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 /** 36 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message 37 * @icmsghdrp: Pointer to msg header structure 38 * @icmsg_negotiate: Pointer to negotiate message structure 39 * @buf: Raw buffer channel data 40 * 41 * @icmsghdrp is of type &struct icmsg_hdr. 42 * @negop is of type &struct icmsg_negotiate. 43 * Set up and fill in default negotiate response message. 44 * 45 * The fw_version specifies the framework version that 46 * we can support and srv_version specifies the service 47 * version we can support. 48 * 49 * Mainly used by Hyper-V drivers. 50 */ 51 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, 52 struct icmsg_negotiate *negop, u8 *buf, 53 int fw_version, int srv_version) 54 { 55 int icframe_major, icframe_minor; 56 int icmsg_major, icmsg_minor; 57 int fw_major, fw_minor; 58 int srv_major, srv_minor; 59 int i; 60 bool found_match = false; 61 62 icmsghdrp->icmsgsize = 0x10; 63 fw_major = (fw_version >> 16); 64 fw_minor = (fw_version & 0xFFFF); 65 66 srv_major = (srv_version >> 16); 67 srv_minor = (srv_version & 0xFFFF); 68 69 negop = (struct icmsg_negotiate *)&buf[ 70 sizeof(struct vmbuspipe_hdr) + 71 sizeof(struct icmsg_hdr)]; 72 73 icframe_major = negop->icframe_vercnt; 74 icframe_minor = 0; 75 76 icmsg_major = negop->icmsg_vercnt; 77 icmsg_minor = 0; 78 79 /* 80 * Select the framework version number we will 81 * support. 82 */ 83 84 for (i = 0; i < negop->icframe_vercnt; i++) { 85 if ((negop->icversion_data[i].major == fw_major) && 86 (negop->icversion_data[i].minor == fw_minor)) { 87 icframe_major = negop->icversion_data[i].major; 88 icframe_minor = negop->icversion_data[i].minor; 89 found_match = true; 90 } 91 } 92 93 if (!found_match) 94 goto fw_error; 95 96 found_match = false; 97 98 for (i = negop->icframe_vercnt; 99 (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) { 100 if ((negop->icversion_data[i].major == srv_major) && 101 (negop->icversion_data[i].minor == srv_minor)) { 102 icmsg_major = negop->icversion_data[i].major; 103 icmsg_minor = negop->icversion_data[i].minor; 104 found_match = true; 105 } 106 } 107 108 /* 109 * Respond with the framework and service 110 * version numbers we can support. 111 */ 112 113 fw_error: 114 if (!found_match) { 115 negop->icframe_vercnt = 0; 116 negop->icmsg_vercnt = 0; 117 } else { 118 negop->icframe_vercnt = 1; 119 negop->icmsg_vercnt = 1; 120 } 121 122 negop->icversion_data[0].major = icframe_major; 123 negop->icversion_data[0].minor = icframe_minor; 124 negop->icversion_data[1].major = icmsg_major; 125 negop->icversion_data[1].minor = icmsg_minor; 126 return found_match; 127 } 128 129 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp); 130 131 /* 132 * alloc_channel - Allocate and initialize a vmbus channel object 133 */ 134 static struct vmbus_channel *alloc_channel(void) 135 { 136 static atomic_t chan_num = ATOMIC_INIT(0); 137 struct vmbus_channel *channel; 138 139 channel = kzalloc(sizeof(*channel), GFP_ATOMIC); 140 if (!channel) 141 return NULL; 142 143 channel->id = atomic_inc_return(&chan_num); 144 spin_lock_init(&channel->inbound_lock); 145 spin_lock_init(&channel->lock); 146 147 INIT_LIST_HEAD(&channel->sc_list); 148 INIT_LIST_HEAD(&channel->percpu_list); 149 150 return channel; 151 } 152 153 /* 154 * free_channel - Release the resources used by the vmbus channel object 155 */ 156 static void free_channel(struct vmbus_channel *channel) 157 { 158 kfree(channel); 159 } 160 161 static void percpu_channel_enq(void *arg) 162 { 163 struct vmbus_channel *channel = arg; 164 int cpu = smp_processor_id(); 165 166 list_add_tail(&channel->percpu_list, &hv_context.percpu_list[cpu]); 167 } 168 169 static void percpu_channel_deq(void *arg) 170 { 171 struct vmbus_channel *channel = arg; 172 173 list_del(&channel->percpu_list); 174 } 175 176 177 void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) 178 { 179 struct vmbus_channel_relid_released msg; 180 unsigned long flags; 181 struct vmbus_channel *primary_channel; 182 183 