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_host_handshake_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_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
  86 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
  87
  88 static const char kvp_devname[] = "vmbus/hv_kvp";
  89 static u8 *recv_buffer;
  90 static struct hvutil_transport *hvt;
  91 /*
  92  * Register the kernel component with the user-level daemon.
  93  * As part of this registration, pass the LIC version number.
  94  * This number has no meaning, it satisfies the registration protocol.
  95  */
  96 #define HV_DRV_VERSION           "3.1"
  97
  98 static void kvp_poll_wrapper(void *channel)
  99 {
 100         /* Transaction is finished, reset the state here to avoid races. */
 101         kvp_transaction.state = HVUTIL_READY;
 102         hv_kvp_onchannelcallback(channel);
 103 }
 104
 105 static void
 106 kvp_register(int reg_value)
 107 {
 108
 109         struct hv_kvp_msg *kvp_msg;
 110         char *version;
 111
 112         kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
 113
 114         if (kvp_msg) {
 115                 version = kvp_msg->body.kvp_register.version;
 116                 kvp_msg->kvp_hdr.operation = reg_value;
 117                 strcpy(version, HV_DRV_VERSION);
 118
 119                 hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg));
 120                 kfree(kvp_msg);
 121         }
 122 }
 123
 124 static void kvp_timeout_func(struct work_struct *dummy)
 125 {
 126         /*
 127          * If the timer fires, the user-mode component has not responded;
 128          * process the pending transaction.
 129          */
 130         kvp_respond_to_host(NULL, HV_E_FAIL);
 131
 132         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 133 }
 134
 135 static void kvp_host_handshake_func(struct work_struct *dummy)
 136 {
 137         hv_poll_channel(kvp_transaction.recv_channel, hv_kvp_onchannelcallback);
 138 }
 139
 140 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 141 {
 142         switch (msg->kvp_hdr.operation) {
 143         case KVP_OP_REGISTER:
 144                 dm_reg_value = KVP_OP_REGISTER;
 145                 pr_info("KVP: IP injection functionality not available\n");
 146                 pr_info("KVP: Upgrade the KVP daemon\n");
 147                 break;
 148         case KVP_OP_REGISTER1:
 149                 dm_reg_value = KVP_OP_REGISTER1;
 150                 break;
 151         default:
 152                 pr_info("KVP: incompatible daemon\n");
 153                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 154                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 155                 return -EINVAL;
 156         }
 157
 158         /*
 159          * We have a compatible daemon; complete the handshake.
 160          */
 161         pr_debug("KVP: userspace daemon ver. %d registered\n",
 162                  KVP_OP_REGISTER);
 163         kvp_register(dm_reg_value);
 164
 165         /*
 166          * If we're still negotiating with the host cancel the timeout
 167          * work to not poll the channel twice.
 168          */
 169         cancel_delayed_work_sync(&kvp_host_handshake_work);
 170         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 171
 172         return 0;
 173 }
 174
 175
 176 /*
 177  * Callback when data is received from user mode.
 178  */
 179
 180 static int kvp_on_msg(void *msg, int len)
 181 {
 182         struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
 183         struct hv_kvp_msg_enumerate *data;
 184         int     error = 0;
 185
 186         if (len < sizeof(*message))
 187                 return -EINVAL;
 188
 189         /*
 190          * If we are negotiating the version information
 191          * with the daemon; handle that first.
 192          */
 193
 194         if (kvp_transaction.state < HVUTIL_READY) {
 195                 return kvp_handle_handshake(message);
 196         }
 197
 198         /* We didn't send anything to userspace so the reply is spurious */
 199         if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
 200                 return -EINVAL;
 201
 202         kvp_transaction.state = HVUTIL_USERSPACE_RECV;
 203
 204         /*
 205          * Based on the version of the daemon, we propagate errors from the
 206          * daemon differently.
 207          */
 208
 209         data = &message->body.kvp_enum_data;
 210
 211         switch (dm_reg_value) {
 212         case KVP_OP_REGISTER:
 213                 /*
 214                  * Null string is used to pass back error condition.
 215                  */
 216                 if (data->data.key[0] == 0)
 217                         error = HV_S_CONT;
 218                 break;
 219
 220         case KVP_OP_REGISTER1:
 221                 /*
 222                  * We use the message header information from
 223                  * the user level daemon to transmit errors.
