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 static atomic_t chan_num = ATOMIC_INIT(0); 143 struct vmbus_channel *channel; 144 145 channel = kzalloc(sizeof(*channel), GFP_ATOMIC); 146 if (!channel) 147 return NULL; 148 149 channel->id = atomic_inc_return(&chan_num); 150 spin_lock_init(&channel->inbound_lock); 151 spin_lock_init(&channel->lock); 152 153 INIT_LIST_HEAD(&channel->sc_list); 154 INIT_LIST_HEAD(&channel->percpu_list); 155 156 channel->controlwq = alloc_workqueue("hv_vmbus_ctl/%d", WQ_MEM_RECLAIM, 157 1, channel->id); 158 if (!channel->controlwq) { 159 kfree(channel); 160 return NULL; 161 } 162 163 return channel; 164 } 165 166 /* 167 * release_hannel - Release the vmbus channel object itself 168 */ 169 static void release_channel(struct work_struct *work) 170 { 171 struct vmbus_channel *channel = container_of(work, 172 struct vmbus_channel, 173 work); 174 175 destroy_workqueue(channel->controlwq); 176 177 kfree(channel); 178 } 179 180 /* 181 * free_channel - Release the resources used by the vmbus channel object 182 */ 183 static void free_channel(struct vmbus_channel *channel) 184 { 185 186 /* 187 * We have to release the channel's workqueue/thread in the vmbus's 188 * workqueue/thread context 189 * ie we can't destroy ourselves. 190 */ 191 INIT_WORK(&channel->work, release_channel); 192 queue_work(vmbus_connection.work_queue, &channel->work); 193 } 194 195 static void percpu_channel_enq(void *arg) 196 { 197 struct vmbus_channel *channel = arg; 198 int cpu = smp_processor_id(); 199 200 list_add_tail(&channel->percpu_list, &hv_context.percpu_list[cpu]); 201 } 202 203 static void percpu_channel_deq(void *arg) 204 { 205 struct vmbus_channel *channel = arg; 206 207 list_del(&channel->percpu_list); 208 } 209 210 /* 211 * vmbus_process_rescind_offer - 212 * Rescind the offer by initiating a device removal 213 */ 214 static void vmbus_process_rescind_offer(struct work_struct *work) 215 { 216 struct vmbus_channel *channel = container_of(work, 217 struct vmbus_channel, 218 work); 219 unsigned long flags; 220 struct vmbus_channel *primary_channel; 221 struct vmbus_channel_relid_released msg; 222 struct device *dev; 223 224 if (channel->device_obj) { 225 dev = get_device(&channel->device_obj->device); 226 if (dev) { 227 vmbus_device_unregister(channel->device_obj); 228 put_device(dev); 229 } 230 } 231 232 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 233 msg.child_relid = channel->offermsg.child_relid; 234 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 235 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released)); 236 237 if (channel->target_cpu != get_cpu()) { 238 put_cpu(); 239 smp_call_function_single(channel->target_cpu, 240 percpu_channel_deq, channel, true); 241 } else { 242 percpu_channel_deq(channel); 243 put_cpu(); 244 } 245 246 if (channel->primary_channel == NULL) { 247 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 248 list_del(&channel->listentry); 249 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 250 } else { 251 primary_channel = channel->primary_channel; 252 spin_lock_irqsave(&primary_channel->lock, flags); 253 list_del(&channel->sc_list); 254 spin_unlock_irqrestore(&primary_channel->lock, flags); 255 } 256 free_channel(channel); 257 } 258 259 void vmbus_free_channels(void) 260 { 261 struct vmbus_channel *channel; 262 263 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 264 vmbus_device_unregister(channel->device_obj); 265 kfree(channel->device_obj); 266 free_channel(channel); 267 } 268 } 269 270 /* 271 * vmbus_process_offer - Process the offer by creating a channel/device 272 * associated with this offer 273 */ 274 static void vmbus_process_offer(struct work_struct *work) 275 { 276 struct vmbus_channel *newchannel = container_of(work, 277 struct vmbus_channel, 278 work); 279 struct vmbus_channel *channel; 280 bool fnew = true; 281 bool enq = false; 282 int ret; 283 unsigned long flags; 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->lock, flags); 327 list_add_tail(&newchannel->sc_list, &channel->sc_list); 328 spin_unlock_irqrestore(&channel->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 goto done_init_rescind; 345 } 346 347 goto err_free_chan; 348 } 349 350 /* 351 * This state is used to indicate