sys/dev/hyperv/vmbus/hv_channel_mgmt.c

   1 /*-
   2  * Copyright (c) 2009-2012 Microsoft Corp.
   3  * Copyright (c) 2012 NetApp Inc.
   4  * Copyright (c) 2012 Citrix Inc.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice unmodified, this list of conditions, and the following
  12  *    disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/mbuf.h>
  34
  35 #include "hv_vmbus_priv.h"
  36
  37 /*
  38  * Internal functions
  39  */
  40
  41 static void vmbus_channel_on_offer(hv_vmbus_channel_msg_header* hdr);
  42 static void vmbus_channel_on_offer_internal(void* context);
  43 static void vmbus_channel_on_open_result(hv_vmbus_channel_msg_header* hdr);
  44 static void vmbus_channel_on_offer_rescind(hv_vmbus_channel_msg_header* hdr);
  45 static void vmbus_channel_on_offer_rescind_internal(void* context);
  46 static void vmbus_channel_on_gpadl_created(hv_vmbus_channel_msg_header* hdr);
  47 static void vmbus_channel_on_gpadl_torndown(hv_vmbus_channel_msg_header* hdr);
  48 static void vmbus_channel_on_offers_delivered(hv_vmbus_channel_msg_header* hdr);
  49 static void vmbus_channel_on_version_response(hv_vmbus_channel_msg_header* hdr);
  50
  51 /**
  52  * Channel message dispatch table
  53  */
  54 hv_vmbus_channel_msg_table_entry
  55     g_channel_message_table[HV_CHANNEL_MESSAGE_COUNT] = {
  56         { HV_CHANNEL_MESSAGE_INVALID,
  57                 NULL },
  58         { HV_CHANNEL_MESSAGE_OFFER_CHANNEL,
  59                 vmbus_channel_on_offer },
  60         { HV_CHANNEL_MESSAGE_RESCIND_CHANNEL_OFFER,
  61                 vmbus_channel_on_offer_rescind },
  62         { HV_CHANNEL_MESSAGE_REQUEST_OFFERS,
  63                 NULL },
  64         { HV_CHANNEL_MESSAGE_ALL_OFFERS_DELIVERED,
  65                 vmbus_channel_on_offers_delivered },
  66         { HV_CHANNEL_MESSAGE_OPEN_CHANNEL,
  67                 NULL },
  68         { HV_CHANNEL_MESSAGE_OPEN_CHANNEL_RESULT,
  69                 vmbus_channel_on_open_result },
  70         { HV_CHANNEL_MESSAGE_CLOSE_CHANNEL,
  71                 NULL },
  72         { HV_CHANNEL_MESSAGEL_GPADL_HEADER,
  73                 NULL },
  74         { HV_CHANNEL_MESSAGE_GPADL_BODY,
  75                 NULL },
  76         { HV_CHANNEL_MESSAGE_GPADL_CREATED,
  77                 vmbus_channel_on_gpadl_created },
  78         { HV_CHANNEL_MESSAGE_GPADL_TEARDOWN,
  79                 NULL },
  80         { HV_CHANNEL_MESSAGE_GPADL_TORNDOWN,
  81                 vmbus_channel_on_gpadl_torndown },
  82         { HV_CHANNEL_MESSAGE_REL_ID_RELEASED,
  83                 NULL },
  84         { HV_CHANNEL_MESSAGE_INITIATED_CONTACT,
  85                 NULL },
  86         { HV_CHANNEL_MESSAGE_VERSION_RESPONSE,
  87                 vmbus_channel_on_version_response },
  88         { HV_CHANNEL_MESSAGE_UNLOAD,
  89                 NULL }
  90 };
  91
  92 typedef struct hv_work_item {
  93         struct task     work;
  94         void            (*callback)(void *);
  95         void*           context;
  96 } hv_work_item;
  97
  98 /**
  99  * Implementation of the work abstraction.
