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 static void init_vp_index(struct vmbus_channel *channel, 36 const uuid_le *type_guid); 37 38 /** 39 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message 40 * @icmsghdrp: Pointer to msg header structure 41 * @icmsg_negotiate: Pointer to negotiate message structure 42 * @buf: Raw buffer channel data 43 * 44 * @icmsghdrp is of type &struct icmsg_hdr. 45 * @negop is of type &struct icmsg_negotiate. 46 * Set up and fill in default negotiate response message. 47 * 48 * The fw_version specifies the framework version that 49 * we can support and srv_version specifies the service 50 * version we can support. 51 * 52 * Mainly used by Hyper-V drivers. 53 */ 54 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, 55 struct icmsg_negotiate *negop, u8 *buf, 56 int fw_version, int srv_version) 57 { 58 int icframe_major, icframe_minor; 59 int icmsg_major, icmsg_minor; 60 int fw_major, fw_minor; 61 int srv_major, srv_minor; 62 int i; 63 bool found_match = false; 64 65 icmsghdrp->icmsgsize = 0x10; 66 fw_major = (fw_version >> 16); 67 fw_minor = (fw_version & 0xFFFF); 68 69 srv_major = (srv_version >> 16); 70 srv_minor = (srv_version & 0xFFFF); 71 72 negop = (struct icmsg_negotiate *)&buf[ 73 sizeof(struct vmbuspipe_hdr) + 74 sizeof(struct icmsg_hdr)]; 75 76 icframe_major = negop->icframe_vercnt; 77 icframe_minor = 0; 78 79 icmsg_major = negop->icmsg_vercnt; 80 icmsg_minor = 0; 81 82 /* 83 * Select the framework version number we will 84 * support. 85 */ 86 87 for (i = 0; i < negop->icframe_vercnt; i++) { 88 if ((negop->icversion_data[i].major == fw_major) && 89 (negop->icversion_data[i].minor == fw_minor)) { 90 icframe_major = negop->icversion_data[i].major; 91 icframe_minor = negop->icversion_data[i].minor; 92 found_match = true; 93 } 94 } 95 96 if (!found_match) 97 goto fw_error; 98 99 found_match = false; 100 101 for (i = negop->icframe_vercnt; 102 (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) { 103 if ((negop->icversion_data[i].major == srv_major) && 104 (negop->icversion_data[i].minor == srv_minor)) { 105 icmsg_major = negop->icversion_data[i].major; 106 icmsg_minor = negop->icversion_data[i].minor; 107 found_match = true; 108 } 109 } 110 111 /* 112 * Respond with the framework and service 113 * version numbers we can support. 114 */ 115 116 fw_error: 117 if (!found_match) { 118 negop->icframe_vercnt = 0; 119 negop->icmsg_vercnt = 0; 120 } else { 121 negop->icframe_vercnt = 1; 122 negop->icmsg_vercnt = 1; 123 } 124 125 negop->icversion_data[0].major = icframe_major; 126 negop->icversion_data[0].minor = icframe_minor; 127 negop->icversion_data[1].major = icmsg_major; 128 negop->icversion_data[1].minor = icmsg_minor; 129 return found_match; 130 } 131 132 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp); 133 134 /* 135 * alloc_channel - Allocate and initialize a vmbus channel object 136 */ 137 static struct vmbus_channel *alloc_channel(void) 138 { 139 static atomic_t chan_num = ATOMIC_INIT(0); 140 struct vmbus_channel *channel; 141 142 channel = kzalloc(sizeof(*channel), GFP_ATOMIC); 143 if (!channel) 144 return NULL; 145 146 channel->id = atomic_inc_return(&chan_num); 147 spin_lock_init(&channel->inbound_lock); 148 spin_lock_init(&channel->lock); 149 150 INIT_LIST_HEAD(&channel->sc_list); 151 INIT_LIST_HEAD(&channel->percpu_list); 152 153 return channel; 154 } 155 156 /* 157 * free_channel - Release the resources used by the vmbus channel object 158 */ 159 static void free_channel(struct vmbus_channel *channel) 160 { 161 kfree(channel); 162 } 163 164 static void percpu_channel_enq(void *arg) 165 { 166 struct vmbus_channel *channel = arg; 167 int cpu = smp_processor_id(); 168 169 list_add_tail(&channel->percpu_list, &hv_context.percpu_list[cpu]); 170 } 171 172 static void percpu_channel_deq(void *arg) 173 { 174 struct vmbus_channel *channel = arg; 175 176 list_del(&channel->percpu_list); 177 } 178 179 180 void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) 181 { 182 struct vmbus_channel_relid_released msg; 183 unsigned long flags; 184 struct vmbus_channel *primary_channel; 185 186 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 