsave(&channel->sc_lock, flags); 283 list_add_tail(&newchannel->sc_list, &channel->sc_list); 284 spin_unlock_irqrestore(&channel->sc_lock, flags); 285 newchannel->state = CHANNEL_OPEN_STATE; 286 if (channel->sc_creation_callback != NULL) 287 channel->sc_creation_callback(newchannel); 288 289 return; 290 } 291 292 free_channel(newchannel); 293 return; 294 } 295 296 /* 297 * This state is used to indicate a successful open 298 * so that when we do close the channel normally, we 299 * can cleanup properly 300 */ 301 newchannel->state = CHANNEL_OPEN_STATE; 302 303 /* 304 * Start the process of binding this offer to the driver 305 * We need to set the DeviceObject field before calling 306 * vmbus_child_dev_add() 307 */ 308 newchannel->device_obj = vmbus_device_create( 309 &newchannel->offermsg.offer.if_type, 310 &newchannel->offermsg.offer.if_instance, 311 newchannel); 312 313 /* 314 * Add the new device to the bus. This will kick off device-driver 315 * binding which eventually invokes the device driver's AddDevice() 316 * method. 317 */ 318 ret = vmbus_device_register(newchannel->device_obj); 319 if (ret != 0) { 320 pr_err("unable to add child device object (relid %d)\n", 321 newchannel->offermsg.child_relid); 322 323 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 324 list_del(&newchannel->listentry); 325 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 326 kfree(newchannel->device_obj); 327 328 free_channel(newchannel); 329 } 330 } 331 332 enum { 333 IDE = 0, 334 SCSI, 335 NIC, 336 MAX_PERF_CHN, 337 }; 338 339 /* 340 * This is an array of device_ids (device types) that are performance critical. 341 * We attempt to distribute the interrupt load for these devices across 342 * all available CPUs. 343 */ 344 static const struct hv_vmbus_device_id hp_devs[] = { 345 /* IDE */ 346 { HV_IDE_GUID, }, 347 /* Storage - SCSI */ 348 { HV_SCSI_GUID, }, 349 /* Network */ 350 { HV_NIC_GUID, }, 351 }; 352 353 354 /* 355 * We use this state to statically distribute the channel interrupt load. 356 */ 357 static u32 next_vp; 358 359 /* 360 * Starting with Win8, we can statically distribute the incoming 361 * channel interrupt load by binding a channel to VCPU. We 362 * implement here a simple round robin scheme for distributing 363 * the interrupt load. 364 * We will bind channels that are not performance critical to cpu 0 and 365 * performance critical channels (IDE, SCSI and Network) will be uniformly 366 * distributed across all available CPUs. 367 */ 368 static void init_vp_index(struct vmbus_channel *channel, uuid_le *type_guid) 369 { 370 u32 cur_cpu; 371 int i; 372 bool perf_chn = false; 373 u32 max_cpus = num_online_cpus(); 374 375 for (i = IDE; i < MAX_PERF_CHN; i++) { 376 if (!memcmp(type_guid->b, hp_devs[i].guid, 377 sizeof(uuid_le))) { 378 perf_chn = true; 379 break; 380 } 381 } 382 if ((vmbus_proto_version == VERSION_WS2008) || 383 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 384 /* 385 * Prior to win8, all channel interrupts are 386 * delivered on cpu 0. 387 * Also if the channel is not a performance critical 388 * channel, bind it to cpu 0. 389 */ 390 channel->target_cpu = 0; 391 channel->target_vp = 0; 392 return; 393 } 394 cur_cpu = (++next_vp % max_cpus); 395 channel->target_cpu = cur_cpu; 396 channel->target_vp = hv_context.vp_index[cur_cpu]; 397 } 398 399 /* 400 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 401 * 402 */ 403 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 404 { 405 struct vmbus_channel_offer_channel *offer; 406 struct vmbus_channel *newchannel; 407 408 offer = (struct vmbus_channel_offer_channel *)hdr; 409 410 /* Allocate the channel object and save this offer. */ 411 newchannel = alloc_channel(); 412 if (!newchannel) { 413 pr_err("Unable to allocate channel object\n"); 414 return; 415 } 416 417 /* 418 * By default we setup state to enable batched 419 * reading. A specific service can choose to 420 * disable this prior to opening the channel. 