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 static struct completion release_event;
  92 /*
  93  * Register the kernel component with the user-level daemon.
  94  * As part of this registration, pass the LIC version number.
  95  * This number has no meaning, it satisfies the registration protocol.
  96  */
  97 #define HV_DRV_VERSION           "3.1"
  98
  99 static void kvp_poll_wrapper(void *channel)
 100 {
 101         /* Transaction is finished, reset the state here to avoid races. */
 102         kvp_transaction.state = HVUTIL_READY;
 103         hv_kvp_onchannelcallback(channel);
 104 }
 105
 106 static void
 107 kvp_register(int reg_value)
 108 {
 109
 110         struct hv_kvp_msg *kvp_msg;
 111         char *version;
 112
 113         kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
 114
 115         if (kvp_msg) {
 116                 version = kvp_msg->body.kvp_register.version;
 117                 kvp_msg->kvp_hdr.operation = reg_value;
 118                 strcpy(version, HV_DRV_VERSION);
 119
 120                 hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg));
 121                 kfree(kvp_msg);
 122         }
 123 }
 124
 125 static void kvp_timeout_func(struct work_struct *dummy)
 126 {
 127         /*
 128          * If the timer fires, the user-mode component has not responded;
 129          * process the pending transaction.
 130          */
 131         kvp_respond_to_host(NULL, HV_E_FAIL);
 132
 133         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 134 }
 135
 136 static void kvp_host_handshake_func(struct work_struct *dummy)
 137 {
 138         hv_poll_channel(kvp_transaction.recv_channel, hv_kvp_onchannelcallback);
 139 }
 140
 141 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 142 {
 143         switch (msg->kvp_hdr.operation) {
 144         case KVP_OP_REGISTER:
 145                 dm_reg_value = KVP_OP_REGISTER;
 146                 pr_info("KVP: IP injection functionality not available\n");
 147                 pr_info("KVP: Upgrade the KVP daemon\n");
 148                 break;
 149         case KVP_OP_REGISTER1:
 150                 dm_reg_value = KVP_OP_REGISTER1;
 151                 break;
 152         default:
 153                 pr_info("KVP: incompatible daemon\n");
 154                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
 155                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
 156                 return -EINVAL;
 157         }
 158
 159         /*
 160          * We have a compatible daemon; complete the handshake.
 161          */
 162         pr_debug("KVP: userspace daemon ver. %d registered\n",
 163                  KVP_OP_REGISTER);
 164         kvp_register(dm_reg_value);
 165
 166         /*
 167          * If we're still negotiating with the host cancel the timeout
 168          * work to not poll the channel twice.
 169          */
 170         cancel_delayed_work_sync(&kvp_host_handshake_work);
 171         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 172
 173         return 0;
 174 }
 175
 176
 177 /*
 178  * Callback when data is received from user mode.
 179  */
 180
 181 static int kvp_on_msg(void *msg, int len)
 182 {
 183         struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
 184         struct hv_kvp_msg_enumerate *data;
 185         int     error = 0;
 186
 187         if (len < sizeof(*message))
 188                 return -EINVAL;
 189
 190         /*
 191          * If we are negotiating the version information
 192          * with the daemon; handle that first.
 193          */
 194
 195         if (kvp_transaction.state < HVUTIL_READY) {
 196                 return kvp_handle_handshake(message);
 197         }
 198
 199         /* We didn't send anything to userspace so the reply is spurious */
 200         if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
 201                 return -EINVAL;
 202
 203         kvp_transaction.state = HVUTIL_USERSPACE_RECV;
 204
 205         /*
 206          * Based on the version of the daemon, we propagate errors from the
 207          * daemon differently.
 208          */
 209
 210         data = &message->body.kvp_enum_data;
 211
 212         switch (dm_reg_value) {
 213         case KVP_OP_REGISTER:
 214                 /*
 215                  * Null string is used to pass back error condition.
 216                  */
 217                 if (data->data.key[0] == 0)
 218                         error = HV_S_CONT;
 219                 break;
 220
 221         case KVP_OP_REGISTER1:
 222                 /*
 223                  * We use the message header information from
 224                  * the user level daemon to transmit errors.