187 msg.child_relid = relid; 188 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 189 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released)); 190 191 if (channel == NULL) 192 return; 193 194 if (channel->target_cpu != get_cpu()) { 195 put_cpu(); 196 smp_call_function_single(channel->target_cpu, 197 percpu_channel_deq, channel, true); 198 } else { 199 percpu_channel_deq(channel); 200 put_cpu(); 201 } 202 203 if (channel->primary_channel == NULL) { 204 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 205 list_del(&channel->listentry); 206 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 207 } else { 208 primary_channel = channel->primary_channel; 209 spin_lock_irqsave(&primary_channel->lock, flags); 210 list_del(&channel->sc_list); 211 primary_channel->num_sc--; 212 spin_unlock_irqrestore(&primary_channel->lock, flags); 213 } 214 free_channel(channel); 215 } 216 217 void vmbus_free_channels(void) 218 { 219 struct vmbus_channel *channel, *tmp; 220 221 list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, 222 listentry) { 223 /* if we don't set rescind to true, vmbus_close_internal() 224 * won't invoke hv_process_channel_removal(). 225 */ 226 channel->rescind = true; 227 228 vmbus_device_unregister(channel->device_obj); 229 } 230 } 231 232 /* 233 * vmbus_process_offer - Process the offer by creating a channel/device 234 * associated with this offer 235 */ 236 static void vmbus_process_offer(struct vmbus_channel *newchannel) 237 { 238 struct vmbus_channel *channel; 239 bool fnew = true; 240 unsigned long flags; 241 242 /* Make sure this is a new offer */ 243 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 244 245 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 246 if (!uuid_le_cmp(channel->offermsg.offer.if_type, 247 newchannel->offermsg.offer.if_type) && 248 !uuid_le_cmp(channel->offermsg.offer.if_instance, 249 newchannel->offermsg.offer.if_instance)) { 250 fnew = false; 251 break; 252 } 253 } 254 255 if (fnew) 256 list_add_tail(&newchannel->listentry, 257 &vmbus_connection.chn_list); 258 259 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 260 261 if (!fnew) { 262 /* 263 * Check to see if this is a sub-channel. 264 */ 265 if (newchannel->offermsg.offer.sub_channel_index != 0) { 266 /* 267 * Process the sub-channel. 268 */ 269 newchannel->primary_channel = channel; 270 spin_lock_irqsave(&channel->lock, flags); 271 list_add_tail(&newchannel->sc_list, &channel->sc_list); 272 channel->num_sc++; 273 spin_unlock_irqrestore(&channel->lock, flags); 274 } else 275 goto err_free_chan; 276 } 277 278 init_vp_index(newchannel, &newchannel->offermsg.offer.if_type); 279 280 if (newchannel->target_cpu != get_cpu()) { 281 put_cpu(); 282 smp_call_function_single(newchannel->target_cpu, 283 percpu_channel_enq, 284 newchannel, true); 285 } else { 286 percpu_channel_enq(newchannel); 287 put_cpu(); 288 } 289 290 /* 291 * This state is used to indicate a successful open 292 * so that when we do close the channel normally, we 293 * can cleanup properly 294 */ 295 newchannel->state = CHANNEL_OPEN_STATE; 296 297 if (!fnew) { 298 if (channel->sc_creation_callback != NULL) 299 channel->sc_creation_callback(newchannel); 300 return; 301 } 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 if (!newchannel->device_obj) 313 goto err_deq_chan; 314 315 /* 316 * Add the new device to the bus. This will kick off device-driver 317 * binding which eventually invokes the device driver's AddDevice() 318 * method. 319 */ 320 if (vmbus_device_register(newchannel->device_obj) != 0) { 321 pr_err("unable to add child device object (relid %d)\n", 322 newchannel->offermsg.child_relid); 323 kfree(newchannel->device_obj); 324 goto err_deq_chan; 325 } 326 return; 327 328 err_deq_chan: 329 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 330 list_del(&newchannel->listentry); 331 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 332 333 if (newchannel->target_cpu != get_cpu()) { 334 put_cpu(); 335 smp_call_function_single(newchannel->target_cpu, 336 percpu_channel_deq, newchannel, true); 337 } else { 338 percpu_channel_deq(newchannel); 339 put_cpu(); 340 } 341 342 err_free_chan: 343 free_channel(newchannel); 344 } 345 346 enum { 347 IDE = 0, 348 SCSI, 349 NIC, 350 MAX_PERF_CHN, 351 }; 352 353 /* 354 * This is an array of device_ids (device types) that are performance critical. 