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 free_channel(channel); 266 } 267 } 268 269 /* 270 * vmbus_process_offer - Process the offer by creating a channel/device 271 * associated with this offer 272 */ 273 static void vmbus_process_offer(struct work_struct *work) 274 { 275 struct vmbus_channel *newchannel = container_of(work, 276 struct vmbus_channel, 277 work); 278 struct vmbus_channel *channel; 279 bool fnew = true; 280 bool enq = false; 281 int ret; 282 unsigned long flags; 283 284 /* Make sure this is a new offer */ 285 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 286 287 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 288 if (!uuid_le_cmp(channel->offermsg.offer.if_type, 289 newchannel->offermsg.offer.if_type) && 290 !uuid_le_cmp(channel->offermsg.offer.if_instance, 291 newchannel->offermsg.offer.if_instance)) { 292 fnew = false; 293 break; 294 } 295 } 296 297 if (fnew) { 298 list_add_tail(&newchannel->listentry, 299 &vmbus_connection.chn_list); 300 enq = true; 301 } 302 303 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 304 305 if (enq) { 306 if (newchannel->target_cpu != get_cpu()) { 307 put_cpu(); 308 smp_call_function_single(newchannel->target_cpu, 309 percpu_channel_enq, 310 newchannel, true); 311 } else { 312 percpu_channel_enq(newchannel); 313 put_cpu(); 314 } 315 } 316 if (!fnew) { 317 /* 318 * Check to see if this is a sub-channel. 319 */ 320 if (newchannel->offermsg.offer.sub_channel_index != 0) { 321 /* 322 * Process the sub-channel. 323 */ 324 newchannel->primary_channel = channel; 325 spin_lock_irqsave(&channel->lock, flags); 326 list_add_tail(&newchannel->sc_list, &channel->sc_list); 327 spin_unlock_irqrestore(&channel->lock, flags); 328 329 if (newchannel->target_cpu != get_cpu()) { 330 put_cpu(); 331 smp_call_function_single(newchannel->target_cpu, 332 percpu_channel_enq, 333 newchannel, true); 334 } else { 335 percpu_channel_enq(newchannel); 336 put_cpu(); 337 } 338 339 newchannel->state = CHANNEL_OPEN_STATE; 340 if (channel->sc_creation_callback != NULL) 341 channel->sc_creation_callback(newchannel); 342 343 goto done_init_rescind; 344 } 345 346 goto err_free_chan; 347 } 348 349 /* 350 * This state is used to indicate a successful open 351 * so that when we do close the channel normally, we 352 * can cleanup properly 353 */ 354 newchannel->state = CHANNEL_OPEN_STATE; 355 356 /* 357 * Start the process of binding this offer to the driver 358 * We need to set the DeviceObject field before calling 359 * vmbus_child_dev_add() 360 */ 361 newchannel->device_obj = vmbus_device_create( 362 &newchannel->offermsg.offer.if_type, 363 &newchannel->offermsg.offer.if_instance, 364 newchannel); 365 if (!newchannel->device_obj) 366 goto err_free_chan; 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 goto err_free_chan; 383 } 384 done_init_rescind: 385 spin_lock_irqsave(&newchannel->lock, flags); 386 /* The next possible work is rescind handling */ 387 INIT_WORK(&newchannel->work, vmbus_process_rescind_offer); 388 /* Check if rescind offer was already received */ 389 if (newchannel->rescind) 390 queue_work(newchannel->controlwq, &newchannel->work); 391 spin_unlock_irqrestore(&newchannel->lock, flags); 392 return; 393 err_free_chan: 394 free_channel(newchannel); 395 } 396 397 enum { 398 IDE = 0, 399 SCSI, 400 NIC, 401 MAX_PERF_CHN, 402 }; 403 404 /* 405 * This is an array of device_ids (device types) that are performance critical. 406 * We attempt to distribute the interrupt load for these devices across 407 * all available CPUs. 408 */ 409 static const struct hv_vmbus_device_id hp_devs[] = { 410 /* IDE */ 411 { HV_IDE_GUID, }, 412 /* Storage - SCSI */ 413 { HV_SCSI_GUID, }, 414 /* Network */ 415 { HV_NIC_GUID, }, 416 /* NetworkDirect Guest RDMA */ 417 { HV_ND_GUID, }, 418 }; 419 420 421 /* 422 * We use this state to statically distribute the channel interrupt load. 423 */ 424 static u32 next_vp; 425 426 /* 427 * Starting with Win8, we can statically distribute the incoming 428 * channel interrupt load by binding a channel to VCPU. We 429 * implement here a simple round robin scheme for distributing 430 * the interrupt load. 431 * We will bind channels that are not performance critical to cpu 0 and 432 * performance critical channels (IDE, SCSI and Network) will be uniformly 433 * distributed across all available CPUs. 434 */ 435 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid) 436 { 437 u32 cur_cpu; 438 int i; 439 bool perf_chn = false; 440 u32 max_cpus = num_online_cpus(); 441 442 for (i = IDE; i < MAX_PERF_CHN; i++) { 443 if (!memcmp(type_guid->b, hp_devs[i].guid, 444 sizeof(uuid_le))) { 445 perf_chn = true; 446 break; 447 } 448 } 449 if ((vmbus_proto_version == VERSION_WS2008) || 450 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 451 /* 452 * Prior to win8, all channel interrupts are 453 * delivered on cpu 0. 