 100  */
 101 static void
 102 work_item_callback(void *work, int pending)
 103 {
 104         struct hv_work_item *w = (struct hv_work_item *)work;
 105
 106         w->callback(w->context);
 107
 108         free(w, M_DEVBUF);
 109 }
 110
 111 /**
 112  * @brief Create work item
 113  */
 114 static int
 115 hv_queue_work_item(
 116         void (*callback)(void *), void *context)
 117 {
 118         struct hv_work_item *w = malloc(sizeof(struct hv_work_item),
 119                                         M_DEVBUF, M_NOWAIT);
 120         KASSERT(w != NULL, ("Error VMBUS: Failed to allocate WorkItem\n"));
 121         if (w == NULL)
 122             return (ENOMEM);
 123
 124         w->callback = callback;
 125         w->context = context;
 126
 127         TASK_INIT(&w->work, 0, work_item_callback, w);
 128
 129         return (taskqueue_enqueue(taskqueue_thread, &w->work));
 130 }
 131
 132
 133 /**
 134  * @brief Allocate and initialize a vmbus channel object
 135  */
 136 hv_vmbus_channel*
 137 hv_vmbus_allocate_channel(void)
 138 {
 139         hv_vmbus_channel* channel;
 140
 141         channel = (hv_vmbus_channel*) malloc(
 142                                         sizeof(hv_vmbus_channel),
 143                                         M_DEVBUF,
 144                                         M_WAITOK | M_ZERO);
 145
 146         mtx_init(&channel->sc_lock, "vmbus multi channel", NULL, MTX_DEF);
 147         TAILQ_INIT(&channel->sc_list_anchor);
 148
 149         return (channel);
 150 }
 151
 152 /**
 153  * @brief Release the resources used by the vmbus channel object
 154  */
 155 void
 156 hv_vmbus_free_vmbus_channel(hv_vmbus_channel* channel)
 157 {
 158         mtx_destroy(&channel->sc_lock);
 159         free(channel, M_DEVBUF);
 160 }
 161
 162 /**
 163  * @brief Process the offer by creating a channel/device
 164  * associated with this offer
 165  */
 166 static void
 167 vmbus_channel_process_offer(hv_vmbus_channel *new_channel)
 168 {
 169         boolean_t               f_new;
 170         hv_vmbus_channel*       channel;
 171         int                     ret;
 172         uint32_t                relid;
 173
 174         f_new = TRUE;
 175         channel = NULL;
 176         relid = new_channel->offer_msg.child_rel_id;
 177         /*
 178          * Make sure this is a new offer
 179          */
 180         mtx_lock(&hv_vmbus_g_connection.channel_lock);
 181         hv_vmbus_g_connection.channels[relid] = new_channel;
 182
 183         TAILQ_FOREACH(channel, &hv_vmbus_g_connection.channel_anchor,
 184             list_entry)
 185         {
 186                 if (memcmp(&channel->offer_msg.offer.interface_type,
 187                     &new_channel->offer_msg.offer.interface_type,
 188                     sizeof(hv_guid)) == 0 &&
 189                     memcmp(&channel->offer_msg.offer.interface_instance,
 190                     &new_channel->offer_msg.offer.interface_instance,
 191                     sizeof(hv_guid)) == 0) {
 192                         f_new = FALSE;
 193                         break;
 194                 }
 195         }
 196
 197         if (f_new) {
 198                 /* Insert at tail */
 199                 TAILQ_INSERT_TAIL(
 200                     &hv_vmbus_g_connection.channel_anchor,
 201                     new_channel,
 202                     list_entry);
 203         }
 204         mtx_unlock(&hv_vmbus_g_connection.channel_lock);
 205
 206         /*XXX add new channel to percpu_list */
 207
 208         if (!f_new) {
 209                 /*
 210                  * Check if this is a sub channel.
 211                  */
 212                 if (new_channel->offer_msg.offer.sub_channel_index != 0) {
 213                         /*
 214                          * It is a sub channel offer, process it.
