Pileus Git - ~andy/linux/blob - 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 /*
 261  * vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
 262  *
 263  */
 264 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 265 {
 266         struct vmbus_channel_offer_channel *offer;
 267         struct vmbus_channel *newchannel;
 268
 269         offer = (struct vmbus_channel_offer_channel *)hdr;
 270
 271         /* Allocate the channel object and save this offer. */
 272         newchannel = alloc_channel();
 273         if (!newchannel) {
 274                 pr_err("Unable to allocate channel object\n");
 275                 return;
 276         }
 277
 278         memcpy(&newchannel->offermsg, offer,
 279                sizeof(struct vmbus_channel_offer_channel));
 280         newchannel->monitor_grp = (u8)offer->monitorid / 32;
 281         newchannel->monitor_bit = (u8)offer->monitorid % 32;
 282
 283         INIT_WORK(&newchannel->work, vmbus_process_offer);
 284         queue_work(newchannel->controlwq, &newchannel->work);
 285 }
 286
 287 /*
 288  * vmbus_onoffer_rescind - Rescind offer handler.
 289  *
 290  * We queue a work item to process this offer synchronously
 291  */
 292 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 293 {
 294         struct vmbus_channel_rescind_offer *rescind;
 295         struct vmbus_channel *channel;
 296
 297         rescind = (struct vmbus_channel_rescind_offer *)hdr;
 298         channel = relid2channel(rescind->child_relid);
 299
 300         if (channel == NULL)
 301                 /* Just return here, no channel found */
 302                 return;
 303
 304         /* work is initialized for vmbus_process_rescind_offer() from
 305          * vmbus_process_offer() where the channel got created */
 306         queue_work(channel->controlwq, &channel->work);
 307 }
 308
 309 /*
 310  * vmbus_onoffers_delivered -
 311  * This is invoked when all offers have been delivered.
 312  *
 313  * Nothing to do here.
 314  */
 315 static void vmbus_onoffers_delivered(
 316                         struct vmbus_channel_message_header *hdr)
 317 {
 318 }
 319
 320 /*
 321  * vmbus_onopen_result - Open result handler.
 322  *
 323  * This is invoked when we received a response to our channel open request.
 324  * Find the matching request, copy the response and signal the requesting
 325  * thread.
 326  */
 327 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
 328 {
 329         struct vmbus_channel_open_result *result;
 330         struct vmbus_channel_msginfo *msginfo;
 331         struct vmbus_channel_message_header *requestheader;
 332         struct vmbus_channel_open_channel *openmsg;
 333         unsigned long flags;
 334
 335         result = (struct vmbus_channel_open_result *)hdr;
 336
 337         /*
 338          * Find the open msg, copy the result and signal/unblock the wait event
 339          */
 340         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 341
 342         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 343                                 msglistentry) {
 344                 requestheader =
 345                         (struct vmbus_channel_message_header *)msginfo->msg;
 346
 347                 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
 348                         openmsg =
 349                         (struct vmbus_channel_open_channel *)msginfo->msg;
 350                         if (openmsg->child_relid == result->child_relid &&
 351                             openmsg->openid == result->openid) {
 352                                 memcpy(&msginfo->response.open_result,
 353                                        result,
 354                                        sizeof(
 355                                         struct vmbus_channel_open_result));
 356                                 complete(&msginfo->waitevent);
 357                                 break;
 358                         }
 359                 }
 360         }
 361         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 362 }
 363
 364 /*
 365  * vmbus_ongpadl_created - GPADL created handler.
 366  *
 367  * This is invoked when we received a response to our gpadl create request.
 368  * Find the matching request, copy the response and signal the requesting
 369  * thread.
 370  */
 371 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
 372 {
 373         struct vmbus_channel_gpadl_created *gpadlcreated;
 374         struct vmbus_channel_msginfo *msginfo;
 375         struct vmbus_channel_message_header *requestheader;
 376         struct vmbus_channel_gpadl_header *gpadlheader;
 377         unsigned long flags;
 378
 379         gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;
 380
 381         /*
 382          * Find the establish msg, copy the result and signal/unblock the wait
 383          * event
 384          */
 385         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 386
 387         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 388                                 msglistentry) {
 389                 requestheader =
 390                         (struct vmbus_channel_message_header *)msginfo->msg;
 391
 392                 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
 393                         gpadlheader =
 394                         (struct vmbus_channel_gpadl_header *)requestheader;
 395
 396                         if ((gpadlcreated->child_relid ==
 397                              gpadlheader->child_relid) &&
 398                             (gpadlcreated->gpadl == gpadlheader->gpadl)) {
 399                                 memcpy(&msginfo->response.gpadl_created,
 400                                        gpadlcreated,
 401                                        sizeof(
 402                                         struct vmbus_channel_gpadl_created));
 403                                 complete(&msginfo->waitevent);
 404                                 break;
 405                         }
 406                 }
 407         }
 408         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 409 }
 410
 411 /*
 412  * vmbus_ongpadl_torndown - GPADL torndown handler.
 413  *
 414  * This is invoked when we received a response to our gpadl teardown request.
 415  * Find the matching request, copy the response and signal the requesting
 416  * thread.