355 * We attempt to distribute the interrupt load for these devices across 356 * all available CPUs. 357 */ 358 static const struct hv_vmbus_device_id hp_devs[] = { 359 /* IDE */ 360 { HV_IDE_GUID, }, 361 /* Storage - SCSI */ 362 { HV_SCSI_GUID, }, 363 /* Network */ 364 { HV_NIC_GUID, }, 365 /* NetworkDirect Guest RDMA */ 366 { HV_ND_GUID, }, 367 }; 368 369 370 /* 371 * We use this state to statically distribute the channel interrupt load. 372 */ 373 static u32 next_vp; 374 375 /* 376 * Starting with Win8, we can statically distribute the incoming 377 * channel interrupt load by binding a channel to VCPU. We 378 * implement here a simple round robin scheme for distributing 379 * the interrupt load. 380 * We will bind channels that are not performance critical to cpu 0 and 381 * performance critical channels (IDE, SCSI and Network) will be uniformly 382 * distributed across all available CPUs. 383 */ 384 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid) 385 { 386 u32 cur_cpu; 387 int i; 388 bool perf_chn = false; 389 u32 max_cpus = num_online_cpus(); 390 struct vmbus_channel *primary = channel->primary_channel, *prev; 391 unsigned long flags; 392 393 for (i = IDE; i < MAX_PERF_CHN; i++) { 394 if (!memcmp(type_guid->b, hp_devs[i].guid, 395 sizeof(uuid_le))) { 396 perf_chn = true; 397 break; 398 } 399 } 400 if ((vmbus_proto_version == VERSION_WS2008) || 401 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 402 /* 403 * Prior to win8, all channel interrupts are 404 * delivered on cpu 0. 405 * Also if the channel is not a performance critical 406 * channel, bind it to cpu 0. 407 */ 408 channel->target_cpu = 0; 409 channel->target_vp = 0; 410 return; 411 } 412 413 /* 414 * Primary channels are distributed evenly across all vcpus we have. 415 * When the host asks us to create subchannels it usually makes us 416 * num_cpus-1 offers and we are supposed to distribute the work evenly 417 * among the channel itself and all its subchannels. Make sure they are 418 * all assigned to different vcpus. 419 */ 420 if (!primary) 421 cur_cpu = (++next_vp % max_cpus); 422 else { 423 /* 424 * Let's assign the first subchannel of a channel to the 425 * primary->target_cpu+1 and all the subsequent channels to 426 * the prev->target_cpu+1. 427 */ 428 spin_lock_irqsave(&primary->lock, flags); 429 if (primary->num_sc == 1) 430 cur_cpu = (primary->target_cpu + 1) % max_cpus; 431 else { 432 prev = list_prev_entry(channel, sc_list); 433 cur_cpu = (prev->target_cpu + 1) % max_cpus; 434 } 435 spin_unlock_irqrestore(&primary->lock, flags); 436 } 437 438 channel->target_cpu = cur_cpu; 439 channel->target_vp = hv_context.vp_index[cur_cpu]; 440 } 441 442 /* 443 * vmbus_unload_response - Handler for the unload response. 444 */ 445 static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) 446 { 447 /* 448 * This is a global event; just wakeup the waiting thread. 449 * Once we successfully unload, we can cleanup the monitor state. 450 */ 451 complete(&vmbus_connection.unload_event); 452 } 453 454 void vmbus_initiate_unload(void) 455 { 456 struct vmbus_channel_message_header hdr; 457 458 init_completion(&vmbus_connection.unload_event); 459 memset(&hdr, 0, sizeof(struct vmbus_channel_message_header)); 460 hdr.msgtype = CHANNELMSG_UNLOAD; 461 vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header)); 462 463 wait_for_completion(&vmbus_connection.unload_event); 464 } 465 466 /* 467 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 468 * 469 */ 470 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 471 { 472 struct vmbus_channel_offer_channel *offer; 473 struct vmbus_channel *newchannel; 474 475 offer = (struct vmbus_channel_offer_channel *)hdr; 476 477 /* Allocate the channel object and save this offer. */ 478 newchannel = alloc_channel(); 479 if (!newchannel) { 480 pr_err("Unable to allocate channel object\n"); 481 return; 482 } 483 484 /* 485 * By default we setup state to enable batched 486 * reading. A specific service can choose to 487 * disable this prior to opening the channel. 