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(); 390 391 for (i = IDE; i < MAX_PERF_CHN; i++) { 392 if (!memcmp(type_guid->b, hp_devs[i].guid, 393 sizeof(uuid_le))) { 394 perf_chn = true; 395 break; 396 } 397 } 398 if ((vmbus_proto_version == VERSION_WS2008) || 399 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 400 /* 401 * Prior to win8, all channel interrupts are 402 * delivered on cpu 0. 403 * Also if the channel is not a performance critical 404 * channel, bind it to cpu 0. 405 */ 406 channel->target_cpu = 0; 407 channel->target_vp = 0; 408 return; 409 } 410 cur_cpu = (++next_vp % max_cpus); 411 channel->target_cpu = cur_cpu; 412 channel->target_vp = hv_context.vp_index[cur_cpu]; 413 } 414 415 /* 416 * vmbus_unload_response - Handler for the unload response. 417 */ 418 static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) 419 { 420 /* 421 * This is a global event; just wakeup the waiting thread. 422 * Once we successfully unload, we can cleanup the monitor state. 423 */ 424 complete(&vmbus_connection.unload_event); 425 } 426 427 void vmbus_initiate_unload(void) 428 { 429 struct vmbus_channel_message_header hdr; 430 431 init_completion(&vmbus_connection.unload_event); 432 memset(&hdr, 0, sizeof(struct vmbus_channel_message_header)); 433 hdr.msgtype = CHANNELMSG_UNLOAD; 434 vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header)); 435 436 wait_for_completion(&vmbus_connection.unload_event); 437 } 438 439 /* 440 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 441 * 442 */ 443 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 444 { 445 struct vmbus_channel_offer_channel *offer; 446 struct vmbus_channel *newchannel; 447 448 offer = (struct vmbus_channel_offer_channel *)hdr; 449 450 /* Allocate the channel object and save this offer. */ 451 newchannel = alloc_channel(); 452 if (!newchannel) { 453 pr_err("Unable to allocate channel object\n"); 454 return; 455 } 456 457 /* 458 * By default we setup state to enable batched 459 * reading. A specific service can choose to 460 * disable this prior to opening the channel. 461 */ 462 newchannel->batched_reading = true; 463 464 /* 465 * Setup state for signalling the host. 466 */ 467 newchannel->sig_event = (struct hv_input_signal_event *) 468 (ALIGN((unsigned long) 469 &newchannel->sig_buf, 470 HV_HYPERCALL_PARAM_ALIGN)); 471 472 newchannel->sig_event->connectionid.asu32 = 0; 473 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 474 newchannel->sig_event->flag_number = 0; 475 newchannel->sig_event->rsvdz = 0; 476 477 if (vmbus_proto_version != VERSION_WS2008) { 478 newchannel->is_dedicated_interrupt = 479 (offer->is_dedicated_interrupt != 0); 480 newchannel->sig_event->connectionid.u.id = 481 offer->connection_id; 482 } 483 484 memcpy(&newchannel->offermsg, offer, 485 sizeof(struct vmbus_channel_offer_channel)); 486 newchannel->monitor_grp = (u8)offer->monitorid / 32; 487 newchannel->monitor_bit = (u8)offer->monitorid % 32; 488 489 vmbus_process_offer(newchannel); 490 } 491 492 /* 493 * vmbus_onoffer_rescind - Rescind offer handler. 494 * 495 * We queue a work item to process this offer synchronously 496 */ 497 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 498 { 499 struct vmbus_channel_rescind_offer *rescind; 500 struct vmbus_channel *channel; 501 unsigned long flags; 502 struct device *dev; 503 504 rescind = (struct vmbus_channel_rescind_offer *)hdr; 505 channel = relid2channel(rescind->child_relid); 506 507 if (channel == NULL) { 508 hv_process_channel_removal(NULL, rescind->child_relid); 509 return; 510 } 511 512 spin_lock_irqsave(&channel->lock, flags); 513 channel->rescind = true; 514 spin_unlock_irqrestore(&channel->lock, flags); 515 516 if (channel->device_obj) { 517 /* 518 * We will have to unregister this device from the 519 * driver core. 520 */ 521 dev = get_device(&channel->device_obj->device); 522 if (dev) { 523 vmbus_device_unregister(channel->device_obj); 524 put_device(dev); 525 } 526 } else { 527 hv_process_channel_removal(channel, 528 channel->offermsg.child_relid); 529 } 530 } 531 532 /* 533 * vmbus_onoffers_delivered - 534 * This is invoked when all offers have been delivered. 535 * 536 * Nothing to do here. 537 */ 538 static void vmbus_onoffers_delivered( 539 struct vmbus_channel_message_header *hdr) 540 { 541 } 542 543 /* 544 * vmbus_onopen_result - Open result handler. 545 * 546 * This is invoked when we received a response to our channel open request. 547 * Find the matching request, copy the response and signal the requesting 548 * thread. 