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 = false, 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 guid_t 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 guid_t *guid) 175 { 176 int i; 177 178 for (i = 0; i < ARRAY_SIZE(vmbus_unsupported_devs); i++) 179 if (guid_equal(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 guid_t *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 (guid_equal(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 Negotiate message 202 * @icmsghdrp: Pointer to msg header structure 203 * @buf: Raw buffer channel data 204 * @fw_version: The framework versions we can support. 205 * @fw_vercnt: The size of @fw_version. 206 * @srv_version: The service versions we can support. 207 * @srv_vercnt: The size of @srv_version. 208 * @nego_fw_version: The selected framework version. 209 * @nego_srv_version: The selected service version. 210 * 211 * Note: Versions are given in decreasing order. 212 * 213 * Set up and fill in default negotiate response message. 214 * Mainly used by Hyper-V drivers. 215 */ 216 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, 217 u8 *buf, const int *fw_version, int fw_vercnt, 218 const int *srv_version, int srv_vercnt, 219 int *nego_fw_version, int *nego_srv_version) 220 { 221 int icframe_major, icframe_minor; 222 int icmsg_major, icmsg_minor; 223 int fw_major, fw_minor; 224 int srv_major, srv_minor; 225 int i, j; 226 bool found_match = false; 227 struct icmsg_negotiate *negop; 228 229 icmsghdrp->icmsgsize = 0x10; 230 negop = (struct icmsg_negotiate *)&buf[ 231 sizeof(struct vmbuspipe_hdr) + 232 sizeof(struct icmsg_hdr)]; 233 234 icframe_major = negop->icframe_vercnt; 235 icframe_minor = 0; 236 237 icmsg_major = negop->icmsg_vercnt; 238 icmsg_minor = 0; 239 240 /* 241 * Select the framework version number we will 242 * support. 243 */ 244 245 for (i = 0; i < fw_vercnt; i++) { 246 fw_major = (fw_version[i] >> 16); 247 fw_minor = (fw_version[i] & 0xFFFF); 248 249 for (j = 0; j < negop->icframe_vercnt; j++) { 250 if ((negop->icversion_data[j].major == fw_major) && 251 (negop->icversion_data[j].minor == fw_minor)) { 252 icframe_major = negop->icversion_data[j].major; 253 icframe_minor = negop->icversion_data[j].minor; 254 found_match = true; 255 break; 256 } 257 } 258 259 if (found_match) 260 break; 261 } 262 263 if (!found_match) 264 goto fw_error; 265 266 found_match = false; 267 268 for (i = 0; i < srv_vercnt; i++) { 269 srv_major = (srv_version[i] >> 16); 270 srv_minor = (srv_version[i] & 0xFFFF); 271 272 for (j = negop->icframe_vercnt; 273 (j < negop->icframe_vercnt + negop->icmsg_vercnt); 274 j++) { 275 276 if ((negop->icversion_data[j].major == srv_major) && 277 (negop->icversion_data[j].minor == srv_minor)) { 278 279 icmsg_major = negop->icversion_data[j].major; 280 icmsg_minor = negop->icversion_data[j].minor; 281 found_match = true; 282 break; 283 } 284 } 285 286 if (found_match) 287 break; 288 } 289 290 /* 291 * Respond with the framework and service 292 * version numbers we can support. 293 */ 294 295 fw_error: 296 if (!found_match) { 297 negop->icframe_vercnt = 0; 298 negop->icmsg_vercnt = 0; 299 } else { 300 negop->icframe_vercnt = 1; 301 negop->icmsg_vercnt = 1; 302 } 303 304 if (nego_fw_version) 305 *nego_fw_version = (icframe_major << 16) | icframe_minor; 306 307 if (nego_srv_version) 308 *nego_srv_version = (icmsg_major << 16) | icmsg_minor; 309 310 negop->icversion_data[0].major = icframe_major; 311 negop->icversion_data[0].minor = icframe_minor; 312 negop->icversion_data[1].major = icmsg_major; 313 negop->icversion_data[1].minor = icmsg_minor; 314 return found_match; 315 } 316 317 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp); 318 319 /* 320 * alloc_channel - Allocate and initialize a vmbus channel object 321 */ 322 static struct vmbus_channel *alloc_channel(void) 323 { 324 struct vmbus_channel *channel; 325 326 channel = kzalloc(sizeof(*channel), GFP_ATOMIC); 327 if (!channel) 328 return NULL; 329 330 spin_lock_init(&channel->lock); 331 init_completion(&channel->rescind_event); 332 333 INIT_LIST_HEAD(&channel->sc_list); 334 INIT_LIST_HEAD(&channel->percpu_list); 335 336 tasklet_init(&channel->callback_event, 337 vmbus_on_event, (unsigned long)channel); 338 339 hv_ringbuffer_pre_init(channel); 340 341 return channel; 342 } 343 344 /* 345 * free_channel - Release the resources