454 * Also if the channel is not a performance critical 455 * channel, bind it to cpu 0. 456 */ 457 channel->target_cpu = 0; 458 channel->target_vp = 0; 459 return; 460 } 461 cur_cpu = (++next_vp % max_cpus); 462 channel->target_cpu = cur_cpu; 463 channel->target_vp = hv_context.vp_index[cur_cpu]; 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 init_vp_index(newchannel, &offer->offer.if_type); 512 513 memcpy(&newchannel->offermsg, offer, 514 sizeof(struct vmbus_channel_offer_channel)); 515 newchannel->monitor_grp = (u8)offer->monitorid / 32; 516 newchannel->monitor_bit = (u8)offer->monitorid % 32; 517 518 INIT_WORK(&newchannel->work, vmbus_process_offer); 519 queue_work(newchannel->controlwq, &newchannel->work); 520 } 521 522 /* 523 * vmbus_onoffer_rescind - Rescind offer handler. 524 * 525 * We queue a work item to process this offer synchronously 526 */ 527 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 528 { 529 struct vmbus_channel_rescind_offer *rescind; 530 struct vmbus_channel *channel; 531 unsigned long flags; 532 533 rescind = (struct vmbus_channel_rescind_offer *)hdr; 534 channel = relid2channel(rescind->child_relid); 535 536 if (channel == NULL) 537 /* Just return here, no channel found */ 538 return; 539 540 spin_lock_irqsave(&channel->lock, flags); 541 channel->rescind = true; 542 /* 543 * channel->work.func != vmbus_process_rescind_offer means we are still 544 * processing offer request and the rescind offer processing should be 545 * postponed. It will be done at the very end of vmbus_process_offer() 546 * as rescind flag is being checked there. 547 */ 548 if (channel->work.func == vmbus_process_rescind_offer) 549 /* work is initialized for vmbus_process_rescind_offer() from 550 * vmbus_process_offer() where the channel got created */ 551 queue_work(channel->controlwq, &channel->work); 552 553 spin_unlock_irqrestore(&channel->lock, flags); 554 } 555 556 /* 557 * vmbus_onoffers_delivered - 558 * This is invoked when all offers have been delivered. 559 * 560 * Nothing to do here. 561 */ 562 static void vmbus_onoffers_delivered( 563 struct vmbus_channel_message_header *hdr) 564 { 565 } 566 567 /* 568 * vmbus_onopen_result - Open result handler. 569 * 570 * This is invoked when we received a response to our channel open request. 571 * Find the matching request, copy the response and signal the requesting 572 * thread. 573 */ 574 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 575 { 576 struct vmbus_channel_open_result *result; 577 struct vmbus_channel_msginfo *msginfo; 578 struct vmbus_channel_message_header *requestheader; 579 struct vmbus_channel_open_channel *openmsg; 580 unsigned long flags; 581 582 result = (struct vmbus_channel_open_result *)hdr; 583 584 /* 585 * Find the open msg, copy the result and signal/unblock the wait event 586 */ 587 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 588 589 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 590 msglistentry) { 591 requestheader = 592 (struct vmbus_channel_message_header *)msginfo->msg; 593 594 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 595 openmsg = 596 (struct vmbus_channel_open_channel *)msginfo->msg; 597 if (openmsg->child_relid == result->child_relid && 598 openmsg->openid == result->openid) { 599 memcpy(&msginfo->response.open_result, 600 result, 601 sizeof( 602 struct vmbus_channel_open_result)); 603 complete(&msginfo->waitevent); 604 break; 605 } 606 } 607 } 608 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 609 } 610 611 /* 612 * vmbus_ongpadl_created - GPADL created handler. 613 * 614 * This is invoked when we received a response to our gpadl create request. 615 * Find the matching request, copy the response and signal the requesting 616 * thread. 