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 184 msg.child_relid = relid; 185 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 186 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released)); 187 188 if (channel == NULL) 189 return; 190 191 if (channel->target_cpu != get_cpu()) { 192 put_cpu(); 193 smp_call_function_single(channel->target_cpu, 194 percpu_channel_deq, channel, true); 195 } else { 196 percpu_channel_deq(channel); 197 put_cpu(); 198 } 199 200 if (channel->primary_channel == NULL) { 201 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 202 list_del(&channel->listentry); 203 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 204 } else { 205 primary_channel = channel->primary_channel; 206 spin_lock_irqsave(&primary_channel->lock, flags); 207 list_del(&channel->sc_list); 208 primary_channel->num_sc--; 209 spin_unlock_irqrestore(&primary_channel->lock, flags); 210 } 211 free_channel(channel); 212 } 213 214 void vmbus_free_channels(void) 215 { 216 struct vmbus_channel *channel, *tmp; 217 218 list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, 219 listentry) { 220 /* if we don't set rescind to true, vmbus_close_internal() 221 * won't invoke hv_process_channel_removal(). 222 */ 223 channel->rescind = true; 224 225 vmbus_device_unregister(channel->device_obj); 226 } 227 } 228 229 /* 230 * vmbus_process_offer - Process the offer by creating a channel/device 231 * associated with this offer 232 */ 233 static void vmbus_process_offer(struct vmbus_channel *newchannel) 234 { 235 struct vmbus_channel *channel; 236 bool fnew = true; 237 unsigned long flags; 238 239 /* Make sure this is a new offer */ 240 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 241 242 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 243 if (!uuid_le_cmp(channel->offermsg.offer.if_type, 244 newchannel->offermsg.offer.if_type) && 245 !uuid_le_cmp(channel->offermsg.offer.if_instance, 246 newchannel->offermsg.offer.if_instance)) { 247 fnew = false; 248 break; 249 } 250 } 251 252 if (fnew) 253 list_add_tail(&newchannel->listentry, 254 &vmbus_connection.chn_list); 255 256 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 257 258 if (!fnew) { 259 /* 260 * Check to see if this is a sub-channel. 261 */ 262 if (newchannel->offermsg.offer.sub_channel_index != 0) { 263 /* 264 * Process the sub-channel. 265 */ 266 newchannel->primary_channel = channel; 267 spin_lock_irqsave(&channel->lock, flags); 268 list_add_tail(&newchannel->sc_list, &channel->sc_list); 269 channel->num_sc++; 270 spin_unlock_irqrestore(&channel->lock, flags); 271 } else 272 goto err_free_chan; 273 } 274 275 if (newchannel->target_cpu != get_cpu()) { 276 put_cpu(); 277 smp_call_function_single(newchannel->target_cpu, 278 percpu_channel_enq, 279 newchannel, true); 280 } else { 281 percpu_channel_enq(newchannel); 282 put_cpu(); 283 } 284 285 /* 286 * This state is used to indicate a successful open 287 * so that when we do close the channel normally, we 288 * can cleanup properly 289 */ 290 newchannel->state = CHANNEL_OPEN_STATE; 291 292 if (!fnew) { 293 if (channel->sc_creation_callback != NULL) 294 channel->sc_creation_callback(newchannel); 295 return; 296 } 297 298 /* 299 * Start the process of binding this offer to the driver 300 * We need to set the DeviceObject field before calling 301 * vmbus_child_dev_add() 302 */ 303 newchannel->device_obj = vmbus_device_create( 304 &newchannel->offermsg.offer.if_type, 305 &newchannel->offermsg.offer.if_instance, 306 newchannel); 307 if (!newchannel->device_obj) 308 goto err_deq_chan; 309 310 /* 311 * Add the new device to the bus. This will kick off device-driver 312 * binding which eventually invokes the device driver's AddDevice() 313 * method. 