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