549 */ 550 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 551 { 552 struct vmbus_channel_open_result *result; 553 struct vmbus_channel_msginfo *msginfo; 554 struct vmbus_channel_message_header *requestheader; 555 struct vmbus_channel_open_channel *openmsg; 556 unsigned long flags; 557 558 result = (struct vmbus_channel_open_result *)hdr; 559 560 /* 561 * Find the open msg, copy the result and signal/unblock the wait event 562 */ 563 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 564 565 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 566 msglistentry) { 567 requestheader = 568 (struct vmbus_channel_message_header *)msginfo->msg; 569 570 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 571 openmsg = 572 (struct vmbus_channel_open_channel *)msginfo->msg; 573 if (openmsg->child_relid == result->child_relid && 574 openmsg->openid == result->openid) { 575 memcpy(&msginfo->response.open_result, 576 result, 577 sizeof( 578 struct vmbus_channel_open_result)); 579 complete(&msginfo->waitevent); 580 break; 581 } 582 } 583 } 584 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 585 } 586 587 /* 588 * vmbus_ongpadl_created - GPADL created handler. 589 * 590 * This is invoked when we received a response to our gpadl create request. 591 * Find the matching request, copy the response and signal the requesting 592 * thread. 593 */ 594 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 595 { 596 struct vmbus_channel_gpadl_created *gpadlcreated; 597 struct vmbus_channel_msginfo *msginfo; 598 struct vmbus_channel_message_header *requestheader; 599 struct vmbus_channel_gpadl_header *gpadlheader; 600 unsigned long flags; 601 602 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 603 604 /* 605 * Find the establish msg, copy the result and signal/unblock the wait 606 * event 607 */ 608 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 609 610 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 611 msglistentry) { 612 requestheader = 613 (struct vmbus_channel_message_header *)msginfo->msg; 614 615 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 616 gpadlheader = 617 (struct vmbus_channel_gpadl_header *)requestheader; 618 619 if ((gpadlcreated->child_relid == 620 gpadlheader->child_relid) && 621 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 622 memcpy(&msginfo->response.gpadl_created, 623 gpadlcreated, 624 sizeof( 625 struct vmbus_channel_gpadl_created)); 626 complete(&msginfo->waitevent); 627 break; 628 } 629 } 630 } 631 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 632 } 633 634 /* 635 * vmbus_ongpadl_torndown - GPADL torndown handler. 636 * 637 * This is invoked when we received a response to our gpadl teardown request. 638 * Find the matching request, copy the response and signal the requesting 639 * thread. 640 */ 641 static void vmbus_ongpadl_torndown( 642 struct vmbus_channel_message_header *hdr) 643 { 644 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 645 struct vmbus_channel_msginfo *msginfo; 646 struct vmbus_channel_message_header *requestheader; 647 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 648 unsigned long flags; 649 650 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 651 652 /* 653 * Find the open msg, copy the result and signal/unblock the wait event 654 */ 655 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 656 657 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 658 msglistentry) { 659 requestheader = 660 (struct vmbus_channel_message_header *)msginfo->msg; 661 662 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 663 gpadl_teardown = 664 (struct vmbus_channel_gpadl_teardown *)requestheader; 665 666 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 667 memcpy(&msginfo->response.gpadl_torndown, 668 gpadl_torndown, 669 sizeof( 670 struct vmbus_channel_gpadl_torndown)); 671 complete(&msginfo->waitevent); 672 break; 673 } 674 } 675 } 676 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 677 } 678 679 /* 680 * vmbus_onversion_response - Version response handler 681 * 682 * This is invoked when we received a response to our initiate contact request. 683 * Find the matching request, copy the response and signal the requesting 684 * thread. 685 */ 686 static void vmbus_onversion_response( 687 struct vmbus_channel_message_header *hdr) 688 { 689 struct vmbus_channel_msginfo *msginfo; 690 struct vmbus_channel_message_header *requestheader; 691 struct vmbus_channel_version_response *version_response; 692 unsigned long flags; 693 694 version_response = (struct vmbus_channel_version_response *)hdr; 695 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 696 697 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 698 msglistentry) { 699 requestheader = 700 (struct vmbus_channel_message_header *)msginfo->msg; 701 702 if (requestheader->msgtype == 703 CHANNELMSG_INITIATE_CONTACT) { 704 memcpy(&msginfo->response.version_response, 705 version_response, 706 sizeof(struct vmbus_channel_version_response)); 707 complete(&msginfo->waitevent); 708 } 709 } 710 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 711 } 712 713 /* Channel message dispatch table */ 714 struct