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 int kvp_handle_handshake(struct hv_kvp_msg *msg)
 131 {
 132         int ret = 1;
 133
 134         switch (msg->kvp_hdr.operation) {
 135         case KVP_OP_REGISTER:
 136                 dm_reg_value = KVP_OP_REGISTER;
 137                 pr_info("KVP: IP injection functionality not available\n");
 138                 pr_info("KVP: Upgrade the KVP daemon\n");
 139                 break;
 140         case KVP_OP_REGISTER1:
 141                 dm_reg_value = KVP_OP_REGISTER1;
 142                 break;
 143         default:
 144                 pr_info("KVP: incompatible daemon\n");
 145                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 146                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 147                 ret = 0;
 148         }
 149
 150         if (ret) {
 151                 /*
 152                  * We have a compatible daemon; complete the handshake.
 153                  */
 154                 pr_info("KVP: user-mode registering done.\n");
 155                 kvp_register(dm_reg_value);
 156                 kvp_transaction.active = false;
 157                 if (kvp_transaction.kvp_context)
 158                         hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
 159         }
 160         return ret;
 161 }
 162
 163
 164 /*
 165  * Callback when data is received from user mode.
 166  */
 167
 168 static void
 169 kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 170 {
 171         struct hv_kvp_msg *message;
 172         struct hv_kvp_msg_enumerate *data;
 173         int     error = 0;
 174
 175         message = (struct hv_kvp_msg *)msg->data;
 176
 177         /*
 178          * If we are negotiating the version information
 179          * with the daemon; handle that first.
 180          */
 181
 182         if (in_hand_shake) {
 183                 if (kvp_handle_handshake(message))
 184                         in_hand_shake = false;
 185                 return;
 186         }
 187
 188         /*
 189          * Based on the version of the daemon, we propagate errors from the
 190          * daemon differently.
 191          */
 192
 193         data = &message->body.kvp_enum_data;
 194
 195         switch (dm_reg_value) {
 196         case KVP_OP_REGISTER:
 197                 /*
 198                  * Null string is used to pass back error condition.
 199                  */
 200                 if (data->data.key[0] == 0)
 201                         error = HV_S_CONT;
 202                 break;
 203
 204         case KVP_OP_REGISTER1:
 205                 /*
 206                  * We use the message header information from
 207                  * the user level daemon to transmit errors.
 208                  */
 209                 error = message->error;
 210                 break;
 211         }
 212
 213         /*
 214          * Complete the transaction by forwarding the key value
 215          * to the host. But first, cancel the timeout.
 216          */
 217         if (cancel_delayed_work_sync(&kvp_work))
 218                 kvp_respond_to_host(message, error);
 219 }
 220
 221
 222 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 223 {
 224         struct hv_kvp_msg *in = in_msg;
 225         struct hv_kvp_ip_msg *out = out_msg;
 226         int len;
 227
 228         switch (op) {
 229         case KVP_OP_GET_IP_INFO:
 230                 /*
 231                  * Transform all parameters into utf16 encoding.
 232                  */
 233                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 234                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 235                                 UTF16_HOST_ENDIAN,
 236                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 237                                 MAX_IP_ADDR_SIZE);
 238                 if (len < 0)
 239                         return len;
 240
 241                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 242                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 243                                 UTF16_HOST_ENDIAN,
 244                                 (wchar_t *)out->kvp_ip_val.sub_net,
 245                                 MAX_IP_ADDR_SIZE);
 246                 if (len < 0)
 247                         return len;
 248
 249                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 250                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 251                                 UTF16_HOST_ENDIAN,
 252                                 (wchar_t *)out->kvp_ip_val.gate_way,
 253                                 MAX_GATEWAY_SIZE);
 254                 if (len < 0)
 255                         return len;
 256
 257                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 258                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 259                                 UTF16_HOST_ENDIAN,
 260                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 261                                 MAX_IP_ADDR_SIZE);
 262                 if (len < 0)
 263                         return len;
 264
 265                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 266                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 267                                 UTF16_HOST_ENDIAN,
 268                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 269                                 MAX_IP_ADDR_SIZE);
 270                 if (len < 0)
 271                         return len;
 272
 273                 out->kvp_ip_val.dhcp_enabled =
 274                         in->body.kvp_ip_val.dhcp_enabled;
 275                 out->kvp_ip_val.addr_family =
 276                         in->body.kvp_ip_val.addr_family;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 283 {
 284         struct hv_kvp_ip_msg *in = in_msg;
 285         struct hv_kvp_msg *out = out_msg;
 286
 287         switch (op) {
 288         case KVP_OP_SET_IP_INFO:
 289                 /*
 290                  * Transform all parameters into utf8 encoding.