488 */ 489 newchannel->batched_reading = true; 490 491 /* 492 * Setup state for signalling the host. 493 */ 494 newchannel->sig_event = (struct hv_input_signal_event *) 495 (ALIGN((unsigned long) 496 &newchannel->sig_buf, 497 HV_HYPERCALL_PARAM_ALIGN)); 498 499 newchannel->sig_event->connectionid.asu32 = 0; 500 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 501 newchannel->sig_event->flag_number = 0; 502 newchannel->sig_event->rsvdz = 0; 503 504 if (vmbus_proto_version != VERSION_WS2008) { 505 newchannel->is_dedicated_interrupt = 506 (offer->is_dedicated_interrupt != 0); 507 newchannel->sig_event->connectionid.u.id = 508 offer->connection_id; 509 } 510 511 memcpy(&newchannel->offermsg, offer, 512 sizeof(struct vmbus_channel_offer_channel)); 513 newchannel->monitor_grp = (u8)offer->monitorid / 32; 514 newchannel->monitor_bit = (u8)offer->monitorid % 32; 515 516 vmbus_process_offer(newchannel); 517 } 518 519 /* 520 * vmbus_onoffer_rescind - Rescind offer handler. 521 * 522 * We queue a work item to process this offer synchronously 523 */ 524 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 525 { 526 struct vmbus_channel_rescind_offer *rescind; 527 struct vmbus_channel *channel; 528 unsigned long flags; 529 struct device *dev; 530 531 rescind = (struct vmbus_channel_rescind_offer *)hdr; 532 channel = relid2channel(rescind->child_relid); 533 534 if (channel == NULL) { 535 hv_process_channel_removal(NULL, rescind->child_relid); 536 return; 537 } 538 539 spin_lock_irqsave(&channel->lock, flags); 540 channel->rescind = true; 541 spin_unlock_irqrestore(&channel->lock, flags); 542 543 if (channel->device_obj) { 544 /* 545 * We will have to unregister this device from the 546 * driver core. 547 */ 548 dev = get_device(&channel->device_obj->device); 549 if (dev) { 550 vmbus_device_unregister(channel->device_obj); 551 put_device(dev); 552 } 553 } else { 554 hv_process_channel_removal(channel, 555 channel->offermsg.child_relid); 556 } 557 } 558 559 /* 560 * vmbus_onoffers_delivered - 561 * This is invoked when all offers have been delivered. 562 * 563 * Nothing to do here. 564 */ 565 static void vmbus_onoffers_delivered( 566 struct vmbus_channel_message_header *hdr) 567 { 568 } 569 570 /* 571 * vmbus_onopen_result - Open result handler. 572 * 573 * This is invoked when we received a response to our channel open request. 574 * Find the matching request, copy the response and signal the requesting 575 * thread. 576 */ 577 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 578 { 579 struct vmbus_channel_open_result *result; 580 struct vmbus_channel_msginfo *msginfo; 581 struct vmbus_channel_message_header *requestheader; 582 struct vmbus_channel_open_channel *openmsg; 583 unsigned long flags; 584 585 result = (struct vmbus_channel_open_result *)hdr; 586 587 /* 588 * Find the open msg, copy the result and signal/unblock the wait event 589 */ 590 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 591 592 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 593 msglistentry) { 594 requestheader = 595 (struct vmbus_channel_message_header *)msginfo->msg; 596 597 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 598 openmsg = 599 (struct vmbus_channel_open_channel *)msginfo->msg; 600 if (openmsg->child_relid == result->child_relid && 601 openmsg->openid == result->openid) { 602 memcpy(&msginfo->response.open_result, 603 result, 604 sizeof( 605 struct vmbus_channel_open_result)); 606 complete(&msginfo->waitevent); 607 break; 608 } 609 } 610 } 611 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 612 } 613 614 /* 615 * vmbus_ongpadl_created - GPADL created handler. 616 * 617 * This is invoked when we received a response to our gpadl create request. 618 * Find the matching request, copy the response and signal the requesting 619 * thread. 