314 */ 315 if (vmbus_device_register(newchannel->device_obj) != 0) { 316 pr_err("unable to add child device object (relid %d)\n", 317 newchannel->offermsg.child_relid); 318 kfree(newchannel->device_obj); 319 goto err_deq_chan; 320 } 321 return; 322 323 err_deq_chan: 324 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 325 list_del(&newchannel->listentry); 326 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 327 328 if (newchannel->target_cpu != get_cpu()) { 329 put_cpu(); 330 smp_call_function_single(newchannel->target_cpu, 331 percpu_channel_deq, newchannel, true); 332 } else { 333 percpu_channel_deq(newchannel); 334 put_cpu(); 335 } 336 337 err_free_chan: 338 free_channel(newchannel); 339 } 340 341 enum { 342 IDE = 0, 343 SCSI, 344 NIC, 345 MAX_PERF_CHN, 346 }; 347 348 /* 349 * This is an array of device_ids (device types) that are performance critical. 350 * We attempt to distribute the interrupt load for these devices across 351 * all available CPUs. 352 */ 353 static const struct hv_vmbus_device_id hp_devs[] = { 354 /* IDE */ 355 { HV_IDE_GUID, }, 356 /* Storage - SCSI */ 357 { HV_SCSI_GUID, }, 358 /* Network */ 359 { HV_NIC_GUID, }, 360 /* NetworkDirect Guest RDMA */ 361 { HV_ND_GUID, }, 362 }; 363 364 365 /* 366 * We use this state to statically distribute the channel interrupt load. 367 */ 368 static u32 next_vp; 369 370 /* 371 * Starting with Win8, we can statically distribute the incoming 372 * channel interrupt load by binding a channel to VCPU. We 373 * implement here a simple round robin scheme for distributing 374 * the interrupt load. 375 * We will bind channels that are not performance critical to cpu 0 and 376 * performance critical channels (IDE, SCSI and Network) will be uniformly 377 * distributed across all available CPUs. 378 */ 379 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid) 380 { 381 u32 cur_cpu; 382 int i; 383 bool perf_chn = false; 384 u32 max_cpus = num_online_cpus(); 385 386 for (i = IDE; i < MAX_PERF_CHN; i++) { 387 if (!memcmp(type_guid->b, hp_devs[i].guid, 388 sizeof(uuid_le))) { 389 perf_chn = true; 390 break; 391 } 392 } 393 if ((vmbus_proto_version == VERSION_WS2008) || 394 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 395 /* 396 * Prior to win8, all channel interrupts are 397 * delivered on cpu 0. 398 * Also if the channel is not a performance critical 399 * channel, bind it to cpu 0. 400 */ 401 channel->target_cpu = 0; 402 channel->target_vp = 0; 403 return; 404 } 405 cur_cpu = (++next_vp % max_cpus); 406 channel->target_cpu = cur_cpu; 407 channel->target_vp = hv_context.vp_index[cur_cpu]; 408 } 409 410 /* 411 * vmbus_unload_response - Handler for the unload response. 412 */ 413 static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) 414 { 415 /* 416 * This is a global event; just wakeup the waiting thread. 417 * Once we successfully unload, we can cleanup the monitor state. 418 */ 419 complete(&vmbus_connection.unload_event); 420 } 421 422 void vmbus_initiate_unload(void) 423 { 424 struct vmbus_channel_message_header hdr; 425 426 init_completion(&vmbus_connection.unload_event); 427 memset(&hdr, 0, sizeof(struct vmbus_channel_message_header)); 428 hdr.msgtype = CHANNELMSG_UNLOAD; 429 vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header)); 430 431 wait_for_completion(&vmbus_connection.unload_event); 432 } 433 434 /* 435 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 436 * 437 */ 438 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 439 { 440 struct vmbus_channel_offer_channel *offer; 441 struct vmbus_channel *newchannel; 442 443 offer = (struct vmbus_channel_offer_channel *)hdr; 444 445 /* Allocate the channel object and save this offer. */ 446 newchannel = alloc_channel(); 447 if (!newchannel) { 448 pr_err("Unable to allocate channel object\n"); 449 return; 450 } 451 452 /* 453 * By default we setup state to enable batched 454 * reading. A specific service can choose to 455 * disable this prior to opening the channel. 