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/interrupt.h> 25 #include <linux/sched.h> 26 #include <linux/wait.h> 27 #include <linux/mm.h> 28 #include <linux/slab.h> 29 #include <linux/list.h> 30 #include <linux/module.h> 31 #include <linux/completion.h> 32 #include <linux/delay.h> 33 #include <linux/hyperv.h> 34 #include <asm/mshyperv.h> 35 36 #include "hyperv_vmbus.h" 37 38 static void init_vp_index(struct vmbus_channel *channel, u16 dev_type); 39 40 static const struct vmbus_device vmbus_devs[] = { 41 /* IDE */ 42 { .dev_type = HV_IDE, 43 HV_IDE_GUID, 44 .perf_device = true, 45 }, 46 47 /* SCSI */ 48 { .dev_type = HV_SCSI, 49 HV_SCSI_GUID, 50 .perf_device = true, 51 }, 52 53 /* Fibre Channel */ 54 { .dev_type = HV_FC, 55 HV_SYNTHFC_GUID, 56 .perf_device = true, 57 }, 58 59 /* Synthetic NIC */ 60 { .dev_type = HV_NIC, 61 HV_NIC_GUID, 62 .perf_device = true, 63 }, 64 65 /* Network Direct */ 66 { .dev_type = HV_ND, 67 HV_ND_GUID, 68 .perf_device = true, 69 }, 70 71 /* PCIE */ 72 { .dev_type = HV_PCIE, 73 HV_PCIE_GUID, 74 .perf_device = true, 75 }, 76 77 /* Synthetic Frame Buffer */ 78 { .dev_type = HV_FB, 79 HV_SYNTHVID_GUID, 80 .perf_device = false, 81 }, 82 83 /* Synthetic Keyboard */ 84 { .dev_type = HV_KBD, 85 HV_KBD_GUID, 86 .perf_device = false, 87 }, 88 89 /* Synthetic MOUSE */ 90 { .dev_type = HV_MOUSE, 91 HV_MOUSE_GUID, 92 .perf_device = false, 93 }, 94 95 /* KVP */ 96 { .dev_type = HV_KVP, 97 HV_KVP_GUID, 98 .perf_device = false, 99 }, 100 101 /* Time Synch */ 102 { .dev_type = HV_TS, 103 HV_TS_GUID, 104 .perf_device = false, 105 }, 106 107 /* Heartbeat */ 108 { .dev_type = HV_HB, 109 HV_HEART_BEAT_GUID, 110 .perf_device = false, 111 }, 112 113 /* Shutdown */ 114 { .dev_type = HV_SHUTDOWN, 115 HV_SHUTDOWN_GUID, 116 .perf_device = false, 117 }, 118 119 /* File copy */ 120 { .dev_type = HV_FCOPY, 121 HV_FCOPY_GUID, 122 .perf_device = false, 123 }, 124 125 /* Backup */ 126 { .dev_type = HV_BACKUP, 127 HV_VSS_GUID, 128 .perf_device = false, 129 }, 130 131 /* Dynamic Memory */ 132 { .dev_type = HV_DM, 133 HV_DM_GUID, 134 .perf_device = false, 135 }, 136 137 /* Unknown GUID */ 138 { .dev_type = HV_UNKNOWN, 139 .perf_device = false, 140 }, 141 }; 142 143 static const struct { 144 uuid_le guid; 145 } vmbus_unsupported_devs[] = { 146 { HV_AVMA1_GUID }, 147 { HV_AVMA2_GUID }, 148 { HV_RDV_GUID }, 149 }; 150 151 /* 152 * The rescinded channel may be blocked waiting for a response from the host; 153 * take care of that. 154 */ 155 static void vmbus_rescind_cleanup(struct vmbus_channel *channel) 156 { 157 struct vmbus_channel_msginfo *msginfo; 158 unsigned long flags; 159 160 161 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 162 channel->rescind = true; 163 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 164 msglistentry) { 165 166 if (msginfo->waiting_channel == channel) { 167 complete(&msginfo->waitevent); 168 break; 169 } 170 } 171 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 172 } 173 174 static bool is_unsupported_vmbus_devs(const uuid_le *guid) 175 { 176 int i; 177 178 for (i = 0; i < ARRAY_SIZE(vmbus_unsupported_devs); i++) 179 if (!uuid_le_cmp(*guid, vmbus_unsupported_devs[i].guid)) 180 return true; 181 return false; 182 } 183 184 static u16 hv_get_dev_type(const struct vmbus_channel *channel) 185 { 186 const uuid_le *guid = &channel->offermsg.offer.if_type; 187 u16 i; 188 189 if (is_hvsock_channel(channel) || is_unsupported_vmbus_devs(guid)) 190 return HV_UNKNOWN; 191 192 for (i = HV_IDE; i < HV_UNKNOWN; i++) { 193 if (!uuid_le_cmp(*guid, vmbus_devs[i].guid)) 194 return i; 195 } 196 pr_info("Unknown GUID: %pUl\n", guid); 197 return i; 198 } 199 200 /** 201 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message 202 * @icmsghdrp: Pointer to msg header structure 203 * @icmsg_negotiate: Pointer to negotiate message structure 204 * @buf: Raw buffer channel data 205 * 206 * @icmsghdrp is of type &struct icmsg_hdr. 207 * Set up and fill in default negotiate response message. 208 * 209 * The fw_version and fw_vercnt specifies the framework version that 210 * we can support. 211 * 212 * The srv_version and srv_vercnt specifies the service 213 * versions we can support. 214 * 215 * Versions are given in decreasing order. 216 * 217 * nego_fw_version and nego_srv_version store the selected protocol versions. 218 * 219 * Mainly used by Hyper-V drivers. 