drivers/hv/channel_mgmt.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/wait.h>
  26 #include <linux/mm.h>
  27 #include <linux/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/module.h>
  30 #include <linux/completion.h>
  31 #include <linux/hyperv.h>
  32
  33 #include "hyperv_vmbus.h"
  34
  35 struct vmbus_channel_message_table_entry {
  36         enum vmbus_channel_message_type message_type;
  37         void (*message_handler)(struct vmbus_channel_message_header *msg);
  38 };
  39
  40
  41 /**
  42  * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
  43  * @icmsghdrp: Pointer to msg header structure
  44  * @icmsg_negotiate: Pointer to negotiate message structure
  45  * @buf: Raw buffer channel data
  46  *
  47  * @icmsghdrp is of type &struct icmsg_hdr.
  48  * @negop is of type &struct icmsg_negotiate.
  49  * Set up and fill in default negotiate response message.
  50  *
  51  * The max_fw_version specifies the maximum framework version that
  52  * we can support and max _srv_version specifies the maximum service
  53  * version we can support. A special value MAX_SRV_VER can be
  54  * specified to indicate that we can handle the maximum version
  55  * exposed by the host.
  56  *
  57  * Mainly used by Hyper-V drivers.
  58  */
  59 void vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
  60                                 struct icmsg_negotiate *negop, u8 *buf,
  61                                 int max_fw_version, int max_srv_version)
  62 {
  63         int icframe_vercnt;
  64         int icmsg_vercnt;
  65         int i;
  66
  67         icmsghdrp->icmsgsize = 0x10;
  68
  69         negop = (struct icmsg_negotiate *)&buf[
  70                 sizeof(struct vmbuspipe_hdr) +
  71                 sizeof(struct icmsg_hdr)];
  72
  73         icframe_vercnt = negop->icframe_vercnt;
  74         icmsg_vercnt = negop->icmsg_vercnt;
  75
  76         /*
  77          * Select the framework version number we will
  78          * support.
  79          */
  80
  81         for (i = 0; i < negop->icframe_vercnt; i++) {
  82                 if (negop->icversion_data[i].major <= max_fw_version)
  83                         icframe_vercnt = negop->icversion_data[i].major;
  84         }
  85
  86         for (i = negop->icframe_vercnt;
  87                  (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
  88                 if (negop->icversion_data[i].major <= max_srv_version)
  89                         icmsg_vercnt = negop->icversion_data[i].major;
  90         }
  91
  92         /*
  93          * Respond with the maximum framework and service
  94          * version numbers we can support.
  95          */
  96         negop->icframe_vercnt = 1;
  97         negop->icmsg_vercnt = 1;
  98         negop->icversion_data[0].major = icframe_vercnt;
  99         negop->icversion_data[0].minor = 0;
 100         negop->icversion_data[1].major = icmsg_vercnt;
 101         negop->icversion_data[1].minor = 0;
 102 }
 103
 104 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
 105
 106 /*
 107  * alloc_channel - Allocate and initialize a vmbus channel object
 108  */
 109 static struct vmbus_channel *alloc_channel(void)
 110 {
 111         struct vmbus_channel *channel;
 112
 113         channel = kzalloc(sizeof(*channel), GFP_ATOMIC);
 114         if (!channel)
 115                 return NULL;
 116
 117         spin_lock_init(&channel->inbound_lock);
 118
 119         channel->controlwq = create_workqueue("hv_vmbus_ctl");
 120         if (!channel->controlwq) {
 121                 kfree(channel);
 122                 return NULL;
 123         }
 124
 125         return channel;
 126 }
 127
 128 /*
 129  * release_hannel - Release the vmbus channel object itself
 130  */
 131 static void release_channel(struct work_struct *work)
 132 {
 133         struct vmbus_channel *channel = container_of(work,
 134                                                      struct vmbus_channel,
 135                                                      work);
 136
 137         destroy_workqueue(channel->controlwq);
 138
 139         kfree(channel);
 140 }
 141
 142 /*
 143  * free_channel - Release the resources used by the vmbus channel object
 144  */
 145 static void free_channel(struct vmbus_channel *channel)
 146 {
 147
 148         /*
 149          * We have to release the channel's workqueue/thread in the vmbus's
 150          * workqueue/thread context
 151          * ie we can't destroy ourselves.