 215                          */
 216                         new_channel->primary_channel = channel;
 217                         new_channel->device = channel->device;
 218                         mtx_lock(&channel->sc_lock);
 219                         TAILQ_INSERT_TAIL(
 220                             &channel->sc_list_anchor,
 221                             new_channel,
 222                             sc_list_entry);
 223                         mtx_unlock(&channel->sc_lock);
 224
 225                         /* Insert new channel into channel_anchor. */
 226                         printf("VMBUS get multi-channel offer, rel=%u,sub=%u\n",
 227                             new_channel->offer_msg.child_rel_id,
 228                             new_channel->offer_msg.offer.sub_channel_index);
 229                         mtx_lock(&hv_vmbus_g_connection.channel_lock);
 230                         TAILQ_INSERT_TAIL(&hv_vmbus_g_connection.channel_anchor,
 231                             new_channel, list_entry);
 232                         mtx_unlock(&hv_vmbus_g_connection.channel_lock);
 233
 234                         if(bootverbose)
 235                                 printf("VMBUS: new multi-channel offer <%p>, "
 236                                     "its primary channel is <%p>.\n",
 237                                     new_channel, new_channel->primary_channel);
 238
 239                         /*XXX add it to percpu_list */
 240
 241                         new_channel->state = HV_CHANNEL_OPEN_STATE;
 242                         if (channel->sc_creation_callback != NULL) {
 243                                 channel->sc_creation_callback(new_channel);
 244                         }
 245                         return;
 246                 }
 247
 248             hv_vmbus_free_vmbus_channel(new_channel);
 249             return;
 250         }
 251
 252         new_channel->state = HV_CHANNEL_OPEN_STATE;
 253
 254         /*
 255          * Start the process of binding this offer to the driver
 256          * (We need to set the device field before calling
 257          * hv_vmbus_child_device_add())
 258          */
 259         new_channel->device = hv_vmbus_child_device_create(
 260             new_channel->offer_msg.offer.interface_type,
 261             new_channel->offer_msg.offer.interface_instance, new_channel);
 262
 263         /*
 264          * Add the new device to the bus. This will kick off device-driver
 265          * binding which eventually invokes the device driver's AddDevice()
 266          * method.
 267          */
 268         ret = hv_vmbus_child_device_register(new_channel->device);
 269         if (ret != 0) {
 270                 mtx_lock(&hv_vmbus_g_connection.channel_lock);
 271                 TAILQ_REMOVE(
 272                     &hv_vmbus_g_connection.channel_anchor,
 273                     new_channel,
 274                     list_entry);
 275                 mtx_unlock(&hv_vmbus_g_connection.channel_lock);
 276                 hv_vmbus_free_vmbus_channel(new_channel);
 277         }
 278 }
 279
 280 static void
 281 vmbus_channel_cpu_set(struct hv_vmbus_channel *chan, int cpu)
 282 {
 283         KASSERT(cpu >= 0 && cpu < mp_ncpus, ("invalid cpu %d", cpu));
 284
 285         if (hv_vmbus_protocal_version == HV_VMBUS_VERSION_WS2008 ||
 286             hv_vmbus_protocal_version == HV_VMBUS_VERSION_WIN7) {
 287                 /* Only cpu0 is supported */
 288                 cpu = 0;
 289         }
 290
 291         chan->target_cpu = cpu;
 292         chan->target_vcpu = hv_vmbus_g_context.hv_vcpu_index[cpu];
 293
 294         if (bootverbose) {
 295                 printf("vmbus_chan%u: assigned to cpu%u [vcpu%u]\n",
 296                     chan->offer_msg.child_rel_id,
 297                     chan->target_cpu, chan->target_vcpu);
 298         }
 299 }
 300
 301 /**
 302  * Array of device guids that are performance critical. We try to distribute
 303  * the interrupt load for these devices across all online cpus.
 304  */
 305 static const hv_guid high_perf_devices[] = {
 306         {HV_NIC_GUID, },
 307         {HV_IDE_GUID, },
 308         {HV_SCSI_GUID, },
 309 };
 310
 311 enum {
 312         PERF_CHN_NIC = 0,
 313         PERF_CHN_IDE,
 314         PERF_CHN_SCSI,
 315         MAX_PERF_CHN,
 316 };
 317
 318 /*
 319  * We use this static number to distribute the channel interrupt load.
 320  */
 321 static uint32_t next_vcpu;
 322
 323 /**
 324  * Starting with Win8, we can statically distribute the incoming
 325  * channel interrupt load by binding a channel to VCPU. We
 326  * implement here a simple round robin scheme for distributing
 327  * the interrupt load.
 328  * We will bind channels that are not performance critical to cpu 0 and
 329  * performance critical channels (IDE, SCSI and Network) will be uniformly
 330  * distributed across all available CPUs.