421 */ 422 newchannel->batched_reading = true; 423 424 /* 425 * Setup state for signalling the host. 426 */ 427 newchannel->sig_event = (struct hv_input_signal_event *) 428 (ALIGN((unsigned long) 429 &newchannel->sig_buf, 430 HV_HYPERCALL_PARAM_ALIGN)); 431 432 newchannel->sig_event->connectionid.asu32 = 0; 433 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 434 newchannel->sig_event->flag_number = 0; 435 newchannel->sig_event->rsvdz = 0; 436 437 if (vmbus_proto_version != VERSION_WS2008) { 438 newchannel->is_dedicated_interrupt = 439 (offer->is_dedicated_interrupt != 0); 440 newchannel->sig_event->connectionid.u.id = 441 offer->connection_id; 442 } 443 444 init_vp_index(newchannel, &offer->offer.if_type); 445 446 memcpy(&newchannel->offermsg, offer, 447 sizeof(struct vmbus_channel_offer_channel)); 448 newchannel->monitor_grp = (u8)offer->monitorid / 32; 449 newchannel->monitor_bit = (u8)offer->monitorid % 32; 450 451 INIT_WORK(&newchannel->work, vmbus_process_offer); 452 queue_work(newchannel->controlwq, &newchannel->work); 453 } 454 455 /* 456 * vmbus_onoffer_rescind - Rescind offer handler. 457 * 458 * We queue a work item to process this offer synchronously 459 */ 460 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 461 { 462 struct vmbus_channel_rescind_offer *rescind; 463 struct vmbus_channel *channel; 464 465 rescind = (struct vmbus_channel_rescind_offer *)hdr; 466 channel = relid2channel(rescind->child_relid); 467 468 if (channel == NULL) 469 /* Just return here, no channel found */ 470 return; 471 472 /* work is initialized for vmbus_process_rescind_offer() from 473 * vmbus_process_offer() where the channel got created */ 474 queue_work(channel->controlwq, &channel->work); 475 } 476 477 /* 478 * vmbus_onoffers_delivered - 479 * This is invoked when all offers have been delivered. 480 * 481 * Nothing to do here. 482 */ 483 static void vmbus_onoffers_delivered( 484 struct vmbus_channel_message_header *hdr) 485 { 486 } 487 488 /* 489 * vmbus_onopen_result - Open result handler. 490 * 491 * This is invoked when we received a response to our channel open request. 492 * Find the matching request, copy the response and signal the requesting 493 * thread. 494 */ 495 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 496 { 497 struct vmbus_channel_open_result *result; 498 struct vmbus_channel_msginfo *msginfo; 499 struct vmbus_channel_message_header *requestheader; 500 struct vmbus_channel_open_channel *openmsg; 501 unsigned long flags; 502 503 result = (struct vmbus_channel_open_result *)hdr; 504 505 /* 506 * Find the open msg, copy the result and signal/unblock the wait event 507 */ 508 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 509 510 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 511 msglistentry) { 512 requestheader = 513 (struct vmbus_channel_message_header *)msginfo->msg; 514 515 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 516 openmsg = 517 (struct vmbus_channel_open_channel *)msginfo->msg; 518 if (openmsg->child_relid == result->child_relid && 519 openmsg->openid == result->openid) { 520 memcpy(&msginfo->response.open_result, 521 result, 522 sizeof( 523 struct vmbus_channel_open_result)); 524 complete(&msginfo->waitevent); 525 break; 526 } 527 } 528 } 529 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 530 } 531 532 /* 533 * vmbus_ongpadl_created - GPADL created handler. 534 * 535 * This is invoked when we received a response to our gpadl create request. 536 * Find the matching request, copy the response and signal the requesting 537 * thread. 538 */ 539 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 540 { 541 struct vmbus_channel_gpadl_created *gpadlcreated; 542 struct vmbus_channel_msginfo *msginfo; 543 struct vmbus_channel_message_header *requestheader; 544 struct vmbus_channel_gpadl_header *gpadlheader; 545 unsigned long flags; 546 547 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 548 549 /* 550 * Find the establish msg, copy the result and signal/unblock the wait 551 * event 552 */ 553 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 554 555 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 556 msglistentry) { 557 requestheader = 558 (struct vmbus_channel_message_header *)msginfo->msg; 559 560 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 561 gpadlheader = 562 (struct vmbus_channel_gpadl_header *)requestheader; 563 564 if ((gpadlcreated->child_relid == 565 gpadlheader->child_relid) && 566 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 567 memcpy(&msginfo->response.gpadl_created, 568 gpadlcreated, 569 sizeof( 570 struct vmbus_channel_gpadl_created)); 571 complete(&msginfo->waitevent); 572 break; 573 } 574 } 575 } 576 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 577 } 578 579 /* 580 * vmbus_ongpadl_torndown - GPADL torndown handler. 