456 */ 457 newchannel->batched_reading = true; 458 459 /* 460 * Setup state for signalling the host. 461 */ 462 newchannel->sig_event = (struct hv_input_signal_event *) 463 (ALIGN((unsigned long) 464 &newchannel->sig_buf, 465 HV_HYPERCALL_PARAM_ALIGN)); 466 467 newchannel->sig_event->connectionid.asu32 = 0; 468 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 469 newchannel->sig_event->flag_number = 0; 470 newchannel->sig_event->rsvdz = 0; 471 472 if (vmbus_proto_version != VERSION_WS2008) { 473 newchannel->is_dedicated_interrupt = 474 (offer->is_dedicated_interrupt != 0); 475 newchannel->sig_event->connectionid.u.id = 476 offer->connection_id; 477 } 478 479 init_vp_index(newchannel, &offer->offer.if_type); 480 481 memcpy(&newchannel->offermsg, offer, 482 sizeof(struct vmbus_channel_offer_channel)); 483 newchannel->monitor_grp = (u8)offer->monitorid / 32; 484 newchannel->monitor_bit = (u8)offer->monitorid % 32; 485 486 vmbus_process_offer(newchannel); 487 } 488 489 /* 490 * vmbus_onoffer_rescind - Rescind offer handler. 491 * 492 * We queue a work item to process this offer synchronously 493 */ 494 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 495 { 496 struct vmbus_channel_rescind_offer *rescind; 497 struct vmbus_channel *channel; 498 unsigned long flags; 499 struct device *dev; 500 501 rescind = (struct vmbus_channel_rescind_offer *)hdr; 502 channel = relid2channel(rescind->child_relid); 503 504 if (channel == NULL) { 505 hv_process_channel_removal(NULL, rescind->child_relid); 506 return; 507 } 508 509 spin_lock_irqsave(&channel->lock, flags); 510 channel->rescind = true; 511 spin_unlock_irqrestore(&channel->lock, flags); 512 513 if (channel->device_obj) { 514 /* 515 * We will have to unregister this device from the 516 * driver core. 517 */ 518 dev = get_device(&channel->device_obj->device); 519 if (dev) { 520 vmbus_device_unregister(channel->device_obj); 521 put_device(dev); 522 } 523 } else { 524 hv_process_channel_removal(channel, 525 channel->offermsg.child_relid); 526 } 527 } 528 529 /* 530 * vmbus_onoffers_delivered - 531 * This is invoked when all offers have been delivered. 532 * 533 * Nothing to do here. 534 */ 535 static void vmbus_onoffers_delivered( 536 struct vmbus_channel_message_header *hdr) 537 { 538 } 539 540 /* 541 * vmbus_onopen_result - Open result handler. 542 * 543 * This is invoked when we received a response to our channel open request. 544 * Find the matching request, copy the response and signal the requesting 545 * thread. 546 */ 547 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 548 { 549 struct vmbus_channel_open_result *result; 550 struct vmbus_channel_msginfo *msginfo; 551 struct vmbus_channel_message_header *requestheader; 552 struct vmbus_channel_open_channel *openmsg; 553 unsigned long flags; 554 555 result = (struct vmbus_channel_open_result *)hdr; 556 557 /* 558 * Find the open msg, copy the result and signal/unblock the wait event 559 */ 560 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 561 562 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 563 msglistentry) { 564 requestheader = 565 (struct vmbus_channel_message_header *)msginfo->msg; 566 567 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 568 openmsg = 569 (struct vmbus_channel_open_channel *)msginfo->msg; 570 if (openmsg->child_relid == result->child_relid && 571 openmsg->openid == result->openid) { 572 memcpy(&msginfo->response.open_result, 573 result, 574 sizeof( 575 struct vmbus_channel_open_result)); 576 complete(&msginfo->waitevent); 577 break; 578 } 579 } 580 } 581 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 582 } 583 584 /* 585 * vmbus_ongpadl_created - GPADL created handler. 586 * 587 * This is invoked when we received a response to our gpadl create request. 588 * Find the matching request, copy the response and signal the requesting 589 * thread. 