 152          */
 153         INIT_WORK(&channel->work, release_channel);
 154         queue_work(vmbus_connection.work_queue, &channel->work);
 155 }
 156
 157
 158
 159 /*
 160  * vmbus_process_rescind_offer -
 161  * Rescind the offer by initiating a device removal
 162  */
 163 static void vmbus_process_rescind_offer(struct work_struct *work)
 164 {
 165         struct vmbus_channel *channel = container_of(work,
 166                                                      struct vmbus_channel,
 167                                                      work);
 168
 169         vmbus_device_unregister(channel->device_obj);
 170 }
 171
 172 void vmbus_free_channels(void)
 173 {
 174         struct vmbus_channel *channel;
 175
 176         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 177                 vmbus_device_unregister(channel->device_obj);
 178                 kfree(channel->device_obj);
 179                 free_channel(channel);
 180         }
 181 }
 182
 183 /*
 184  * vmbus_process_offer - Process the offer by creating a channel/device
 185  * associated with this offer
 186  */
 187 static void vmbus_process_offer(struct work_struct *work)
 188 {
 189         struct vmbus_channel *newchannel = container_of(work,
 190                                                         struct vmbus_channel,
 191                                                         work);
 192         struct vmbus_channel *channel;
 193         bool fnew = true;
 194         int ret;
 195         unsigned long flags;
 196
 197         /* The next possible work is rescind handling */
 198         INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);
 199
 200         /* Make sure this is a new offer */
 201         spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 202
 203         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 204                 if (!uuid_le_cmp(channel->offermsg.offer.if_type,
 205                         newchannel->offermsg.offer.if_type) &&
 206                         !uuid_le_cmp(channel->offermsg.offer.if_instance,
 207                                 newchannel->offermsg.offer.if_instance)) {
 208                         fnew = false;
 209                         break;
 210                 }
 211         }
 212
 213         if (fnew)
 214                 list_add_tail(&newchannel->listentry,
 215                               &vmbus_connection.chn_list);
 216
 217         spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 218
 219         if (!fnew) {
 220                 free_channel(newchannel);
 221                 return;
 222         }
 223
 224         /*
 225          * Start the process of binding this offer to the driver
 226          * We need to set the DeviceObject field before calling
 227          * vmbus_child_dev_add()
 228          */
 229         newchannel->device_obj = vmbus_device_create(
 230                 &newchannel->offermsg.offer.if_type,
 231                 &newchannel->offermsg.offer.if_instance,
 232                 newchannel);
 233
 234         /*
 235          * Add the new device to the bus. This will kick off device-driver
 236          * binding which eventually invokes the device driver's AddDevice()
 237          * method.
 238          */
 239         ret = vmbus_device_register(newchannel->device_obj);
 240         if (ret != 0) {
 241                 pr_err("unable to add child device object (relid %d)\n",
 242                            newchannel->offermsg.child_relid);
 243
 244                 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 245                 list_del(&newchannel->listentry);
 246                 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 247                 kfree(newchannel->device_obj);
 248
 249                 free_channel(newchannel);
 250         } else {
 251                 /*
 252                  * This state is used to indicate a successful open
 253                  * so that when we do close the channel normally, we
 254                  * can cleanup properly
 255                  */
 256                 newchannel->state = CHANNEL_OPEN_STATE;
 257         }
 258 }
 259
 260 enum {
 261         IDE = 0,
 262         SCSI,
 263         NIC,
 264         MAX_PERF_CHN,
 265 };
 266
 267 /*
 268  * This is an array of channels (devices) that are performance critical.
 269  * We attempt to distribute the interrupt load for these devices across
 270  * all available CPUs.
 271  */
 272 static const uuid_le hp_devs[] = {
 273         /* {32412632-86cb-44a2-9b5c-50d1417354f5} */
 274         /* IDE */
 275         {
 276                 .b = {
 277                         0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44,
 278                         0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5
 279                 }
 280         },
 281         /* {ba6163d9-04a1-4d29-b605-72e2ffb1dc7f} */
 282         /* Storage - SCSI */
 283         {
 284                 .b  = {
 285                         0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
 286                         0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f
 287                 }
 288         },
 289         /* {F8615163-DF3E-46c5-913F-F2D2F965ED0E} */
 290         /* Network */
 291         {
 292                 .b = {
 293                         0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46,
 294                         0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E
 295                 }
 296         },
 297
 298 };
 299
 300
 301 /*
 302  * We use this state to statically distribute the channel interrupt load.
 303  */
 304 static u32  next_vp;
 305
 306 /*
 307  * Starting with Win8, we can statically distribute the incoming
 308  * channel interrupt load by binding a channel to VCPU. We
 309  * implement here a simple round robin scheme for distributing
 310  * the interrupt load.
