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 } kvp_transaction;
  70
  71 /*
  72  * This state maintains the version number registered by the daemon.
  73  */
  74 static int dm_reg_value;
  75
  76 static void kvp_send_key(struct work_struct *dummy);
  77
  78
  79 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
  80 static void kvp_timeout_func(struct work_struct *dummy);
  81 static void kvp_register(int);
  82
  83 static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
  84 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
  85
  86 static const char kvp_devname[] = "vmbus/hv_kvp";
  87 static u8 *recv_buffer;
  88 static struct hvutil_transport *hvt;
  89 /*
  90  * Register the kernel component with the user-level daemon.
  91  * As part of this registration, pass the LIC version number.
  92  * This number has no meaning, it satisfies the registration protocol.
  93  */
  94 #define HV_DRV_VERSION           "3.1"
  95
  96 static void kvp_poll_wrapper(void *channel)
  97 {
  98         /* Transaction is finished, reset the state here to avoid races. */
  99         kvp_transaction.state = HVUTIL_READY;
 100         hv_kvp_onchannelcallback(channel);
 101 }
 102
 103 static void
 104 kvp_register(int reg_value)
 105 {
 106
 107         struct hv_kvp_msg *kvp_msg;
 108         char *version;
 109
 110         kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
 111
 112         if (kvp_msg) {
 113                 version = kvp_msg->body.kvp_register.version;
 114                 kvp_msg->kvp_hdr.operation = reg_value;
 115                 strcpy(version, HV_DRV_VERSION);
 116
 117                 hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg));
 118                 kfree(kvp_msg);
 119         }
 120 }
 121
 122 static void kvp_timeout_func(struct work_struct *dummy)
 123 {
 124         /*
 125          * If the timer fires, the user-mode component has not responded;
 126          * process the pending transaction.
 127          */
 128         kvp_respond_to_host(NULL, HV_E_FAIL);
 129
 130         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 131 }
 132
 133 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 134 {
 135         switch (msg->kvp_hdr.operation) {
 136         case KVP_OP_REGISTER:
 137                 dm_reg_value = KVP_OP_REGISTER;
 138                 pr_info("KVP: IP injection functionality not available\n");
 139                 pr_info("KVP: Upgrade the KVP daemon\n");
 140                 break;
 141         case KVP_OP_REGISTER1:
 142                 dm_reg_value = KVP_OP_REGISTER1;
 143                 break;
 144         default:
 145                 pr_info("KVP: incompatible daemon\n");
 146                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 147                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 148                 return -EINVAL;
 149         }
 150
 151         /*
 152          * We have a compatible daemon; complete the handshake.
 153          */
 154         pr_debug("KVP: userspace daemon ver. %d registered\n",
 155                  KVP_OP_REGISTER);
 156         kvp_register(dm_reg_value);
 157         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 158
 159         return 0;
 160 }
 161
 162
 163 /*
 164  * Callback when data is received from user mode.
 165  */
 166
 167 static int kvp_on_msg(void *msg, int len)
 168 {
 169         struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
 170         struct hv_kvp_msg_enumerate *data;
 171         int     error = 0;
 172
 173         if (len < sizeof(*message))
 174                 return -EINVAL;
 175
 176         /*
 177          * If we are negotiating the version information
 178          * with the daemon; handle that first.
 179          */
 180
 181         if (kvp_transaction.state < HVUTIL_READY) {
 182                 return kvp_handle_handshake(message);
 183         }
 184
 185         /* We didn't send anything to userspace so the reply is spurious */
 186         if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
 187                 return -EINVAL;
 188
 189         kvp_transaction.state = HVUTIL_USERSPACE_RECV;
 190
 191         /*
 192          * Based on the version of the daemon, we propagate errors from the
 193          * daemon differently.
 194          */
 195
 196         data = &message->body.kvp_enum_data;
 197
 198         switch (dm_reg_value) {
 199         case KVP_OP_REGISTER:
 200                 /*
 201                  * Null string is used to pass back error condition.