220 */ 221 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, 222 u8 *buf, const int *fw_version, int fw_vercnt, 223 const int *srv_version, int srv_vercnt, 224 int *nego_fw_version, int *nego_srv_version) 225 { 226 int icframe_major, icframe_minor; 227 int icmsg_major, icmsg_minor; 228 int fw_major, fw_minor; 229 int srv_major, srv_minor; 230 int i, j; 231 bool found_match = false; 232 struct icmsg_negotiate *negop; 233 234 icmsghdrp->icmsgsize = 0x10; 235 negop = (struct icmsg_negotiate *)&buf[ 236 sizeof(struct vmbuspipe_hdr) + 237 sizeof(struct icmsg_hdr)]; 238 239 icframe_major = negop->icframe_vercnt; 240 icframe_minor = 0; 241 242 icmsg_major = negop->icmsg_vercnt; 243 icmsg_minor = 0; 244 245 /* 246 * Select the framework version number we will 247 * support. 248 */ 249 250 for (i = 0; i < fw_vercnt; i++) { 251 fw_major = (fw_version[i] >> 16); 252 fw_minor = (fw_version[i] & 0xFFFF); 253 254 for (j = 0; j < negop->icframe_vercnt; j++) { 255 if ((negop->icversion_data[j].major == fw_major) && 256 (negop->icversion_data[j].minor == fw_minor)) { 257 icframe_major = negop->icversion_data[j].major; 258 icframe_minor = negop->icversion_data[j].minor; 259 found_match = true; 260 break; 261 } 262 } 263 264 if (found_match) 265 break; 266 } 267 268 if (!found_match) 269 goto fw_error; 270 271 found_match = false; 272 273 for (i = 0; i < srv_vercnt; i++) { 274 srv_major = (srv_version[i] >> 16); 275 srv_minor = (srv_version[i] & 0xFFFF); 276 277 for (j = negop->icframe_vercnt; 278 (j < negop->icframe_vercnt + negop->icmsg_vercnt); 279 j++) { 280 281 if ((negop->icversion_data[j].major == srv_major) && 282 (negop->icversion_data[j].minor == srv_minor)) { 283 284 icmsg_major = negop->icversion_data[j].major; 285 icmsg_minor = negop->icversion_data[j].minor; 286 found_match = true; 287 break; 288 } 289 } 290 291 if (found_match) 292 break; 293 } 294 295 /* 296 * Respond with the framework and service 297 * version numbers we can support. 298 */ 299 300 fw_error: 301 if (!found_match) { 302 negop->icframe_vercnt = 0; 303 negop->icmsg_vercnt = 0; 304 } else { 305 negop->icframe_vercnt = 1; 306 negop->icmsg_vercnt = 1; 307 } 308 309 if (nego_fw_version) 310 *nego_fw_version = (icframe_major << 16) | icframe_minor; 311 312 if (nego_srv_version) 313 *nego_srv_version = (icmsg_major << 16) | icmsg_minor; 314 315 negop->icversion_data[0].major = icframe_major; 316 negop->icversion_data[0].minor = icframe_minor; 317 negop->icversion_data[1].major = icmsg_major; 318 negop->icversion_data[1].minor = icmsg_minor; 319 return found_match; 320 } 321 322 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp); 323 324 /* 325 * alloc_channel - Allocate and initialize a vmbus channel object 326 */ 327 static struct vmbus_channel *alloc_channel(void) 328 { 329 struct vmbus_channel *channel; 330 331 channel = kzalloc(sizeof(*channel), GFP_ATOMIC); 332 if (!channel) 333 return NULL; 334 335 spin_lock_init(&channel->lock); 336 337 INIT_LIST_HEAD(&channel->sc_list); 338 INIT_LIST_HEAD(&channel->percpu_list); 339 340 tasklet_init(&channel->callback_event, 341 vmbus_on_event, (unsigned long)channel); 342 343 return channel; 344 } 345 346 /* 347 * free_channel - Release the resources used by the vmbus channel object 348 */ 349 static void free_channel(struct vmbus_channel *channel) 350 { 351 tasklet_kill(&channel->callback_event); 352 353 kfree_rcu(channel, rcu); 354 } 355 356 static void percpu_channel_enq(void *arg) 357 { 358 struct vmbus_channel *channel = arg; 359 struct hv_per_cpu_context *hv_cpu 360 = this_cpu_ptr(hv_context.cpu_context); 361 362 list_add_tail_rcu(&channel->percpu_list, &hv_cpu->chan_list); 363 } 364 365 static void percpu_channel_deq(void *arg) 366 { 367 struct vmbus_channel *channel = arg; 368 369 list_del_rcu(&channel->percpu_list); 370 } 371 372 373 static void vmbus_release_relid(u32 relid) 374 { 375 struct vmbus_channel_relid_released msg; 376 377 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 378 msg.child_relid = relid; 379 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 380 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released), 381 true); 382 } 383 384 void hv_process_channel_removal(u32 relid) 385 { 386 unsigned long flags; 387 struct vmbus_channel *primary_channel, *channel; 388 389 BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); 390 391 /* 392 * Make sure channel is valid as we may have raced. 