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 spin_unlock_irqrestore(&primary_channel->lock, flags); 209 } 210 free_channel(channel); 211 } 212 213 void vmbus_free_channels(void) 214 { 215 struct vmbus_channel *channel, *tmp; 216 217 list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, 218 listentry) { 219 /* if we don't set rescind to true, vmbus_close_internal() 220 * won't invoke hv_process_channel_removal(). 221 */ 222 channel->rescind = true; 223 224 vmbus_device_unregister(channel->device_obj); 225 } 226 } 227 228 /* 229 * vmbus_process_offer - Process the offer by creating a channel/device 230 * associated with this offer 231 */ 232 static void vmbus_process_offer(struct vmbus_channel *newchannel) 233 { 234 struct vmbus_channel *channel; 235 bool fnew = true; 236 bool enq = false; 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 enq = true; 256 } 257 258 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 259 260 if (enq) { 261 if (newchannel->target_cpu != get_cpu()) { 262 put_cpu(); 263 smp_call_function_single(newchannel->target_cpu, 264 percpu_channel_enq, 265 newchannel, true); 266 } else { 267 percpu_channel_enq(newchannel); 268 put_cpu(); 269 } 270 } 271 if (!fnew) { 272 /* 273 * Check to see if this is a sub-channel. 274 */ 275 if (newchannel->offermsg.offer.sub_channel_index != 0) { 276 /* 277 * Process the sub-channel. 278 */ 279 newchannel->primary_channel = channel; 280 spin_lock_irqsave(&channel->lock, flags); 281 list_add_tail(&newchannel->sc_list, &channel->sc_list); 282 spin_unlock_irqrestore(&channel->lock, flags); 283 284 if (newchannel->target_cpu != get_cpu()) { 285 put_cpu(); 286 smp_call_function_single(newchannel->target_cpu, 287 percpu_channel_enq, 288 newchannel, true); 289 } else { 290 percpu_channel_enq(newchannel); 291 put_cpu(); 292 } 293 294 newchannel->state = CHANNEL_OPEN_STATE; 295 channel->num_sc++; 296 if (channel->sc_creation_callback != NULL) 297 channel->sc_creation_callback(newchannel); 298 299 return; 300 } 301 302 goto err_free_chan; 303 } 304 305 /* 306 * This state is used to indicate a successful open 307 * so that when we do close the channel normally, we 308 * can cleanup properly 309 */ 310 newchannel->state = CHANNEL_OPEN_STATE; 311 312 /* 313 * Start the process of binding this offer to the driver 314 * We need to set the DeviceObject field before calling 315 * vmbus_child_dev_add() 316 */ 317 newchannel->device_obj = vmbus_device_create( 318 &newchannel->offermsg.offer.if_type, 319 &newchannel->offermsg.offer.if_instance, 320 newchannel); 321 if (!newchannel->device_obj) 322 goto err_deq_chan; 323 324 /* 325 * Add the new device to the bus. This will kick off device-driver 326 * binding which eventually invokes the device driver's AddDevice() 327 * method. 328 */ 329 if (vmbus_device_register(newchannel->device_obj) != 0) { 330 pr_err("unable to add child device object (relid %d)\n", 331 newchannel->offermsg.child_relid); 332 kfree(newchannel->device_obj); 333 goto err_deq_chan; 334 } 335 return; 336 337 err_deq_chan: 338 spin_lock_irqsave(&vmbus_connection.channel_lock, flags); 339 list_del(&newchannel->listentry); 340 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); 341 342 if (newchannel->target_cpu != get_cpu()) { 343 put_cpu(); 344 smp_call_function_single(newchannel->target_cpu, 345 percpu_channel_deq, newchannel, true); 346 } else { 347 percpu_channel_deq(newchannel); 348 put_cpu(); 349 } 350 351 err_free_chan: 352 free_channel(newchannel); 353 } 354 355 enum { 356 IDE = 0, 357 SCSI, 358 NIC, 359 MAX_PERF_CHN, 360 }; 361 362 /* 363 * This is an array of device_ids (device types) that are performance critical. 364 * We attempt to distribute the interrupt load for these devices across 365 * all available CPUs. 366 */ 367 static const struct hv_vmbus_device_id hp_devs[] = { 368 /* IDE */ 369 { HV_IDE_GUID, }, 370 /* Storage - SCSI */ 371 { HV_SCSI_GUID, }, 372 /* Network */ 373 { HV_NIC_GUID, }, 374 /* NetworkDirect Guest RDMA */ 375 { HV_ND_GUID, }, 376 }; 377 378 379 /* 380 * We use this state to statically distribute the channel interrupt load. 381 */ 382 static u32 next_vp; 383 384 /* 385 * Starting with Win8, we can statically distribute the incoming 386 * channel interrupt load by binding a channel to VCPU. We 387 * implement here a simple round robin scheme for distributing 388 * the interrupt load. 389 * We will bind channels that are not performance critical to cpu 0 and 390 * performance critical channels (IDE, SCSI and Network) will be uniformly 391 * distributed across all available CPUs. 392 */ 393 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid) 394 { 395 u32 cur_cpu; 396 int i; 397 bool perf_chn = false; 398 u32 max_cpus = num_online_cpus(); 399 400 for (i = IDE; i < MAX_PERF_CHN; i++) { 401 if (!memcmp(type_guid->b, hp_devs[i].guid, 402 sizeof(uuid_le))) { 403 perf_chn = true; 404 break; 405 } 406 } 407 if ((vmbus_proto_version == VERSION_WS2008) || 408 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 409 /* 410 * Prior to win8, all channel interrupts are 411 * delivered on cpu 0. 