vmbus_channel_message_table_entry 715 channel_message_table[CHANNELMSG_COUNT] = { 716 {CHANNELMSG_INVALID, 0, NULL}, 717 {CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer}, 718 {CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind}, 719 {CHANNELMSG_REQUESTOFFERS, 0, NULL}, 720 {CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered}, 721 {CHANNELMSG_OPENCHANNEL, 0, NULL}, 722 {CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result}, 723 {CHANNELMSG_CLOSECHANNEL, 0, NULL}, 724 {CHANNELMSG_GPADL_HEADER, 0, NULL}, 725 {CHANNELMSG_GPADL_BODY, 0, NULL}, 726 {CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created}, 727 {CHANNELMSG_GPADL_TEARDOWN, 0, NULL}, 728 {CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown}, 729 {CHANNELMSG_RELID_RELEASED, 0, NULL}, 730 {CHANNELMSG_INITIATE_CONTACT, 0, NULL}, 731 {CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response}, 732 {CHANNELMSG_UNLOAD, 0, NULL}, 733 {CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response}, 734 }; 735 736 /* 737 * vmbus_onmessage - Handler for channel protocol messages. 738 * 739 * This is invoked in the vmbus worker thread context. 740 */ 741 void vmbus_onmessage(void *context) 742 { 743 struct hv_message *msg = context; 744 struct vmbus_channel_message_header *hdr; 745 int size; 746 747 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 748 size = msg->header.payload_size; 749 750 if (hdr->msgtype >= CHANNELMSG_COUNT) { 751 pr_err("Received invalid channel message type %d size %d\n", 752 hdr->msgtype, size); 753 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 754 (unsigned char *)msg->u.payload, size); 755 return; 756 } 757 758 if (channel_message_table[hdr->msgtype].message_handler) 759 channel_message_table[hdr->msgtype].message_handler(hdr); 760 else 761 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 762 } 763 764 /* 765 * vmbus_request_offers - Send a request to get all our pending offers. 766 */ 767 int vmbus_request_offers(void) 768 { 769 struct vmbus_channel_message_header *msg; 770 struct vmbus_channel_msginfo *msginfo; 771 int ret; 772 773 msginfo = kmalloc(sizeof(*msginfo) + 774 sizeof(struct vmbus_channel_message_header), 775 GFP_KERNEL); 776 if (!msginfo) 777 return -ENOMEM; 778 779 msg = (struct vmbus_channel_message_header *)msginfo->msg; 780 781 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 782 783 784 ret = vmbus_post_msg(msg, 785 sizeof(struct vmbus_channel_message_header)); 786 if (ret != 0) { 787 pr_err("Unable to request offers - %d\n", ret); 788 789 goto cleanup; 790 } 791 792 cleanup: 793 kfree(msginfo); 794 795 return ret; 796 } 797 798 /* 799 * Retrieve the (sub) channel on which to send an outgoing request. 800 * When a primary channel has multiple sub-channels, we try to 801 * distribute the load equally amongst all available channels. 802 */ 803 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 804 { 805 struct list_head *cur, *tmp; 806 int cur_cpu; 807 struct vmbus_channel *cur_channel; 808 struct vmbus_channel *outgoing_channel = primary; 809 int next_channel; 810 int i = 1; 811 812 if (list_empty(&primary->sc_list)) 813 return outgoing_channel; 814 815 next_channel = primary->next_oc++; 816 817 if (next_channel > (primary->num_sc)) { 818 primary->next_oc = 0; 819 return outgoing_channel; 820 } 821 822 cur_cpu = hv_context.vp_index[get_cpu()]; 823 put_cpu(); 824 list_for_each_safe(cur, tmp, &primary->sc_list) { 825 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 826 if (cur_channel->state != CHANNEL_OPENED_STATE) 827 continue; 828 829 if (cur_channel->target_vp == cur_cpu) 830 return cur_channel; 831 832 if (i == next_channel) 833 return cur_channel; 834 835 i++; 836 } 837 838 return outgoing_channel; 839 } 840 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 841 842 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 843 { 844 struct list_head *cur, *tmp; 845 struct vmbus_channel *cur_channel; 846 847 if (primary_channel->sc_creation_callback == NULL) 848 return; 849 850 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 851 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 852 853 primary_channel->sc_creation_callback(cur_channel); 854 } 855 } 856 857 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 858 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 859 { 860 primary_channel->sc_creation_callback = sc_cr_cb; 861 } 862 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 863 864 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 865 { 866 bool ret; 867 868 ret = !list_empty(&primary->sc_list); 869 870 if (ret) { 871 /* 872 * Invoke the callback on sub-channel creation. 873 * This will present a uniform interface to the 874 * clients. 875 */ 876 invoke_sc_cb(primary); 877 } 878 879 return ret; 880 } 881 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 882