 225                  */
 226                 error = message->error;
 227                 break;
 228         }
 229
 230         /*
 231          * Complete the transaction by forwarding the key value
 232          * to the host. But first, cancel the timeout.
 233          */
 234         if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 235                 kvp_respond_to_host(message, error);
 236                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 237         }
 238
 239         return 0;
 240 }
 241
 242
 243 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
 244 {
 245         struct hv_kvp_msg *in = in_msg;
 246         struct hv_kvp_ip_msg *out = out_msg;
 247         int len;
 248
 249         switch (op) {
 250         case KVP_OP_GET_IP_INFO:
 251                 /*
 252                  * Transform all parameters into utf16 encoding.
 253                  */
 254                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
 255                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
 256                                 UTF16_HOST_ENDIAN,
 257                                 (wchar_t *)out->kvp_ip_val.ip_addr,
 258                                 MAX_IP_ADDR_SIZE);
 259                 if (len < 0)
 260                         return len;
 261
 262                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
 263                                 strlen((char *)in->body.kvp_ip_val.sub_net),
 264                                 UTF16_HOST_ENDIAN,
 265                                 (wchar_t *)out->kvp_ip_val.sub_net,
 266                                 MAX_IP_ADDR_SIZE);
 267                 if (len < 0)
 268                         return len;
 269
 270                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
 271                                 strlen((char *)in->body.kvp_ip_val.gate_way),
 272                                 UTF16_HOST_ENDIAN,
 273                                 (wchar_t *)out->kvp_ip_val.gate_way,
 274                                 MAX_GATEWAY_SIZE);
 275                 if (len < 0)
 276                         return len;
 277
 278                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
 279                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
 280                                 UTF16_HOST_ENDIAN,
 281                                 (wchar_t *)out->kvp_ip_val.dns_addr,
 282                                 MAX_IP_ADDR_SIZE);
 283                 if (len < 0)
 284                         return len;
 285
 286                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
 287                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
 288                                 UTF16_HOST_ENDIAN,
 289                                 (wchar_t *)out->kvp_ip_val.adapter_id,
 290                                 MAX_IP_ADDR_SIZE);
 291                 if (len < 0)
 292                         return len;
 293
 294                 out->kvp_ip_val.dhcp_enabled =
 295                         in->body.kvp_ip_val.dhcp_enabled;
 296                 out->kvp_ip_val.addr_family =
 297                         in->body.kvp_ip_val.addr_family;
 298         }
 299
 300         return 0;
 301 }
 302
 303 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 304 {
 305         struct hv_kvp_ip_msg *in = in_msg;
 306         struct hv_kvp_msg *out = out_msg;
 307
 308         switch (op) {
 309         case KVP_OP_SET_IP_INFO:
 310                 /*
 311                  * Transform all parameters into utf8 encoding.
 312                  */
 313                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
 314                                 MAX_IP_ADDR_SIZE,
 315                                 UTF16_LITTLE_ENDIAN,
 316                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
 317                                 MAX_IP_ADDR_SIZE);
 318
 319                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
 320                                 MAX_IP_ADDR_SIZE,
 321                                 UTF16_LITTLE_ENDIAN,
 322                                 (__u8 *)out->body.kvp_ip_val.sub_net,
 323                                 MAX_IP_ADDR_SIZE);
 324
 325                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
 326                                 MAX_GATEWAY_SIZE,
 327                                 UTF16_LITTLE_ENDIAN,
 328                                 (__u8 *)out->body.kvp_ip_val.gate_way,
 329                                 MAX_GATEWAY_SIZE);
 330
 331                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
 332                                 MAX_IP_ADDR_SIZE,
 333                                 UTF16_LITTLE_ENDIAN,
 334                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
 335                                 MAX_IP_ADDR_SIZE);
 336
 337                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
 338
 339         default:
 340                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
 341                                 MAX_ADAPTER_ID_SIZE,
 342                                 UTF16_LITTLE_ENDIAN,
 343                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
 344                                 MAX_ADAPTER_ID_SIZE);
 345
 346                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
 347         }
 348 }
 349
 350
 351
 352
 353 static void
 354 kvp_send_key(struct work_struct *dummy)
 355 {
 356         struct hv_kvp_msg *message;
 357         struct hv_kvp_msg *in_msg;
 358         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
 359         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
 360         __u32 val32;
 361         __u64 val64;
 362         int rc;
 363
 364         /* The transaction state is wrong. */
 365         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
 366                 return;
 367
 368         message = kzalloc(sizeof(*message), GFP_KERNEL);
 369         if (!message)
 370                 return;
 371
 372         message->kvp_hdr.operation = operation;
 373         message->kvp_hdr.pool = pool;
 374         in_msg = kvp_transaction.kvp_msg;
 375
 376         /*
 377          * The key/value strings sent from the host are encoded in
 378          * in utf16; convert it to utf8 strings.