a successful open 352 * so that when we do close the channel normally, we 353 * can cleanup properly 354 */ 355 newchannel->state = CHANNEL_OPEN_STATE; 356 357 /* 358 * Start the process of binding this offer to the driver 359 * We need to set the DeviceObject field before calling 360 * vmbus_child_dev_add() 361 */ 362 newchannel->device_obj = vmbus_device_create( 363 &newchannel->offermsg.offer.if_type, 364 &newchannel->offermsg.offer.if_instance, 365 newchannel); 366 if (!newchannel->device_obj) 367 goto err_free_chan; 368 369 /* 370 * Add the new device to the bus. This will kick off device-driver 371 * binding which eventually invokes the device driver's AddDevice() 372 * method. 373 */ 374 ret = vmbus_device_register(newchannel->device_obj); 375 if (ret != 0) { 376 pr_err("unable to add child device object (relid %d)\n", 377 newchannel->offermsg.child_relid); 378 379 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 380 list_del(&newchannel->listentry); 381 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 382 kfree(newchannel->device_obj); 383 goto err_free_chan; 384 } 385 done_init_rescind: 386 spin_lock_irqsave(&newchannel->lock, flags); 387 /* The next possible work is rescind handling */ 388 INIT_WORK(&newchannel->work, vmbus_process_rescind_offer); 389 /* Check if rescind offer was already received */ 390 if (newchannel->rescind) 391 queue_work(newchannel->controlwq, &newchannel->work); 392 spin_unlock_irqrestore(&newchannel->lock, flags); 393 return; 394 err_free_chan: 395 free_channel(newchannel); 396 } 397 398 enum { 399 IDE = 0, 400 SCSI, 401 NIC, 402 MAX_PERF_CHN, 403 }; 404 405 /* 406 * This is an array of device_ids (device types) that are performance critical. 407 * We attempt to distribute the interrupt load for these devices across 408 * all available CPUs. 409 */ 410 static const struct hv_vmbus_device_id hp_devs[] = { 411 /* IDE */ 412 { HV_IDE_GUID, }, 413 /* Storage - SCSI */ 414 { HV_SCSI_GUID, }, 415 /* Network */ 416 { HV_NIC_GUID, }, 417 }; 418 419 420 /* 421 * We use this state to statically distribute the channel interrupt load. 422 */ 423 static u32 next_vp; 424 425 /* 426 * Starting with Win8, we can statically distribute the incoming 427 * channel interrupt load by binding a channel to VCPU. We 428 * implement here a simple round robin scheme for distributing 429 * the interrupt load. 430 * We will bind channels that are not performance critical to cpu 0 and 431 * performance critical channels (IDE, SCSI and Network) will be uniformly 432 * distributed across all available CPUs. 433 */ 434 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid) 435 { 436 u32 cur_cpu; 437 int i; 438 bool perf_chn = false; 439 u32 max_cpus = num_online_cpus(); 440 441 for (i = IDE; i < MAX_PERF_CHN; i++) { 442 if (!memcmp(type_guid->b, hp_devs[i].guid, 443 sizeof(uuid_le))) { 444 perf_chn = true; 445 break; 446 } 447 } 448 if ((vmbus_proto_version == VERSION_WS2008) || 449 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 450 /* 451 * Prior to win8, all channel interrupts are 452 * delivered on cpu 0. 453 * Also if the channel is not a performance critical 454 * channel, bind it to cpu 0. 455 */ 456 channel->target_cpu = 0; 457 channel->target_vp = 0; 458 return; 459 } 460 cur_cpu = (++next_vp % max_cpus); 461 channel->target_cpu = cur_cpu; 462 channel->target_vp = hv_context.vp_index[cur_cpu]; 463 } 464 465 /* 466 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 467 * 468 */ 469 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 470 { 471 struct vmbus_channel_offer_channel *offer; 472 struct vmbus_channel *newchannel; 473 474 offer = (struct vmbus_channel_offer_channel *)hdr; 475 476 /* Allocate the channel object and save this offer. */ 477 newchannel = alloc_channel(); 478 if (!newchannel) { 479 pr_err("Unable to allocate channel object\n"); 480 return; 481 } 482 483 /* 484 * By default we setup state to enable batched 485 * reading. A specific service can choose to 486 * disable this prior to opening the channel. 