used by the vmbus channel object 346 */ 347 static void free_channel(struct vmbus_channel *channel) 348 { 349 tasklet_kill(&channel->callback_event); 350 vmbus_remove_channel_attr_group(channel); 351 352 kobject_put(&channel->kobj); 353 } 354 355 static void percpu_channel_enq(void *arg) 356 { 357 struct vmbus_channel *channel = arg; 358 struct hv_per_cpu_context *hv_cpu 359 = this_cpu_ptr(hv_context.cpu_context); 360 361 list_add_tail_rcu(&channel->percpu_list, &hv_cpu->chan_list); 362 } 363 364 static void percpu_channel_deq(void *arg) 365 { 366 struct vmbus_channel *channel = arg; 367 368 list_del_rcu(&channel->percpu_list); 369 } 370 371 372 static void vmbus_release_relid(u32 relid) 373 { 374 struct vmbus_channel_relid_released msg; 375 int ret; 376 377 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); 378 msg.child_relid = relid; 379 msg.header.msgtype = CHANNELMSG_RELID_RELEASED; 380 ret = vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released), 381 true); 382 383 trace_vmbus_release_relid(&msg, ret); 384 } 385 386 void hv_process_channel_removal(struct vmbus_channel *channel) 387 { 388 struct vmbus_channel *primary_channel; 389 unsigned long flags; 390 391 BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); 392 BUG_ON(!channel->rescind); 393 394 if (channel->target_cpu != get_cpu()) { 395 put_cpu(); 396 smp_call_function_single(channel->target_cpu, 397 percpu_channel_deq, channel, true); 398 } else { 399 percpu_channel_deq(channel); 400 put_cpu(); 401 } 402 403 if (channel->primary_channel == NULL) { 404 list_del(&channel->listentry); 405 406 primary_channel = channel; 407 } else { 408 primary_channel = channel->primary_channel; 409 spin_lock_irqsave(&primary_channel->lock, flags); 410 list_del(&channel->sc_list); 411 spin_unlock_irqrestore(&primary_channel->lock, flags); 412 } 413 414 /* 415 * We need to free the bit for init_vp_index() to work in the case 416 * of sub-channel, when we reload drivers like hv_netvsc. 417 */ 418 if (channel->affinity_policy == HV_LOCALIZED) 419 cpumask_clear_cpu(channel->target_cpu, 420 &primary_channel->alloced_cpus_in_node); 421 422 vmbus_release_relid(channel->offermsg.child_relid); 423 424 free_channel(channel); 425 } 426 427 void vmbus_free_channels(void) 428 { 429 struct vmbus_channel *channel, *tmp; 430 431 list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, 432 listentry) { 433 /* hv_process_channel_removal() needs this */ 434 channel->rescind = true; 435 436 vmbus_device_unregister(channel->device_obj); 437 } 438 } 439 440 /* Note: the function can run concurrently for primary/sub channels. */ 441 static void vmbus_add_channel_work(struct work_struct *work) 442 { 443 struct vmbus_channel *newchannel = 444 container_of(work, struct vmbus_channel, add_channel_work); 445 struct vmbus_channel *primary_channel = newchannel->primary_channel; 446 unsigned long flags; 447 u16 dev_type; 448 int ret; 449 450 dev_type = hv_get_dev_type(newchannel); 451 452 init_vp_index(newchannel, dev_type); 453 454 if (newchannel->target_cpu != get_cpu()) { 455 put_cpu(); 456 smp_call_function_single(newchannel->target_cpu, 457 percpu_channel_enq, 458 newchannel, true); 459 } else { 460 percpu_channel_enq(newchannel); 461 put_cpu(); 462 } 463 464 /* 465 * This state is used to indicate a successful open 466 * so that when we do close the channel normally, we 467 * can cleanup properly. 468 */ 469 newchannel->state = CHANNEL_OPEN_STATE; 470 471 if (primary_channel != NULL) { 472 /* newchannel is a sub-channel. */ 473 struct hv_device *dev = primary_channel->device_obj; 474 475 if (vmbus_add_channel_kobj(dev, newchannel)) 476 goto err_deq_chan; 477 478 if (primary_channel->sc_creation_callback != NULL) 479 primary_channel->sc_creation_callback(newchannel); 480 481 newchannel->probe_done = true; 482 return; 483 } 484 485 /* 486 * Start the process of binding the primary channel to the driver 487 */ 488 newchannel->device_obj = vmbus_device_create( 489 &newchannel->offermsg.offer.if_type, 490 &newchannel->offermsg.offer.if_instance, 491 newchannel); 492 if (!newchannel->device_obj) 493 goto err_deq_chan; 494 495 newchannel->device_obj->device_id = dev_type; 496 /* 497 * Add the new device to the bus. This will kick off device-driver 498 * binding which eventually invokes the device driver's AddDevice() 499 * method. 