 311  * We will bind channels that are not performance critical to cpu 0 and
 312  * performance critical channels (IDE, SCSI and Network) will be uniformly
 313  * distributed across all available CPUs.
 314  */
 315 static u32 get_vp_index(uuid_le *type_guid)
 316 {
 317         u32 cur_cpu;
 318         int i;
 319         bool perf_chn = false;
 320         u32 max_cpus = num_online_cpus();
 321
 322         for (i = IDE; i < MAX_PERF_CHN; i++) {
 323                 if (!memcmp(type_guid->b, hp_devs[i].b,
 324                                  sizeof(uuid_le))) {
 325                         perf_chn = true;
 326                         break;
 327                 }
 328         }
 329         if ((vmbus_proto_version == VERSION_WS2008) ||
 330             (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
 331                 /*
 332                  * Prior to win8, all channel interrupts are
 333                  * delivered on cpu 0.
 334                  * Also if the channel is not a performance critical
 335                  * channel, bind it to cpu 0.
 336                  */
 337                 return 0;
 338         }
 339         cur_cpu = (++next_vp % max_cpus);
 340         return 0;
 341 }
 342
 343 /*
 344  * vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
 345  *
 346  */
 347 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 348 {
 349         struct vmbus_channel_offer_channel *offer;
 350         struct vmbus_channel *newchannel;
 351
 352         offer = (struct vmbus_channel_offer_channel *)hdr;
 353
 354         /* Allocate the channel object and save this offer. */
 355         newchannel = alloc_channel();
 356         if (!newchannel) {
 357                 pr_err("Unable to allocate channel object\n");
 358                 return;
 359         }
 360
 361         /*
 362          * By default we setup state to enable batched
 363          * reading. A specific service can choose to
 364          * disable this prior to opening the channel.
 365          */
 366         newchannel->batched_reading = true;
 367
 368         /*
 369          * Setup state for signalling the host.
 370          */
 371         newchannel->sig_event = (struct hv_input_signal_event *)
 372                                 (ALIGN((unsigned long)
 373                                 &newchannel->sig_buf,
 374                                 HV_HYPERCALL_PARAM_ALIGN));
 375
 376         newchannel->sig_event->connectionid.asu32 = 0;
 377         newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
 378         newchannel->sig_event->flag_number = 0;
 379         newchannel->sig_event->rsvdz = 0;
 380
 381         if (vmbus_proto_version != VERSION_WS2008) {
 382                 newchannel->is_dedicated_interrupt =
 383                                 (offer->is_dedicated_interrupt != 0);
 384                 newchannel->sig_event->connectionid.u.id =
 385                                 offer->connection_id;
 386         }
 387
 388         newchannel->target_vp = get_vp_index(&offer->offer.if_type);
 389
 390         memcpy(&newchannel->offermsg, offer,
 391                sizeof(struct vmbus_channel_offer_channel));
 392         newchannel->monitor_grp = (u8)offer->monitorid / 32;
 393         newchannel->monitor_bit = (u8)offer->monitorid % 32;
 394
 395         INIT_WORK(&newchannel->work, vmbus_process_offer);
 396         queue_work(newchannel->controlwq, &newchannel->work);
 397 }
 398
 399 /*
 400  * vmbus_onoffer_rescind - Rescind offer handler.
 401  *
 402  * We queue a work item to process this offer synchronously
 403  */
 404 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 405 {
 406         struct vmbus_channel_rescind_offer *rescind;
 407         struct vmbus_channel *channel;
 408
 409         rescind = (struct vmbus_channel_rescind_offer *)hdr;
 410         channel = relid2channel(rescind->child_relid);
 411
 412         if (channel == NULL)
 413                 /* Just return here, no channel found */
 414                 return;
 415
 416         /* work is initialized for vmbus_process_rescind_offer() from
 417          * vmbus_process_offer() where the channel got created */
 418         queue_work(channel->controlwq, &channel->work);
 419 }
 420
 421 /*
 422  * vmbus_onoffers_delivered -
 423  * This is invoked when all offers have been delivered.
 424  *
 425  * Nothing to do here.
 426  */
 427 static void vmbus_onoffers_delivered(
 428                         struct vmbus_channel_message_header *hdr)
 429 {
 430 }
 431
 432 /*
 433  * vmbus_onopen_result - Open result handler.
 434  *
 435  * This is invoked when we received a response to our channel open request.
 436  * Find the matching request, copy the response and signal the requesting
 437  * thread.