412 * Also if the channel is not a performance critical 413 * channel, bind it to cpu 0. 414 */ 415 channel->target_cpu = 0; 416 channel->target_vp = 0; 417 return; 418 } 419 cur_cpu = (++next_vp % max_cpus); 420 channel->target_cpu = cur_cpu; 421 channel->target_vp = hv_context.vp_index[cur_cpu]; 422 } 423 424 /* 425 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 426 * 427 */ 428 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 429 { 430 struct vmbus_channel_offer_channel *offer; 431 struct vmbus_channel *newchannel; 432 433 offer = (struct vmbus_channel_offer_channel *)hdr; 434 435 /* Allocate the channel object and save this offer. */ 436 newchannel = alloc_channel(); 437 if (!newchannel) { 438 pr_err("Unable to allocate channel object\n"); 439 return; 440 } 441 442 /* 443 * By default we setup state to enable batched 444 * reading. A specific service can choose to 445 * disable this prior to opening the channel. 446 */ 447 newchannel->batched_reading = true; 448 449 /* 450 * Setup state for signalling the host. 451 */ 452 newchannel->sig_event = (struct hv_input_signal_event *) 453 (ALIGN((unsigned long) 454 &newchannel->sig_buf, 455 HV_HYPERCALL_PARAM_ALIGN)); 456 457 newchannel->sig_event->connectionid.asu32 = 0; 458 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID; 459 newchannel->sig_event->flag_number = 0; 460 newchannel->sig_event->rsvdz = 0; 461 462 if (vmbus_proto_version != VERSION_WS2008) { 463 newchannel->is_dedicated_interrupt = 464 (offer->is_dedicated_interrupt != 0); 465 newchannel->sig_event->connectionid.u.id = 466 offer->connection_id; 467 } 468 469 init_vp_index(newchannel, &offer->offer.if_type); 470 471 memcpy(&newchannel->offermsg, offer, 472 sizeof(struct vmbus_channel_offer_channel)); 473 newchannel->monitor_grp = (u8)offer->monitorid / 32; 474 newchannel->monitor_bit = (u8)offer->monitorid % 32; 475 476 vmbus_process_offer(newchannel); 477 } 478 479 /* 480 * vmbus_onoffer_rescind - Rescind offer handler. 481 * 482 * We queue a work item to process this offer synchronously 483 */ 484 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 485 { 486 struct vmbus_channel_rescind_offer *rescind; 487 struct vmbus_channel *channel; 488 unsigned long flags; 489 struct device *dev; 490 491 rescind = (struct vmbus_channel_rescind_offer *)hdr; 492 channel = relid2channel(rescind->child_relid); 493 494 if (channel == NULL) { 495 hv_process_channel_removal(NULL, rescind->child_relid); 496 return; 497 } 498 499 spin_lock_irqsave(&channel->lock, flags); 500 channel->rescind = true; 501 spin_unlock_irqrestore(&channel->lock, flags); 502 503 if (channel->device_obj) { 504 /* 505 * We will have to unregister this device from the 506 * driver core. 507 */ 508 dev = get_device(&channel->device_obj->device); 509 if (dev) { 510 vmbus_device_unregister(channel->device_obj); 511 put_device(dev); 512 } 513 } else { 514 hv_process_channel_removal(channel, 515 channel->offermsg.child_relid); 516 } 517 } 518 519 /* 520 * vmbus_onoffers_delivered - 521 * This is invoked when all offers have been delivered. 522 * 523 * Nothing to do here. 524 */ 525 static void vmbus_onoffers_delivered( 526 struct vmbus_channel_message_header *hdr) 527 { 528 } 529 530 /* 531 * vmbus_onopen_result - Open result handler. 532 * 533 * This is invoked when we received a response to our channel open request. 534 * Find the matching request, copy the response and signal the requesting 535 * thread. 536 */ 537 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 538 { 539 struct vmbus_channel_open_result *result; 540 struct vmbus_channel_msginfo *msginfo; 541 struct vmbus_channel_message_header *requestheader; 542 struct vmbus_channel_open_channel *openmsg; 543 unsigned long flags; 544 545 result = (struct vmbus_channel_open_result *)hdr; 546 547 /* 548 * Find the open msg, copy the result and signal/unblock the wait event 549 */ 550 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 551 552 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 553 msglistentry) { 554 requestheader = 555 (struct vmbus_channel_message_header *)msginfo->msg; 556 557 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 558 openmsg = 559 (struct vmbus_channel_open_channel *)msginfo->msg; 560 if (openmsg->child_relid == result->child_relid && 561 openmsg->openid == result->openid) { 562 memcpy(&msginfo->response.open_result, 563 result, 564 sizeof( 565 struct vmbus_channel_open_result)); 566 complete(&msginfo->waitevent); 567 break; 568 } 569 } 570 } 571 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 572 } 573 574 /* 575 * vmbus_ongpadl_created - GPADL created handler. 