393 */ 394 channel = relid2channel(relid); 395 if (!channel) 396 return; 397 398 BUG_ON(!channel->rescind); 399 if (channel->target_cpu != get_cpu()) { 400 put_cpu(); 401 smp_call_function_single(channel->target_cpu, 402 percpu_channel_deq, channel, true); 403 } else { 404 percpu_channel_deq(channel); 405 put_cpu(); 406 } 407 408 if (channel->primary_channel == NULL) { 409 list_del(&channel->listentry); 410 411 primary_channel = channel; 412 } else { 413 primary_channel = channel->primary_channel; 414 spin_lock_irqsave(&primary_channel->lock, flags); 415 list_del(&channel->sc_list); 416 primary_channel->num_sc--; 417 spin_unlock_irqrestore(&primary_channel->lock, flags); 418 } 419 420 /* 421 * We need to free the bit for init_vp_index() to work in the case 422 * of sub-channel, when we reload drivers like hv_netvsc. 423 */ 424 if (channel->affinity_policy == HV_LOCALIZED) 425 cpumask_clear_cpu(channel->target_cpu, 426 &primary_channel->alloced_cpus_in_node); 427 428 vmbus_release_relid(relid); 429 430 free_channel(channel); 431 } 432 433 void vmbus_free_channels(void) 434 { 435 struct vmbus_channel *channel, *tmp; 436 437 list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, 438 listentry) { 439 /* hv_process_channel_removal() needs this */ 440 channel->rescind = true; 441 442 vmbus_device_unregister(channel->device_obj); 443 } 444 } 445 446 /* 447 * vmbus_process_offer - Process the offer by creating a channel/device 448 * associated with this offer 449 */ 450 static void vmbus_process_offer(struct vmbus_channel *newchannel) 451 { 452 struct vmbus_channel *channel; 453 bool fnew = true; 454 unsigned long flags; 455 u16 dev_type; 456 int ret; 457 458 /* Make sure this is a new offer */ 459 mutex_lock(&vmbus_connection.channel_mutex); 460 461 /* 462 * Now that we have acquired the channel_mutex, 463 * we can release the potentially racing rescind thread. 464 */ 465 atomic_dec(&vmbus_connection.offer_in_progress); 466 467 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 468 if (!uuid_le_cmp(channel->offermsg.offer.if_type, 469 newchannel->offermsg.offer.if_type) && 470 !uuid_le_cmp(channel->offermsg.offer.if_instance, 471 newchannel->offermsg.offer.if_instance)) { 472 fnew = false; 473 break; 474 } 475 } 476 477 if (fnew) 478 list_add_tail(&newchannel->listentry, 479 &vmbus_connection.chn_list); 480 481 mutex_unlock(&vmbus_connection.channel_mutex); 482 483 if (!fnew) { 484 /* 485 * Check to see if this is a sub-channel. 486 */ 487 if (newchannel->offermsg.offer.sub_channel_index != 0) { 488 /* 489 * Process the sub-channel. 490 */ 491 newchannel->primary_channel = channel; 492 spin_lock_irqsave(&channel->lock, flags); 493 list_add_tail(&newchannel->sc_list, &channel->sc_list); 494 channel->num_sc++; 495 spin_unlock_irqrestore(&channel->lock, flags); 496 } else { 497 goto err_free_chan; 498 } 499 } 500 501 dev_type = hv_get_dev_type(newchannel); 502 503 init_vp_index(newchannel, dev_type); 504 505 if (newchannel->target_cpu != get_cpu()) { 506 put_cpu(); 507 smp_call_function_single(newchannel->target_cpu, 508 percpu_channel_enq, 509 newchannel, true); 510 } else { 511 percpu_channel_enq(newchannel); 512 put_cpu(); 513 } 514 515 /* 516 * This state is used to indicate a successful open 517 * so that when we do close the channel normally, we 518 * can cleanup properly 519 */ 520 newchannel->state = CHANNEL_OPEN_STATE; 521 522 if (!fnew) { 523 if (channel->sc_creation_callback != NULL) 524 channel->sc_creation_callback(newchannel); 525 newchannel->probe_done = true; 526 return; 527 } 528 529 /* 530 * Start the process of binding this offer to the driver 531 * We need to set the DeviceObject field before calling 532 * vmbus_child_dev_add() 533 */ 534 newchannel->device_obj = vmbus_device_create( 535 &newchannel->offermsg.offer.if_type, 536 &newchannel->offermsg.offer.if_instance, 537 newchannel); 538 if (!newchannel->device_obj) 539 goto err_deq_chan; 540 541 newchannel->device_obj->device_id = dev_type; 542 /* 543 * Add the new device to the bus. This will kick off device-driver 544 * binding which eventually invokes the device driver's AddDevice() 545 * method. 