 438  */
 439 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
 440 {
 441         struct vmbus_channel_open_result *result;
 442         struct vmbus_channel_msginfo *msginfo;
 443         struct vmbus_channel_message_header *requestheader;
 444         struct vmbus_channel_open_channel *openmsg;
 445         unsigned long flags;
 446
 447         result = (struct vmbus_channel_open_result *)hdr;
 448
 449         /*
 450          * Find the open msg, copy the result and signal/unblock the wait event
 451          */
 452         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 453
 454         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 455                                 msglistentry) {
 456                 requestheader =
 457                         (struct vmbus_channel_message_header *)msginfo->msg;
 458
 459                 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
 460                         openmsg =
 461                         (struct vmbus_channel_open_channel *)msginfo->msg;
 462                         if (openmsg->child_relid == result->child_relid &&
 463                             openmsg->openid == result->openid) {
 464                                 memcpy(&msginfo->response.open_result,
 465                                        result,
 466                                        sizeof(
 467                                         struct vmbus_channel_open_result));
 468                                 complete(&msginfo->waitevent);
 469                                 break;
 470                         }
 471                 }
 472         }
 473         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 474 }
 475
 476 /*
 477  * vmbus_ongpadl_created - GPADL created handler.
 478  *
 479  * This is invoked when we received a response to our gpadl create request.
 480  * Find the matching request, copy the response and signal the requesting
 481  * thread.
 482  */
 483 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
 484 {
 485         struct vmbus_channel_gpadl_created *gpadlcreated;
 486         struct vmbus_channel_msginfo *msginfo;
 487         struct vmbus_channel_message_header *requestheader;
 488         struct vmbus_channel_gpadl_header *gpadlheader;
 489         unsigned long flags;
 490
 491         gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;
 492
 493         /*
 494          * Find the establish msg, copy the result and signal/unblock the wait
 495          * event
 496          */
 497         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 498
 499         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 500                                 msglistentry) {
 501                 requestheader =
 502                         (struct vmbus_channel_message_header *)msginfo->msg;
 503
 504                 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
 505                         gpadlheader =
 506                         (struct vmbus_channel_gpadl_header *)requestheader;
 507
 508                         if ((gpadlcreated->child_relid ==
 509                              gpadlheader->child_relid) &&
 510                             (gpadlcreated->gpadl == gpadlheader->gpadl)) {
 511                                 memcpy(&msginfo->response.gpadl_created,
 512                                        gpadlcreated,
 513                                        sizeof(
 514                                         struct vmbus_channel_gpadl_created));
 515                                 complete(&msginfo->waitevent);
 516                                 break;
 517                         }
 518                 }
 519         }
 520         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 521 }
 522
 523 /*
 524  * vmbus_ongpadl_torndown - GPADL torndown handler.
 525  *
 526  * This is invoked when we received a response to our gpadl teardown request.
 527  * Find the matching request, copy the response and signal the requesting
 528  * thread.
 529  */
 530 static void vmbus_ongpadl_torndown(
 531                         struct vmbus_channel_message_header *hdr)
 532 {
 533         struct vmbus_channel_gpadl_torndown *gpadl_torndown;
 534         struct vmbus_channel_msginfo *msginfo;
 535         struct vmbus_channel_message_header *requestheader;
 536         struct vmbus_channel_gpadl_teardown *gpadl_teardown;
 537         unsigned long flags;
 538
 539         gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;
 540
 541         /*
 542          * Find the open msg, copy the result and signal/unblock the wait event
 543          */
 544         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 545
 546         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 547                                 msglistentry) {
 548                 requestheader =
 549                         (struct vmbus_channel_message_header *)msginfo->msg;
 550
 551                 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
 552                         gpadl_teardown =
 553                         (struct vmbus_channel_gpadl_teardown *)requestheader;
 554
 555                         if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
 556                                 memcpy(&msginfo->response.gpadl_torndown,
 557                                        gpadl_torndown,
 558                                        sizeof(
 559                                         struct vmbus_channel_gpadl_torndown));
 560                                 complete(&msginfo->waitevent);
 561                                 break;
 562                         }
 563                 }
 564         }
 565         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 566 }
 567
 568 /*
 569  * vmbus_onversion_response - Version response handler
 570  *
 571  * This is invoked when we received a response to our initiate contact request.
 572  * Find the matching request, copy the response and signal the requesting
 573  * thread.
