kernel/drivers/hv/hv_kvp.c

   1 /*
   2  * An implementation of key value pair (KVP) functionality for Linux.
   3  *
   4  *
   5  * Copyright (C) 2010, Novell, Inc.
   6  * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published
  10  * by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  15  * NON INFRINGEMENT.  See the GNU General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  21  *
  22  */
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/net.h>
  26 #include <linux/nls.h>
  27 #include <linux/connector.h>
  28 #include <linux/workqueue.h>
  29 #include <linux/hyperv.h>
  30
  31
  32 /*
  33  * Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
  34  */
  35 #define WS2008_SRV_MAJOR        1
  36 #define WS2008_SRV_MINOR        0
  37 #define WS2008_SRV_VERSION     (WS2008_SRV_MAJOR << 16 | WS2008_SRV_MINOR)
  38
  39 #define WIN7_SRV_MAJOR   3
  40 #define WIN7_SRV_MINOR   0
  41 #define WIN7_SRV_VERSION     (WIN7_SRV_MAJOR << 16 | WIN7_SRV_MINOR)
  42
  43 #define WIN8_SRV_MAJOR   4
  44 #define WIN8_SRV_MINOR   0
  45 #define WIN8_SRV_VERSION     (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
  46
  47 /*
  48  * Global state maintained for transaction that is being processed.
  49  * Note that only one transaction can be active at any point in time.
  50  *
  51  * This state is set when we receive a request from the host; we
  52  * cleanup this state when the transaction is completed - when we respond
  53  * to the host with the key value.
  54  */
  55
  56 static struct {
  57         bool active; /* transaction status - active or not */
  58         int recv_len; /* number of bytes received. */
  59         struct hv_kvp_msg  *kvp_msg; /* current message */
  60         struct vmbus_channel *recv_channel; /* chn we got the request */
  61         u64 recv_req_id; /* request ID. */
  62         void *kvp_context; /* for the channel callback */
  63 } kvp_transaction;
  64
  65 /*
  66  * Before we can accept KVP messages from the host, we need
  67  * to handshake with the user level daemon. This state tracks
  68  * if we are in the handshake phase.
  69  */
  70 static bool in_hand_shake = true;
  71
  72 /*
  73  * This state maintains the version number registered by the daemon.
  74  */
  75 static int dm_reg_value;
  76
  77 static void kvp_send_key(struct work_struct *dummy);
  78
  79
  80 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
  81 static void kvp_work_func(struct work_struct *dummy);
  82 static void kvp_register(int);
  83
  84 static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
  85 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
  86
  87 static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
  88 static const char kvp_name[] = "kvp_kernel_module";
  89 static u8 *recv_buffer;
  90 /*
  91  * Register the kernel component with the user-level daemon.
  92  * As part of this registration, pass the LIC version number.
  93  * This number has no meaning, it satisfies the registration protocol.
  94  */
  95 #define HV_DRV_VERSION           "3.1"
  96
  97 static void
  98 kvp_register(int reg_value)
  99 {
 100
 101         struct cn_msg *msg;
 102         struct hv_kvp_msg *kvp_msg;
 103         char *version;
 104
 105         msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
 106
 107         if (msg) {
 108                 kvp_msg = (struct hv_kvp_msg *)msg->data;
 109                 version = kvp_msg->body.kvp_register.version;
 110                 msg->id.idx =  CN_KVP_IDX;
 111                 msg->id.val = CN_KVP_VAL;
 112
 113                 kvp_msg->kvp_hdr.operation = reg_value;
 114                 strcpy(version, HV_DRV_VERSION);
 115                 msg->len = sizeof(struct hv_kvp_msg);
 116                 cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
 117                 kfree(msg);
 118         }
 119 }
 120 static void
 121 kvp_work_func(struct work_struct *dummy)
 122 {
 123         /*
 124          * If the timer fires, the user-mode component has not responded;
 125          * process the pending transaction.
