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 INIT_LIST_HEAD(&channel->percpu_list); 153 154 channel->controlwq = create_workqueue("hv_vmbus_ctl"); 155 if (!channel->controlwq) { 156 kfree(channel); 157 return NULL; 158 } 159 160 return channel; 161 } 162 163 /* 164 * release_hannel - Release the vmbus channel object itself 165 */ 166 static void release_channel(struct work_struct *work) 167 { 168 struct vmbus_channel *channel = container_of(work, 169 struct vmbus_channel, 170 work); 171 172 destroy_workqueue(channel->controlwq); 173 174 kfree(channel); 175 } 176 177 /* 178 * free_channel - Release the resources used by the vmbus channel object 179 */ 180 static void free_channel(struct vmbus_channel *channel) 181 { 182 183 /* 184 * We have to release the channel's workqueue/thread in the vmbus's 185 * workqueue/thread context 186 * ie we can't destroy ourselves. 187 */ 188 INIT_WORK(&channel->work, release_channel); 189 queue_work(vmbus_connection.work_queue, &channel->work); 190 } 191 192 static void percpu_channel_enq(void *arg) 193 { 194 struct vmbus_channel *channel = arg; 195 int cpu = smp_processor_id(); 196 197 list_add_tail(&channel->percpu_list, &hv_context.percpu_list[cpu]); 198 } 199 200 static void percpu_channel_deq(void *arg) 201 { 202 struct vmbus_channel *channel = arg; 203 204 list_del(&channel->percpu_list); 205 } 206 207 /* 208 * vmbus_process_rescind_offer - 209 * Rescind the offer by initiating a device removal 210 */ 211 static void vmbus_process_rescind_offer(struct work_struct *work) 212 { 213 struct vmbus_channel *channel = container_of(work, 214 struct vmbus_channel, 215 work); 216 unsigned long flags; 217 struct vmbus_channel *primary_channel; 218 struct vmbus_channel_relid_released msg; 219 struct device *dev; 220 221 if (channel->device_obj) { 222 dev = get_device(&channel->device_obj->device); 223 if (dev) { 224 vmbus_device_unregister(channel->device_obj); 225 put_device(dev); 226 } 227 } 228 229 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 230 msg.child_relid = channel->offermsg.child_relid; 231 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 232 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released)); 233 234 if (channel->target_cpu != get_cpu()) { 235 put_cpu(); 236 smp_call_function_single(channel->target_cpu, 237 percpu_channel_deq, channel, true); 238 } else { 239 percpu_channel_deq(channel); 240 put_cpu(); 241 } 242 243 if (channel->primary_channel == NULL) { 244 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 245 list_del(&channel->listentry); 246 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 247 } else { 248 primary_channel = channel->primary_channel; 249 spin_lock_irqsave(&primary_channel->sc_lock, flags); 250 list_del(&channel->sc_list); 251 spin_unlock_irqrestore(&primary_channel->sc_lock, flags); 252 } 253 free_channel(channel); 254 } 255 256 void vmbus_free_channels(void) 257 { 258 struct vmbus_channel *channel; 259 260 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 261 vmbus_device_unregister(channel->device_obj); 262 kfree(channel->device_obj); 263 free_channel(channel); 264 } 265 } 266 267 /* 268 * vmbus_process_offer - Process the offer by creating a channel/device 269 * associated with this offer 270 */ 271 static void vmbus_process_offer(struct work_struct *work) 272 { 273 struct vmbus_channel *newchannel = container_of(work, 274 struct vmbus_channel, 275 work); 276 struct vmbus_channel *channel; 277 bool fnew = true; 278 bool enq = false; 279 int ret; 280 unsigned long flags; 281 282 /* The next possible work is rescind handling */ 283 INIT_WORK(&newchannel->work, vmbus_process_rescind_offer); 284 285 /* Make sure this is a new offer */ 286 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 287 288 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 289 if (!uuid_le_cmp(channel->offermsg.offer.if_type, 290 newchannel->offermsg.offer.if_type) && 291 !uuid_le_cmp(channel->offermsg.offer.if_instance, 292 newchannel->offermsg.offer.if_instance)) { 293 fnew = false; 294 break; 295 } 296 } 297 298 if (fnew) { 299 list_add_tail(&newchannel->listentry, 300 &vmbus_connection.chn_list); 301 enq = true; 302 } 303 304 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 305 306 if (enq) { 307 if (newchannel->target_cpu != get_cpu()) { 308 put_cpu(); 309 smp_call_function_single(newchannel->target_cpu, 310 percpu_channel_enq, 311 newchannel, true); 312 } else { 313 percpu_channel_enq(newchannel); 314 put_cpu(); 315 } 316 } 317 if (!fnew) { 318 /* 319 * Check to see if this is a sub-channel. 