500 */ 501 ret = vmbus_device_register(newchannel->device_obj); 502 503 if (ret != 0) { 504 pr_err("unable to add child device object (relid %d)\n", 505 newchannel->offermsg.child_relid); 506 kfree(newchannel->device_obj); 507 goto err_deq_chan; 508 } 509 510 newchannel->probe_done = true; 511 return; 512 513 err_deq_chan: 514 mutex_lock(&vmbus_connection.channel_mutex); 515 516 /* 517 * We need to set the flag, otherwise 518 * vmbus_onoffer_rescind() can be blocked. 519 */ 520 newchannel->probe_done = true; 521 522 if (primary_channel == NULL) { 523 list_del(&newchannel->listentry); 524 } else { 525 spin_lock_irqsave(&primary_channel->lock, flags); 526 list_del(&newchannel->sc_list); 527 spin_unlock_irqrestore(&primary_channel->lock, flags); 528 } 529 530 mutex_unlock(&vmbus_connection.channel_mutex); 531 532 if (newchannel->target_cpu != get_cpu()) { 533 put_cpu(); 534 smp_call_function_single(newchannel->target_cpu, 535 percpu_channel_deq, 536 newchannel, true); 537 } else { 538 percpu_channel_deq(newchannel); 539 put_cpu(); 540 } 541 542 vmbus_release_relid(newchannel->offermsg.child_relid); 543 544 free_channel(newchannel); 545 } 546 547 /* 548 * vmbus_process_offer - Process the offer by creating a channel/device 549 * associated with this offer 550 */ 551 static void vmbus_process_offer(struct vmbus_channel *newchannel) 552 { 553 struct vmbus_channel *channel; 554 struct workqueue_struct *wq; 555 unsigned long flags; 556 bool fnew = true; 557 558 mutex_lock(&vmbus_connection.channel_mutex); 559 560 /* 561 * Now that we have acquired the channel_mutex, 562 * we can release the potentially racing rescind thread. 563 */ 564 atomic_dec(&vmbus_connection.offer_in_progress); 565 566 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { 567 if (guid_equal(&channel->offermsg.offer.if_type, 568 &newchannel->offermsg.offer.if_type) && 569 guid_equal(&channel->offermsg.offer.if_instance, 570 &newchannel->offermsg.offer.if_instance)) { 571 fnew = false; 572 break; 573 } 574 } 575 576 if (fnew) 577 list_add_tail(&newchannel->listentry, 578 &vmbus_connection.chn_list); 579 else { 580 /* 581 * Check to see if this is a valid sub-channel. 582 */ 583 if (newchannel->offermsg.offer.sub_channel_index == 0) { 584 mutex_unlock(&vmbus_connection.channel_mutex); 585 /* 586 * Don't call free_channel(), because newchannel->kobj 587 * is not initialized yet. 588 */ 589 kfree(newchannel); 590 WARN_ON_ONCE(1); 591 return; 592 } 593 /* 594 * Process the sub-channel. 595 */ 596 newchannel->primary_channel = channel; 597 spin_lock_irqsave(&channel->lock, flags); 598 list_add_tail(&newchannel->sc_list, &channel->sc_list); 599 spin_unlock_irqrestore(&channel->lock, flags); 600 } 601 602 mutex_unlock(&vmbus_connection.channel_mutex); 603 604 /* 605 * vmbus_process_offer() mustn't call channel->sc_creation_callback() 606 * directly for sub-channels, because sc_creation_callback() -> 607 * vmbus_open() may never get the host's response to the 608 * OPEN_CHANNEL message (the host may rescind a channel at any time, 609 * e.g. in the case of hot removing a NIC), and vmbus_onoffer_rescind() 610 * may not wake up the vmbus_open() as it's blocked due to a non-zero 611 * vmbus_connection.offer_in_progress, and finally we have a deadlock. 612 * 613 * The above is also true for primary channels, if the related device 614 * drivers use sync probing mode by default. 615 * 616 * And, usually the handling of primary channels and sub-channels can 617 * depend on each other, so we should offload them to different 618 * workqueues to avoid possible deadlock, e.g. in sync-probing mode, 619 * NIC1's netvsc_subchan_work() can race with NIC2's netvsc_probe() -> 620 * rtnl_lock(), and causes deadlock: the former gets the rtnl_lock 621 * and waits for all the sub-channels to appear, but the latter 622 * can't get the rtnl_lock and this blocks the handling of 623 * sub-channels. 624 */ 625 INIT_WORK(&newchannel->add_channel_work, vmbus_add_channel_work); 626 wq = fnew ? vmbus_connection.handle_primary_chan_wq : 627 vmbus_connection.handle_sub_chan_wq; 628 queue_work(wq, &newchannel->add_channel_work); 629 } 630 631 /* 632 * We use this state to statically distribute the channel interrupt load. 633 */ 634 static int next_numa_node_id; 635 /* 636 * init_vp_index() accesses global variables like next_numa_node_id, and 637 * it can run concurrently for primary channels and sub-channels: see 638 * vmbus_process_offer(), so we need the lock to protect the global 639 * variables. 