 224                  */
 225                 error = message->error;
 226                 break;
 227         }
 228
 229         /*
 230          * Complete the transaction by forwarding the key value
 231          * to the host. But first, cancel the timeout.
 232          */
 233         if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 234                 kvp_respond_to_host(message, error);
 235                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 236         }
 237
 238         return 0;
 239 }
 240
 241
 242 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 243 {
 244         struct hv_kvp_msg *in = in_msg;
 245         struct hv_kvp_ip_msg *out = out_msg;
 246         int len;
 247
 248         switch (op) {
 249         case KVP_OP_GET_IP_INFO:
 250                 /*
 251                  * Transform all parameters into utf16 encoding.
 252                  */
 253                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 254                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 255                                 UTF16_HOST_ENDIAN,
 256                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 257                                 MAX_IP_ADDR_SIZE);
 258                 if (len < 0)
 259                         return len;
 260
 261                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 262                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 263                                 UTF16_HOST_ENDIAN,
 264                                 (wchar_t *)out->kvp_ip_val.sub_net,
 265                                 MAX_IP_ADDR_SIZE);
 266                 if (len < 0)
 267                         return len;
 268
 269                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 270                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 271                                 UTF16_HOST_ENDIAN,
 272                                 (wchar_t *)out->kvp_ip_val.gate_way,
 273                                 MAX_GATEWAY_SIZE);
 274                 if (len < 0)
 275                         return len;
 276
 277                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 278                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 279                                 UTF16_HOST_ENDIAN,
 280                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 281                                 MAX_IP_ADDR_SIZE);
 282                 if (len < 0)
 283                         return len;
 284
 285                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 286                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 287                                 UTF16_HOST_ENDIAN,
 288                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 289                                 MAX_IP_ADDR_SIZE);
 290                 if (len < 0)
 291                         return len;
 292
 293                 out->kvp_ip_val.dhcp_enabled =
 294                         in->body.kvp_ip_val.dhcp_enabled;
 295                 out->kvp_ip_val.addr_family =
 296                         in->body.kvp_ip_val.addr_family;
 297         }
 298
 299         return 0;
 300 }
 301
 302 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 303 {
 304         struct hv_kvp_ip_msg *in = in_msg;
 305         struct hv_kvp_msg *out = out_msg;
 306
 307         switch (op) {
 308         case KVP_OP_SET_IP_INFO:
 309                 /*
 310                  * Transform all parameters into utf8 encoding.
 311                  */
 312                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 313                                 MAX_IP_ADDR_SIZE,
 314                                 UTF16_LITTLE_ENDIAN,
 315                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 316                                 MAX_IP_ADDR_SIZE);
 317
 318                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 319                                 MAX_IP_ADDR_SIZE,
 320                                 UTF16_LITTLE_ENDIAN,
 321                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 322                                 MAX_IP_ADDR_SIZE);
 323
 324                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 325                                 MAX_GATEWAY_SIZE,
 326                                 UTF16_LITTLE_ENDIAN,
 327                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 328                                 MAX_GATEWAY_SIZE);
 329
 330                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 331                                 MAX_IP_ADDR_SIZE,
 332                                 UTF16_LITTLE_ENDIAN,
 333                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 334                                 MAX_IP_ADDR_SIZE);
 335
 336                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 337
 338         default:
 339                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 340                                 MAX_ADAPTER_ID_SIZE,
 341                                 UTF16_LITTLE_ENDIAN,
 342                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 343                                 MAX_ADAPTER_ID_SIZE);
 344
 345                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 346         }
 347 }
 348
 349
 350
 351
 352 static void
 353 kvp_send_key(struct work_struct *dummy)
 354 {
 355         struct hv_kvp_msg *message;
 356         struct hv_kvp_msg *in_msg;
 357         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 358         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 359         __u32 val32;
 360         __u64 val64;
 361         int rc;
 362
 363         /* The transaction state is wrong. */
 364         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
 365                 return;
 366
 367         message = kzalloc(sizeof(*message), GFP_KERNEL);
 368         if (!message)
 369                 return;
 370
 371         message->kvp_hdr.operation = operation;
 372         message->kvp_hdr.pool = pool;
 373         in_msg = kvp_transaction.kvp_msg;
 374
 375         /*
 376          * The key/value strings sent from the host are encoded in
 377          * in utf16; convert it to utf8 strings.