320 */ 321 if (newchannel->offermsg.offer.sub_channel_index != 0) { 322 /* 323 * Process the sub-channel. 324 */ 325 newchannel->primary_channel = channel; 326 spin_lock_irqsave(&channel->sc_lock, flags); 327 list_add_tail(&newchannel->sc_list, &channel->sc_list); 328 spin_unlock_irqrestore(&channel->sc_lock, flags); 329 330 if (newchannel->target_cpu != get_cpu()) { 331 put_cpu(); 332 smp_call_function_single(newchannel->target_cpu, 333 percpu_channel_enq, 334 newchannel, true); 335 } else { 336 percpu_channel_enq(newchannel); 337 put_cpu(); 338 } 339 340 newchannel->state = CHANNEL_OPEN_STATE; 341 if (channel->sc_creation_callback != NULL) 342 channel->sc_creation_callback(newchannel); 343 344 return; 345 } 346 347 free_channel(newchannel); 348 return; 349 } 350 351 /* 352 * This state is used to indicate a successful open 353 * so that when we do close the channel normally, we 354 * can cleanup properly 355 */ 356 newchannel->state = CHANNEL_OPEN_STATE; 357 358 /* 359 * Start the process of binding this offer to the driver 360 * We need to set the DeviceObject field before calling 361 * vmbus_child_dev_add() 362 */ 363 newchannel->device_obj = vmbus_device_create( 364 &newchannel->offermsg.offer.if_type, 365 &newchannel->offermsg.offer.if_instance, 366 newchannel); 367 368 /* 369 * Add the new device to the bus. This will kick off device-driver 370 * binding which eventually invokes the device driver's AddDevice() 371 * method. 372 */ 373 ret = vmbus_device_register(newchannel->device_obj); 374 if (ret != 0) { 375 pr_err("unable to add child device object (relid %d)\n", 376 newchannel->offermsg.child_relid); 377 378 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 379 list_del(&newchannel->listentry); 380 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 381 kfree(newchannel->device_obj); 382 383 free_channel(newchannel); 384 } 385 } 386 387 enum { 388 IDE = 0, 389 SCSI, 390 NIC, 391 MAX_PERF_CHN, 392 }; 393 394 /* 395 * This is an array of device_ids (device types) that are performance critical. 396 * We attempt to distribute the interrupt load for these devices across 397 * all available CPUs. 398 */ 399 static const struct hv_vmbus_device_id hp_devs[] = { 400 /* IDE */ 401 { HV_IDE_GUID, }, 402 /* Storage - SCSI */ 403 { HV_SCSI_GUID, }, 404 /* Network */ 405 { HV_NIC_GUID, }, 406 }; 407 408 409 /* 410 * We use this state to statically distribute the channel interrupt load. 411 */ 412 static u32 next_vp; 413 414 /* 415 * Starting with Win8, we can statically distribute the incoming 416 * channel interrupt load by binding a channel to VCPU. We 417 * implement here a simple round robin scheme for distributing 418 * the interrupt load. 419 * We will bind channels that are not performance critical to cpu 0 and 420 * performance critical channels (IDE, SCSI and Network) will be uniformly 421 * distributed across all available CPUs. 422 */ 423 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid) 424 { 425 u32 cur_cpu; 426 int i; 427 bool perf_chn = false; 428 u32 max_cpus = num_online_cpus(); 429 430 for (i = IDE; i < MAX_PERF_CHN; i++) { 431 if (!memcmp(type_guid->b, hp_devs[i].guid, 432 sizeof(uuid_le))) { 433 perf_chn = true; 434 break; 435 } 436 } 437 if ((vmbus_proto_version == VERSION_WS2008) || 438 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 439 /* 440 * Prior to win8, all channel interrupts are 441 * delivered on cpu 0. 442 * Also if the channel is not a performance critical 443 * channel, bind it to cpu 0. 444 */ 445 channel->target_cpu = 0; 446 channel->target_vp = 0; 447 return; 448 } 449 cur_cpu = (++next_vp % max_cpus); 450 channel->target_cpu = cur_cpu; 451 channel->target_vp = hv_context.vp_index[cur_cpu]; 452 } 453 454 /* 455 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 456 * 457 */ 458 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 459 { 460 struct vmbus_channel_offer_channel *offer; 461 struct vmbus_channel *newchannel; 462 463 offer = (struct vmbus_channel_offer_channel *)hdr; 464 465 /* Allocate the channel object and save this offer. */ 466 newchannel = alloc_channel(); 467 if (!newchannel) { 468 pr_err("Unable to allocate channel object\n"); 469 return; 470 } 471 472 /* 473 * By default we setup state to enable batched 474 * reading. A specific service can choose to 475 * disable this prior to opening the channel. 