546 */ 547 ret = vmbus_device_register(newchannel->device_obj); 548 549 if (ret != 0) { 550 pr_err("unable to add child device object (relid %d)\n", 551 newchannel->offermsg.child_relid); 552 kfree(newchannel->device_obj); 553 goto err_deq_chan; 554 } 555 556 newchannel->probe_done = true; 557 return; 558 559 err_deq_chan: 560 mutex_lock(&vmbus_connection.channel_mutex); 561 list_del(&newchannel->listentry); 562 mutex_unlock(&vmbus_connection.channel_mutex); 563 564 if (newchannel->target_cpu != get_cpu()) { 565 put_cpu(); 566 smp_call_function_single(newchannel->target_cpu, 567 percpu_channel_deq, newchannel, true); 568 } else { 569 percpu_channel_deq(newchannel); 570 put_cpu(); 571 } 572 573 vmbus_release_relid(newchannel->offermsg.child_relid); 574 575 err_free_chan: 576 free_channel(newchannel); 577 } 578 579 /* 580 * We use this state to statically distribute the channel interrupt load. 581 */ 582 static int next_numa_node_id; 583 584 /* 585 * Starting with Win8, we can statically distribute the incoming 586 * channel interrupt load by binding a channel to VCPU. 587 * We do this in a hierarchical fashion: 588 * First distribute the primary channels across available NUMA nodes 589 * and then distribute the subchannels amongst the CPUs in the NUMA 590 * node assigned to the primary channel. 591 * 592 * For pre-win8 hosts or non-performance critical channels we assign the 593 * first CPU in the first NUMA node. 594 */ 595 static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) 596 { 597 u32 cur_cpu; 598 bool perf_chn = vmbus_devs[dev_type].perf_device; 599 struct vmbus_channel *primary = channel->primary_channel; 600 int next_node; 601 struct cpumask available_mask; 602 struct cpumask *alloced_mask; 603 604 if ((vmbus_proto_version == VERSION_WS2008) || 605 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) { 606 /* 607 * Prior to win8, all channel interrupts are 608 * delivered on cpu 0. 609 * Also if the channel is not a performance critical 610 * channel, bind it to cpu 0. 611 */ 612 channel->numa_node = 0; 613 channel->target_cpu = 0; 614 channel->target_vp = hv_cpu_number_to_vp_number(0); 615 return; 616 } 617 618 /* 619 * Based on the channel affinity policy, we will assign the NUMA 620 * nodes. 621 */ 622 623 if ((channel->affinity_policy == HV_BALANCED) || (!primary)) { 624 while (true) { 625 next_node = next_numa_node_id++; 626 if (next_node == nr_node_ids) { 627 next_node = next_numa_node_id = 0; 628 continue; 629 } 630 if (cpumask_empty(cpumask_of_node(next_node))) 631 continue; 632 break; 633 } 634 channel->numa_node = next_node; 635 primary = channel; 636 } 637 alloced_mask = &hv_context.hv_numa_map[primary->numa_node]; 638 639 if (cpumask_weight(alloced_mask) == 640 cpumask_weight(cpumask_of_node(primary->numa_node))) { 641 /* 642 * We have cycled through all the CPUs in the node; 643 * reset the alloced map. 644 */ 645 cpumask_clear(alloced_mask); 646 } 647 648 cpumask_xor(&available_mask, alloced_mask, 649 cpumask_of_node(primary->numa_node)); 650 651 cur_cpu = -1; 652 653 if (primary->affinity_policy == HV_LOCALIZED) { 654 /* 655 * Normally Hyper-V host doesn't create more subchannels 656 * than there are VCPUs on the node but it is possible when not 657 * all present VCPUs on the node are initialized by guest. 658 * Clear the alloced_cpus_in_node to start over. 659 */ 660 if (cpumask_equal(&primary->alloced_cpus_in_node, 661 cpumask_of_node(primary->numa_node))) 662 cpumask_clear(&primary->alloced_cpus_in_node); 663 } 664 665 while (true) { 666 cur_cpu = cpumask_next(cur_cpu, &available_mask); 667 if (cur_cpu >= nr_cpu_ids) { 668 cur_cpu = -1; 669 cpumask_copy(&available_mask, 670 cpumask_of_node(primary->numa_node)); 671 continue; 672 } 673 674 if (primary->affinity_policy == HV_LOCALIZED) { 675 /* 676 * NOTE: in the case of sub-channel, we clear the 677 * sub-channel related bit(s) in 678 * primary->alloced_cpus_in_node in 679 * hv_process_channel_removal(), so when we 680 * reload drivers like hv_netvsc in SMP guest, here 681 * we're able to re-allocate 682 * bit from primary->alloced_cpus_in_node. 683 */ 684 if (!cpumask_test_cpu(cur_cpu, 685 &primary->alloced_cpus_in_node)) { 686 cpumask_set_cpu(cur_cpu, 687 &primary->alloced_cpus_in_node); 688 cpumask_set_cpu(cur_cpu, alloced_mask); 689 break; 690 } 691 } else { 692 cpumask_set_cpu(cur_cpu, alloced_mask); 693 break; 694 } 695 } 696 697 channel->target_cpu = cur_cpu; 698 channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu); 699 } 700 701 static void vmbus_wait_for_unload(void) 702 { 703 int cpu; 704 void *page_addr; 705 struct hv_message *msg; 706 struct vmbus_channel_message_header *hdr; 707 u32 message_type; 708 709 /* 710 * CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was 711 * used for initial contact or to CPU0 depending on host version. When 712 * we're crashing on a different CPU let's hope that IRQ handler on 713 * the cpu which receives CHANNELMSG_UNLOAD_RESPONSE is still 714 * functional and vmbus_unload_response() will complete 715 * vmbus_connection.unload_event. If not, the last thing we can do is 716 * read message pages for all CPUs directly. 