576 * 577 * This is invoked when we received a response to our gpadl create request. 578 * Find the matching request, copy the response and signal the requesting 579 * thread. 580 */ 581 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 582 { 583 struct vmbus_channel_gpadl_created *gpadlcreated; 584 struct vmbus_channel_msginfo *msginfo; 585 struct vmbus_channel_message_header *requestheader; 586 struct vmbus_channel_gpadl_header *gpadlheader; 587 unsigned long flags; 588 589 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 590 591 /* 592 * Find the establish msg, copy the result and signal/unblock the wait 593 * event 594 */ 595 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 596 597 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 598 msglistentry) { 599 requestheader = 600 (struct vmbus_channel_message_header *)msginfo->msg; 601 602 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 603 gpadlheader = 604 (struct vmbus_channel_gpadl_header *)requestheader; 605 606 if ((gpadlcreated->child_relid == 607 gpadlheader->child_relid) && 608 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 609 memcpy(&msginfo->response.gpadl_created, 610 gpadlcreated, 611 sizeof( 612 struct vmbus_channel_gpadl_created)); 613 complete(&msginfo->waitevent); 614 break; 615 } 616 } 617 } 618 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 619 } 620 621 /* 622 * vmbus_ongpadl_torndown - GPADL torndown handler. 623 * 624 * This is invoked when we received a response to our gpadl teardown request. 625 * Find the matching request, copy the response and signal the requesting 626 * thread. 627 */ 628 static void vmbus_ongpadl_torndown( 629 struct vmbus_channel_message_header *hdr) 630 { 631 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 632 struct vmbus_channel_msginfo *msginfo; 633 struct vmbus_channel_message_header *requestheader; 634 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 635 unsigned long flags; 636 637 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 638 639 /* 640 * Find the open msg, copy the result and signal/unblock the wait event 641 */ 642 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 643 644 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 645 msglistentry) { 646 requestheader = 647 (struct vmbus_channel_message_header *)msginfo->msg; 648 649 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 650 gpadl_teardown = 651 (struct vmbus_channel_gpadl_teardown *)requestheader; 652 653 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 654 memcpy(&msginfo->response.gpadl_torndown, 655 gpadl_torndown, 656 sizeof( 657 struct vmbus_channel_gpadl_torndown)); 658 complete(&msginfo->waitevent); 659 break; 660 } 661 } 662 } 663 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 664 } 665 666 /* 667 * vmbus_onversion_response - Version response handler 668 * 669 * This is invoked when we received a response to our initiate contact request. 670 * Find the matching request, copy the response and signal the requesting 671 * thread. 672 */ 673 static void vmbus_onversion_response( 674 struct vmbus_channel_message_header *hdr) 675 { 676 struct vmbus_channel_msginfo *msginfo; 677 struct vmbus_channel_message_header *requestheader; 678 struct vmbus_channel_version_response *version_response; 679 unsigned long flags; 680 681 version_response = (struct vmbus_channel_version_response *)hdr; 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 == 690 CHANNELMSG_INITIATE_CONTACT) { 691 memcpy(&msginfo->response.version_response, 692 version_response, 693 sizeof(struct vmbus_channel_version_response)); 694 complete(&msginfo->waitevent); 695 } 696 } 697 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 698 } 699 700 /* Channel message dispatch table */ 701 struct vmbus_channel_message_table_entry 702 channel_message_table[CHANNELMSG_COUNT] = { 703 {CHANNELMSG_INVALID, 0, NULL}, 704 {CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer}, 705 {CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind}, 706 {CHANNELMSG_REQUESTOFFERS, 0, NULL}, 707 {CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered}, 708 {CHANNELMSG_OPENCHANNEL, 0, NULL}, 709 {CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result}, 710 {CHANNELMSG_CLOSECHANNEL, 0, NULL}, 711 {CHANNELMSG_GPADL_HEADER, 0, NULL}, 712 {CHANNELMSG_GPADL_BODY, 0, NULL}, 713 {CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created}, 714 {CHANNELMSG_GPADL_TEARDOWN, 0, NULL}, 715 {CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown}, 716 {CHANNELMSG_RELID_RELEASED, 0, NULL}, 717 {CHANNELMSG_INITIATE_CONTACT, 0, NULL}, 718 {CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response}, 719 {CHANNELMSG_UNLOAD, 0, NULL}, 720 }; 721 722 /* 723 * vmbus_onmessage - Handler for channel protocol messages. 724 * 725 * This is invoked in the vmbus worker thread context. 726 */ 727 void vmbus_onmessage(void *context) 728 { 729 struct hv_message *msg = context; 730 struct vmbus_channel_message_header *hdr; 731 int size; 732 733 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 734 size = msg->header.payload_size; 735 736 if (hdr->msgtype >= CHANNELMSG_COUNT) { 737 pr_err("Received invalid channel message type %d size %d\n", 738 hdr->msgtype, size); 739 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 740 (unsigned char *)msg->u.payload, size); 741 return; 742 } 743 744 if (channel_message_table[hdr->msgtype].message_handler) 745 channel_message_table[hdr->msgtype].message_handler(hdr); 746 else 747 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 748 } 749 750 /* 751 * vmbus_request_offers - Send a request to get all our pending offers. 752 */ 753 int vmbus_request_offers(void) 754 { 755 struct vmbus_channel_message_header *msg; 756 struct vmbus_channel_msginfo *msginfo; 757 int ret; 758 759 msginfo = kmalloc(sizeof(*msginfo) + 760 sizeof(struct vmbus_channel_message_header), 761 GFP_KERNEL); 762 if (!msginfo) 763 return -ENOMEM; 764 765 msg = (struct vmbus_channel_message_header *)msginfo->msg; 766 767 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 768 769 770 ret = vmbus_post_msg(msg, 771 sizeof(struct vmbus_channel_message_header)); 772 if (ret != 0) { 773 pr_err("Unable to request offers - %d\n", ret); 774 775 goto cleanup; 776 } 777 778 cleanup: 779 kfree(msginfo); 780 781 return ret; 782 } 783 784 /* 785 * Retrieve the (sub) channel on which to send an outgoing request. 786 * When a primary channel has multiple sub-channels, we try to 787 * distribute the load equally amongst all available channels. 788 */ 789 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 790 { 791 struct list_head *cur, *tmp; 792 int cur_cpu; 793 struct vmbus_channel *cur_channel; 794 struct vmbus_channel *outgoing_channel = primary; 795 int next_channel; 796 int i = 1; 797 798 if (list_empty(&primary->sc_list)) 799 return outgoing_channel; 800 801 next_channel = primary->next_oc++; 802 803 if (next_channel > (primary->num_sc)) { 804 primary->next_oc = 0; 805 return outgoing_channel; 806 } 807 808 cur_cpu = hv_context.vp_index[get_cpu()]; 809 put_cpu(); 810 list_for_each_safe(cur, tmp, &primary->sc_list) { 811 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 812 if (cur_channel->state != CHANNEL_OPENED_STATE) 813 continue; 814 815 if (cur_channel->target_vp == cur_cpu) 816 return cur_channel; 817 818 if (i == next_channel) 819 return cur_channel; 820 821 i++; 822 } 823 824 return outgoing_channel; 825 } 826 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 827 828 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 829 { 830 struct list_head *cur, *tmp; 831 struct vmbus_channel *cur_channel; 832 833 if (primary_channel->sc_creation_callback == NULL) 834 return; 835 836 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 837 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 838 839 primary_channel->sc_creation_callback(cur_channel); 840 } 841 } 842 843 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 844 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 845 { 846 primary_channel->sc_creation_callback = sc_cr_cb; 847 } 848 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 849 850 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 851 { 852 bool ret; 853 854 ret = !list_empty(&primary->sc_list); 855 856 if (ret) { 857 /* 858 * Invoke the callback on sub-channel creation. 859 * This will present a uniform interface to the 860 * clients. 861 */ 862 invoke_sc_cb(primary); 863 } 864 865 return ret; 866 } 867 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 868