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