620 */ 621 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 622 { 623 struct vmbus_channel_gpadl_created *gpadlcreated; 624 struct vmbus_channel_msginfo *msginfo; 625 struct vmbus_channel_message_header *requestheader; 626 struct vmbus_channel_gpadl_header *gpadlheader; 627 unsigned long flags; 628 629 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 630 631 /* 632 * Find the establish msg, copy the result and signal/unblock the wait 633 * event 634 */ 635 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 636 637 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 638 msglistentry) { 639 requestheader = 640 (struct vmbus_channel_message_header *)msginfo->msg; 641 642 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 643 gpadlheader = 644 (struct vmbus_channel_gpadl_header *)requestheader; 645 646 if ((gpadlcreated->child_relid == 647 gpadlheader->child_relid) && 648 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 649 memcpy(&msginfo->response.gpadl_created, 650 gpadlcreated, 651 sizeof( 652 struct vmbus_channel_gpadl_created)); 653 complete(&msginfo->waitevent); 654 break; 655 } 656 } 657 } 658 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 659 } 660 661 /* 662 * vmbus_ongpadl_torndown - GPADL torndown handler. 663 * 664 * This is invoked when we received a response to our gpadl teardown request. 665 * Find the matching request, copy the response and signal the requesting 666 * thread. 667 */ 668 static void vmbus_ongpadl_torndown( 669 struct vmbus_channel_message_header *hdr) 670 { 671 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 672 struct vmbus_channel_msginfo *msginfo; 673 struct vmbus_channel_message_header *requestheader; 674 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 675 unsigned long flags; 676 677 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 678 679 /* 680 * Find the open msg, copy the result and signal/unblock the wait event 681 */ 682 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 683 684 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 685 msglistentry) { 686 requestheader = 687 (struct vmbus_channel_message_header *)msginfo->msg; 688 689 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 690 gpadl_teardown = 691 (struct vmbus_channel_gpadl_teardown *)requestheader; 692 693 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 694 memcpy(&msginfo->response.gpadl_torndown, 695 gpadl_torndown, 696 sizeof( 697 struct vmbus_channel_gpadl_torndown)); 698 complete(&msginfo->waitevent); 699 break; 700 } 701 } 702 } 703 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 704 } 705 706 /* 707 * vmbus_onversion_response - Version response handler 708 * 709 * This is invoked when we received a response to our initiate contact request. 710 * Find the matching request, copy the response and signal the requesting 711 * thread. 712 */ 713 static void vmbus_onversion_response( 714 struct vmbus_channel_message_header *hdr) 715 { 716 struct vmbus_channel_msginfo *msginfo; 717 struct vmbus_channel_message_header *requestheader; 718 struct vmbus_channel_version_response *version_response; 719 unsigned long flags; 720 721 version_response = (struct vmbus_channel_version_response *)hdr; 722 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 723 724 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 725 msglistentry) { 726 requestheader = 727 (struct vmbus_channel_message_header *)msginfo->msg; 728 729 if (requestheader->msgtype == 730 CHANNELMSG_INITIATE_CONTACT) { 731 memcpy(&msginfo->response.version_response, 732 version_response, 733 sizeof(struct vmbus_channel_version_response)); 734 complete(&msginfo->waitevent); 735 } 736 } 737 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 738 } 739 740 /* Channel message dispatch table */ 741 struct vmbus_channel_message_table_entry 742 channel_message_table[CHANNELMSG_COUNT] = { 743 {CHANNELMSG_INVALID, 0, NULL}, 744 {CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer}, 745 {CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind}, 746 {CHANNELMSG_REQUESTOFFERS, 0, NULL}, 747 {CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered}, 748 {CHANNELMSG_OPENCHANNEL, 0, NULL}, 749 {CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result}, 750 {CHANNELMSG_CLOSECHANNEL, 0, NULL}, 751 {CHANNELMSG_GPADL_HEADER, 0, NULL}, 752 {CHANNELMSG_GPADL_BODY, 0, NULL}, 753 {CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created}, 754 {CHANNELMSG_GPADL_TEARDOWN, 0, NULL}, 755 {CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown}, 756 {CHANNELMSG_RELID_RELEASED, 0, NULL}, 757 {CHANNELMSG_INITIATE_CONTACT, 0, NULL}, 758 {CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response}, 759 {CHANNELMSG_UNLOAD, 0, NULL}, 760 {CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response}, 761 }; 762 763 /* 764 * vmbus_onmessage - Handler for channel protocol messages. 