717 */ 718 while (1) { 719 if (completion_done(&vmbus_connection.unload_event)) 720 break; 721 722 for_each_online_cpu(cpu) { 723 struct hv_per_cpu_context *hv_cpu 724 = per_cpu_ptr(hv_context.cpu_context, cpu); 725 726 page_addr = hv_cpu->synic_message_page; 727 msg = (struct hv_message *)page_addr 728 + VMBUS_MESSAGE_SINT; 729 730 message_type = READ_ONCE(msg->header.message_type); 731 if (message_type == HVMSG_NONE) 732 continue; 733 734 hdr = (struct vmbus_channel_message_header *) 735 msg->u.payload; 736 737 if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE) 738 complete(&vmbus_connection.unload_event); 739 740 vmbus_signal_eom(msg, message_type); 741 } 742 743 mdelay(10); 744 } 745 746 /* 747 * We're crashing and already got the UNLOAD_RESPONSE, cleanup all 748 * maybe-pending messages on all CPUs to be able to receive new 749 * messages after we reconnect. 750 */ 751 for_each_online_cpu(cpu) { 752 struct hv_per_cpu_context *hv_cpu 753 = per_cpu_ptr(hv_context.cpu_context, cpu); 754 755 page_addr = hv_cpu->synic_message_page; 756 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; 757 msg->header.message_type = HVMSG_NONE; 758 } 759 } 760 761 /* 762 * vmbus_unload_response - Handler for the unload response. 763 */ 764 static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) 765 { 766 /* 767 * This is a global event; just wakeup the waiting thread. 768 * Once we successfully unload, we can cleanup the monitor state. 769 */ 770 complete(&vmbus_connection.unload_event); 771 } 772 773 void vmbus_initiate_unload(bool crash) 774 { 775 struct vmbus_channel_message_header hdr; 776 777 /* Pre-Win2012R2 hosts don't support reconnect */ 778 if (vmbus_proto_version < VERSION_WIN8_1) 779 return; 780 781 init_completion(&vmbus_connection.unload_event); 782 memset(&hdr, 0, sizeof(struct vmbus_channel_message_header)); 783 hdr.msgtype = CHANNELMSG_UNLOAD; 784 vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header), 785 !crash); 786 787 /* 788 * vmbus_initiate_unload() is also called on crash and the crash can be 789 * happening in an interrupt context, where scheduling is impossible. 790 */ 791 if (!crash) 792 wait_for_completion(&vmbus_connection.unload_event); 793 else 794 vmbus_wait_for_unload(); 795 } 796 797 /* 798 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 799 * 800 */ 801 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 802 { 803 struct vmbus_channel_offer_channel *offer; 804 struct vmbus_channel *newchannel; 805 806 offer = (struct vmbus_channel_offer_channel *)hdr; 807 808 /* Allocate the channel object and save this offer. */ 809 newchannel = alloc_channel(); 810 if (!newchannel) { 811 vmbus_release_relid(offer->child_relid); 812 atomic_dec(&vmbus_connection.offer_in_progress); 813 pr_err("Unable to allocate channel object\n"); 814 return; 815 } 816 817 /* 818 * Setup state for signalling the host. 819 */ 820 newchannel->sig_event = VMBUS_EVENT_CONNECTION_ID; 821 822 if (vmbus_proto_version != VERSION_WS2008) { 823 newchannel->is_dedicated_interrupt = 824 (offer->is_dedicated_interrupt != 0); 825 newchannel->sig_event = offer->connection_id; 826 } 827 828 memcpy(&newchannel->offermsg, offer, 829 sizeof(struct vmbus_channel_offer_channel)); 830 newchannel->monitor_grp = (u8)offer->monitorid / 32; 831 newchannel->monitor_bit = (u8)offer->monitorid % 32; 832 833 vmbus_process_offer(newchannel); 834 } 835 836 /* 837 * vmbus_onoffer_rescind - Rescind offer handler. 838 * 839 * We queue a work item to process this offer synchronously 840 */ 841 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 842 { 843 struct vmbus_channel_rescind_offer *rescind; 844 struct vmbus_channel *channel; 845 struct device *dev; 846 847 rescind = (struct vmbus_channel_rescind_offer *)hdr; 848 849 /* 850 * The offer msg and the corresponding rescind msg 851 * from the host are guranteed to be ordered - 852 * offer comes in first and then the rescind. 853 * Since we process these events in work elements, 854 * and with preemption, we may end up processing 855 * the events out of order. Given that we handle these 856 * work elements on the same CPU, this is possible only 857 * in the case of preemption. In any case wait here 858 * until the offer processing has moved beyond the 859 * point where the channel is discoverable. 