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