 378          * The host assures us that the utf16 strings will not exceed
 379          * the max lengths specified. We will however, reserve room
 380          * for the string terminating character - in the utf16s_utf8s()
 381          * function we limit the size of the buffer where the converted
 382          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 383          * that the strings can be properly terminated!
 384          */
 385
 386         switch (message->kvp_hdr.operation) {
 387         case KVP_OP_SET_IP_INFO:
 388                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 389                 break;
 390         case KVP_OP_GET_IP_INFO:
 391                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 392                 break;
 393         case KVP_OP_SET:
 394                 switch (in_msg->body.kvp_set.data.value_type) {
 395                 case REG_SZ:
 396                         /*
 397                          * The value is a string - utf16 encoding.
 398                          */
 399                         message->body.kvp_set.data.value_size =
 400                                 utf16s_to_utf8s(
 401                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 402                                 in_msg->body.kvp_set.data.value_size,
 403                                 UTF16_LITTLE_ENDIAN,
 404                                 message->body.kvp_set.data.value,
 405                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 406                                 break;
 407
 408                 case REG_U32:
 409                         /*
 410                          * The value is a 32 bit scalar.
 411                          * We save this as a utf8 string.
 412                          */
 413                         val32 = in_msg->body.kvp_set.data.value_u32;
 414                         message->body.kvp_set.data.value_size =
 415                                 sprintf(message->body.kvp_set.data.value,
 416                                         "%d", val32) + 1;
 417                         break;
 418
 419                 case REG_U64:
 420                         /*
 421                          * The value is a 64 bit scalar.
 422                          * We save this as a utf8 string.
 423                          */
 424                         val64 = in_msg->body.kvp_set.data.value_u64;
 425                         message->body.kvp_set.data.value_size =
 426                                 sprintf(message->body.kvp_set.data.value,
 427                                         "%llu", val64) + 1;
 428                         break;
 429
 430                 }
 431         case KVP_OP_GET:
 432                 message->body.kvp_set.data.key_size =
 433                         utf16s_to_utf8s(
 434                         (wchar_t *)in_msg->body.kvp_set.data.key,
 435                         in_msg->body.kvp_set.data.key_size,
 436                         UTF16_LITTLE_ENDIAN,
 437                         message->body.kvp_set.data.key,
 438                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 439                         break;
 440
 441         case KVP_OP_DELETE:
 442                 message->body.kvp_delete.key_size =
 443                         utf16s_to_utf8s(
 444                         (wchar_t *)in_msg->body.kvp_delete.key,
 445                         in_msg->body.kvp_delete.key_size,
 446                         UTF16_LITTLE_ENDIAN,
 447                         message->body.kvp_delete.key,
 448                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 449                         break;
 450
 451         case KVP_OP_ENUMERATE:
 452                 message->body.kvp_enum_data.index =
 453                         in_msg->body.kvp_enum_data.index;
 454                         break;
 455         }
 456
 457         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
 458         rc = hvutil_transport_send(hvt, message, sizeof(*message));
 459         if (rc) {
 460                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 461                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 462                         kvp_respond_to_host(message, HV_E_FAIL);
 463                         kvp_transaction.state = HVUTIL_READY;
 464                 }
 465         }
 466
 467         kfree(message);
 468
 469         return;
 470 }
 471
 472 /*
 473  * Send a response back to the host.
 474  */
 475
 476 static void
 477 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 478 {
 479         struct hv_kvp_msg  *kvp_msg;
 480         struct hv_kvp_exchg_msg_value  *kvp_data;
 481         char    *key_name;
 482         char    *value;
 483         struct icmsg_hdr *icmsghdrp;
 484         int     keylen = 0;
 485         int     valuelen = 0;
 486         u32     buf_len;
 487         struct vmbus_channel *channel;
 488         u64     req_id;
 489         int ret;
 490
 491         /*
 492          * Copy the global state for completing the transaction. Note that
 493          * only one transaction can be active at a time.