476 */ 477 newchannel->batched_reading = true; 478 479 /* 480 * Setup state for signalling the host. 481 */ 482 newchannel->sig_event = (struct hv_input_signal_event *) 483 (ALIGN((unsigned long) 484 &newchannel->sig_buf, 485 HV_HYPERCALL_PARAM_ALIGN)); 486 487 newchannel->sig_event->connectionid.asu32 = 0; 488 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 489 newchannel->sig_event->flag_number = 0; 490 newchannel->sig_event->rsvdz = 0; 491 492 if (vmbus_proto_version != VERSION_WS2008) { 493 newchannel->is_dedicated_interrupt = 494 (offer->is_dedicated_interrupt != 0); 495 newchannel->sig_event->connectionid.u.id = 496 offer->connection_id; 497 } 498 499 init_vp_index(newchannel, &offer->offer.if_type); 500 501 memcpy(&newchannel->offermsg, offer, 502 sizeof(struct vmbus_channel_offer_channel)); 503 newchannel->monitor_grp = (u8)offer->monitorid / 32; 504 newchannel->monitor_bit = (u8)offer->monitorid % 32; 505 506 INIT_WORK(&newchannel->work, vmbus_process_offer); 507 queue_work(newchannel->controlwq, &newchannel->work); 508 } 509 510 /* 511 * vmbus_onoffer_rescind - Rescind offer handler. 512 * 513 * We queue a work item to process this offer synchronously 514 */ 515 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 516 { 517 struct vmbus_channel_rescind_offer *rescind; 518 struct vmbus_channel *channel; 519 520 rescind = (struct vmbus_channel_rescind_offer *)hdr; 521 channel = relid2channel(rescind->child_relid); 522 523 if (channel == NULL) 524 /* Just return here, no channel found */ 525 return; 526 527 channel->rescind = true; 528 529 /* work is initialized for vmbus_process_rescind_offer() from 530 * vmbus_process_offer() where the channel got created */ 531 queue_work(channel->controlwq, &channel->work); 532 } 533 534 /* 535 * vmbus_onoffers_delivered - 536 * This is invoked when all offers have been delivered. 537 * 538 * Nothing to do here. 539 */ 540 static void vmbus_onoffers_delivered( 541 struct vmbus_channel_message_header *hdr) 542 { 543 } 544 545 /* 546 * vmbus_onopen_result - Open result handler. 547 * 548 * This is invoked when we received a response to our channel open request. 549 * Find the matching request, copy the response and signal the requesting 550 * thread. 551 */ 552 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 553 { 554 struct vmbus_channel_open_result *result; 555 struct vmbus_channel_msginfo *msginfo; 556 struct vmbus_channel_message_header *requestheader; 557 struct vmbus_channel_open_channel *openmsg; 558 unsigned long flags; 559 560 result = (struct vmbus_channel_open_result *)hdr; 561 562 /* 563 * Find the open msg, copy the result and signal/unblock the wait event 564 */ 565 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 566 567 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 568 msglistentry) { 569 requestheader = 570 (struct vmbus_channel_message_header *)msginfo->msg; 571 572 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 573 openmsg = 574 (struct vmbus_channel_open_channel *)msginfo->msg; 575 if (openmsg->child_relid == result->child_relid && 576 openmsg->openid == result->openid) { 577 memcpy(&msginfo->response.open_result, 578 result, 579 sizeof( 580 struct vmbus_channel_open_result)); 581 complete(&msginfo->waitevent); 582 break; 583 } 584 } 585 } 586 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 587 } 588 589 /* 590 * vmbus_ongpadl_created - GPADL created handler. 591 * 592 * This is invoked when we received a response to our gpadl create request. 593 * Find the matching request, copy the response and signal the requesting 594 * thread. 