 574  */
 575 static void vmbus_onversion_response(
 576                 struct vmbus_channel_message_header *hdr)
 577 {
 578         struct vmbus_channel_msginfo *msginfo;
 579         struct vmbus_channel_message_header *requestheader;
 580         struct vmbus_channel_version_response *version_response;
 581         unsigned long flags;
 582
 583         version_response = (struct vmbus_channel_version_response *)hdr;
 584         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 585
 586         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 587                                 msglistentry) {
 588                 requestheader =
 589                         (struct vmbus_channel_message_header *)msginfo->msg;
 590
 591                 if (requestheader->msgtype ==
 592                     CHANNELMSG_INITIATE_CONTACT) {
 593                         memcpy(&msginfo->response.version_response,
 594                               version_response,
 595                               sizeof(struct vmbus_channel_version_response));
 596                         complete(&msginfo->waitevent);
 597                 }
 598         }
 599         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 600 }
 601
 602 /* Channel message dispatch table */
 603 static struct vmbus_channel_message_table_entry
 604         channel_message_table[CHANNELMSG_COUNT] = {
 605         {CHANNELMSG_INVALID,                    NULL},
 606         {CHANNELMSG_OFFERCHANNEL,               vmbus_onoffer},
 607         {CHANNELMSG_RESCIND_CHANNELOFFER,       vmbus_onoffer_rescind},
 608         {CHANNELMSG_REQUESTOFFERS,              NULL},
 609         {CHANNELMSG_ALLOFFERS_DELIVERED,        vmbus_onoffers_delivered},
 610         {CHANNELMSG_OPENCHANNEL,                NULL},
 611         {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
 612         {CHANNELMSG_CLOSECHANNEL,               NULL},
 613         {CHANNELMSG_GPADL_HEADER,               NULL},
 614         {CHANNELMSG_GPADL_BODY,         NULL},
 615         {CHANNELMSG_GPADL_CREATED,              vmbus_ongpadl_created},
 616         {CHANNELMSG_GPADL_TEARDOWN,             NULL},
 617         {CHANNELMSG_GPADL_TORNDOWN,             vmbus_ongpadl_torndown},
 618         {CHANNELMSG_RELID_RELEASED,             NULL},
 619         {CHANNELMSG_INITIATE_CONTACT,           NULL},
 620         {CHANNELMSG_VERSION_RESPONSE,           vmbus_onversion_response},
 621         {CHANNELMSG_UNLOAD,                     NULL},
 622 };
 623
 624 /*
 625  * vmbus_onmessage - Handler for channel protocol messages.
 626  *
 627  * This is invoked in the vmbus worker thread context.
 628  */
 629 void vmbus_onmessage(void *context)
 630 {
 631         struct hv_message *msg = context;
 632         struct vmbus_channel_message_header *hdr;
 633         int size;
 634
 635         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 636         size = msg->header.payload_size;
 637
 638         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 639                 pr_err("Received invalid channel message type %d size %d\n",
 640                            hdr->msgtype, size);
 641                 print_hex_dump_bytes("", DUMP_PREFIX_NONE,
 642                                      (unsigned char *)msg->u.payload, size);
 643                 return;
 644         }
 645
 646         if (channel_message_table[hdr->msgtype].message_handler)
 647                 channel_message_table[hdr->msgtype].message_handler(hdr);
 648         else
 649                 pr_err("Unhandled channel message type %d\n", hdr->msgtype);
 650 }
 651
 652 /*
 653  * vmbus_request_offers - Send a request to get all our pending offers.
 654  */
 655 int vmbus_request_offers(void)
 656 {
 657         struct vmbus_channel_message_header *msg;
 658         struct vmbus_channel_msginfo *msginfo;
 659         int ret, t;
 660
 661         msginfo = kmalloc(sizeof(*msginfo) +
 662                           sizeof(struct vmbus_channel_message_header),
 663                           GFP_KERNEL);
 664         if (!msginfo)
 665                 return -ENOMEM;
 666
 667         init_completion(&msginfo->waitevent);
 668
 669         msg = (struct vmbus_channel_message_header *)msginfo->msg;
 670
 671         msg->msgtype = CHANNELMSG_REQUESTOFFERS;
 672
 673
 674         ret = vmbus_post_msg(msg,
 675                                sizeof(struct vmbus_channel_message_header));
 676         if (ret != 0) {
 677                 pr_err("Unable to request offers - %d\n", ret);
 678
 679                 goto cleanup;
 680         }
 681
 682         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
 683         if (t == 0) {
 684                 ret = -ETIMEDOUT;
 685                 goto cleanup;
 686         }
 687
 688
 689
 690 cleanup:
 691         kfree(msginfo);
 692
 693         return ret;
 694 }
 695
 696 /* eof */