617 */ 618 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 619 { 620 struct vmbus_channel_gpadl_created *gpadlcreated; 621 struct vmbus_channel_msginfo *msginfo; 622 struct vmbus_channel_message_header *requestheader; 623 struct vmbus_channel_gpadl_header *gpadlheader; 624 unsigned long flags; 625 626 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 627 628 /* 629 * Find the establish msg, copy the result and signal/unblock the wait 630 * event 631 */ 632 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 633 634 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 635 msglistentry) { 636 requestheader = 637 (struct vmbus_channel_message_header *)msginfo->msg; 638 639 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 640 gpadlheader = 641 (struct vmbus_channel_gpadl_header *)requestheader; 642 643 if ((gpadlcreated->child_relid == 644 gpadlheader->child_relid) && 645 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 646 memcpy(&msginfo->response.gpadl_created, 647 gpadlcreated, 648 sizeof( 649 struct vmbus_channel_gpadl_created)); 650 complete(&msginfo->waitevent); 651 break; 652 } 653 } 654 } 655 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 656 } 657 658 /* 659 * vmbus_ongpadl_torndown - GPADL torndown handler. 660 * 661 * This is invoked when we received a response to our gpadl teardown request. 662 * Find the matching request, copy the response and signal the requesting 663 * thread. 664 */ 665 static void vmbus_ongpadl_torndown( 666 struct vmbus_channel_message_header *hdr) 667 { 668 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 669 struct vmbus_channel_msginfo *msginfo; 670 struct vmbus_channel_message_header *requestheader; 671 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 672 unsigned long flags; 673 674 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 675 676 /* 677 * Find the open msg, copy the result and signal/unblock the wait event 678 */ 679 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 680 681 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 682 msglistentry) { 683 requestheader = 684 (struct vmbus_channel_message_header *)msginfo->msg; 685 686 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 687 gpadl_teardown = 688 (struct vmbus_channel_gpadl_teardown *)requestheader; 689 690 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 691 memcpy(&msginfo->response.gpadl_torndown, 692 gpadl_torndown, 693 sizeof( 694 struct vmbus_channel_gpadl_torndown)); 695 complete(&msginfo->waitevent); 696 break; 697 } 698 } 699 } 700 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 701 } 702 703 /* 704 * vmbus_onversion_response - Version response handler 705 * 706 * This is invoked when we received a response to our initiate contact request. 707 * Find the matching request, copy the response and signal the requesting 708 * thread. 709 */ 710 static void vmbus_onversion_response( 711 struct vmbus_channel_message_header *hdr) 712 { 713 struct vmbus_channel_msginfo *msginfo; 714 struct vmbus_channel_message_header *requestheader; 715 struct vmbus_channel_version_response *version_response; 716 unsigned long flags; 717 718 version_response = (struct vmbus_channel_version_response *)hdr; 719 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 720 721 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 722 msglistentry) { 723 requestheader = 724 (struct vmbus_channel_message_header *)msginfo->msg; 725 726 if (requestheader->msgtype == 727 CHANNELMSG_INITIATE_CONTACT) { 728 memcpy(&msginfo->response.version_response, 729 version_response, 730 sizeof(struct vmbus_channel_version_response)); 731 complete(&msginfo->waitevent); 732 } 733 } 734 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 735 } 736 737 /* Channel message dispatch table */ 738 static struct vmbus_channel_message_table_entry 739 channel_message_table[CHANNELMSG_COUNT] = { 740 {CHANNELMSG_INVALID, NULL}, 741 {CHANNELMSG_OFFERCHANNEL, vmbus_onoffer}, 742 {CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind}, 743 {CHANNELMSG_REQUESTOFFERS, NULL}, 744 {CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered}, 745 {CHANNELMSG_OPENCHANNEL, NULL}, 746 {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result}, 747 {CHANNELMSG_CLOSECHANNEL, NULL}, 748 {CHANNELMSG_GPADL_HEADER, NULL}, 749 {CHANNELMSG_GPADL_BODY, NULL}, 750 {CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created}, 751 {CHANNELMSG_GPADL_TEARDOWN, NULL}, 752 {CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown}, 753 {CHANNELMSG_RELID_RELEASED, NULL}, 754 {CHANNELMSG_INITIATE_CONTACT, NULL}, 755 {CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response}, 756 {CHANNELMSG_UNLOAD, NULL}, 757 }; 758 759 /* 760 * vmbus_onmessage - Handler for channel protocol messages. 