 379          * The host assures us that the utf16 strings will not exceed
 380          * the max lengths specified. We will however, reserve room
 381          * for the string terminating character - in the utf16s_utf8s()
 382          * function we limit the size of the buffer where the converted
 383          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
 384          * that the strings can be properly terminated!
 385          */
 386
 387         switch (message->kvp_hdr.operation) {
 388         case KVP_OP_SET_IP_INFO:
 389                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
 390                 break;
 391         case KVP_OP_GET_IP_INFO:
 392                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
 393                 break;
 394         case KVP_OP_SET:
 395                 switch (in_msg->body.kvp_set.data.value_type) {
 396                 case REG_SZ:
 397                         /*
 398                          * The value is a string - utf16 encoding.
 399                          */
 400                         message->body.kvp_set.data.value_size =
 401                                 utf16s_to_utf8s(
 402                                 (wchar_t *)in_msg->body.kvp_set.data.value,
 403                                 in_msg->body.kvp_set.data.value_size,
 404                                 UTF16_LITTLE_ENDIAN,
 405                                 message->body.kvp_set.data.value,
 406                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
 407                                 break;
 408
 409                 case REG_U32:
 410                         /*
 411                          * The value is a 32 bit scalar.
 412                          * We save this as a utf8 string.
 413                          */
 414                         val32 = in_msg->body.kvp_set.data.value_u32;
 415                         message->body.kvp_set.data.value_size =
 416                                 sprintf(message->body.kvp_set.data.value,
 417                                         "%d", val32) + 1;
 418                         break;
 419
 420                 case REG_U64:
 421                         /*
 422                          * The value is a 64 bit scalar.
 423                          * We save this as a utf8 string.
 424                          */
 425                         val64 = in_msg->body.kvp_set.data.value_u64;
 426                         message->body.kvp_set.data.value_size =
 427                                 sprintf(message->body.kvp_set.data.value,
 428                                         "%llu", val64) + 1;
 429                         break;
 430
 431                 }
 432         case KVP_OP_GET:
 433                 message->body.kvp_set.data.key_size =
 434                         utf16s_to_utf8s(
 435                         (wchar_t *)in_msg->body.kvp_set.data.key,
 436                         in_msg->body.kvp_set.data.key_size,
 437                         UTF16_LITTLE_ENDIAN,
 438                         message->body.kvp_set.data.key,
 439                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 440                         break;
 441
 442         case KVP_OP_DELETE:
 443                 message->body.kvp_delete.key_size =
 444                         utf16s_to_utf8s(
 445                         (wchar_t *)in_msg->body.kvp_delete.key,
 446                         in_msg->body.kvp_delete.key_size,
 447                         UTF16_LITTLE_ENDIAN,
 448                         message->body.kvp_delete.key,
 449                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
 450                         break;
 451
 452         case KVP_OP_ENUMERATE:
 453                 message->body.kvp_enum_data.index =
 454                         in_msg->body.kvp_enum_data.index;
 455                         break;
 456         }
 457
 458         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
 459         rc = hvutil_transport_send(hvt, message, sizeof(*message));
 460         if (rc) {
 461                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
 462                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 463                         kvp_respond_to_host(message, HV_E_FAIL);
 464                         kvp_transaction.state = HVUTIL_READY;
 465                 }
 466         }
 467
 468         kfree(message);
 469
 470         return;
 471 }
 472
 473 /*
 474  * Send a response back to the host.