 126          */
 127         kvp_respond_to_host(NULL, HV_E_FAIL);
 128 }
 129
 130 static void poll_channel(struct vmbus_channel *channel)
 131 {
 132         if (channel->target_cpu != smp_processor_id())
 133                 smp_call_function_single(channel->target_cpu,
 134                                          hv_kvp_onchannelcallback,
 135                                          channel, true);
 136         else
 137                 hv_kvp_onchannelcallback(channel);
 138 }
 139
 140
 141 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 142 {
 143         int ret = 1;
 144
 145         switch (msg->kvp_hdr.operation) {
 146         case KVP_OP_REGISTER:
 147                 dm_reg_value = KVP_OP_REGISTER;
 148                 pr_info("KVP: IP injection functionality not available\n");
 149                 pr_info("KVP: Upgrade the KVP daemon\n");
 150                 break;
 151         case KVP_OP_REGISTER1:
 152                 dm_reg_value = KVP_OP_REGISTER1;
 153                 break;
 154         default:
 155                 pr_info("KVP: incompatible daemon\n");
 156                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 157                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 158                 ret = 0;
 159         }
 160
 161         if (ret) {
 162                 /*
 163                  * We have a compatible daemon; complete the handshake.
 164                  */
 165                 pr_info("KVP: user-mode registering done.\n");
 166                 kvp_register(dm_reg_value);
 167                 kvp_transaction.active = false;
 168                 if (kvp_transaction.kvp_context)
 169                         poll_channel(kvp_transaction.kvp_context);
 170         }
 171         return ret;
 172 }
 173
 174
 175 /*
 176  * Callback when data is received from user mode.
 177  */
 178
 179 static void
 180 kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 181 {
 182         struct hv_kvp_msg *message;
 183         struct hv_kvp_msg_enumerate *data;
 184         int     error = 0;
 185
 186         message = (struct hv_kvp_msg *)msg->data;
 187
 188         /*
 189          * If we are negotiating the version information
 190          * with the daemon; handle that first.
 191          */
 192
 193         if (in_hand_shake) {
 194                 if (kvp_handle_handshake(message))
 195                         in_hand_shake = false;
 196                 return;
 197         }
 198
 199         /*
 200          * Based on the version of the daemon, we propagate errors from the
 201          * daemon differently.
 202          */
 203
 204         data = &message->body.kvp_enum_data;
 205
 206         switch (dm_reg_value) {
 207         case KVP_OP_REGISTER:
 208                 /*
 209                  * Null string is used to pass back error condition.
 210                  */
 211                 if (data->data.key[0] == 0)
 212                         error = HV_S_CONT;
 213                 break;
 214
 215         case KVP_OP_REGISTER1:
 216                 /*
 217                  * We use the message header information from
 218                  * the user level daemon to transmit errors.
 219                  */
 220                 error = message->error;
 221                 break;
 222         }
 223
 224         /*
 225          * Complete the transaction by forwarding the key value
 226          * to the host. But first, cancel the timeout.
 227          */
 228         if (cancel_delayed_work_sync(&kvp_work))
 229                 kvp_respond_to_host(message, error);
 230 }
 231
 232
 233 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 234 {
 235         struct hv_kvp_msg *in = in_msg;
 236         struct hv_kvp_ip_msg *out = out_msg;
 237         int len;
 238
 239         switch (op) {
 240         case KVP_OP_GET_IP_INFO:
 241                 /*
 242                  * Transform all parameters into utf16 encoding.
 243                  */
 244                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 245                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 246                                 UTF16_HOST_ENDIAN,
 247                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 248                                 MAX_IP_ADDR_SIZE);
 249                 if (len < 0)
 250                         return len;
 251
 252                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 253                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 254                                 UTF16_HOST_ENDIAN,
 255                                 (wchar_t *)out->kvp_ip_val.sub_net,
 256                                 MAX_IP_ADDR_SIZE);
 257                 if (len < 0)
 258                         return len;
 259
 260                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 261                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 262                                 UTF16_HOST_ENDIAN,
 263                                 (wchar_t *)out->kvp_ip_val.gate_way,
 264                                 MAX_GATEWAY_SIZE);
 265                 if (len < 0)
 266                         return len;
 267
 268                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 269                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 270                                 UTF16_HOST_ENDIAN,
 271                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 272                                 MAX_IP_ADDR_SIZE);
 273                 if (len < 0)
 274                         return len;
 275
 276                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 277                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 278                                 UTF16_HOST_ENDIAN,
 279                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 280                                 MAX_IP_ADDR_SIZE);
 281                 if (len < 0)
 282                         return len;
 283
 284                 out->kvp_ip_val.dhcp_enabled =
 285                         in->body.kvp_ip_val.dhcp_enabled;
 286                 out->kvp_ip_val.addr_family =
 287                         in->body.kvp_ip_val.addr_family;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 294 {
 295         struct hv_kvp_ip_msg *in = in_msg;
 296         struct hv_kvp_msg *out = out_msg;
 297
 298         switch (op) {
 299         case KVP_OP_SET_IP_INFO:
 300                 /*
 301                  * Transform all parameters into utf8 encoding.