 331  */
 332 static void
 333 vmbus_channel_select_defcpu(struct hv_vmbus_channel *channel)
 334 {
 335         uint32_t current_cpu;
 336         int i;
 337         boolean_t is_perf_channel = FALSE;
 338         const hv_guid *guid = &channel->offer_msg.offer.interface_type;
 339
 340         for (i = PERF_CHN_NIC; i < MAX_PERF_CHN; i++) {
 341                 if (memcmp(guid->data, high_perf_devices[i].data,
 342                     sizeof(hv_guid)) == 0) {
 343                         is_perf_channel = TRUE;
 344                         break;
 345                 }
 346         }
 347
 348         if (!is_perf_channel) {
 349                 /* Stick to cpu0 */
 350                 vmbus_channel_cpu_set(channel, 0);
 351                 return;
 352         }
 353         /* mp_ncpus should have the number cpus currently online */
 354         current_cpu = (++next_vcpu % mp_ncpus);
 355         vmbus_channel_cpu_set(channel, current_cpu);
 356 }
 357
 358 /**
 359  * @brief Handler for channel offers from Hyper-V/Azure
 360  *
 361  * Handler for channel offers from vmbus in parent partition. We ignore
 362  * all offers except network and storage offers. For each network and storage
 363  * offers, we create a channel object and queue a work item to the channel
 364  * object to process the offer synchronously
 365  */
 366 static void
 367 vmbus_channel_on_offer(hv_vmbus_channel_msg_header* hdr)
 368 {
 369         hv_vmbus_channel_offer_channel* offer;
 370         hv_vmbus_channel_offer_channel* copied;
 371
 372         offer = (hv_vmbus_channel_offer_channel*) hdr;
 373
 374         hv_guid *guidType;
 375         hv_guid *guidInstance;
 376
 377         guidType = &offer->offer.interface_type;
 378         guidInstance = &offer->offer.interface_instance;
 379
 380         // copy offer data
 381         copied = malloc(sizeof(*copied), M_DEVBUF, M_NOWAIT);
 382         if (copied == NULL) {
 383                 printf("fail to allocate memory\n");
 384                 return;
 385         }
 386
 387         memcpy(copied, hdr, sizeof(*copied));
 388         hv_queue_work_item(vmbus_channel_on_offer_internal, copied);
 389 }
 390
 391 static void
 392 vmbus_channel_on_offer_internal(void* context)
 393 {
 394         hv_vmbus_channel* new_channel;
 395
 396         hv_vmbus_channel_offer_channel* offer = (hv_vmbus_channel_offer_channel*)context;
 397         /* Allocate the channel object and save this offer */
 398         new_channel = hv_vmbus_allocate_channel();
 399
 400         /*
 401          * By default we setup state to enable batched
 402          * reading. A specific service can choose to
 403          * disable this prior to opening the channel.
 404          */
 405         new_channel->batched_reading = TRUE;
 406
 407         new_channel->signal_event_param =
 408             (hv_vmbus_input_signal_event *)
 409             (HV_ALIGN_UP((unsigned long)
 410                 &new_channel->signal_event_buffer,
 411                 HV_HYPERCALL_PARAM_ALIGN));
 412
 413         new_channel->signal_event_param->connection_id.as_uint32_t = 0;
 414         new_channel->signal_event_param->connection_id.u.id =
 415             HV_VMBUS_EVENT_CONNECTION_ID;
 416         new_channel->signal_event_param->flag_number = 0;
 417         new_channel->signal_event_param->rsvd_z = 0;
 418
 419         if (hv_vmbus_protocal_version != HV_VMBUS_VERSION_WS2008) {
 420                 new_channel->is_dedicated_interrupt =
 421                     (offer->is_dedicated_interrupt != 0);
 422                 new_channel->signal_event_param->connection_id.u.id =
 423                     offer->connection_id;
 424         }
 425
 426         memcpy(&new_channel->offer_msg, offer,
 427             sizeof(hv_vmbus_channel_offer_channel));
 428         new_channel->monitor_group = (uint8_t) offer->monitor_id / 32;
 429         new_channel->monitor_bit = (uint8_t) offer->monitor_id % 32;
 430
 431         /* Select default cpu for this channel. */
 432         vmbus_channel_select_defcpu(new_channel);
 433
 434         vmbus_channel_process_offer(new_channel);
 435
 436         free(offer, M_DEVBUF);
 437 }
 438
 439 /**
 440  * @brief Rescind offer handler.