487 */ 488 newchannel->batched_reading = true; 489 490 /* 491 * Setup state for signalling the host. 492 */ 493 newchannel->sig_event = (struct hv_input_signal_event *) 494 (ALIGN((unsigned long) 495 &newchannel->sig_buf, 496 HV_HYPERCALL_PARAM_ALIGN)); 497 498 newchannel->sig_event->connectionid.asu32 = 0; 499 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 500 newchannel->sig_event->flag_number = 0; 501 newchannel->sig_event->rsvdz = 0; 502 503 if (vmbus_proto_version != VERSION_WS2008) { 504 newchannel->is_dedicated_interrupt = 505 (offer->is_dedicated_interrupt != 0); 506 newchannel->sig_event->connectionid.u.id = 507 offer->connection_id; 508 } 509 510 init_vp_index(newchannel, &offer->offer.if_type); 511 512 memcpy(&newchannel->offermsg, offer, 513 sizeof(struct vmbus_channel_offer_channel)); 514 newchannel->monitor_grp = (u8)offer->monitorid / 32; 515 newchannel->monitor_bit = (u8)offer->monitorid % 32; 516 517 INIT_WORK(&newchannel->work, vmbus_process_offer); 518 queue_work(newchannel->controlwq, &newchannel->work); 519 } 520 521 /* 522 * vmbus_onoffer_rescind - Rescind offer handler. 523 * 524 * We queue a work item to process this offer synchronously 525 */ 526 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 527 { 528 struct vmbus_channel_rescind_offer *rescind; 529 struct vmbus_channel *channel; 530 unsigned long flags; 531 532 rescind = (struct vmbus_channel_rescind_offer *)hdr; 533 channel = relid2channel(rescind->child_relid); 534 535 if (channel == NULL) 536 /* Just return here, no channel found */ 537 return; 538 539 spin_lock_irqsave(&channel->lock, flags); 540 channel->rescind = true; 541 /* 542 * channel->work.func != vmbus_process_rescind_offer means we are still 543 * processing offer request and the rescind offer processing should be 544 * postponed. It will be done at the very end of vmbus_process_offer() 545 * as rescind flag is being checked there. 546 */ 547 if (channel->work.func == vmbus_process_rescind_offer) 548 /* work is initialized for vmbus_process_rescind_offer() from 549 * vmbus_process_offer() where the channel got created */ 550 queue_work(channel->controlwq, &channel->work); 551 552 spin_unlock_irqrestore(&channel->lock, flags); 553 } 554 555 /* 556 * vmbus_onoffers_delivered - 557 * This is invoked when all offers have been delivered. 558 * 559 * Nothing to do here. 560 */ 561 static void vmbus_onoffers_delivered( 562 struct vmbus_channel_message_header *hdr) 563 { 564 } 565 566 /* 567 * vmbus_onopen_result - Open result handler. 568 * 569 * This is invoked when we received a response to our channel open request. 570 * Find the matching request, copy the response and signal the requesting 571 * thread. 572 */ 573 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 574 { 575 struct vmbus_channel_open_result *result; 576 struct vmbus_channel_msginfo *msginfo; 577 struct vmbus_channel_message_header *requestheader; 578 struct vmbus_channel_open_channel *openmsg; 579 unsigned long flags; 580 581 result = (struct vmbus_channel_open_result *)hdr; 582 583 /* 584 * Find the open msg, copy the result and signal/unblock the wait event 585 */ 586 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 587 588 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 589 msglistentry) { 590 requestheader = 591 (struct vmbus_channel_message_header *)msginfo->msg; 592 593 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 594 openmsg = 595 (struct vmbus_channel_open_channel *)msginfo->msg; 596 if (openmsg->child_relid == result->child_relid && 597 openmsg->openid == result->openid) { 598 memcpy(&msginfo->response.open_result, 599 result, 600 sizeof( 601 struct vmbus_channel_open_result)); 602 complete(&msginfo->waitevent); 603 break; 604 } 605 } 606 } 607 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 608 } 609 610 /* 611 * vmbus_ongpadl_created - GPADL created handler. 612 * 613 * This is invoked when we received a response to our gpadl create request. 614 * Find the matching request, copy the response and signal the requesting 615 * thread. 