 494          */
 495
 496         buf_len = kvp_transaction.recv_len;
 497         channel = kvp_transaction.recv_channel;
 498         req_id = kvp_transaction.recv_req_id;
 499
 500         icmsghdrp = (struct icmsg_hdr *)
 501                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 502
 503         if (channel->onchannel_callback == NULL)
 504                 /*
 505                  * We have raced with util driver being unloaded;
 506                  * silently return.
 507                  */
 508                 return;
 509
 510         icmsghdrp->status = error;
 511
 512         /*
 513          * If the error parameter is set, terminate the host's enumeration
 514          * on this pool.
 515          */
 516         if (error) {
 517                 /*
 518                  * Something failed or we have timedout;
 519                  * terminate the current host-side iteration.
 520                  */
 521                 goto response_done;
 522         }
 523
 524         kvp_msg = (struct hv_kvp_msg *)
 525                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 526                         sizeof(struct icmsg_hdr)];
 527
 528         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 529         case KVP_OP_GET_IP_INFO:
 530                 ret = process_ob_ipinfo(msg_to_host,
 531                                  (struct hv_kvp_ip_msg *)kvp_msg,
 532                                  KVP_OP_GET_IP_INFO);
 533                 if (ret < 0)
 534                         icmsghdrp->status = HV_E_FAIL;
 535
 536                 goto response_done;
 537         case KVP_OP_SET_IP_INFO:
 538                 goto response_done;
 539         case KVP_OP_GET:
 540                 kvp_data = &kvp_msg->body.kvp_get.data;
 541                 goto copy_value;
 542
 543         case KVP_OP_SET:
 544         case KVP_OP_DELETE:
 545                 goto response_done;
 546
 547         default:
 548                 break;
 549         }
 550
 551         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 552         key_name = msg_to_host->body.kvp_enum_data.data.key;
 553
 554         /*
 555          * The windows host expects the key/value pair to be encoded
 556          * in utf16. Ensure that the key/value size reported to the host
 557          * will be less than or equal to the MAX size (including the
 558          * terminating character).
 559          */
 560         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 561                                 (wchar_t *) kvp_data->key,
 562                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 563         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 564
 565 copy_value:
 566         value = msg_to_host->body.kvp_enum_data.data.value;
 567         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 568                                 (wchar_t *) kvp_data->value,
 569                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 570         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 571
 572         /*
 573          * If the utf8s to utf16s conversion failed; notify host
 574          * of the error.
 575          */
 576         if ((keylen < 0) || (valuelen < 0))
 577                 icmsghdrp->status = HV_E_FAIL;
 578
 579         kvp_data->value_type = REG_SZ; /* all our values are strings */
 580
 581 response_done:
 582         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 583
 584         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 585                                 VM_PKT_DATA_INBAND, 0);
 586 }
 587
 588 /*
 589  * This callback is invoked when we get a KVP message from the host.
 590  * The host ensures that only one KVP transaction can be active at a time.
 591  * KVP implementation in Linux needs to forward the key to a user-mde
 592  * component to retrive the corresponding value. Consequently, we cannot
 593  * respond to the host in the conext of this callback. Since the host
 594  * guarantees that at most only one transaction can be active at a time,
 595  * we stash away the transaction state in a set of global variables.
 596  */
 597
 598 void hv_kvp_onchannelcallback(void *context)
 599 {
 600         struct vmbus_channel *channel = context;
 601         u32 recvlen;
 602         u64 requestid;
 603
 604         struct hv_kvp_msg *kvp_msg;
 605
 606         struct icmsg_hdr *icmsghdrp;
 607         struct icmsg_negotiate *negop = NULL;
 608         int util_fw_version;
 609         int kvp_srv_version;
 610         static enum {NEGO_NOT_STARTED,
 611                      NEGO_IN_PROGRESS,
 612                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
 613
 614         if (host_negotiatied == NEGO_NOT_STARTED &&
 615             kvp_transaction.state < HVUTIL_READY) {
 616                 /*
 617                  * If userspace daemon is not connected and host is asking
 618                  * us to negotiate we need to delay to not lose messages.
 619                  * This is important for Failover IP setting.