 202                  */
 203                 if (data->data.key[0] == 0)
 204                         error = HV_S_CONT;
 205                 break;
 206
 207         case KVP_OP_REGISTER1:
 208                 /*
 209                  * We use the message header information from
 210                  * the user level daemon to transmit errors.
 211                  */
 212                 error = message->error;
 213                 break;
 214         }
 215
 216         /*
 217          * Complete the transaction by forwarding the key value
 218          * to the host. But first, cancel the timeout.
 219          */
 220         if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 221                 kvp_respond_to_host(message, error);
 222                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 223         }
 224
 225         return 0;
 226 }
 227
 228
 229 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 230 {
 231         struct hv_kvp_msg *in = in_msg;
 232         struct hv_kvp_ip_msg *out = out_msg;
 233         int len;
 234
 235         switch (op) {
 236         case KVP_OP_GET_IP_INFO:
 237                 /*
 238                  * Transform all parameters into utf16 encoding.
 239                  */
 240                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 241                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 242                                 UTF16_HOST_ENDIAN,
 243                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 244                                 MAX_IP_ADDR_SIZE);
 245                 if (len < 0)
 246                         return len;
 247
 248                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 249                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 250                                 UTF16_HOST_ENDIAN,
 251                                 (wchar_t *)out->kvp_ip_val.sub_net,
 252                                 MAX_IP_ADDR_SIZE);
 253                 if (len < 0)
 254                         return len;
 255
 256                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 257                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 258                                 UTF16_HOST_ENDIAN,
 259                                 (wchar_t *)out->kvp_ip_val.gate_way,
 260                                 MAX_GATEWAY_SIZE);
 261                 if (len < 0)
 262                         return len;
 263
 264                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 265                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 266                                 UTF16_HOST_ENDIAN,
 267                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 268                                 MAX_IP_ADDR_SIZE);
 269                 if (len < 0)
 270                         return len;
 271
 272                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 273                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 274                                 UTF16_HOST_ENDIAN,
 275                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 276                                 MAX_IP_ADDR_SIZE);
 277                 if (len < 0)
 278                         return len;
 279
 280                 out->kvp_ip_val.dhcp_enabled =
 281                         in->body.kvp_ip_val.dhcp_enabled;
 282                 out->kvp_ip_val.addr_family =
 283                         in->body.kvp_ip_val.addr_family;
 284         }
 285
 286         return 0;
 287 }
 288
 289 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 290 {
 291         struct hv_kvp_ip_msg *in = in_msg;
 292         struct hv_kvp_msg *out = out_msg;
 293
 294         switch (op) {
 295         case KVP_OP_SET_IP_INFO:
 296                 /*
 297                  * Transform all parameters into utf8 encoding.
 298                  */
 299                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 300                                 MAX_IP_ADDR_SIZE,
 301                                 UTF16_LITTLE_ENDIAN,
 302                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 303                                 MAX_IP_ADDR_SIZE);
 304
 305                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 306                                 MAX_IP_ADDR_SIZE,
 307                                 UTF16_LITTLE_ENDIAN,
 308                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 309                                 MAX_IP_ADDR_SIZE);
 310
 311                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 312                                 MAX_GATEWAY_SIZE,
 313                                 UTF16_LITTLE_ENDIAN,
 314                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 315                                 MAX_GATEWAY_SIZE);
 316
 317                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 318                                 MAX_IP_ADDR_SIZE,
 319                                 UTF16_LITTLE_ENDIAN,
 320                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 321                                 MAX_IP_ADDR_SIZE);
 322
 323                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 324
 325         default:
 326                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 327                                 MAX_ADAPTER_ID_SIZE,
 328                                 UTF16_LITTLE_ENDIAN,
 329                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 330                                 MAX_ADAPTER_ID_SIZE);
 331
 332                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 333         }
 334 }
 335
 336
 337
 338
 339 static void
 340 kvp_send_key(struct work_struct *dummy)
 341 {
 342         struct hv_kvp_msg *message;
 343         struct hv_kvp_msg *in_msg;
 344         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 345         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 346         __u32 val32;
 347         __u64 val64;
 348         int rc;
 349
 350         /* The transaction state is wrong. */
 351         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
 352                 return;
 353
 354         message = kzalloc(sizeof(*message), GFP_KERNEL);
 355         if (!message)
 356                 return;
 357
 358         message->kvp_hdr.operation = operation;
 359         message->kvp_hdr.pool = pool;
 360         in_msg = kvp_transaction.kvp_msg;
 361
 362         /*
 363          * The key/value strings sent from the host are encoded in
 364          * in utf16; convert it to utf8 strings.