765 * 766 * This is invoked in the vmbus worker thread context. 767 */ 768 void vmbus_onmessage(void *context) 769 { 770 struct hv_message *msg = context; 771 struct vmbus_channel_message_header *hdr; 772 int size; 773 774 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 775 size = msg->header.payload_size; 776 777 if (hdr->msgtype >= CHANNELMSG_COUNT) { 778 pr_err("Received invalid channel message type %d size %d\n", 779 hdr->msgtype, size); 780 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 781 (unsigned char *)msg->u.payload, size); 782 return; 783 } 784 785 if (channel_message_table[hdr->msgtype].message_handler) 786 channel_message_table[hdr->msgtype].message_handler(hdr); 787 else 788 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 789 } 790 791 /* 792 * vmbus_request_offers - Send a request to get all our pending offers. 793 */ 794 int vmbus_request_offers(void) 795 { 796 struct vmbus_channel_message_header *msg; 797 struct vmbus_channel_msginfo *msginfo; 798 int ret; 799 800 msginfo = kmalloc(sizeof(*msginfo) + 801 sizeof(struct vmbus_channel_message_header), 802 GFP_KERNEL); 803 if (!msginfo) 804 return -ENOMEM; 805 806 msg = (struct vmbus_channel_message_header *)msginfo->msg; 807 808 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 809 810 811 ret = vmbus_post_msg(msg, 812 sizeof(struct vmbus_channel_message_header)); 813 if (ret != 0) { 814 pr_err("Unable to request offers - %d\n", ret); 815 816 goto cleanup; 817 } 818 819 cleanup: 820 kfree(msginfo); 821 822 return ret; 823 } 824 825 /* 826 * Retrieve the (sub) channel on which to send an outgoing request. 827 * When a primary channel has multiple sub-channels, we try to 828 * distribute the load equally amongst all available channels. 829 */ 830 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 831 { 832 struct list_head *cur, *tmp; 833 int cur_cpu; 834 struct vmbus_channel *cur_channel; 835 struct vmbus_channel *outgoing_channel = primary; 836 int next_channel; 837 int i = 1; 838 839 if (list_empty(&primary->sc_list)) 840 return outgoing_channel; 841 842 next_channel = primary->next_oc++; 843 844 if (next_channel > (primary->num_sc)) { 845 primary->next_oc = 0; 846 return outgoing_channel; 847 } 848 849 cur_cpu = hv_context.vp_index[get_cpu()]; 850 put_cpu(); 851 list_for_each_safe(cur, tmp, &primary->sc_list) { 852 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 853 if (cur_channel->state != CHANNEL_OPENED_STATE) 854 continue; 855 856 if (cur_channel->target_vp == cur_cpu) 857 return cur_channel; 858 859 if (i == next_channel) 860 return cur_channel; 861 862 i++; 863 } 864 865 return outgoing_channel; 866 } 867 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 868 869 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 870 { 871 struct list_head *cur, *tmp; 872 struct vmbus_channel *cur_channel; 873 874 if (primary_channel->sc_creation_callback == NULL) 875 return; 876 877 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 878 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 879 880 primary_channel->sc_creation_callback(cur_channel); 881 } 882 } 883 884 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 885 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 886 { 887 primary_channel->sc_creation_callback = sc_cr_cb; 888 } 889 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 890 891 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 892 { 893 bool ret; 894 895 ret = !list_empty(&primary->sc_list); 896 897 if (ret) { 898 /* 899 * Invoke the callback on sub-channel creation. 900 * This will present a uniform interface to the 901 * clients. 902 */ 903 invoke_sc_cb(primary); 904 } 905 906 return ret; 907 } 908 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 909