590 */ 591 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 592 { 593 struct vmbus_channel_gpadl_created *gpadlcreated; 594 struct vmbus_channel_msginfo *msginfo; 595 struct vmbus_channel_message_header *requestheader; 596 struct vmbus_channel_gpadl_header *gpadlheader; 597 unsigned long flags; 598 599 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 600 601 /* 602 * Find the establish msg, copy the result and signal/unblock the wait 603 * event 604 */ 605 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 606 607 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 608 msglistentry) { 609 requestheader = 610 (struct vmbus_channel_message_header *)msginfo->msg; 611 612 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 613 gpadlheader = 614 (struct vmbus_channel_gpadl_header *)requestheader; 615 616 if ((gpadlcreated->child_relid == 617 gpadlheader->child_relid) && 618 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 619 memcpy(&msginfo->response.gpadl_created, 620 gpadlcreated, 621 sizeof( 622 struct vmbus_channel_gpadl_created)); 623 complete(&msginfo->waitevent); 624 break; 625 } 626 } 627 } 628 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 629 } 630 631 /* 632 * vmbus_ongpadl_torndown - GPADL torndown handler. 633 * 634 * This is invoked when we received a response to our gpadl teardown request. 635 * Find the matching request, copy the response and signal the requesting 636 * thread. 637 */ 638 static void vmbus_ongpadl_torndown( 639 struct vmbus_channel_message_header *hdr) 640 { 641 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 642 struct vmbus_channel_msginfo *msginfo; 643 struct vmbus_channel_message_header *requestheader; 644 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 645 unsigned long flags; 646 647 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 648 649 /* 650 * Find the open msg, copy the result and signal/unblock the wait event 651 */ 652 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 653 654 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 655 msglistentry) { 656 requestheader = 657 (struct vmbus_channel_message_header *)msginfo->msg; 658 659 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 660 gpadl_teardown = 661 (struct vmbus_channel_gpadl_teardown *)requestheader; 662 663 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 664 memcpy(&msginfo->response.gpadl_torndown, 665 gpadl_torndown, 666 sizeof( 667 struct vmbus_channel_gpadl_torndown)); 668 complete(&msginfo->waitevent); 669 break; 670 } 671 } 672 } 673 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 674 } 675 676 /* 677 * vmbus_onversion_response - Version response handler 678 * 679 * This is invoked when we received a response to our initiate contact request. 680 * Find the matching request, copy the response and signal the requesting 681 * thread. 682 */ 683 static void vmbus_onversion_response( 684 struct vmbus_channel_message_header *hdr) 685 { 686 struct vmbus_channel_msginfo *msginfo; 687 struct vmbus_channel_message_header *requestheader; 688 struct vmbus_channel_version_response *version_response; 689 unsigned long flags; 690 691 version_response = (struct vmbus_channel_version_response *)hdr; 692 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 693 694 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 695 msglistentry) { 696 requestheader = 697 (struct vmbus_channel_message_header *)msginfo->msg; 698 699 if (requestheader->msgtype == 700 CHANNELMSG_INITIATE_CONTACT) { 701 memcpy(&msginfo->response.version_response, 702 version_response, 703 sizeof(struct vmbus_channel_version_response)); 704 complete(&msginfo->waitevent); 705 } 706 } 707 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 708 } 709 710 /* Channel message dispatch table */ 711 struct vmbus_channel_message_table_entry 712 channel_message_table[CHANNELMSG_COUNT] = { 713 {CHANNELMSG_INVALID, 0, NULL}, 714 {CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer}, 715 {CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind}, 716 {CHANNELMSG_REQUESTOFFERS, 0, NULL}, 717 {CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered}, 718 {CHANNELMSG_OPENCHANNEL, 0, NULL}, 719 {CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result}, 720 {CHANNELMSG_CLOSECHANNEL, 0, NULL}, 721 {CHANNELMSG_GPADL_HEADER, 0, NULL}, 722 {CHANNELMSG_GPADL_BODY, 0, NULL}, 723 {CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created}, 724 {CHANNELMSG_GPADL_TEARDOWN, 0, NULL}, 725 {CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown}, 726 {CHANNELMSG_RELID_RELEASED, 0, NULL}, 727 {CHANNELMSG_INITIATE_CONTACT, 0, NULL}, 728 {CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response}, 729 {CHANNELMSG_UNLOAD, 0, NULL}, 730 {CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response}, 731 }; 732 733 /* 734 * vmbus_onmessage - Handler for channel protocol messages. 