860 */ 861 862 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) { 863 /* 864 * We wait here until any channel offer is currently 865 * being processed. 866 */ 867 msleep(1); 868 } 869 870 mutex_lock(&vmbus_connection.channel_mutex); 871 channel = relid2channel(rescind->child_relid); 872 mutex_unlock(&vmbus_connection.channel_mutex); 873 874 if (channel == NULL) { 875 /* 876 * We failed in processing the offer message; 877 * we would have cleaned up the relid in that 878 * failure path. 879 */ 880 return; 881 } 882 883 /* 884 * Now wait for offer handling to complete. 885 */ 886 while (READ_ONCE(channel->probe_done) == false) { 887 /* 888 * We wait here until any channel offer is currently 889 * being processed. 890 */ 891 msleep(1); 892 } 893 894 /* 895 * At this point, the rescind handling can proceed safely. 896 */ 897 898 if (channel->device_obj) { 899 if (channel->chn_rescind_callback) { 900 channel->chn_rescind_callback(channel); 901 vmbus_rescind_cleanup(channel); 902 return; 903 } 904 /* 905 * We will have to unregister this device from the 906 * driver core. 907 */ 908 dev = get_device(&channel->device_obj->device); 909 if (dev) { 910 vmbus_rescind_cleanup(channel); 911 vmbus_device_unregister(channel->device_obj); 912 put_device(dev); 913 } 914 } 915 if (channel->primary_channel != NULL) { 916 /* 917 * Sub-channel is being rescinded. Following is the channel 918 * close sequence when initiated from the driveri (refer to 919 * vmbus_close() for details): 920 * 1. Close all sub-channels first 921 * 2. Then close the primary channel. 922 */ 923 mutex_lock(&vmbus_connection.channel_mutex); 924 vmbus_rescind_cleanup(channel); 925 if (channel->state == CHANNEL_OPEN_STATE) { 926 /* 927 * The channel is currently not open; 928 * it is safe for us to cleanup the channel. 929 */ 930 hv_process_channel_removal(rescind->child_relid); 931 } 932 mutex_unlock(&vmbus_connection.channel_mutex); 933 } 934 } 935 936 void vmbus_hvsock_device_unregister(struct vmbus_channel *channel) 937 { 938 BUG_ON(!is_hvsock_channel(channel)); 939 940 channel->rescind = true; 941 vmbus_device_unregister(channel->device_obj); 942 } 943 EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister); 944 945 946 /* 947 * vmbus_onoffers_delivered - 948 * This is invoked when all offers have been delivered. 949 * 950 * Nothing to do here. 951 */ 952 static void vmbus_onoffers_delivered( 953 struct vmbus_channel_message_header *hdr) 954 { 955 } 956 957 /* 958 * vmbus_onopen_result - Open result handler. 959 * 960 * This is invoked when we received a response to our channel open request. 961 * Find the matching request, copy the response and signal the requesting 962 * thread. 963 */ 964 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 965 { 966 struct vmbus_channel_open_result *result; 967 struct vmbus_channel_msginfo *msginfo; 968 struct vmbus_channel_message_header *requestheader; 969 struct vmbus_channel_open_channel *openmsg; 970 unsigned long flags; 971 972 result = (struct vmbus_channel_open_result *)hdr; 973 974 /* 975 * Find the open msg, copy the result and signal/unblock the wait event 976 */ 977 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 978 979 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 980 msglistentry) { 981 requestheader = 982 (struct vmbus_channel_message_header *)msginfo->msg; 983 984 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 985 openmsg = 986 (struct vmbus_channel_open_channel *)msginfo->msg; 987 if (openmsg->child_relid == result->child_relid && 988 openmsg->openid == result->openid) { 989 memcpy(&msginfo->response.open_result, 990 result, 991 sizeof( 992 struct vmbus_channel_open_result)); 993 complete(&msginfo->waitevent); 994 break; 995 } 996 } 997 } 998 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 999 } 1000 1001 /* 1002 * vmbus_ongpadl_created - GPADL created handler. 1003 * 1004 * This is invoked when we received a response to our gpadl create request. 1005 * Find the matching request, copy the response and signal the requesting 1006 * thread. 