640 */ 641 static DEFINE_SPINLOCK(bind_channel_to_cpu_lock); 642 643 /* 644 * Starting with Win8, we can statically distribute the incoming 645 * channel interrupt load by binding a channel to VCPU. 646 * We distribute the interrupt loads to one or more NUMA nodes based on 647 * the channel's affinity_policy. 648 * 649 * For pre-win8 hosts or non-performance critical channels we assign the 650 * first CPU in the first NUMA node. 651 */ 652 static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) 653 { 654 u32 cur_cpu; 655 bool perf_chn = vmbus_devs[dev_type].perf_device; 656 struct vmbus_channel *primary = channel->primary_channel; 657 int next_node; 658 cpumask_var_t available_mask; 659 struct cpumask *alloced_mask; 660 661 if ((vmbus_proto_version == VERSION_WS2008) || 662 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn) || 663 !alloc_cpumask_var(&available_mask, GFP_KERNEL)) { 664 /* 665 * Prior to win8, all channel interrupts are 666 * delivered on cpu 0. 667 * Also if the channel is not a performance critical 668 * channel, bind it to cpu 0. 669 * In case alloc_cpumask_var() fails, bind it to cpu 0. 670 */ 671 channel->numa_node = 0; 672 channel->target_cpu = 0; 673 channel->target_vp = hv_cpu_number_to_vp_number(0); 674 return; 675 } 676 677 spin_lock(&bind_channel_to_cpu_lock); 678 679 /* 680 * Based on the channel affinity policy, we will assign the NUMA 681 * nodes. 682 */ 683 684 if ((channel->affinity_policy == HV_BALANCED) || (!primary)) { 685 while (true) { 686 next_node = next_numa_node_id++; 687 if (next_node == nr_node_ids) { 688 next_node = next_numa_node_id = 0; 689 continue; 690 } 691 if (cpumask_empty(cpumask_of_node(next_node))) 692 continue; 693 break; 694 } 695 channel->numa_node = next_node; 696 primary = channel; 697 } 698 alloced_mask = &hv_context.hv_numa_map[primary->numa_node]; 699 700 if (cpumask_weight(alloced_mask) == 701 cpumask_weight(cpumask_of_node(primary->numa_node))) { 702 /* 703 * We have cycled through all the CPUs in the node; 704 * reset the alloced map. 705 */ 706 cpumask_clear(alloced_mask); 707 } 708 709 cpumask_xor(available_mask, alloced_mask, 710 cpumask_of_node(primary->numa_node)); 711 712 cur_cpu = -1; 713 714 if (primary->affinity_policy == HV_LOCALIZED) { 715 /* 716 * Normally Hyper-V host doesn't create more subchannels 717 * than there are VCPUs on the node but it is possible when not 718 * all present VCPUs on the node are initialized by guest. 719 * Clear the alloced_cpus_in_node to start over. 720 */ 721 if (cpumask_equal(&primary->alloced_cpus_in_node, 722 cpumask_of_node(primary->numa_node))) 723 cpumask_clear(&primary->alloced_cpus_in_node); 724 } 725 726 while (true) { 727 cur_cpu = cpumask_next(cur_cpu, available_mask); 728 if (cur_cpu >= nr_cpu_ids) { 729 cur_cpu = -1; 730 cpumask_copy(available_mask, 731 cpumask_of_node(primary->numa_node)); 732 continue; 733 } 734 735 if (primary->affinity_policy == HV_LOCALIZED) { 736 /* 737 * NOTE: in the case of sub-channel, we clear the 738 * sub-channel related bit(s) in 739 * primary->alloced_cpus_in_node in 740 * hv_process_channel_removal(), so when we 741 * reload drivers like hv_netvsc in SMP guest, here 742 * we're able to re-allocate 743 * bit from primary->alloced_cpus_in_node. 744 */ 745 if (!cpumask_test_cpu(cur_cpu, 746 &primary->alloced_cpus_in_node)) { 747 cpumask_set_cpu(cur_cpu, 748 &primary->alloced_cpus_in_node); 749 cpumask_set_cpu(cur_cpu, alloced_mask); 750 break; 751 } 752 } else { 753 cpumask_set_cpu(cur_cpu, alloced_mask); 754 break; 755 } 756 } 757 758 channel->target_cpu = cur_cpu; 759 channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu); 760 761 spin_unlock(&bind_channel_to_cpu_lock); 762 763 free_cpumask_var(available_mask); 764 } 765 766 static void vmbus_wait_for_unload(void) 767 { 768 int cpu; 769 void *page_addr; 770 struct hv_message *msg; 771 struct vmbus_channel_message_header *hdr; 772 u32 message_type; 773 774 /* 775 * CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was 776 * used for initial contact or to CPU0 depending on host version. When 777 * we're crashing on a different CPU let's hope that IRQ handler on 778 * the cpu which receives CHANNELMSG_UNLOAD_RESPONSE is still 779 * functional and vmbus_unload_response() will complete 780 * vmbus_connection.unload_event. If not, the last thing we can do is 781 * read message pages for all CPUs directly. 