 365          * The host assures us that the utf16 strings will not exceed
 366          * the max lengths specified. We will however, reserve room
 367          * for the string terminating character - in the utf16s_utf8s()
 368          * function we limit the size of the buffer where the converted
 369          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 370          * that the strings can be properly terminated!
 371          */
 372
 373         switch (message->kvp_hdr.operation) {
 374         case KVP_OP_SET_IP_INFO:
 375                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 376                 break;
 377         case KVP_OP_GET_IP_INFO:
 378                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 379                 break;
 380         case KVP_OP_SET:
 381                 switch (in_msg->body.kvp_set.data.value_type) {
 382                 case REG_SZ:
 383                         /*
 384                          * The value is a string - utf16 encoding.
 385                          */
 386                         message->body.kvp_set.data.value_size =
 387                                 utf16s_to_utf8s(
 388                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 389                                 in_msg->body.kvp_set.data.value_size,
 390                                 UTF16_LITTLE_ENDIAN,
 391                                 message->body.kvp_set.data.value,
 392                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 393                                 break;
 394
 395                 case REG_U32:
 396                         /*
 397                          * The value is a 32 bit scalar.
 398                          * We save this as a utf8 string.
 399                          */
 400                         val32 = in_msg->body.kvp_set.data.value_u32;
 401                         message->body.kvp_set.data.value_size =
 402                                 sprintf(message->body.kvp_set.data.value,
 403                                         "%d", val32) + 1;
 404                         break;
 405
 406                 case REG_U64:
 407                         /*
 408                          * The value is a 64 bit scalar.
 409                          * We save this as a utf8 string.
 410                          */
 411                         val64 = in_msg->body.kvp_set.data.value_u64;
 412                         message->body.kvp_set.data.value_size =
 413                                 sprintf(message->body.kvp_set.data.value,
 414                                         "%llu", val64) + 1;
 415                         break;
 416
 417                 }
 418         case KVP_OP_GET:
 419                 message->body.kvp_set.data.key_size =
 420                         utf16s_to_utf8s(
 421                         (wchar_t *)in_msg->body.kvp_set.data.key,
 422                         in_msg->body.kvp_set.data.key_size,
 423                         UTF16_LITTLE_ENDIAN,
 424                         message->body.kvp_set.data.key,
 425                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 426                         break;
 427
 428         case KVP_OP_DELETE:
 429                 message->body.kvp_delete.key_size =
 430                         utf16s_to_utf8s(
 431                         (wchar_t *)in_msg->body.kvp_delete.key,
 432                         in_msg->body.kvp_delete.key_size,
 433                         UTF16_LITTLE_ENDIAN,
 434                         message->body.kvp_delete.key,
 435                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 436                         break;
 437
 438         case KVP_OP_ENUMERATE:
 439                 message->body.kvp_enum_data.index =
 440                         in_msg->body.kvp_enum_data.index;
 441                         break;
 442         }
 443
 444         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
 445         rc = hvutil_transport_send(hvt, message, sizeof(*message));
 446         if (rc) {
 447                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 448                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 449                         kvp_respond_to_host(message, HV_E_FAIL);
 450                         kvp_transaction.state = HVUTIL_READY;
 451                 }
 452         }
 453
 454         kfree(message);
 455
 456         return;
 457 }
 458
 459 /*
 460  * Send a response back to the host.