 302                  */
 303                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 304                                 MAX_IP_ADDR_SIZE,
 305                                 UTF16_LITTLE_ENDIAN,
 306                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 307                                 MAX_IP_ADDR_SIZE);
 308
 309                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 310                                 MAX_IP_ADDR_SIZE,
 311                                 UTF16_LITTLE_ENDIAN,
 312                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 313                                 MAX_IP_ADDR_SIZE);
 314
 315                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 316                                 MAX_GATEWAY_SIZE,
 317                                 UTF16_LITTLE_ENDIAN,
 318                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 319                                 MAX_GATEWAY_SIZE);
 320
 321                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 322                                 MAX_IP_ADDR_SIZE,
 323                                 UTF16_LITTLE_ENDIAN,
 324                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 325                                 MAX_IP_ADDR_SIZE);
 326
 327                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 328
 329         default:
 330                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 331                                 MAX_ADAPTER_ID_SIZE,
 332                                 UTF16_LITTLE_ENDIAN,
 333                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 334                                 MAX_ADAPTER_ID_SIZE);
 335
 336                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 337         }
 338 }
 339
 340
 341
 342
 343 static void
 344 kvp_send_key(struct work_struct *dummy)
 345 {
 346         struct cn_msg *msg;
 347         struct hv_kvp_msg *message;
 348         struct hv_kvp_msg *in_msg;
 349         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 350         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 351         __u32 val32;
 352         __u64 val64;
 353         int rc;
 354
 355         msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
 356         if (!msg)
 357                 return;
 358
 359         msg->id.idx =  CN_KVP_IDX;
 360         msg->id.val = CN_KVP_VAL;
 361
 362         message = (struct hv_kvp_msg *)msg->data;
 363         message->kvp_hdr.operation = operation;
 364         message->kvp_hdr.pool = pool;
 365         in_msg = kvp_transaction.kvp_msg;
 366
 367         /*
 368          * The key/value strings sent from the host are encoded in
 369          * in utf16; convert it to utf8 strings.
 370          * The host assures us that the utf16 strings will not exceed
 371          * the max lengths specified. We will however, reserve room
 372          * for the string terminating character - in the utf16s_utf8s()
 373          * function we limit the size of the buffer where the converted
 374          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 375          * that the strings can be properly terminated!
 376          */
 377
 378         switch (message->kvp_hdr.operation) {
 379         case KVP_OP_SET_IP_INFO:
 380                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 381                 break;
 382         case KVP_OP_GET_IP_INFO:
 383                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 384                 break;
 385         case KVP_OP_SET:
 386                 switch (in_msg->body.kvp_set.data.value_type) {
 387                 case REG_SZ:
 388                         /*
 389                          * The value is a string - utf16 encoding.
 390                          */
 391                         message->body.kvp_set.data.value_size =
 392                                 utf16s_to_utf8s(
 393                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 394                                 in_msg->body.kvp_set.data.value_size,
 395                                 UTF16_LITTLE_ENDIAN,
 396                                 message->body.kvp_set.data.value,
 397                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 398                                 break;
 399
 400                 case REG_U32:
 401                         /*
 402                          * The value is a 32 bit scalar.
 403                          * We save this as a utf8 string.
 404                          */
 405                         val32 = in_msg->body.kvp_set.data.value_u32;
 406                         message->body.kvp_set.data.value_size =
 407                                 sprintf(message->body.kvp_set.data.value,
 408                                         "%d", val32) + 1;
 409                         break;
 410
 411                 case REG_U64:
 412                         /*
 413                          * The value is a 64 bit scalar.
 414                          * We save this as a utf8 string.