782 */ 783 while (1) { 784 if (completion_done(&vmbus_connection.unload_event)) 785 break; 786 787 for_each_online_cpu(cpu) { 788 struct hv_per_cpu_context *hv_cpu 789 = per_cpu_ptr(hv_context.cpu_context, cpu); 790 791 page_addr = hv_cpu->synic_message_page; 792 msg = (struct hv_message *)page_addr 793 + VMBUS_MESSAGE_SINT; 794 795 message_type = READ_ONCE(msg->header.message_type); 796 if (message_type == HVMSG_NONE) 797 continue; 798 799 hdr = (struct vmbus_channel_message_header *) 800 msg->u.payload; 801 802 if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE) 803 complete(&vmbus_connection.unload_event); 804 805 vmbus_signal_eom(msg, message_type); 806 } 807 808 mdelay(10); 809 } 810 811 /* 812 * We're crashing and already got the UNLOAD_RESPONSE, cleanup all 813 * maybe-pending messages on all CPUs to be able to receive new 814 * messages after we reconnect. 815 */ 816 for_each_online_cpu(cpu) { 817 struct hv_per_cpu_context *hv_cpu 818 = per_cpu_ptr(hv_context.cpu_context, cpu); 819 820 page_addr = hv_cpu->synic_message_page; 821 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; 822 msg->header.message_type = HVMSG_NONE; 823 } 824 } 825 826 /* 827 * vmbus_unload_response - Handler for the unload response. 828 */ 829 static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) 830 { 831 /* 832 * This is a global event; just wakeup the waiting thread. 833 * Once we successfully unload, we can cleanup the monitor state. 834 */ 835 complete(&vmbus_connection.unload_event); 836 } 837 838 void vmbus_initiate_unload(bool crash) 839 { 840 struct vmbus_channel_message_header hdr; 841 842 /* Pre-Win2012R2 hosts don't support reconnect */ 843 if (vmbus_proto_version < VERSION_WIN8_1) 844 return; 845 846 init_completion(&vmbus_connection.unload_event); 847 memset(&hdr, 0, sizeof(struct vmbus_channel_message_header)); 848 hdr.msgtype = CHANNELMSG_UNLOAD; 849 vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header), 850 !crash); 851 852 /* 853 * vmbus_initiate_unload() is also called on crash and the crash can be 854 * happening in an interrupt context, where scheduling is impossible. 855 */ 856 if (!crash) 857 wait_for_completion(&vmbus_connection.unload_event); 858 else 859 vmbus_wait_for_unload(); 860 } 861 862 /* 863 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. 864 * 865 */ 866 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) 867 { 868 struct vmbus_channel_offer_channel *offer; 869 struct vmbus_channel *newchannel; 870 871 offer = (struct vmbus_channel_offer_channel *)hdr; 872 873 trace_vmbus_onoffer(offer); 874 875 /* Allocate the channel object and save this offer. */ 876 newchannel = alloc_channel(); 877 if (!newchannel) { 878 vmbus_release_relid(offer->child_relid); 879 atomic_dec(&vmbus_connection.offer_in_progress); 880 pr_err("Unable to allocate channel object\n"); 881 return; 882 } 883 884 /* 885 * Setup state for signalling the host. 886 */ 887 newchannel->sig_event = VMBUS_EVENT_CONNECTION_ID; 888 889 if (vmbus_proto_version != VERSION_WS2008) { 890 newchannel->is_dedicated_interrupt = 891 (offer->is_dedicated_interrupt != 0); 892 newchannel->sig_event = offer->connection_id; 893 } 894 895 memcpy(&newchannel->offermsg, offer, 896 sizeof(struct vmbus_channel_offer_channel)); 897 newchannel->monitor_grp = (u8)offer->monitorid / 32; 898 newchannel->monitor_bit = (u8)offer->monitorid % 32; 899 900 vmbus_process_offer(newchannel); 901 } 902 903 /* 904 * vmbus_onoffer_rescind - Rescind offer handler. 905 * 906 * We queue a work item to process this offer synchronously 907 */ 908 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) 909 { 910 struct vmbus_channel_rescind_offer *rescind; 911 struct vmbus_channel *channel; 912 struct device *dev; 913 914 rescind = (struct vmbus_channel_rescind_offer *)hdr; 915 916 trace_vmbus_onoffer_rescind(rescind); 917 918 /* 919 * The offer msg and the corresponding rescind msg 920 * from the host are guranteed to be ordered - 921 * offer comes in first and then the rescind. 