 441  *
 442  * We queue a work item to process this offer
 443  * synchronously
 444  */
 445 static void
 446 vmbus_channel_on_offer_rescind(hv_vmbus_channel_msg_header* hdr)
 447 {
 448         hv_vmbus_channel_rescind_offer* rescind;
 449         hv_vmbus_channel*               channel;
 450
 451         rescind = (hv_vmbus_channel_rescind_offer*) hdr;
 452
 453         channel = hv_vmbus_g_connection.channels[rescind->child_rel_id];
 454         if (channel == NULL)
 455             return;
 456
 457         hv_queue_work_item(vmbus_channel_on_offer_rescind_internal, channel);
 458         hv_vmbus_g_connection.channels[rescind->child_rel_id] = NULL;
 459 }
 460
 461 static void
 462 vmbus_channel_on_offer_rescind_internal(void *context)
 463 {
 464         hv_vmbus_channel*               channel;
 465
 466         channel = (hv_vmbus_channel*)context;
 467         if (HV_VMBUS_CHAN_ISPRIMARY(channel)) {
 468                 /* Only primary channel owns the hv_device */
 469                 hv_vmbus_child_device_unregister(channel->device);
 470         }
 471 }
 472
 473 /**
 474  *
 475  * @brief Invoked when all offers have been delivered.
 476  */
 477 static void
 478 vmbus_channel_on_offers_delivered(hv_vmbus_channel_msg_header* hdr)
 479 {
 480 }
 481
 482 /**
 483  * @brief Open result handler.
 484  *
 485  * This is invoked when we received a response
 486  * to our channel open request. Find the matching request, copy the
 487  * response and signal the requesting thread.
 488  */
 489 static void
 490 vmbus_channel_on_open_result(hv_vmbus_channel_msg_header* hdr)
 491 {
 492         hv_vmbus_channel_open_result*   result;
 493         hv_vmbus_channel_msg_info*      msg_info;
 494         hv_vmbus_channel_msg_header*    requestHeader;
 495         hv_vmbus_channel_open_channel*  openMsg;
 496
 497         result = (hv_vmbus_channel_open_result*) hdr;
 498
 499         /*
 500          * Find the open msg, copy the result and signal/unblock the wait event
 501          */
 502         mtx_lock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 503
 504         TAILQ_FOREACH(msg_info, &hv_vmbus_g_connection.channel_msg_anchor,
 505             msg_list_entry) {
 506             requestHeader = (hv_vmbus_channel_msg_header*) msg_info->msg;
 507
 508             if (requestHeader->message_type ==
 509                     HV_CHANNEL_MESSAGE_OPEN_CHANNEL) {
 510                 openMsg = (hv_vmbus_channel_open_channel*) msg_info->msg;
 511                 if (openMsg->child_rel_id == result->child_rel_id
 512                     && openMsg->open_id == result->open_id) {
 513                     memcpy(&msg_info->response.open_result, result,
 514                         sizeof(hv_vmbus_channel_open_result));
 515                     sema_post(&msg_info->wait_sema);
 516                     break;
 517                 }
 518             }
 519         }
 520         mtx_unlock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 521
 522 }
 523
 524 /**
 525  * @brief GPADL created handler.
 526  *
 527  * This is invoked when we received a response
 528  * to our gpadl create request. Find the matching request, copy the
 529  * response and signal the requesting thread.
 530  */
 531 static void
 532 vmbus_channel_on_gpadl_created(hv_vmbus_channel_msg_header* hdr)
 533 {
 534         hv_vmbus_channel_gpadl_created*         gpadl_created;
 535         hv_vmbus_channel_msg_info*              msg_info;
 536         hv_vmbus_channel_msg_header*            request_header;
 537         hv_vmbus_channel_gpadl_header*          gpadl_header;
 538
 539         gpadl_created = (hv_vmbus_channel_gpadl_created*) hdr;
 540
 541         /* Find the establish msg, copy the result and signal/unblock
 542          * the wait event
 543          */
 544         mtx_lock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 545         TAILQ_FOREACH(msg_info, &hv_vmbus_g_connection.channel_msg_anchor,
 546                 msg_list_entry) {
 547             request_header = (hv_vmbus_channel_msg_header*) msg_info->msg;
 548             if (request_header->message_type ==
 549                     HV_CHANNEL_MESSAGEL_GPADL_HEADER) {
 550                 gpadl_header =
 551                     (hv_vmbus_channel_gpadl_header*) request_header;
 552
 553                 if ((gpadl_created->child_rel_id == gpadl_header->child_rel_id)
 554                     && (gpadl_created->gpadl == gpadl_header->gpadl)) {
 555                     memcpy(&msg_info->response.gpadl_created,
 556                         gpadl_created,
 557                         sizeof(hv_vmbus_channel_gpadl_created));
 558                     sema_post(&msg_info->wait_sema);
 559                     break;
 560                 }
 561             }
 562         }
 563         mtx_unlock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 564 }
 565
 566 /**
 567  * @brief GPADL torndown handler.