581 * 582 * This is invoked when we received a response to our gpadl teardown request. 583 * Find the matching request, copy the response and signal the requesting 584 * thread. 585 */ 586 static void vmbus_ongpadl_torndown( 587 struct vmbus_channel_message_header *hdr) 588 { 589 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 590 struct vmbus_channel_msginfo *msginfo; 591 struct vmbus_channel_message_header *requestheader; 592 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 593 unsigned long flags; 594 595 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 596 597 /* 598 * Find the open msg, copy the result and signal/unblock the wait event 599 */ 600 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 601 602 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 603 msglistentry) { 604 requestheader = 605 (struct vmbus_channel_message_header *)msginfo->msg; 606 607 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 608 gpadl_teardown = 609 (struct vmbus_channel_gpadl_teardown *)requestheader; 610 611 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 612 memcpy(&msginfo->response.gpadl_torndown, 613 gpadl_torndown, 614 sizeof( 615 struct vmbus_channel_gpadl_torndown)); 616 complete(&msginfo->waitevent); 617 break; 618 } 619 } 620 } 621 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 622 } 623 624 /* 625 * vmbus_onversion_response - Version response handler 626 * 627 * This is invoked when we received a response to our initiate contact request. 628 * Find the matching request, copy the response and signal the requesting 629 * thread. 630 */ 631 static void vmbus_onversion_response( 632 struct vmbus_channel_message_header *hdr) 633 { 634 struct vmbus_channel_msginfo *msginfo; 635 struct vmbus_channel_message_header *requestheader; 636 struct vmbus_channel_version_response *version_response; 637 unsigned long flags; 638 639 version_response = (struct vmbus_channel_version_response *)hdr; 640 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 641 642 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 643 msglistentry) { 644 requestheader = 645 (struct vmbus_channel_message_header *)msginfo->msg; 646 647 if (requestheader->msgtype == 648 CHANNELMSG_INITIATE_CONTACT) { 649 memcpy(&msginfo->response.version_response, 650 version_response, 651 sizeof(struct vmbus_channel_version_response)); 652 complete(&msginfo->waitevent); 653 } 654 } 655 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 656 } 657 658 /* Channel message dispatch table */ 659 static struct vmbus_channel_message_table_entry 660 channel_message_table[CHANNELMSG_COUNT] = { 661 {CHANNELMSG_INVALID, NULL}, 662 {CHANNELMSG_OFFERCHANNEL, vmbus_onoffer}, 663 {CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind}, 664 {CHANNELMSG_REQUESTOFFERS, NULL}, 665 {CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered}, 666 {CHANNELMSG_OPENCHANNEL, NULL}, 667 {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result}, 668 {CHANNELMSG_CLOSECHANNEL, NULL}, 669 {CHANNELMSG_GPADL_HEADER, NULL}, 670 {CHANNELMSG_GPADL_BODY, NULL}, 671 {CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created}, 672 {CHANNELMSG_GPADL_TEARDOWN, NULL}, 673 {CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown}, 674 {CHANNELMSG_RELID_RELEASED, NULL}, 675 {CHANNELMSG_INITIATE_CONTACT, NULL}, 676 {CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response}, 677 {CHANNELMSG_UNLOAD, NULL}, 678 }; 679 680 /* 681 * vmbus_onmessage - Handler for channel protocol messages. 