616 */ 617 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 618 { 619 struct vmbus_channel_gpadl_created *gpadlcreated; 620 struct vmbus_channel_msginfo *msginfo; 621 struct vmbus_channel_message_header *requestheader; 622 struct vmbus_channel_gpadl_header *gpadlheader; 623 unsigned long flags; 624 625 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 626 627 /* 628 * Find the establish msg, copy the result and signal/unblock the wait 629 * event 630 */ 631 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 632 633 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 634 msglistentry) { 635 requestheader = 636 (struct vmbus_channel_message_header *)msginfo->msg; 637 638 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 639 gpadlheader = 640 (struct vmbus_channel_gpadl_header *)requestheader; 641 642 if ((gpadlcreated->child_relid == 643 gpadlheader->child_relid) && 644 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 645 memcpy(&msginfo->response.gpadl_created, 646 gpadlcreated, 647 sizeof( 648 struct vmbus_channel_gpadl_created)); 649 complete(&msginfo->waitevent); 650 break; 651 } 652 } 653 } 654 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 655 } 656 657 /* 658 * vmbus_ongpadl_torndown - GPADL torndown handler. 659 * 660 * This is invoked when we received a response to our gpadl teardown request. 661 * Find the matching request, copy the response and signal the requesting 662 * thread. 663 */ 664 static void vmbus_ongpadl_torndown( 665 struct vmbus_channel_message_header *hdr) 666 { 667 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 668 struct vmbus_channel_msginfo *msginfo; 669 struct vmbus_channel_message_header *requestheader; 670 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 671 unsigned long flags; 672 673 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 674 675 /* 676 * Find the open msg, copy the result and signal/unblock the wait event 677 */ 678 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 679 680 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 681 msglistentry) { 682 requestheader = 683 (struct vmbus_channel_message_header *)msginfo->msg; 684 685 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 686 gpadl_teardown = 687 (struct vmbus_channel_gpadl_teardown *)requestheader; 688 689 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 690 memcpy(&msginfo->response.gpadl_torndown, 691 gpadl_torndown, 692 sizeof( 693 struct vmbus_channel_gpadl_torndown)); 694 complete(&msginfo->waitevent); 695 break; 696 } 697 } 698 } 699 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 700 } 701 702 /* 703 * vmbus_onversion_response - Version response handler 704 * 705 * This is invoked when we received a response to our initiate contact request. 706 * Find the matching request, copy the response and signal the requesting 707 * thread. 708 */ 709 static void vmbus_onversion_response( 710 struct vmbus_channel_message_header *hdr) 711 { 712 struct vmbus_channel_msginfo *msginfo; 713 struct vmbus_channel_message_header *requestheader; 714 struct vmbus_channel_version_response *version_response; 715 unsigned long flags; 716 717 version_response = (struct vmbus_channel_version_response *)hdr; 718 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 719 720 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 721 msglistentry) { 722 requestheader = 723 (struct vmbus_channel_message_header *)msginfo->msg; 724 725 if (requestheader->msgtype == 726 CHANNELMSG_INITIATE_CONTACT) { 727 memcpy(&msginfo->response.version_response, 728 version_response, 729 sizeof(struct vmbus_channel_version_response)); 730 complete(&msginfo->waitevent); 731 } 732 } 733 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 734 } 735 736 /* Channel message dispatch table */ 737 static struct vmbus_channel_message_table_entry 738 channel_message_table[CHANNELMSG_COUNT] = { 739 {CHANNELMSG_INVALID, NULL}, 740 {CHANNELMSG_OFFERCHANNEL, vmbus_onoffer}, 741 {CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind}, 742 {CHANNELMSG_REQUESTOFFERS, NULL}, 743 {CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered}, 744 {CHANNELMSG_OPENCHANNEL, NULL}, 745 {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result}, 746 {CHANNELMSG_CLOSECHANNEL, NULL}, 747 {CHANNELMSG_GPADL_HEADER, NULL}, 748 {CHANNELMSG_GPADL_BODY, NULL}, 749 {CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created}, 750 {CHANNELMSG_GPADL_TEARDOWN, NULL}, 751 {CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown}, 752 {CHANNELMSG_RELID_RELEASED, NULL}, 753 {CHANNELMSG_INITIATE_CONTACT, NULL}, 754 {CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response}, 755 {CHANNELMSG_UNLOAD, NULL}, 756 }; 757 758 /* 759 * vmbus_onmessage - Handler for channel protocol messages. 