 415                          */
 416                         val64 = in_msg->body.kvp_set.data.value_u64;
 417                         message->body.kvp_set.data.value_size =
 418                                 sprintf(message->body.kvp_set.data.value,
 419                                         "%llu", val64) + 1;
 420                         break;
 421
 422                 }
 423         case KVP_OP_GET:
 424                 message->body.kvp_set.data.key_size =
 425                         utf16s_to_utf8s(
 426                         (wchar_t *)in_msg->body.kvp_set.data.key,
 427                         in_msg->body.kvp_set.data.key_size,
 428                         UTF16_LITTLE_ENDIAN,
 429                         message->body.kvp_set.data.key,
 430                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 431                         break;
 432
 433         case KVP_OP_DELETE:
 434                 message->body.kvp_delete.key_size =
 435                         utf16s_to_utf8s(
 436                         (wchar_t *)in_msg->body.kvp_delete.key,
 437                         in_msg->body.kvp_delete.key_size,
 438                         UTF16_LITTLE_ENDIAN,
 439                         message->body.kvp_delete.key,
 440                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 441                         break;
 442
 443         case KVP_OP_ENUMERATE:
 444                 message->body.kvp_enum_data.index =
 445                         in_msg->body.kvp_enum_data.index;
 446                         break;
 447         }
 448
 449         msg->len = sizeof(struct hv_kvp_msg);
 450         rc = cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
 451         if (rc) {
 452                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 453                 if (cancel_delayed_work_sync(&kvp_work))
 454                         kvp_respond_to_host(message, HV_E_FAIL);
 455         }
 456
 457         kfree(msg);
 458
 459         return;
 460 }
 461
 462 /*
 463  * Send a response back to the host.
 464  */
 465
 466 static void
 467 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 468 {
 469         struct hv_kvp_msg  *kvp_msg;
 470         struct hv_kvp_exchg_msg_value  *kvp_data;
 471         char    *key_name;
 472         char    *value;
 473         struct icmsg_hdr *icmsghdrp;
 474         int     keylen = 0;
 475         int     valuelen = 0;
 476         u32     buf_len;
 477         struct vmbus_channel *channel;
 478         u64     req_id;
 479         int ret;
 480
 481         /*
 482          * If a transaction is not active; log and return.
 483          */
 484
 485         if (!kvp_transaction.active) {
 486                 /*
 487                  * This is a spurious call!
 488                  */
 489                 pr_warn("KVP: Transaction not active\n");
 490                 return;
 491         }
 492         /*
 493          * Copy the global state for completing the transaction. Note that
 494          * only one transaction can be active at a time.
 495          */
 496
 497         buf_len = kvp_transaction.recv_len;
 498         channel = kvp_transaction.recv_channel;
 499         req_id = kvp_transaction.recv_req_id;
 500
 501         kvp_transaction.active = false;
 502
 503         icmsghdrp = (struct icmsg_hdr *)
 504                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 505
 506         if (channel->onchannel_callback == NULL)
 507                 /*
 508                  * We have raced with util driver being unloaded;
 509                  * silently return.
 510                  */
 511                 return;
 512
 513         icmsghdrp->status = error;
 514
 515         /*
 516          * If the error parameter is set, terminate the host's enumeration
 517          * on this pool.
 518          */
 519         if (error) {
 520                 /*
 521                  * Something failed or we have timedout;
 522                  * terminate the current host-side iteration.
 523                  */
 524                 goto response_done;
 525         }
 526
 527         kvp_msg = (struct hv_kvp_msg *)
 528                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 529                         sizeof(struct icmsg_hdr)];
 530
 531         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 532         case KVP_OP_GET_IP_INFO:
 533                 ret = process_ob_ipinfo(msg_to_host,
 534                                  (struct hv_kvp_ip_msg *)kvp_msg,
 535                                  KVP_OP_GET_IP_INFO);
 536                 if (ret < 0)
 537                         icmsghdrp->status = HV_E_FAIL;
 538
 539                 goto response_done;
 540         case KVP_OP_SET_IP_INFO:
 541                 goto response_done;
 542         case KVP_OP_GET:
 543                 kvp_data = &kvp_msg->body.kvp_get.data;
 544                 goto copy_value;
 545
 546         case KVP_OP_SET:
 547         case KVP_OP_DELETE:
 548                 goto response_done;
 549
 550         default:
 551                 break;
 552         }
 553
 554         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 555         key_name = msg_to_host->body.kvp_enum_data.data.key;
 556
 557         /*
 558          * The windows host expects the key/value pair to be encoded
 559          * in utf16. Ensure that the key/value size reported to the host
 560          * will be less than or equal to the MAX size (including the
 561          * terminating character).
 562          */
 563         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 564                                 (wchar_t *) kvp_data->key,
 565                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 566         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 567
 568 copy_value:
 569         value = msg_to_host->body.kvp_enum_data.data.value;
 570         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 571                                 (wchar_t *) kvp_data->value,
 572                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 573         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 574
 575         /*
 576          * If the utf8s to utf16s conversion failed; notify host
 577          * of the error.