 291                  */
 292                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 293                                 MAX_IP_ADDR_SIZE,
 294                                 UTF16_LITTLE_ENDIAN,
 295                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 296                                 MAX_IP_ADDR_SIZE);
 297
 298                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 299                                 MAX_IP_ADDR_SIZE,
 300                                 UTF16_LITTLE_ENDIAN,
 301                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 302                                 MAX_IP_ADDR_SIZE);
 303
 304                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 305                                 MAX_GATEWAY_SIZE,
 306                                 UTF16_LITTLE_ENDIAN,
 307                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 308                                 MAX_GATEWAY_SIZE);
 309
 310                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 311                                 MAX_IP_ADDR_SIZE,
 312                                 UTF16_LITTLE_ENDIAN,
 313                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 314                                 MAX_IP_ADDR_SIZE);
 315
 316                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 317
 318         default:
 319                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 320                                 MAX_ADAPTER_ID_SIZE,
 321                                 UTF16_LITTLE_ENDIAN,
 322                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 323                                 MAX_ADAPTER_ID_SIZE);
 324
 325                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 326         }
 327 }
 328
 329
 330
 331
 332 static void
 333 kvp_send_key(struct work_struct *dummy)
 334 {
 335         struct cn_msg *msg;
 336         struct hv_kvp_msg *message;
 337         struct hv_kvp_msg *in_msg;
 338         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 339         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 340         __u32 val32;
 341         __u64 val64;
 342
 343         msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
 344         if (!msg)
 345                 return;
 346
 347         msg->id.idx =  CN_KVP_IDX;
 348         msg->id.val = CN_KVP_VAL;
 349
 350         message = (struct hv_kvp_msg *)msg->data;
 351         message->kvp_hdr.operation = operation;
 352         message->kvp_hdr.pool = pool;
 353         in_msg = kvp_transaction.kvp_msg;
 354
 355         /*
 356          * The key/value strings sent from the host are encoded in
 357          * in utf16; convert it to utf8 strings.
 358          * The host assures us that the utf16 strings will not exceed
 359          * the max lengths specified. We will however, reserve room
 360          * for the string terminating character - in the utf16s_utf8s()
 361          * function we limit the size of the buffer where the converted
 362          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 363          * that the strings can be properly terminated!
 364          */
 365
 366         switch (message->kvp_hdr.operation) {
 367         case KVP_OP_SET_IP_INFO:
 368                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 369                 break;
 370         case KVP_OP_GET_IP_INFO:
 371                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 372                 break;
 373         case KVP_OP_SET:
 374                 switch (in_msg->body.kvp_set.data.value_type) {
 375                 case REG_SZ:
 376                         /*
 377                          * The value is a string - utf16 encoding.
 378                          */
 379                         message->body.kvp_set.data.value_size =
 380                                 utf16s_to_utf8s(
 381                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 382                                 in_msg->body.kvp_set.data.value_size,
 383                                 UTF16_LITTLE_ENDIAN,
 384                                 message->body.kvp_set.data.value,
 385                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 386                                 break;
 387
 388                 case REG_U32:
 389                         /*
 390                          * The value is a 32 bit scalar.
 391                          * We save this as a utf8 string.
 392                          */
 393                         val32 = in_msg->body.kvp_set.data.value_u32;
 394                         message->body.kvp_set.data.value_size =
 395                                 sprintf(message->body.kvp_set.data.value,
 396                                         "%d", val32) + 1;
 397                         break;
 398
 399                 case REG_U64:
 400                         /*
 401                          * The value is a 64 bit scalar.
 402                          * We save this as a utf8 string.