682 * 683 * This is invoked in the vmbus worker thread context. 684 */ 685 void vmbus_onmessage(void *context) 686 { 687 struct hv_message *msg = context; 688 struct vmbus_channel_message_header *hdr; 689 int size; 690 691 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 692 size = msg->header.payload_size; 693 694 if (hdr->msgtype >= CHANNELMSG_COUNT) { 695 pr_err("Received invalid channel message type %d size %d\n", 696 hdr->msgtype, size); 697 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 698 (unsigned char *)msg->u.payload, size); 699 return; 700 } 701 702 if (channel_message_table[hdr->msgtype].message_handler) 703 channel_message_table[hdr->msgtype].message_handler(hdr); 704 else 705 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 706 } 707 708 /* 709 * vmbus_request_offers - Send a request to get all our pending offers. 710 */ 711 int vmbus_request_offers(void) 712 { 713 struct vmbus_channel_message_header *msg; 714 struct vmbus_channel_msginfo *msginfo; 715 int ret, t; 716 717 msginfo = kmalloc(sizeof(*msginfo) + 718 sizeof(struct vmbus_channel_message_header), 719 GFP_KERNEL); 720 if (!msginfo) 721 return -ENOMEM; 722 723 init_completion(&msginfo->waitevent); 724 725 msg = (struct vmbus_channel_message_header *)msginfo->msg; 726 727 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 728 729 730 ret = vmbus_post_msg(msg, 731 sizeof(struct vmbus_channel_message_header)); 732 if (ret != 0) { 733 pr_err("Unable to request offers - %d\n", ret); 734 735 goto cleanup; 736 } 737 738 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); 739 if (t == 0) { 740 ret = -ETIMEDOUT; 741 goto cleanup; 742 } 743 744 745 746 cleanup: 747 kfree(msginfo); 748 749 return ret; 750 } 751 752 /* 753 * Retrieve the (sub) channel on which to send an outgoing request. 754 * When a primary channel has multiple sub-channels, we choose a 755 * channel whose VCPU binding is closest to the VCPU on which 756 * this call is being made. 757 */ 758 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 759 { 760 struct list_head *cur, *tmp; 761 int cur_cpu = hv_context.vp_index[smp_processor_id()]; 762 struct vmbus_channel *cur_channel; 763 struct vmbus_channel *outgoing_channel = primary; 764 int cpu_distance, new_cpu_distance; 765 766 if (list_empty(&primary->sc_list)) 767 return outgoing_channel; 768 769 list_for_each_safe(cur, tmp, &primary->sc_list) { 770 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 771 if (cur_channel->state != CHANNEL_OPENED_STATE) 772 continue; 773 774 if (cur_channel->target_vp == cur_cpu) 775 return cur_channel; 776 777 cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ? 778 (outgoing_channel->target_vp - cur_cpu) : 779 (cur_cpu - outgoing_channel->target_vp)); 780 781 new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ? 782 (cur_channel->target_vp - cur_cpu) : 783 (cur_cpu - cur_channel->target_vp)); 784 785 if (cpu_distance < new_cpu_distance) 786 continue; 787 788 outgoing_channel = cur_channel; 789 } 790 791 return outgoing_channel; 792 } 793 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 794 795 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 796 { 797 struct list_head *cur, *tmp; 798 struct vmbus_channel *cur_channel; 799 800 if (primary_channel->sc_creation_callback == NULL) 801 return; 802 803 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 804 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 805 806 primary_channel->sc_creation_callback(cur_channel); 807 } 808 } 809 810 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 811 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 812 { 813 primary_channel->sc_creation_callback = sc_cr_cb; 814 } 815 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 816 817 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 818 { 819 bool ret; 820 821 ret = !list_empty(&primary->sc_list); 822 823 if (ret) { 824 /* 825 * Invoke the callback on sub-channel creation. 826 * This will present a uniform interface to the 827 * clients. 828 */ 829 invoke_sc_cb(primary); 830 } 831 832 return ret; 833 } 834 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 835