 578          */
 579         if ((keylen < 0) || (valuelen < 0))
 580                 icmsghdrp->status = HV_E_FAIL;
 581
 582         kvp_data->value_type = REG_SZ; /* all our values are strings */
 583
 584 response_done:
 585         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 586
 587         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 588                                 VM_PKT_DATA_INBAND, 0);
 589         poll_channel(channel);
 590 }
 591
 592 /*
 593  * This callback is invoked when we get a KVP message from the host.
 594  * The host ensures that only one KVP transaction can be active at a time.
 595  * KVP implementation in Linux needs to forward the key to a user-mde
 596  * component to retrive the corresponding value. Consequently, we cannot
 597  * respond to the host in the conext of this callback. Since the host
 598  * guarantees that at most only one transaction can be active at a time,
 599  * we stash away the transaction state in a set of global variables.
 600  */
 601
 602 void hv_kvp_onchannelcallback(void *context)
 603 {
 604         struct vmbus_channel *channel = context;
 605         u32 recvlen;
 606         u64 requestid;
 607
 608         struct hv_kvp_msg *kvp_msg;
 609
 610         struct icmsg_hdr *icmsghdrp;
 611         struct icmsg_negotiate *negop = NULL;
 612         int util_fw_version;
 613         int kvp_srv_version;
 614
 615         if (kvp_transaction.active) {
 616                 /*
 617                  * We will defer processing this callback once
 618                  * the current transaction is complete.
 619                  */
 620                 kvp_transaction.kvp_context = context;
 621                 return;
 622         }
 623
 624         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 625                          &requestid);
 626
 627         if (recvlen > 0) {
 628                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 629                         sizeof(struct vmbuspipe_hdr)];
 630
 631                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 632                         /*
 633                          * Based on the host, select appropriate
 634                          * framework and service versions we will
 635                          * negotiate.
 636                          */
 637                         switch (vmbus_proto_version) {
 638                         case (VERSION_WS2008):
 639                                 util_fw_version = UTIL_WS2K8_FW_VERSION;
 640                                 kvp_srv_version = WS2008_SRV_VERSION;
 641                                 break;
 642                         case (VERSION_WIN7):
 643                                 util_fw_version = UTIL_FW_VERSION;
 644                                 kvp_srv_version = WIN7_SRV_VERSION;
 645                                 break;
 646                         default:
 647                                 util_fw_version = UTIL_FW_VERSION;
 648                                 kvp_srv_version = WIN8_SRV_VERSION;
 649                         }
 650                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 651                                  recv_buffer, util_fw_version,
 652                                  kvp_srv_version);
 653
 654                 } else {
 655                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 656                                 sizeof(struct vmbuspipe_hdr) +
 657                                 sizeof(struct icmsg_hdr)];
 658
 659                         /*
 660                          * Stash away this global state for completing the
 661                          * transaction; note transactions are serialized.
 662                          */
 663
 664                         kvp_transaction.recv_len = recvlen;
 665                         kvp_transaction.recv_channel = channel;
 666                         kvp_transaction.recv_req_id = requestid;
 667                         kvp_transaction.active = true;
 668                         kvp_transaction.kvp_msg = kvp_msg;
 669
 670                         /*
 671                          * Get the information from the
 672                          * user-mode component.
 673                          * component. This transaction will be
 674                          * completed when we get the value from
 675                          * the user-mode component.
 676                          * Set a timeout to deal with
 677                          * user-mode not responding.
 678                          */
 679                         schedule_work(&kvp_sendkey_work);
 680                         schedule_delayed_work(&kvp_work, 5*HZ);
 681
 682                         return;
 683
 684                 }
 685
 686                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 687                         | ICMSGHDRFLAG_RESPONSE;
 688
 689                 vmbus_sendpacket(channel, recv_buffer,
 690                                        recvlen, requestid,
 691                                        VM_PKT_DATA_INBAND, 0);
 692         }
 693
 694 }
 695
 696 int
 697 hv_kvp_init(struct hv_util_service *srv)
 698 {
 699         int err;
 700
 701         err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
 702         if (err)
 703                 return err;
 704         recv_buffer = srv->recv_buffer;
 705
 706         /*
 707          * When this driver loads, the user level daemon that
 708          * processes the host requests may not yet be running.
 709          * Defer processing channel callbacks until the daemon
 710          * has registered.
 711          */
 712         kvp_transaction.active = true;
 713
 714         return 0;
 715 }
 716
 717 void hv_kvp_deinit(void)
 718 {
 719         cn_del_callback(&kvp_id);
 720         cancel_delayed_work_sync(&kvp_work);
 721         cancel_work_sync(&kvp_sendkey_work);
 722 }