1007 */ 1008 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 1009 { 1010 struct vmbus_channel_gpadl_created *gpadlcreated; 1011 struct vmbus_channel_msginfo *msginfo; 1012 struct vmbus_channel_message_header *requestheader; 1013 struct vmbus_channel_gpadl_header *gpadlheader; 1014 unsigned long flags; 1015 1016 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 1017 1018 /* 1019 * Find the establish msg, copy the result and signal/unblock the wait 1020 * event 1021 */ 1022 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1023 1024 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1025 msglistentry) { 1026 requestheader = 1027 (struct vmbus_channel_message_header *)msginfo->msg; 1028 1029 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 1030 gpadlheader = 1031 (struct vmbus_channel_gpadl_header *)requestheader; 1032 1033 if ((gpadlcreated->child_relid == 1034 gpadlheader->child_relid) && 1035 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 1036 memcpy(&msginfo->response.gpadl_created, 1037 gpadlcreated, 1038 sizeof( 1039 struct vmbus_channel_gpadl_created)); 1040 complete(&msginfo->waitevent); 1041 break; 1042 } 1043 } 1044 } 1045 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1046 } 1047 1048 /* 1049 * vmbus_ongpadl_torndown - GPADL torndown handler. 1050 * 1051 * This is invoked when we received a response to our gpadl teardown request. 1052 * Find the matching request, copy the response and signal the requesting 1053 * thread. 1054 */ 1055 static void vmbus_ongpadl_torndown( 1056 struct vmbus_channel_message_header *hdr) 1057 { 1058 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 1059 struct vmbus_channel_msginfo *msginfo; 1060 struct vmbus_channel_message_header *requestheader; 1061 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 1062 unsigned long flags; 1063 1064 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 1065 1066 /* 1067 * Find the open msg, copy the result and signal/unblock the wait event 1068 */ 1069 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1070 1071 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1072 msglistentry) { 1073 requestheader = 1074 (struct vmbus_channel_message_header *)msginfo->msg; 1075 1076 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 1077 gpadl_teardown = 1078 (struct vmbus_channel_gpadl_teardown *)requestheader; 1079 1080 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 1081 memcpy(&msginfo->response.gpadl_torndown, 1082 gpadl_torndown, 1083 sizeof( 1084 struct vmbus_channel_gpadl_torndown)); 1085 complete(&msginfo->waitevent); 1086 break; 1087 } 1088 } 1089 } 1090 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1091 } 1092 1093 /* 1094 * vmbus_onversion_response - Version response handler 1095 * 1096 * This is invoked when we received a response to our initiate contact request. 1097 * Find the matching request, copy the response and signal the requesting 1098 * thread. 1099 */ 1100 static void vmbus_onversion_response( 1101 struct vmbus_channel_message_header *hdr) 1102 { 1103 struct vmbus_channel_msginfo *msginfo; 1104 struct vmbus_channel_message_header *requestheader; 1105 struct vmbus_channel_version_response *version_response; 1106 unsigned long flags; 1107 1108 version_response = (struct vmbus_channel_version_response *)hdr; 1109 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1110 1111 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1112 msglistentry) { 1113 requestheader = 1114 (struct vmbus_channel_message_header *)msginfo->msg; 1115 1116 if (requestheader->msgtype == 1117 CHANNELMSG_INITIATE_CONTACT) { 1118 memcpy(&msginfo->response.version_response, 1119 version_response, 1120 sizeof(struct vmbus_channel_version_response)); 1121 complete(&msginfo->waitevent); 1122 } 1123 } 1124 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1125 } 1126 1127 /* Channel message dispatch table */ 1128 const struct vmbus_channel_message_table_entry 1129 channel_message_table[CHANNELMSG_COUNT] = { 1130 { CHANNELMSG_INVALID, 0, NULL }, 1131 { CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer }, 1132 { CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind }, 1133 { CHANNELMSG_REQUESTOFFERS, 0, NULL }, 1134 { CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered }, 1135 { CHANNELMSG_OPENCHANNEL, 0, NULL }, 1136 { CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result }, 1137 { CHANNELMSG_CLOSECHANNEL, 0, NULL }, 1138 { CHANNELMSG_GPADL_HEADER, 0, NULL }, 1139 { CHANNELMSG_GPADL_BODY, 0, NULL }, 1140 { CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created }, 1141 { CHANNELMSG_GPADL_TEARDOWN, 0, NULL }, 1142 { CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown }, 1143 { CHANNELMSG_RELID_RELEASED, 0, NULL }, 1144 { CHANNELMSG_INITIATE_CONTACT, 0, NULL }, 1145 { CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response }, 1146 { CHANNELMSG_UNLOAD, 0, NULL }, 1147 { CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response }, 1148 { CHANNELMSG_18, 0, NULL }, 1149 { CHANNELMSG_19, 0, NULL }, 1150 { CHANNELMSG_20, 0, NULL }, 1151 { CHANNELMSG_TL_CONNECT_REQUEST, 0, NULL }, 1152 }; 1153 1154 /* 1155 * vmbus_onmessage - Handler for channel protocol messages. 