 403                          */
 404                         val64 = in_msg->body.kvp_set.data.value_u64;
 405                         message->body.kvp_set.data.value_size =
 406                                 sprintf(message->body.kvp_set.data.value,
 407                                         "%llu", val64) + 1;
 408                         break;
 409
 410                 }
 411         case KVP_OP_GET:
 412                 message->body.kvp_set.data.key_size =
 413                         utf16s_to_utf8s(
 414                         (wchar_t *)in_msg->body.kvp_set.data.key,
 415                         in_msg->body.kvp_set.data.key_size,
 416                         UTF16_LITTLE_ENDIAN,
 417                         message->body.kvp_set.data.key,
 418                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 419                         break;
 420
 421         case KVP_OP_DELETE:
 422                 message->body.kvp_delete.key_size =
 423                         utf16s_to_utf8s(
 424                         (wchar_t *)in_msg->body.kvp_delete.key,
 425                         in_msg->body.kvp_delete.key_size,
 426                         UTF16_LITTLE_ENDIAN,
 427                         message->body.kvp_delete.key,
 428                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 429                         break;
 430
 431         case KVP_OP_ENUMERATE:
 432                 message->body.kvp_enum_data.index =
 433                         in_msg->body.kvp_enum_data.index;
 434                         break;
 435         }
 436
 437         msg->len = sizeof(struct hv_kvp_msg);
 438         cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
 439         kfree(msg);
 440
 441         return;
 442 }
 443
 444 /*
 445  * Send a response back to the host.
 446  */
 447
 448 static void
 449 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 450 {
 451         struct hv_kvp_msg  *kvp_msg;
 452         struct hv_kvp_exchg_msg_value  *kvp_data;
 453         char    *key_name;
 454         char    *value;
 455         struct icmsg_hdr *icmsghdrp;
 456         int     keylen = 0;
 457         int     valuelen = 0;
 458         u32     buf_len;
 459         struct vmbus_channel *channel;
 460         u64     req_id;
 461         int ret;
 462
 463         /*
 464          * If a transaction is not active; log and return.
 465          */
 466
 467         if (!kvp_transaction.active) {
 468                 /*
 469                  * This is a spurious call!
 470                  */
 471                 pr_warn("KVP: Transaction not active\n");
 472                 return;
 473         }
 474         /*
 475          * Copy the global state for completing the transaction. Note that
 476          * only one transaction can be active at a time.
 477          */
 478
 479         buf_len = kvp_transaction.recv_len;
 480         channel = kvp_transaction.recv_channel;
 481         req_id = kvp_transaction.recv_req_id;
 482
 483         kvp_transaction.active = false;
 484
 485         icmsghdrp = (struct icmsg_hdr *)
 486                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 487
 488         if (channel->onchannel_callback == NULL)
 489                 /*
 490                  * We have raced with util driver being unloaded;
 491                  * silently return.
 492                  */
 493                 return;
 494
 495         icmsghdrp->status = error;
 496
 497         /*
 498          * If the error parameter is set, terminate the host's enumeration
 499          * on this pool.
 500          */
 501         if (error) {
 502                 /*
 503                  * Something failed or we have timedout;
 504                  * terminate the current host-side iteration.
 505                  */
 506                 goto response_done;
 507         }
 508
 509         kvp_msg = (struct hv_kvp_msg *)
 510                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 511                         sizeof(struct icmsg_hdr)];
 512
 513         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 514         case KVP_OP_GET_IP_INFO:
 515                 ret = process_ob_ipinfo(msg_to_host,
 516                                  (struct hv_kvp_ip_msg *)kvp_msg,
 517                                  KVP_OP_GET_IP_INFO);
 518                 if (ret < 0)
 519                         icmsghdrp->status = HV_E_FAIL;
 520
 521                 goto response_done;
 522         case KVP_OP_SET_IP_INFO:
 523                 goto response_done;
 524         case KVP_OP_GET:
 525                 kvp_data = &kvp_msg->body.kvp_get.data;
 526                 goto copy_value;
 527
 528         case KVP_OP_SET:
 529         case KVP_OP_DELETE:
 530                 goto response_done;
 531
 532         default:
 533                 break;
 534         }
 535
 536         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 537         key_name = msg_to_host->body.kvp_enum_data.data.key;
 538
 539         /*
 540          * The windows host expects the key/value pair to be encoded
 541          * in utf16. Ensure that the key/value size reported to the host
 542          * will be less than or equal to the MAX size (including the
 543          * terminating character).
 544          */
 545         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 546                                 (wchar_t *) kvp_data->key,
 547                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 548         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 549
 550 copy_value:
 551         value = msg_to_host->body.kvp_enum_data.data.value;
 552         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 553                                 (wchar_t *) kvp_data->value,
 554                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 555         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 556
 557         /*
 558          * If the utf8s to utf16s conversion failed; notify host
 559          * of the error.