 461  */
 462
 463 static void
 464 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 465 {
 466         struct hv_kvp_msg  *kvp_msg;
 467         struct hv_kvp_exchg_msg_value  *kvp_data;
 468         char    *key_name;
 469         char    *value;
 470         struct icmsg_hdr *icmsghdrp;
 471         int     keylen = 0;
 472         int     valuelen = 0;
 473         u32     buf_len;
 474         struct vmbus_channel *channel;
 475         u64     req_id;
 476         int ret;
 477
 478         /*
 479          * Copy the global state for completing the transaction. Note that
 480          * only one transaction can be active at a time.
 481          */
 482
 483         buf_len = kvp_transaction.recv_len;
 484         channel = kvp_transaction.recv_channel;
 485         req_id = kvp_transaction.recv_req_id;
 486
 487         icmsghdrp = (struct icmsg_hdr *)
 488                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 489
 490         if (channel->onchannel_callback == NULL)
 491                 /*
 492                  * We have raced with util driver being unloaded;
 493                  * silently return.
 494                  */
 495                 return;
 496
 497         icmsghdrp->status = error;
 498
 499         /*
 500          * If the error parameter is set, terminate the host's enumeration
 501          * on this pool.
 502          */
 503         if (error) {
 504                 /*
 505                  * Something failed or we have timedout;
 506                  * terminate the current host-side iteration.
 507                  */
 508                 goto response_done;
 509         }
 510
 511         kvp_msg = (struct hv_kvp_msg *)
 512                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 513                         sizeof(struct icmsg_hdr)];
 514
 515         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 516         case KVP_OP_GET_IP_INFO:
 517                 ret = process_ob_ipinfo(msg_to_host,
 518                                  (struct hv_kvp_ip_msg *)kvp_msg,
 519                                  KVP_OP_GET_IP_INFO);
 520                 if (ret < 0)
 521                         icmsghdrp->status = HV_E_FAIL;
 522
 523                 goto response_done;
 524         case KVP_OP_SET_IP_INFO:
 525                 goto response_done;
 526         case KVP_OP_GET:
 527                 kvp_data = &kvp_msg->body.kvp_get.data;
 528                 goto copy_value;
 529
 530         case KVP_OP_SET:
 531         case KVP_OP_DELETE:
 532                 goto response_done;
 533
 534         default:
 535                 break;
 536         }
 537
 538         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 539         key_name = msg_to_host->body.kvp_enum_data.data.key;
 540
 541         /*
 542          * The windows host expects the key/value pair to be encoded
 543          * in utf16. Ensure that the key/value size reported to the host
 544          * will be less than or equal to the MAX size (including the
 545          * terminating character).
 546          */
 547         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 548                                 (wchar_t *) kvp_data->key,
 549                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 550         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 551
 552 copy_value:
 553         value = msg_to_host->body.kvp_enum_data.data.value;
 554         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 555                                 (wchar_t *) kvp_data->value,
 556                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 557         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 558
 559         /*
 560          * If the utf8s to utf16s conversion failed; notify host
 561          * of the error.
 562          */
 563         if ((keylen < 0) || (valuelen < 0))
 564                 icmsghdrp->status = HV_E_FAIL;
 565
 566         kvp_data->value_type = REG_SZ; /* all our values are strings */
 567
 568 response_done:
 569         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 570
 571         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 572                                 VM_PKT_DATA_INBAND, 0);
 573 }
 574
 575 /*
 576  * This callback is invoked when we get a KVP message from the host.
 577  * The host ensures that only one KVP transaction can be active at a time.
 578  * KVP implementation in Linux needs to forward the key to a user-mde
 579  * component to retrive the corresponding value. Consequently, we cannot
 580  * respond to the host in the conext of this callback. Since the host
 581  * guarantees that at most only one transaction can be active at a time,
 582  * we stash away the transaction state in a set of global variables.