922 * Since we process these events in work elements, 923 * and with preemption, we may end up processing 924 * the events out of order. Given that we handle these 925 * work elements on the same CPU, this is possible only 926 * in the case of preemption. In any case wait here 927 * until the offer processing has moved beyond the 928 * point where the channel is discoverable. 929 */ 930 931 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) { 932 /* 933 * We wait here until any channel offer is currently 934 * being processed. 935 */ 936 msleep(1); 937 } 938 939 mutex_lock(&vmbus_connection.channel_mutex); 940 channel = relid2channel(rescind->child_relid); 941 mutex_unlock(&vmbus_connection.channel_mutex); 942 943 if (channel == NULL) { 944 /* 945 * We failed in processing the offer message; 946 * we would have cleaned up the relid in that 947 * failure path. 948 */ 949 return; 950 } 951 952 /* 953 * Before setting channel->rescind in vmbus_rescind_cleanup(), we 954 * should make sure the channel callback is not running any more. 955 */ 956 vmbus_reset_channel_cb(channel); 957 958 /* 959 * Now wait for offer handling to complete. 960 */ 961 vmbus_rescind_cleanup(channel); 962 while (READ_ONCE(channel->probe_done) == false) { 963 /* 964 * We wait here until any channel offer is currently 965 * being processed. 966 */ 967 msleep(1); 968 } 969 970 /* 971 * At this point, the rescind handling can proceed safely. 972 */ 973 974 if (channel->device_obj) { 975 if (channel->chn_rescind_callback) { 976 channel->chn_rescind_callback(channel); 977 return; 978 } 979 /* 980 * We will have to unregister this device from the 981 * driver core. 982 */ 983 dev = get_device(&channel->device_obj->device); 984 if (dev) { 985 vmbus_device_unregister(channel->device_obj); 986 put_device(dev); 987 } 988 } 989 if (channel->primary_channel != NULL) { 990 /* 991 * Sub-channel is being rescinded. Following is the channel 992 * close sequence when initiated from the driveri (refer to 993 * vmbus_close() for details): 994 * 1. Close all sub-channels first 995 * 2. Then close the primary channel. 996 */ 997 mutex_lock(&vmbus_connection.channel_mutex); 998 if (channel->state == CHANNEL_OPEN_STATE) { 999 /* 1000 * The channel is currently not open; 1001 * it is safe for us to cleanup the channel. 1002 */ 1003 hv_process_channel_removal(channel); 1004 } else { 1005 complete(&channel->rescind_event); 1006 } 1007 mutex_unlock(&vmbus_connection.channel_mutex); 1008 } 1009 } 1010 1011 void vmbus_hvsock_device_unregister(struct vmbus_channel *channel) 1012 { 1013 BUG_ON(!is_hvsock_channel(channel)); 1014 1015 /* We always get a rescind msg when a connection is closed. */ 1016 while (!READ_ONCE(channel->probe_done) || !READ_ONCE(channel->rescind)) 1017 msleep(1); 1018 1019 vmbus_device_unregister(channel->device_obj); 1020 } 1021 EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister); 1022 1023 1024 /* 1025 * vmbus_onoffers_delivered - 1026 * This is invoked when all offers have been delivered. 1027 * 1028 * Nothing to do here. 1029 */ 1030 static void vmbus_onoffers_delivered( 1031 struct vmbus_channel_message_header *hdr) 1032 { 1033 } 1034 1035 /* 1036 * vmbus_onopen_result - Open result handler. 1037 * 1038 * This is invoked when we received a response to our channel open request. 1039 * Find the matching request, copy the response and signal the requesting 1040 * thread. 1041 */ 1042 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) 1043 { 1044 struct vmbus_channel_open_result *result; 1045 struct vmbus_channel_msginfo *msginfo; 1046 struct vmbus_channel_message_header *requestheader; 1047 struct vmbus_channel_open_channel *openmsg; 1048 unsigned long flags; 1049 1050 result = (struct vmbus_channel_open_result *)hdr; 1051 1052 trace_vmbus_onopen_result(result); 1053 1054 /* 1055 * Find the open msg, copy the result and signal/unblock the wait event 1056 */ 1057 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1058 1059 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1060 msglistentry) { 1061 requestheader = 1062 (struct vmbus_channel_message_header *)msginfo->msg; 1063 1064 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { 1065 openmsg = 1066 (struct vmbus_channel_open_channel *)msginfo->msg; 1067 if (openmsg->child_relid == result->child_relid && 1068 openmsg->openid == result->openid) { 1069 memcpy(&msginfo->response.open_result, 1070 result, 1071 sizeof( 1072 struct vmbus_channel_open_result)); 1073 complete(&msginfo->waitevent); 1074 break; 1075 } 1076 } 1077 } 1078 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1079 } 1080 1081 /* 1082 * vmbus_ongpadl_created - GPADL created handler. 