 560          */
 561         if ((keylen < 0) || (valuelen < 0))
 562                 icmsghdrp->status = HV_E_FAIL;
 563
 564         kvp_data->value_type = REG_SZ; /* all our values are strings */
 565
 566 response_done:
 567         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 568
 569         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 570                                 VM_PKT_DATA_INBAND, 0);
 571
 572 }
 573
 574 /*
 575  * This callback is invoked when we get a KVP message from the host.
 576  * The host ensures that only one KVP transaction can be active at a time.
 577  * KVP implementation in Linux needs to forward the key to a user-mde
 578  * component to retrive the corresponding value. Consequently, we cannot
 579  * respond to the host in the conext of this callback. Since the host
 580  * guarantees that at most only one transaction can be active at a time,
 581  * we stash away the transaction state in a set of global variables.
 582  */
 583
 584 void hv_kvp_onchannelcallback(void *context)
 585 {
 586         struct vmbus_channel *channel = context;
 587         u32 recvlen;
 588         u64 requestid;
 589
 590         struct hv_kvp_msg *kvp_msg;
 591
 592         struct icmsg_hdr *icmsghdrp;
 593         struct icmsg_negotiate *negop = NULL;
 594         int util_fw_version;
 595         int kvp_srv_version;
 596
 597         if (kvp_transaction.active) {
 598                 /*
 599                  * We will defer processing this callback once
 600                  * the current transaction is complete.
 601                  */
 602                 kvp_transaction.kvp_context = context;
 603                 return;
 604         }
 605
 606         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
 607                          &requestid);
 608
 609         if (recvlen > 0) {
 610                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 611                         sizeof(struct vmbuspipe_hdr)];
 612
 613                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 614                         /*
 615                          * Based on the host, select appropriate
 616                          * framework and service versions we will
 617                          * negotiate.
 618                          */
 619                         switch (vmbus_proto_version) {
 620                         case (VERSION_WS2008):
 621                                 util_fw_version = UTIL_WS2K8_FW_VERSION;
 622                                 kvp_srv_version = WS2008_SRV_VERSION;
 623                                 break;
 624                         case (VERSION_WIN7):
 625                                 util_fw_version = UTIL_FW_VERSION;
 626                                 kvp_srv_version = WIN7_SRV_VERSION;
 627                                 break;
 628                         default:
 629                                 util_fw_version = UTIL_FW_VERSION;
 630                                 kvp_srv_version = WIN8_SRV_VERSION;
 631                         }
 632                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 633                                  recv_buffer, util_fw_version,
 634                                  kvp_srv_version);
 635
 636                 } else {
 637                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 638                                 sizeof(struct vmbuspipe_hdr) +
 639                                 sizeof(struct icmsg_hdr)];
 640
 641                         /*
 642                          * Stash away this global state for completing the
 643                          * transaction; note transactions are serialized.
 644                          */
 645
 646                         kvp_transaction.recv_len = recvlen;
 647                         kvp_transaction.recv_channel = channel;
 648                         kvp_transaction.recv_req_id = requestid;
 649                         kvp_transaction.active = true;
 650                         kvp_transaction.kvp_msg = kvp_msg;
 651
 652                         /*
 653                          * Get the information from the
 654                          * user-mode component.
 655                          * component. This transaction will be
 656                          * completed when we get the value from
 657                          * the user-mode component.
 658                          * Set a timeout to deal with
 659                          * user-mode not responding.
 660                          */
 661                         schedule_work(&kvp_sendkey_work);
 662                         schedule_delayed_work(&kvp_work, 5*HZ);
 663
 664                         return;
 665
 666                 }
 667
 668                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 669                         | ICMSGHDRFLAG_RESPONSE;
 670
 671                 vmbus_sendpacket(channel, recv_buffer,
 672                                        recvlen, requestid,
 673                                        VM_PKT_DATA_INBAND, 0);
 674         }
 675
 676 }
 677
 678 int
 679 hv_kvp_init(struct hv_util_service *srv)
 680 {
 681         int err;
 682
 683         err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
 684         if (err)
 685                 return err;
 686         recv_buffer = srv->recv_buffer;
 687
 688         /*
 689          * When this driver loads, the user level daemon that
 690          * processes the host requests may not yet be running.
 691          * Defer processing channel callbacks until the daemon
 692          * has registered.
 693          */
 694         kvp_transaction.active = true;
 695
 696         return 0;
 697 }
 698
 699 void hv_kvp_deinit(void)
 700 {
 701         cn_del_callback(&kvp_id);
 702         cancel_delayed_work_sync(&kvp_work);
 703         cancel_work_sync(&kvp_sendkey_work);
 704 }