 583  */
 584
 585 void hv_kvp_onchannelcallback(void *context)
 586 {
 587         struct vmbus_channel *channel = context;
 588         u32 recvlen;
 589         u64 requestid;
 590
 591         struct hv_kvp_msg *kvp_msg;
 592
 593         struct icmsg_hdr *icmsghdrp;
 594         struct icmsg_negotiate *negop = NULL;
 595         int util_fw_version;
 596         int kvp_srv_version;
 597
 598         if (kvp_transaction.state > HVUTIL_READY)
 599                 return;
 600
 601         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 602                          &requestid);
 603
 604         if (recvlen > 0) {
 605                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 606                         sizeof(struct vmbuspipe_hdr)];
 607
 608                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 609                         /*
 610                          * Based on the host, select appropriate
 611                          * framework and service versions we will
 612                          * negotiate.
 613                          */
 614                         switch (vmbus_proto_version) {
 615                         case (VERSION_WS2008):
 616                                 util_fw_version = UTIL_WS2K8_FW_VERSION;
 617                                 kvp_srv_version = WS2008_SRV_VERSION;
 618                                 break;
 619                         case (VERSION_WIN7):
 620                                 util_fw_version = UTIL_FW_VERSION;
 621                                 kvp_srv_version = WIN7_SRV_VERSION;
 622                                 break;
 623                         default:
 624                                 util_fw_version = UTIL_FW_VERSION;
 625                                 kvp_srv_version = WIN8_SRV_VERSION;
 626                         }
 627                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 628                                  recv_buffer, util_fw_version,
 629                                  kvp_srv_version);
 630
 631                 } else {
 632                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 633                                 sizeof(struct vmbuspipe_hdr) +
 634                                 sizeof(struct icmsg_hdr)];
 635
 636                         /*
 637                          * Stash away this global state for completing the
 638                          * transaction; note transactions are serialized.
 639                          */
 640
 641                         kvp_transaction.recv_len = recvlen;
 642                         kvp_transaction.recv_req_id = requestid;
 643                         kvp_transaction.kvp_msg = kvp_msg;
 644
 645                         if (kvp_transaction.state < HVUTIL_READY) {
 646                                 /* Userspace is not registered yet */
 647                                 kvp_respond_to_host(NULL, HV_E_FAIL);
 648                                 return;
 649                         }
 650                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
 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_timeout_work,
 663                                               HV_UTIL_TIMEOUT * HZ);
 664
 665                         return;
 666
 667                 }
 668
 669                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 670                         | ICMSGHDRFLAG_RESPONSE;
 671
 672                 vmbus_sendpacket(channel, recv_buffer,
 673                                        recvlen, requestid,
 674                                        VM_PKT_DATA_INBAND, 0);
 675         }
 676
 677 }
 678
 679 static void kvp_on_reset(void)
 680 {
 681         if (cancel_delayed_work_sync(&kvp_timeout_work))
 682                 kvp_respond_to_host(NULL, HV_E_FAIL);
 683         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 684 }
 685
 686 int
 687 hv_kvp_init(struct hv_util_service *srv)
 688 {
 689         recv_buffer = srv->recv_buffer;
 690         kvp_transaction.recv_channel = srv->channel;
 691
 692         /*
 693          * When this driver loads, the user level daemon that
 694          * processes the host requests may not yet be running.
 695          * Defer processing channel callbacks until the daemon
 696          * has registered.
 697          */
 698         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 699
 700         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
 701                                     kvp_on_msg, kvp_on_reset);
 702         if (!hvt)
 703                 return -EFAULT;
 704
 705         return 0;
 706 }
 707
 708 void hv_kvp_deinit(void)
 709 {
 710         kvp_transaction.state = HVUTIL_DEVICE_DYING;
 711         cancel_delayed_work_sync(&kvp_timeout_work);
 712         cancel_work_sync(&kvp_sendkey_work);
 713         hvutil_transport_destroy(hvt);
 714 }