1083 * 1084 * This is invoked when we received a response to our gpadl create request. 1085 * Find the matching request, copy the response and signal the requesting 1086 * thread. 1087 */ 1088 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) 1089 { 1090 struct vmbus_channel_gpadl_created *gpadlcreated; 1091 struct vmbus_channel_msginfo *msginfo; 1092 struct vmbus_channel_message_header *requestheader; 1093 struct vmbus_channel_gpadl_header *gpadlheader; 1094 unsigned long flags; 1095 1096 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; 1097 1098 trace_vmbus_ongpadl_created(gpadlcreated); 1099 1100 /* 1101 * Find the establish msg, copy the result and signal/unblock the wait 1102 * event 1103 */ 1104 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1105 1106 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1107 msglistentry) { 1108 requestheader = 1109 (struct vmbus_channel_message_header *)msginfo->msg; 1110 1111 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { 1112 gpadlheader = 1113 (struct vmbus_channel_gpadl_header *)requestheader; 1114 1115 if ((gpadlcreated->child_relid == 1116 gpadlheader->child_relid) && 1117 (gpadlcreated->gpadl == gpadlheader->gpadl)) { 1118 memcpy(&msginfo->response.gpadl_created, 1119 gpadlcreated, 1120 sizeof( 1121 struct vmbus_channel_gpadl_created)); 1122 complete(&msginfo->waitevent); 1123 break; 1124 } 1125 } 1126 } 1127 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1128 } 1129 1130 /* 1131 * vmbus_ongpadl_torndown - GPADL torndown handler. 1132 * 1133 * This is invoked when we received a response to our gpadl teardown request. 1134 * Find the matching request, copy the response and signal the requesting 1135 * thread. 1136 */ 1137 static void vmbus_ongpadl_torndown( 1138 struct vmbus_channel_message_header *hdr) 1139 { 1140 struct vmbus_channel_gpadl_torndown *gpadl_torndown; 1141 struct vmbus_channel_msginfo *msginfo; 1142 struct vmbus_channel_message_header *requestheader; 1143 struct vmbus_channel_gpadl_teardown *gpadl_teardown; 1144 unsigned long flags; 1145 1146 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; 1147 1148 trace_vmbus_ongpadl_torndown(gpadl_torndown); 1149 1150 /* 1151 * Find the open msg, copy the result and signal/unblock the wait event 1152 */ 1153 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1154 1155 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1156 msglistentry) { 1157 requestheader = 1158 (struct vmbus_channel_message_header *)msginfo->msg; 1159 1160 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { 1161 gpadl_teardown = 1162 (struct vmbus_channel_gpadl_teardown *)requestheader; 1163 1164 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { 1165 memcpy(&msginfo->response.gpadl_torndown, 1166 gpadl_torndown, 1167 sizeof( 1168 struct vmbus_channel_gpadl_torndown)); 1169 complete(&msginfo->waitevent); 1170 break; 1171 } 1172 } 1173 } 1174 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1175 } 1176 1177 /* 1178 * vmbus_onversion_response - Version response handler 1179 * 1180 * This is invoked when we received a response to our initiate contact request. 1181 * Find the matching request, copy the response and signal the requesting 1182 * thread. 1183 */ 1184 static void vmbus_onversion_response( 1185 struct vmbus_channel_message_header *hdr) 1186 { 1187 struct vmbus_channel_msginfo *msginfo; 1188 struct vmbus_channel_message_header *requestheader; 1189 struct vmbus_channel_version_response *version_response; 1190 unsigned long flags; 1191 1192 version_response = (struct vmbus_channel_version_response *)hdr; 1193 1194 trace_vmbus_onversion_response(version_response); 1195 1196 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 1197 1198 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, 1199 msglistentry) { 1200 requestheader = 1201 (struct vmbus_channel_message_header *)msginfo->msg; 1202 1203 if (requestheader->msgtype == 1204 CHANNELMSG_INITIATE_CONTACT) { 1205 memcpy(&msginfo->response.version_response, 1206 version_response, 1207 sizeof(struct vmbus_channel_version_response)); 1208 complete(&msginfo->waitevent); 1209 } 1210 } 1211 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 1212 } 1213 1214 /* Channel message dispatch