 475  */
 476
 477 static void
 478 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
 479 {
 480         struct hv_kvp_msg  *kvp_msg;
 481         struct hv_kvp_exchg_msg_value  *kvp_data;
 482         char    *key_name;
 483         char    *value;
 484         struct icmsg_hdr *icmsghdrp;
 485         int     keylen = 0;
 486         int     valuelen = 0;
 487         u32     buf_len;
 488         struct vmbus_channel *channel;
 489         u64     req_id;
 490         int ret;
 491
 492         /*
 493          * Copy the global state for completing the transaction. Note that
 494          * only one transaction can be active at a time.
 495          */
 496
 497         buf_len = kvp_transaction.recv_len;
 498         channel = kvp_transaction.recv_channel;
 499         req_id = kvp_transaction.recv_req_id;
 500
 501         icmsghdrp = (struct icmsg_hdr *)
 502                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
 503
 504         if (channel->onchannel_callback == NULL)
 505                 /*
 506                  * We have raced with util driver being unloaded;
 507                  * silently return.
 508                  */
 509                 return;
 510
 511         icmsghdrp->status = error;
 512
 513         /*
 514          * If the error parameter is set, terminate the host's enumeration
 515          * on this pool.
 516          */
 517         if (error) {
 518                 /*
 519                  * Something failed or we have timedout;
 520                  * terminate the current host-side iteration.
 521                  */
 522                 goto response_done;
 523         }
 524
 525         kvp_msg = (struct hv_kvp_msg *)
 526                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
 527                         sizeof(struct icmsg_hdr)];
 528
 529         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
 530         case KVP_OP_GET_IP_INFO:
 531                 ret = process_ob_ipinfo(msg_to_host,
 532                                  (struct hv_kvp_ip_msg *)kvp_msg,
 533                                  KVP_OP_GET_IP_INFO);
 534                 if (ret < 0)
 535                         icmsghdrp->status = HV_E_FAIL;
 536
 537                 goto response_done;
 538         case KVP_OP_SET_IP_INFO:
 539                 goto response_done;
 540         case KVP_OP_GET:
 541                 kvp_data = &kvp_msg->body.kvp_get.data;
 542                 goto copy_value;
 543
 544         case KVP_OP_SET:
 545         case KVP_OP_DELETE:
 546                 goto response_done;
 547
 548         default:
 549                 break;
 550         }
 551
 552         kvp_data = &kvp_msg->body.kvp_enum_data.data;
 553         key_name = msg_to_host->body.kvp_enum_data.data.key;
 554
 555         /*
 556          * The windows host expects the key/value pair to be encoded
 557          * in utf16. Ensure that the key/value size reported to the host
 558          * will be less than or equal to the MAX size (including the
 559          * terminating character).
 560          */
 561         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
 562                                 (wchar_t *) kvp_data->key,
 563                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
 564         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
 565
 566 copy_value:
 567         value = msg_to_host->body.kvp_enum_data.data.value;
 568         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
 569                                 (wchar_t *) kvp_data->value,
 570                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
 571         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
 572
 573         /*
 574          * If the utf8s to utf16s conversion failed; notify host
 575          * of the error.
 576          */
 577         if ((keylen < 0) || (valuelen < 0))
 578                 icmsghdrp->status = HV_E_FAIL;
 579
 580         kvp_data->value_type = REG_SZ; /* all our values are strings */
 581
 582 response_done:
 583         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
 584
 585         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
 586                                 VM_PKT_DATA_INBAND, 0);
 587 }
 588
 589 /*
 590  * This callback is invoked when we get a KVP message from the host.
 591  * The host ensures that only one KVP transaction can be active at a time.
 592  * KVP implementation in Linux needs to forward the key to a user-mde
 593  * component to retrive the corresponding value. Consequently, we cannot
 594  * respond to the host in the conext of this callback. Since the host
 595  * guarantees that at most only one transaction can be active at a time,
 596  * we stash away the transaction state in a set of global variables.
