linux/drivers/hv/channel_mgmt.c
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   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
  35struct 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 */
  59void 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
 104EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
 105
 106/*
 107 * alloc_channel - Allocate and initialize a vmbus channel object
 108 */
 109static 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 */
 131static 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 */
 145static 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 */
 163static 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
 172void 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 */
 187static 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 */
 264static 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 */
 292static 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 */
 315static 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 */
 327static 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 */
 371static 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 */
 418static 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 */
 463static 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 */
 491static 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 */
 517void 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 */
 543int 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
 578cleanup:
 579        kfree(msginfo);
 580
 581        return ret;
 582}
 583
 584/* eof */
 585
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