 568  *
 569  * This is invoked when we received a respons
 570  * to our gpadl teardown request. Find the matching request, copy the
 571  * response and signal the requesting thread
 572  */
 573 static void
 574 vmbus_channel_on_gpadl_torndown(hv_vmbus_channel_msg_header* hdr)
 575 {
 576         hv_vmbus_channel_gpadl_torndown*        gpadl_torndown;
 577         hv_vmbus_channel_msg_info*              msg_info;
 578         hv_vmbus_channel_msg_header*            requestHeader;
 579         hv_vmbus_channel_gpadl_teardown*        gpadlTeardown;
 580
 581         gpadl_torndown = (hv_vmbus_channel_gpadl_torndown*)hdr;
 582
 583         /*
 584          * Find the open msg, copy the result and signal/unblock the
 585          * wait event.
 586          */
 587
 588         mtx_lock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 589
 590         TAILQ_FOREACH(msg_info, &hv_vmbus_g_connection.channel_msg_anchor,
 591                 msg_list_entry) {
 592             requestHeader = (hv_vmbus_channel_msg_header*) msg_info->msg;
 593
 594             if (requestHeader->message_type
 595                     == HV_CHANNEL_MESSAGE_GPADL_TEARDOWN) {
 596                 gpadlTeardown =
 597                     (hv_vmbus_channel_gpadl_teardown*) requestHeader;
 598
 599                 if (gpadl_torndown->gpadl == gpadlTeardown->gpadl) {
 600                     memcpy(&msg_info->response.gpadl_torndown,
 601                         gpadl_torndown,
 602                         sizeof(hv_vmbus_channel_gpadl_torndown));
 603                     sema_post(&msg_info->wait_sema);
 604                     break;
 605                 }
 606             }
 607         }
 608     mtx_unlock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 609 }
 610
 611 /**
 612  * @brief Version response handler.
 613  *
 614  * This is invoked when we received a response
 615  * to our initiate contact request. Find the matching request, copy th
 616  * response and signal the requesting thread.
 617  */
 618 static void
 619 vmbus_channel_on_version_response(hv_vmbus_channel_msg_header* hdr)
 620 {
 621         hv_vmbus_channel_msg_info*              msg_info;
 622         hv_vmbus_channel_msg_header*            requestHeader;
 623         hv_vmbus_channel_initiate_contact*      initiate;
 624         hv_vmbus_channel_version_response*      versionResponse;
 625
 626         versionResponse = (hv_vmbus_channel_version_response*)hdr;
 627
 628         mtx_lock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 629         TAILQ_FOREACH(msg_info, &hv_vmbus_g_connection.channel_msg_anchor,
 630             msg_list_entry) {
 631             requestHeader = (hv_vmbus_channel_msg_header*) msg_info->msg;
 632             if (requestHeader->message_type
 633                 == HV_CHANNEL_MESSAGE_INITIATED_CONTACT) {
 634                 initiate =
 635                     (hv_vmbus_channel_initiate_contact*) requestHeader;
 636                 memcpy(&msg_info->response.version_response,
 637                     versionResponse,
 638                     sizeof(hv_vmbus_channel_version_response));
 639                 sema_post(&msg_info->wait_sema);
 640             }
 641         }
 642     mtx_unlock_spin(&hv_vmbus_g_connection.channel_msg_lock);
 643
 644 }
 645
 646 /**
 647  *  @brief Send a request to get all our pending offers.