 620                  */
 621                 host_negotiatied = NEGO_IN_PROGRESS;
 622                 schedule_delayed_work(&kvp_host_handshake_work,
 623                                       HV_UTIL_NEGO_TIMEOUT * HZ);
 624                 return;
 625         }
 626         if (kvp_transaction.state > HVUTIL_READY)
 627                 return;
 628
 629         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 630                          &requestid);
 631
 632         if (recvlen > 0) {
 633                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 634                         sizeof(struct vmbuspipe_hdr)];
 635
 636                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 637                         /*
 638                          * Based on the host, select appropriate
 639                          * framework and service versions we will
 640                          * negotiate.
 641                          */
 642                         switch (vmbus_proto_version) {
 643                         case (VERSION_WS2008):
 644                                 util_fw_version = UTIL_WS2K8_FW_VERSION;
 645                                 kvp_srv_version = WS2008_SRV_VERSION;
 646                                 break;
 647                         case (VERSION_WIN7):
 648                                 util_fw_version = UTIL_FW_VERSION;
 649                                 kvp_srv_version = WIN7_SRV_VERSION;
 650                                 break;
 651                         default:
 652                                 util_fw_version = UTIL_FW_VERSION;
 653                                 kvp_srv_version = WIN8_SRV_VERSION;
 654                         }
 655                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 656                                  recv_buffer, util_fw_version,
 657                                  kvp_srv_version);
 658
 659                 } else {
 660                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 661                                 sizeof(struct vmbuspipe_hdr) +
 662                                 sizeof(struct icmsg_hdr)];
 663
 664                         /*
 665                          * Stash away this global state for completing the
 666                          * transaction; note transactions are serialized.
 667                          */
 668
 669                         kvp_transaction.recv_len = recvlen;
 670                         kvp_transaction.recv_req_id = requestid;
 671                         kvp_transaction.kvp_msg = kvp_msg;
 672
 673                         if (kvp_transaction.state < HVUTIL_READY) {
 674                                 /* Userspace is not registered yet */
 675                                 kvp_respond_to_host(NULL, HV_E_FAIL);
 676                                 return;
 677                         }
 678                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
 679
 680                         /*
 681                          * Get the information from the
 682                          * user-mode component.
 683                          * component. This transaction will be
 684                          * completed when we get the value from
 685                          * the user-mode component.
 686                          * Set a timeout to deal with
 687                          * user-mode not responding.
 688                          */
 689                         schedule_work(&kvp_sendkey_work);
 690                         schedule_delayed_work(&kvp_timeout_work,
 691                                               HV_UTIL_TIMEOUT * HZ);
 692
 693                         return;
 694
 695                 }
 696
 697                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 698                         | ICMSGHDRFLAG_RESPONSE;
 699
 700                 vmbus_sendpacket(channel, recv_buffer,
 701                                        recvlen, requestid,
 702                                        VM_PKT_DATA_INBAND, 0);
 703
 704                 host_negotiatied = NEGO_FINISHED;
 705         }
 706
 707 }
 708
 709 static void kvp_on_reset(void)
 710 {
 711         if (cancel_delayed_work_sync(&kvp_timeout_work))
 712                 kvp_respond_to_host(NULL, HV_E_FAIL);
 713         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 714 }
 715
 716 int
 717 hv_kvp_init(struct hv_util_service *srv)
 718 {
 719         recv_buffer = srv->recv_buffer;
 720         kvp_transaction.recv_channel = srv->channel;
 721
 722         /*
 723          * When this driver loads, the user level daemon that
 724          * processes the host requests may not yet be running.
 725          * Defer processing channel callbacks until the daemon
 726          * has registered.
 727          */
 728         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 729
 730         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
 731                                     kvp_on_msg, kvp_on_reset);
 732         if (!hvt)
 733                 return -EFAULT;
 734
 735         return 0;
 736 }
 737
 738 void hv_kvp_deinit(void)
 739 {
 740         kvp_transaction.state = HVUTIL_DEVICE_DYING;
 741         cancel_delayed_work_sync(&kvp_host_handshake_work);
 742         cancel_delayed_work_sync(&kvp_timeout_work);
 743         cancel_work_sync(&kvp_sendkey_work);
 744         hvutil_transport_destroy(hvt);
 745 }