595 */ 596 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 597 { 598 struct vmbus_channel_gpadl_created *gpadlcreated; 599 struct vmbus_channel_msginfo *msginfo; 600 struct vmbus_channel_message_header *requestheader; 601 struct vmbus_channel_gpadl_header *gpadlheader; 602 unsigned long flags; 603 604 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 605 606 /* 607 * Find the establish msg, copy the result and signal/unblock the wait 608 * event 609 */ 610 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 611 612 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 613 msglistentry) { 614 requestheader = 615 (struct vmbus_channel_message_header *)msginfo->msg; 616 617 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 618 gpadlheader = 619 (struct vmbus_channel_gpadl_header *)requestheader; 620 621 if ((gpadlcreated->child_relid == 622 gpadlheader->child_relid) && 623 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 624 memcpy(&msginfo->response.gpadl_created, 625 gpadlcreated, 626 sizeof( 627 struct vmbus_channel_gpadl_created)); 628 complete(&msginfo->waitevent); 629 break; 630 } 631 } 632 } 633 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 634 } 635 636 /* 637 * vmbus_ongpadl_torndown - GPADL torndown handler. 638 * 639 * This is invoked when we received a response to our gpadl teardown request. 640 * Find the matching request, copy the response and signal the requesting 641 * thread. 642 */ 643 static void vmbus_ongpadl_torndown( 644 struct vmbus_channel_message_header *hdr) 645 { 646 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 647 struct vmbus_channel_msginfo *msginfo; 648 struct vmbus_channel_message_header *requestheader; 649 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 650 unsigned long flags; 651 652 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 653 654 /* 655 * Find the open msg, copy the result and signal/unblock the wait event 656 */ 657 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 658 659 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 660 msglistentry) { 661 requestheader = 662 (struct vmbus_channel_message_header *)msginfo->msg; 663 664 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 665 gpadl_teardown = 666 (struct vmbus_channel_gpadl_teardown *)requestheader; 667 668 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 669 memcpy(&msginfo->response.gpadl_torndown, 670 gpadl_torndown, 671 sizeof( 672 struct vmbus_channel_gpadl_torndown)); 673 complete(&msginfo->waitevent); 674 break; 675 } 676 } 677 } 678 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 679 } 680 681 /* 682 * vmbus_onversion_response - Version response handler 683 * 684 * This is invoked when we received a response to our initiate contact request. 685 * Find the matching request, copy the response and signal the requesting 686 * thread. 687 */ 688 static void vmbus_onversion_response( 689 struct vmbus_channel_message_header *hdr) 690 { 691 struct vmbus_channel_msginfo *msginfo; 692 struct vmbus_channel_message_header *requestheader; 693 struct vmbus_channel_version_response *version_response; 694 unsigned long flags; 695 696 version_response = (struct vmbus_channel_version_response *)hdr; 697 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 698 699 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 700 msglistentry) { 701 requestheader = 702 (struct vmbus_channel_message_header *)msginfo->msg; 703 704 if (requestheader->msgtype == 705 CHANNELMSG_INITIATE_CONTACT) { 706 memcpy(&msginfo->response.version_response, 707 version_response, 708 sizeof(struct vmbus_channel_version_response)); 709 complete(&msginfo->waitevent); 710 } 711 } 712 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 713 } 714 715 /* Channel message dispatch table */ 716 static struct vmbus_channel_message_table_entry 717 channel_message_table[CHANNELMSG_COUNT] = { 718 {CHANNELMSG_INVALID, NULL}, 719 {CHANNELMSG_OFFERCHANNEL, vmbus_onoffer}, 720 {CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind}, 721 {CHANNELMSG_REQUESTOFFERS, NULL}, 722 {CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered}, 723 {CHANNELMSG_OPENCHANNEL, NULL}, 724 {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result}, 725 {CHANNELMSG_CLOSECHANNEL, NULL}, 726 {CHANNELMSG_GPADL_HEADER, NULL}, 727 {CHANNELMSG_GPADL_BODY, NULL}, 728 {CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created}, 729 {CHANNELMSG_GPADL_TEARDOWN, NULL}, 730 {CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown}, 731 {CHANNELMSG_RELID_RELEASED, NULL}, 732 {CHANNELMSG_INITIATE_CONTACT, NULL}, 733 {CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response}, 734 {CHANNELMSG_UNLOAD, NULL}, 735 }; 736 737 /* 738 * vmbus_onmessage - Handler for channel protocol messages. 