760 * 761 * This is invoked in the vmbus worker thread context. 762 */ 763 void vmbus_onmessage(void *context) 764 { 765 struct hv_message *msg = context; 766 struct vmbus_channel_message_header *hdr; 767 int size; 768 769 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 770 size = msg->header.payload_size; 771 772 if (hdr->msgtype >= CHANNELMSG_COUNT) { 773 pr_err("Received invalid channel message type %d size %d\n", 774 hdr->msgtype, size); 775 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 776 (unsigned char *)msg->u.payload, size); 777 return; 778 } 779 780 if (channel_message_table[hdr->msgtype].message_handler) 781 channel_message_table[hdr->msgtype].message_handler(hdr); 782 else 783 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 784 } 785 786 /* 787 * vmbus_request_offers - Send a request to get all our pending offers. 788 */ 789 int vmbus_request_offers(void) 790 { 791 struct vmbus_channel_message_header *msg; 792 struct vmbus_channel_msginfo *msginfo; 793 int ret, t; 794 795 msginfo = kmalloc(sizeof(*msginfo) + 796 sizeof(struct vmbus_channel_message_header), 797 GFP_KERNEL); 798 if (!msginfo) 799 return -ENOMEM; 800 801 init_completion(&msginfo->waitevent); 802 803 msg = (struct vmbus_channel_message_header *)msginfo->msg; 804 805 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 806 807 808 ret = vmbus_post_msg(msg, 809 sizeof(struct vmbus_channel_message_header)); 810 if (ret != 0) { 811 pr_err("Unable to request offers - %d\n", ret); 812 813 goto cleanup; 814 } 815 816 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); 817 if (t == 0) { 818 ret = -ETIMEDOUT; 819 goto cleanup; 820 } 821 822 823 824 cleanup: 825 kfree(msginfo); 826 827 return ret; 828 } 829 830 /* 831 * Retrieve the (sub) channel on which to send an outgoing request. 832 * When a primary channel has multiple sub-channels, we choose a 833 * channel whose VCPU binding is closest to the VCPU on which 834 * this call is being made. 835 */ 836 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 837 { 838 struct list_head *cur, *tmp; 839 int cur_cpu; 840 struct vmbus_channel *cur_channel; 841 struct vmbus_channel *outgoing_channel = primary; 842 int cpu_distance, new_cpu_distance; 843 844 if (list_empty(&primary->sc_list)) 845 return outgoing_channel; 846 847 cur_cpu = hv_context.vp_index[get_cpu()]; 848 put_cpu(); 849 list_for_each_safe(cur, tmp, &primary->sc_list) { 850 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 851 if (cur_channel->state != CHANNEL_OPENED_STATE) 852 continue; 853 854 if (cur_channel->target_vp == cur_cpu) 855 return cur_channel; 856 857 cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ? 858 (outgoing_channel->target_vp - cur_cpu) : 859 (cur_cpu - outgoing_channel->target_vp)); 860 861 new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ? 862 (cur_channel->target_vp - cur_cpu) : 863 (cur_cpu - cur_channel->target_vp)); 864 865 if (cpu_distance < new_cpu_distance) 866 continue; 867 868 outgoing_channel = cur_channel; 869 } 870 871 return outgoing_channel; 872 } 873 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 874 875 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 876 { 877 struct list_head *cur, *tmp; 878 struct vmbus_channel *cur_channel; 879 880 if (primary_channel->sc_creation_callback == NULL) 881 return; 882 883 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 884 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 885 886 primary_channel->sc_creation_callback(cur_channel); 887 } 888 } 889 890 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 891 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 892 { 893 primary_channel->sc_creation_callback = sc_cr_cb; 894 } 895 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 896 897 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 898 { 899 bool ret; 900 901 ret = !list_empty(&primary->sc_list); 902 903 if (ret) { 904 /* 905 * Invoke the callback on sub-channel creation. 906 * This will present a uniform interface to the 907 * clients. 908 */ 909 invoke_sc_cb(primary); 910 } 911 912 return ret; 913 } 914 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 915