735 * 736 * This is invoked in the vmbus worker thread context. 737 */ 738 void vmbus_onmessage(void *context) 739 { 740 struct hv_message *msg = context; 741 struct vmbus_channel_message_header *hdr; 742 int size; 743 744 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 745 size = msg->header.payload_size; 746 747 if (hdr->msgtype >= CHANNELMSG_COUNT) { 748 pr_err("Received invalid channel message type %d size %d\n", 749 hdr->msgtype, size); 750 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 751 (unsigned char *)msg->u.payload, size); 752 return; 753 } 754 755 if (channel_message_table[hdr->msgtype].message_handler) 756 channel_message_table[hdr->msgtype].message_handler(hdr); 757 else 758 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 759 } 760 761 /* 762 * vmbus_request_offers - Send a request to get all our pending offers. 763 */ 764 int vmbus_request_offers(void) 765 { 766 struct vmbus_channel_message_header *msg; 767 struct vmbus_channel_msginfo *msginfo; 768 int ret; 769 770 msginfo = kmalloc(sizeof(*msginfo) + 771 sizeof(struct vmbus_channel_message_header), 772 GFP_KERNEL); 773 if (!msginfo) 774 return -ENOMEM; 775 776 msg = (struct vmbus_channel_message_header *)msginfo->msg; 777 778 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 779 780 781 ret = vmbus_post_msg(msg, 782 sizeof(struct vmbus_channel_message_header)); 783 if (ret != 0) { 784 pr_err("Unable to request offers - %d\n", ret); 785 786 goto cleanup; 787 } 788 789 cleanup: 790 kfree(msginfo); 791 792 return ret; 793 } 794 795 /* 796 * Retrieve the (sub) channel on which to send an outgoing request. 797 * When a primary channel has multiple sub-channels, we try to 798 * distribute the load equally amongst all available channels. 799 */ 800 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 801 { 802 struct list_head *cur, *tmp; 803 int cur_cpu; 804 struct vmbus_channel *cur_channel; 805 struct vmbus_channel *outgoing_channel = primary; 806 int next_channel; 807 int i = 1; 808 809 if (list_empty(&primary->sc_list)) 810 return outgoing_channel; 811 812 next_channel = primary->next_oc++; 813 814 if (next_channel > (primary->num_sc)) { 815 primary->next_oc = 0; 816 return outgoing_channel; 817 } 818 819 cur_cpu = hv_context.vp_index[get_cpu()]; 820 put_cpu(); 821 list_for_each_safe(cur, tmp, &primary->sc_list) { 822 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 823 if (cur_channel->state != CHANNEL_OPENED_STATE) 824 continue; 825 826 if (cur_channel->target_vp == cur_cpu) 827 return cur_channel; 828 829 if (i == next_channel) 830 return cur_channel; 831 832 i++; 833 } 834 835 return outgoing_channel; 836 } 837 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 838 839 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 840 { 841 struct list_head *cur, *tmp; 842 struct vmbus_channel *cur_channel; 843 844 if (primary_channel->sc_creation_callback == NULL) 845 return; 846 847 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 848 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 849 850 primary_channel->sc_creation_callback(cur_channel); 851 } 852 } 853 854 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 855 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 856 { 857 primary_channel->sc_creation_callback = sc_cr_cb; 858 } 859 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 860 861 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 862 { 863 bool ret; 864 865 ret = !list_empty(&primary->sc_list); 866 867 if (ret) { 868 /* 869 * Invoke the callback on sub-channel creation. 870 * This will present a uniform interface to the 871 * clients. 872 */ 873 invoke_sc_cb(primary); 874 } 875 876 return ret; 877 } 878 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 879