739 * 740 * This is invoked in the vmbus worker thread context. 741 */ 742 void vmbus_onmessage(void *context) 743 { 744 struct hv_message *msg = context; 745 struct vmbus_channel_message_header *hdr; 746 int size; 747 748 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 749 size = msg->header.payload_size; 750 751 if (hdr->msgtype >= CHANNELMSG_COUNT) { 752 pr_err("Received invalid channel message type %d size %d\n", 753 hdr->msgtype, size); 754 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 755 (unsigned char *)msg->u.payload, size); 756 return; 757 } 758 759 if (channel_message_table[hdr->msgtype].message_handler) 760 channel_message_table[hdr->msgtype].message_handler(hdr); 761 else 762 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 763 } 764 765 /* 766 * vmbus_request_offers - Send a request to get all our pending offers. 767 */ 768 int vmbus_request_offers(void) 769 { 770 struct vmbus_channel_message_header *msg; 771 struct vmbus_channel_msginfo *msginfo; 772 int ret, t; 773 774 msginfo = kmalloc(sizeof(*msginfo) + 775 sizeof(struct vmbus_channel_message_header), 776 GFP_KERNEL); 777 if (!msginfo) 778 return -ENOMEM; 779 780 init_completion(&msginfo->waitevent); 781 782 msg = (struct vmbus_channel_message_header *)msginfo->msg; 783 784 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 785 786 787 ret = vmbus_post_msg(msg, 788 sizeof(struct vmbus_channel_message_header)); 789 if (ret != 0) { 790 pr_err("Unable to request offers - %d\n", ret); 791 792 goto cleanup; 793 } 794 795 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); 796 if (t == 0) { 797 ret = -ETIMEDOUT; 798 goto cleanup; 799 } 800 801 802 803 cleanup: 804 kfree(msginfo); 805 806 return ret; 807 } 808 809 /* 810 * Retrieve the (sub) channel on which to send an outgoing request. 811 * When a primary channel has multiple sub-channels, we choose a 812 * channel whose VCPU binding is closest to the VCPU on which 813 * this call is being made. 814 */ 815 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 816 { 817 struct list_head *cur, *tmp; 818 int cur_cpu = hv_context.vp_index[smp_processor_id()]; 819 struct vmbus_channel *cur_channel; 820 struct vmbus_channel *outgoing_channel = primary; 821 int cpu_distance, new_cpu_distance; 822 823 if (list_empty(&primary->sc_list)) 824 return outgoing_channel; 825 826 list_for_each_safe(cur, tmp, &primary->sc_list) { 827 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 828 if (cur_channel->state != CHANNEL_OPENED_STATE) 829 continue; 830 831 if (cur_channel->target_vp == cur_cpu) 832 return cur_channel; 833 834 cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ? 835 (outgoing_channel->target_vp - cur_cpu) : 836 (cur_cpu - outgoing_channel->target_vp)); 837 838 new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ? 839 (cur_channel->target_vp - cur_cpu) : 840 (cur_cpu - cur_channel->target_vp)); 841 842 if (cpu_distance < new_cpu_distance) 843 continue; 844 845 outgoing_channel = cur_channel; 846 } 847 848 return outgoing_channel; 849 } 850 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 851 852 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 853 { 854 struct list_head *cur, *tmp; 855 struct vmbus_channel *cur_channel; 856 857 if (primary_channel->sc_creation_callback == NULL) 858 return; 859 860 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 861 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 862 863 primary_channel->sc_creation_callback(cur_channel); 864 } 865 } 866 867 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 868 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 869 { 870 primary_channel->sc_creation_callback = sc_cr_cb; 871 } 872 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 873 874 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 875 { 876 bool ret; 877 878 ret = !list_empty(&primary->sc_list); 879 880 if (ret) { 881 /* 882 * Invoke the callback on sub-channel creation. 883 * This will present a uniform interface to the 884 * clients. 885 */ 886 invoke_sc_cb(primary); 887 } 888 889 return ret; 890 } 891 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 892