 417  */
 418 static void vmbus_ongpadl_torndown(
 419                         struct vmbus_channel_message_header *hdr)
 420 {
 421         struct vmbus_channel_gpadl_torndown *gpadl_torndown;
 422         struct vmbus_channel_msginfo *msginfo;
 423         struct vmbus_channel_message_header *requestheader;
 424         struct vmbus_channel_gpadl_teardown *gpadl_teardown;
 425         unsigned long flags;
 426
 427         gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;
 428
 429         /*
 430          * Find the open msg, copy the result and signal/unblock the wait event
 431          */
 432         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 433
 434         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 435                                 msglistentry) {
 436                 requestheader =
 437                         (struct vmbus_channel_message_header *)msginfo->msg;
 438
 439                 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
 440                         gpadl_teardown =
 441                         (struct vmbus_channel_gpadl_teardown *)requestheader;
 442
 443                         if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
 444                                 memcpy(&msginfo->response.gpadl_torndown,
 445                                        gpadl_torndown,
 446                                        sizeof(
 447                                         struct vmbus_channel_gpadl_torndown));
 448                                 complete(&msginfo->waitevent);
 449                                 break;
 450                         }
 451                 }
 452         }
 453         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 454 }
 455
 456 /*
 457  * vmbus_onversion_response - Version response handler
 458  *
 459  * This is invoked when we received a response to our initiate contact request.
 460  * Find the matching request, copy the response and signal the requesting
 461  * thread.
 462  */
 463 static void vmbus_onversion_response(
 464                 struct vmbus_channel_message_header *hdr)
 465 {
 466         struct vmbus_channel_msginfo *msginfo;
 467         struct vmbus_channel_message_header *requestheader;
 468         struct vmbus_channel_version_response *version_response;
 469         unsigned long flags;
 470
 471         version_response = (struct vmbus_channel_version_response *)hdr;
 472         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 473
 474         list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
 475                                 msglistentry) {
 476                 requestheader =
 477                         (struct vmbus_channel_message_header *)msginfo->msg;
 478
 479                 if (requestheader->msgtype ==
 480                     CHANNELMSG_INITIATE_CONTACT) {
 481                         memcpy(&msginfo->response.version_response,
 482                               version_response,
 483                               sizeof(struct vmbus_channel_version_response));
 484                         complete(&msginfo->waitevent);
 485                 }
 486         }
 487         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 488 }
 489
 490 /* Channel message dispatch table */
 491 static struct vmbus_channel_message_table_entry
 492         channel_message_table[CHANNELMSG_COUNT] = {
 493         {CHANNELMSG_INVALID,                    NULL},
 494         {CHANNELMSG_OFFERCHANNEL,               vmbus_onoffer},
 495         {CHANNELMSG_RESCIND_CHANNELOFFER,       vmbus_onoffer_rescind},
 496         {CHANNELMSG_REQUESTOFFERS,              NULL},
 497         {CHANNELMSG_ALLOFFERS_DELIVERED,        vmbus_onoffers_delivered},
 498         {CHANNELMSG_OPENCHANNEL,                NULL},
 499         {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
 500         {CHANNELMSG_CLOSECHANNEL,               NULL},
 501         {CHANNELMSG_GPADL_HEADER,               NULL},
 502         {CHANNELMSG_GPADL_BODY,         NULL},
 503         {CHANNELMSG_GPADL_CREATED,              vmbus_ongpadl_created},
 504         {CHANNELMSG_GPADL_TEARDOWN,             NULL},
 505         {CHANNELMSG_GPADL_TORNDOWN,             vmbus_ongpadl_torndown},
 506         {CHANNELMSG_RELID_RELEASED,             NULL},
 507         {CHANNELMSG_INITIATE_CONTACT,           NULL},
 508         {CHANNELMSG_VERSION_RESPONSE,           vmbus_onversion_response},
 509         {CHANNELMSG_UNLOAD,                     NULL},
 510 };
 511
 512 /*
 513  * vmbus_onmessage - Handler for channel protocol messages.
 514  *
 515  * This is invoked in the vmbus worker thread context.
 516  */
 517 void vmbus_onmessage(void *context)
 518 {
 519         struct hv_message *msg = context;
 520         struct vmbus_channel_message_header *hdr;
 521         int size;
 522
 523         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 524         size = msg->header.payload_size;
 525
 526         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 527                 pr_err("Received invalid channel message type %d size %d\n",
 528                            hdr->msgtype, size);
 529                 print_hex_dump_bytes("", DUMP_PREFIX_NONE,
 530                                      (unsigned char *)msg->u.payload, size);
 531                 return;
 532         }
 533
 534         if (channel_message_table[hdr->msgtype].message_handler)
 535                 channel_message_table[hdr->msgtype].message_handler(hdr);
 536         else
 537                 pr_err("Unhandled channel message type %d\n", hdr->msgtype);
 538 }
 539
 540 /*
 541  * vmbus_request_offers - Send a request to get all our pending offers.
 542  */
 543 int vmbus_request_offers(void)
 544 {
 545         struct vmbus_channel_message_header *msg;
 546         struct vmbus_channel_msginfo *msginfo;
 547         int ret, t;
 548
 549         msginfo = kmalloc(sizeof(*msginfo) +
 550                           sizeof(struct vmbus_channel_message_header),
 551                           GFP_KERNEL);
 552         if (!msginfo)
 553                 return -ENOMEM;
 554
 555         init_completion(&msginfo->waitevent);
 556
 557         msg = (struct vmbus_channel_message_header *)msginfo->msg;
 558
 559         msg->msgtype = CHANNELMSG_REQUESTOFFERS;
 560
 561
 562         ret = vmbus_post_msg(msg,
 563                                sizeof(struct vmbus_channel_message_header));
 564         if (ret != 0) {
 565                 pr_err("Unable to request offers - %d\n", ret);
 566
 567                 goto cleanup;
 568         }
 569
 570         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
 571         if (t == 0) {
 572                 ret = -ETIMEDOUT;
 573                 goto cleanup;
 574         }
 575
 576
 577
 578 cleanup:
 579         kfree(msginfo);
 580
 581         return ret;
 582 }
 583
 584 /* eof */