1156 * 1157 * This is invoked in the vmbus worker thread context. 1158 */ 1159 void vmbus_onmessage(void *context) 1160 { 1161 struct hv_message *msg = context; 1162 struct vmbus_channel_message_header *hdr; 1163 int size; 1164 1165 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 1166 size = msg->header.payload_size; 1167 1168 if (hdr->msgtype >= CHANNELMSG_COUNT) { 1169 pr_err("Received invalid channel message type %d size %d\n", 1170 hdr->msgtype, size); 1171 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 1172 (unsigned char *)msg->u.payload, size); 1173 return; 1174 } 1175 1176 if (channel_message_table[hdr->msgtype].message_handler) 1177 channel_message_table[hdr->msgtype].message_handler(hdr); 1178 else 1179 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 1180 } 1181 1182 /* 1183 * vmbus_request_offers - Send a request to get all our pending offers. 1184 */ 1185 int vmbus_request_offers(void) 1186 { 1187 struct vmbus_channel_message_header *msg; 1188 struct vmbus_channel_msginfo *msginfo; 1189 int ret; 1190 1191 msginfo = kmalloc(sizeof(*msginfo) + 1192 sizeof(struct vmbus_channel_message_header), 1193 GFP_KERNEL); 1194 if (!msginfo) 1195 return -ENOMEM; 1196 1197 msg = (struct vmbus_channel_message_header *)msginfo->msg; 1198 1199 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 1200 1201 1202 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_message_header), 1203 true); 1204 if (ret != 0) { 1205 pr_err("Unable to request offers - %d\n", ret); 1206 1207 goto cleanup; 1208 } 1209 1210 cleanup: 1211 kfree(msginfo); 1212 1213 return ret; 1214 } 1215 1216 /* 1217 * Retrieve the (sub) channel on which to send an outgoing request. 1218 * When a primary channel has multiple sub-channels, we try to 1219 * distribute the load equally amongst all available channels. 1220 */ 1221 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) 1222 { 1223 struct list_head *cur, *tmp; 1224 int cur_cpu; 1225 struct vmbus_channel *cur_channel; 1226 struct vmbus_channel *outgoing_channel = primary; 1227 int next_channel; 1228 int i = 1; 1229 1230 if (list_empty(&primary->sc_list)) 1231 return outgoing_channel; 1232 1233 next_channel = primary->next_oc++; 1234 1235 if (next_channel > (primary->num_sc)) { 1236 primary->next_oc = 0; 1237 return outgoing_channel; 1238 } 1239 1240 cur_cpu = hv_cpu_number_to_vp_number(smp_processor_id()); 1241 list_for_each_safe(cur, tmp, &primary->sc_list) { 1242 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 1243 if (cur_channel->state != CHANNEL_OPENED_STATE) 1244 continue; 1245 1246 if (cur_channel->target_vp == cur_cpu) 1247 return cur_channel; 1248 1249 if (i == next_channel) 1250 return cur_channel; 1251 1252 i++; 1253 } 1254 1255 return outgoing_channel; 1256 } 1257 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); 1258 1259 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 1260 { 1261 struct list_head *cur, *tmp; 1262 struct vmbus_channel *cur_channel; 1263 1264 if (primary_channel->sc_creation_callback == NULL) 1265 return; 1266 1267 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 1268 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 1269 1270 primary_channel->sc_creation_callback(cur_channel); 1271 } 1272 } 1273 1274 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 1275 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 1276 { 1277 primary_channel->sc_creation_callback = sc_cr_cb; 1278 } 1279 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 1280 1281 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 1282 { 1283 bool ret; 1284 1285 ret = !list_empty(&primary->sc_list); 1286 1287 if (ret) { 1288 /* 1289 * Invoke the callback on sub-channel creation. 1290 * This will present a uniform interface to the 1291 * clients. 1292 */ 1293 invoke_sc_cb(primary); 1294 } 1295 1296 return ret; 1297 } 1298 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 1299 1300 void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel, 1301 void (*chn_rescind_cb)(struct vmbus_channel *)) 1302 { 1303 channel->chn_rescind_callback = chn_rescind_cb; 1304 } 1305 EXPORT_SYMBOL_GPL(vmbus_set_chn_rescind_callback); 1306