table */ 1215 const struct vmbus_channel_message_table_entry 1216 channel_message_table[CHANNELMSG_COUNT] = { 1217 { CHANNELMSG_INVALID, 0, NULL }, 1218 { CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer }, 1219 { CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind }, 1220 { CHANNELMSG_REQUESTOFFERS, 0, NULL }, 1221 { CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered }, 1222 { CHANNELMSG_OPENCHANNEL, 0, NULL }, 1223 { CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result }, 1224 { CHANNELMSG_CLOSECHANNEL, 0, NULL }, 1225 { CHANNELMSG_GPADL_HEADER, 0, NULL }, 1226 { CHANNELMSG_GPADL_BODY, 0, NULL }, 1227 { CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created }, 1228 { CHANNELMSG_GPADL_TEARDOWN, 0, NULL }, 1229 { CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown }, 1230 { CHANNELMSG_RELID_RELEASED, 0, NULL }, 1231 { CHANNELMSG_INITIATE_CONTACT, 0, NULL }, 1232 { CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response }, 1233 { CHANNELMSG_UNLOAD, 0, NULL }, 1234 { CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response }, 1235 { CHANNELMSG_18, 0, NULL }, 1236 { CHANNELMSG_19, 0, NULL }, 1237 { CHANNELMSG_20, 0, NULL }, 1238 { CHANNELMSG_TL_CONNECT_REQUEST, 0, NULL }, 1239 }; 1240 1241 /* 1242 * vmbus_onmessage - Handler for channel protocol messages. 1243 * 1244 * This is invoked in the vmbus worker thread context. 1245 */ 1246 void vmbus_onmessage(void *context) 1247 { 1248 struct hv_message *msg = context; 1249 struct vmbus_channel_message_header *hdr; 1250 int size; 1251 1252 hdr = (struct vmbus_channel_message_header *)msg->u.payload; 1253 size = msg->header.payload_size; 1254 1255 trace_vmbus_on_message(hdr); 1256 1257 if (hdr->msgtype >= CHANNELMSG_COUNT) { 1258 pr_err("Received invalid channel message type %d size %d\n", 1259 hdr->msgtype, size); 1260 print_hex_dump_bytes("", DUMP_PREFIX_NONE, 1261 (unsigned char *)msg->u.payload, size); 1262 return; 1263 } 1264 1265 if (channel_message_table[hdr->msgtype].message_handler) 1266 channel_message_table[hdr->msgtype].message_handler(hdr); 1267 else 1268 pr_err("Unhandled channel message type %d\n", hdr->msgtype); 1269 } 1270 1271 /* 1272 * vmbus_request_offers - Send a request to get all our pending offers. 1273 */ 1274 int vmbus_request_offers(void) 1275 { 1276 struct vmbus_channel_message_header *msg; 1277 struct vmbus_channel_msginfo *msginfo; 1278 int ret; 1279 1280 msginfo = kmalloc(sizeof(*msginfo) + 1281 sizeof(struct vmbus_channel_message_header), 1282 GFP_KERNEL); 1283 if (!msginfo) 1284 return -ENOMEM; 1285 1286 msg = (struct vmbus_channel_message_header *)msginfo->msg; 1287 1288 msg->msgtype = CHANNELMSG_REQUESTOFFERS; 1289 1290 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_message_header), 1291 true); 1292 1293 trace_vmbus_request_offers(ret); 1294 1295 if (ret != 0) { 1296 pr_err("Unable to request offers - %d\n", ret); 1297 1298 goto cleanup; 1299 } 1300 1301 cleanup: 1302 kfree(msginfo); 1303 1304 return ret; 1305 } 1306 1307 static void invoke_sc_cb(struct vmbus_channel *primary_channel) 1308 { 1309 struct list_head *cur, *tmp; 1310 struct vmbus_channel *cur_channel; 1311 1312 if (primary_channel->sc_creation_callback == NULL) 1313 return; 1314 1315 list_for_each_safe(cur, tmp, &primary_channel->sc_list) { 1316 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 1317 1318 primary_channel->sc_creation_callback(cur_channel); 1319 } 1320 } 1321 1322 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, 1323 void (*sc_cr_cb)(struct vmbus_channel *new_sc)) 1324 { 1325 primary_channel->sc_creation_callback = sc_cr_cb; 1326 } 1327 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); 1328 1329 bool vmbus_are_subchannels_present(struct vmbus_channel *primary) 1330 { 1331 bool ret; 1332 1333 ret = !list_empty(&primary->sc_list); 1334 1335 if (ret) { 1336 /* 1337 * Invoke the callback on sub-channel creation. 1338 * This will present a uniform interface to the 1339 * clients. 1340 */ 1341 invoke_sc_cb(primary); 1342 } 1343 1344 return ret; 1345 } 1346 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); 1347 1348 void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel, 1349 void (*chn_rescind_cb)(struct vmbus_channel *)) 1350 { 1351 channel->chn_rescind_callback = chn_rescind_cb; 1352 } 1353 EXPORT_SYMBOL_GPL(vmbus_set_chn_rescind_callback); 1354