 648  */
 649 int
 650 hv_vmbus_request_channel_offers(void)
 651 {
 652         int                             ret;
 653         hv_vmbus_channel_msg_header*    msg;
 654         hv_vmbus_channel_msg_info*      msg_info;
 655
 656         msg_info = (hv_vmbus_channel_msg_info *)
 657             malloc(sizeof(hv_vmbus_channel_msg_info)
 658                     + sizeof(hv_vmbus_channel_msg_header), M_DEVBUF, M_NOWAIT);
 659
 660         if (msg_info == NULL) {
 661             if(bootverbose)
 662                 printf("Error VMBUS: malloc failed for Request Offers\n");
 663             return (ENOMEM);
 664         }
 665
 666         msg = (hv_vmbus_channel_msg_header*) msg_info->msg;
 667         msg->message_type = HV_CHANNEL_MESSAGE_REQUEST_OFFERS;
 668
 669         ret = hv_vmbus_post_message(msg, sizeof(hv_vmbus_channel_msg_header));
 670
 671         free(msg_info, M_DEVBUF);
 672
 673         return (ret);
 674 }
 675
 676 /**
 677  * @brief Release channels that are unattached/unconnected (i.e., no drivers associated)
 678  */
 679 void
 680 hv_vmbus_release_unattached_channels(void)
 681 {
 682         hv_vmbus_channel *channel;
 683
 684         mtx_lock(&hv_vmbus_g_connection.channel_lock);
 685
 686         while (!TAILQ_EMPTY(&hv_vmbus_g_connection.channel_anchor)) {
 687             channel = TAILQ_FIRST(&hv_vmbus_g_connection.channel_anchor);
 688             TAILQ_REMOVE(&hv_vmbus_g_connection.channel_anchor,
 689                             channel, list_entry);
 690
 691             if (HV_VMBUS_CHAN_ISPRIMARY(channel)) {
 692                 /* Only primary channel owns the hv_device */
 693                 hv_vmbus_child_device_unregister(channel->device);
 694             }
 695             hv_vmbus_free_vmbus_channel(channel);
 696         }
 697         bzero(hv_vmbus_g_connection.channels,
 698                 sizeof(hv_vmbus_channel*) * HV_CHANNEL_MAX_COUNT);
 699         mtx_unlock(&hv_vmbus_g_connection.channel_lock);
 700 }
 701
 702 /**
 703  * @brief Select the best outgoing channel
 704  *
 705  * The channel whose vcpu binding is closest to the currect vcpu will
 706  * be selected.
 707  * If no multi-channel, always select primary channel
 708  *
 709  * @param primary - primary channel
 710  */
 711 struct hv_vmbus_channel *
 712 vmbus_select_outgoing_channel(struct hv_vmbus_channel *primary)
 713 {
 714         hv_vmbus_channel *new_channel = NULL;
 715         hv_vmbus_channel *outgoing_channel = primary;
 716         int old_cpu_distance = 0;
 717         int new_cpu_distance = 0;
 718         int cur_vcpu = 0;
 719         int smp_pro_id = PCPU_GET(cpuid);
 720
 721         if (TAILQ_EMPTY(&primary->sc_list_anchor)) {
 722                 return outgoing_channel;
 723         }
 724
 725         if (smp_pro_id >= MAXCPU) {
 726                 return outgoing_channel;
 727         }
 728
 729         cur_vcpu = hv_vmbus_g_context.hv_vcpu_index[smp_pro_id];
 730
 731         TAILQ_FOREACH(new_channel, &primary->sc_list_anchor, sc_list_entry) {
 732                 if (new_channel->state != HV_CHANNEL_OPENED_STATE){
 733                         continue;
 734                 }
 735
 736                 if (new_channel->target_vcpu == cur_vcpu){
 737                         return new_channel;
 738                 }
 739
 740                 old_cpu_distance = ((outgoing_channel->target_vcpu > cur_vcpu) ?
 741                     (outgoing_channel->target_vcpu - cur_vcpu) :
 742                     (cur_vcpu - outgoing_channel->target_vcpu));
 743
 744                 new_cpu_distance = ((new_channel->target_vcpu > cur_vcpu) ?
 745                     (new_channel->target_vcpu - cur_vcpu) :
 746                     (cur_vcpu - new_channel->target_vcpu));
 747
 748                 if (old_cpu_distance < new_cpu_distance) {
 749                         continue;
 750                 }
 751
 752                 outgoing_channel = new_channel;
 753         }
 754
 755         return(outgoing_channel);
 756 }