761 * 762 * This is invoked in the vmbus worker thread context. 763 */ 764 void vmbus_onmessage(void *context) 765 { 766 struct hv_message *msg = context; 767 struct vmbus_channel_message_header *hdr; 768 int size; 769 770 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 771 size = msg->header.payload_size; 772 773 if (hdr->msgtype >= CHANNELMSG_COUNT) { 774 pr_err("Received invalid channel message type %d size %d\n", 775 hdr->msgtype, size); 776 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 777 (unsigned char *)msg->u.payload, size); 778 return; 779 } 780 781 if (channel_message_table[hdr->msgtype].message_handler) 782 channel_message_table[hdr->msgtype].message_handler(hdr); 783 else 784 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 785 } 786 787 /* 788 * vmbus_request_offers - Send a request to get all our pending offers. 789 */ 790 int vmbus_request_offers(void) 791 { 792 struct vmbus_channel_message_header *msg; 793 struct vmbus_channel_msginfo *msginfo; 794 int ret; 795 unsigned long t; 796 797 msginfo = kmalloc(sizeof(*msginfo) + 798 sizeof(struct vmbus_channel_message_header), 799 GFP_KERNEL); 800 if (!msginfo) 801 return -ENOMEM; 802 803 init_completion(&msginfo->waitevent); 804 805 msg = (struct vmbus_channel_message_header *)msginfo->msg; 806 807 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 808 809 810 ret = vmbus_post_msg(msg, 811 sizeof(struct vmbus_channel_message_header)); 812 if (ret != 0) { 813 pr_err("Unable to request offers - %d\n", ret); 814 815 goto cleanup; 816 } 817 818 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); 819 if (t == 0) { 820 ret = -ETIMEDOUT; 821 goto cleanup; 822 } 823 824 825 826 cleanup: 827 kfree(msginfo); 828 829 return ret; 830 } 831 832 /* 833 * Retrieve the (sub) channel on which to send an outgoing request. 834 * When a primary channel has multiple sub-channels, we choose a 835 * channel whose VCPU binding is closest to the VCPU on which 836 * this call is being made. 837 */ 838 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 839 { 840 struct list_head *cur, *tmp; 841 int cur_cpu; 842 struct vmbus_channel *cur_channel; 843 struct vmbus_channel *outgoing_channel = primary; 844 int cpu_distance, new_cpu_distance; 845 846 if (list_empty(&primary->sc_list)) 847 return outgoing_channel; 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 cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ? 860 (outgoing_channel->target_vp - cur_cpu) : 861 (cur_cpu - outgoing_channel->target_vp)); 862 863 new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ? 864 (cur_channel->target_vp - cur_cpu) : 865 (cur_cpu - cur_channel->target_vp)); 866 867 if (cpu_distance < new_cpu_distance) 868 continue; 869 870 outgoing_channel = cur_channel; 871 } 872 873 return outgoing_channel; 874 } 875 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 876 877 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 878 { 879 struct list_head *cur, *tmp; 880 struct vmbus_channel *cur_channel; 881 882 if (primary_channel->sc_creation_callback == NULL) 883 return; 884 885 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 886 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 887 888 primary_channel->sc_creation_callback(cur_channel); 889 } 890 } 891 892 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 893 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 894 { 895 primary_channel->sc_creation_callback = sc_cr_cb; 896 } 897 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 898 899 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 900 { 901 bool ret; 902 903 ret = !list_empty(&primary->sc_list); 904 905 if (ret) { 906 /* 907 * Invoke the callback on sub-channel creation. 908 * This will present a uniform interface to the 909 * clients. 910 */ 911 invoke_sc_cb(primary); 912 } 913 914 return ret; 915 } 916 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 917