 597  */
 598
 599 void hv_kvp_onchannelcallback(void *context)
 600 {
 601         struct vmbus_channel *channel = context;
 602         u32 recvlen;
 603         u64 requestid;
 604
 605         struct hv_kvp_msg *kvp_msg;
 606
 607         struct icmsg_hdr *icmsghdrp;
 608         struct icmsg_negotiate *negop = NULL;
 609         int util_fw_version;
 610         int kvp_srv_version;
 611         static enum {NEGO_NOT_STARTED,
 612                      NEGO_IN_PROGRESS,
 613                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
 614
 615         if (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                 if (host_negotiatied == NEGO_NOT_STARTED) {
 622                         host_negotiatied = NEGO_IN_PROGRESS;
 623                         schedule_delayed_work(&kvp_host_handshake_work,
 624                                       HV_UTIL_NEGO_TIMEOUT * HZ);
 625                 }
 626                 return;
 627         }
 628         if (kvp_transaction.state > HVUTIL_READY)
 629                 return;
 630 recheck:
 631         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 632                          &requestid);
 633
 634         if (recvlen > 0) {
 635                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
 636                         sizeof(struct vmbuspipe_hdr)];
 637
 638                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 639                         /*
 640                          * Based on the host, select appropriate
 641                          * framework and service versions we will
 642                          * negotiate.
 643                          */
 644                         switch (vmbus_proto_version) {
 645                         case (VERSION_WS2008):
 646                                 util_fw_version = UTIL_WS2K8_FW_VERSION;
 647                                 kvp_srv_version = WS2008_SRV_VERSION;
 648                                 break;
 649                         case (VERSION_WIN7):
 650                                 util_fw_version = UTIL_FW_VERSION;
 651                                 kvp_srv_version = WIN7_SRV_VERSION;
 652                                 break;
 653                         default:
 654                                 util_fw_version = UTIL_FW_VERSION;
 655                                 kvp_srv_version = WIN8_SRV_VERSION;
 656                         }
 657                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 658                                  recv_buffer, util_fw_version,
 659                                  kvp_srv_version);
 660
 661                 } else {
 662                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
 663                                 sizeof(struct vmbuspipe_hdr) +
 664                                 sizeof(struct icmsg_hdr)];
 665
 666                         /*
 667                          * Stash away this global state for completing the
 668                          * transaction; note transactions are serialized.
 669                          */
 670
 671                         kvp_transaction.recv_len = recvlen;
 672                         kvp_transaction.recv_req_id = requestid;
 673                         kvp_transaction.kvp_msg = kvp_msg;
 674
 675                         if (kvp_transaction.state < HVUTIL_READY) {
 676                                 /* Userspace is not registered yet */
 677                                 kvp_respond_to_host(NULL, HV_E_FAIL);
 678                                 return;
 679                         }
 680                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
 681
 682                         /*
 683                          * Get the information from the
 684                          * user-mode component.
 685                          * component. This transaction will be
 686                          * completed when we get the value from
 687                          * the user-mode component.
 688                          * Set a timeout to deal with
 689                          * user-mode not responding.
 690                          */
 691                         schedule_work(&kvp_sendkey_work);
 692                         schedule_delayed_work(&kvp_timeout_work,
 693                                               HV_UTIL_TIMEOUT * HZ);
 694
 695                         return;
 696
 697                 }
 698
 699                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 700                         | ICMSGHDRFLAG_RESPONSE;
 701
 702                 vmbus_sendpacket(channel, recv_buffer,
 703                                        recvlen, requestid,
 704                                        VM_PKT_DATA_INBAND, 0);
 705
 706                 host_negotiatied = NEGO_FINISHED;
 707
 708                 goto recheck;
 709         }
 710
 711 }
 712
 713 static void kvp_on_reset(void)
 714 {
 715         if (cancel_delayed_work_sync(&kvp_timeout_work))
 716                 kvp_respond_to_host(NULL, HV_E_FAIL);
 717         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 718         complete(&release_event);
 719 }
 720
 721 int
 722 hv_kvp_init(struct hv_util_service *srv)
 723 {
 724         recv_buffer = srv->recv_buffer;
 725         kvp_transaction.recv_channel = srv->channel;
 726
 727         init_completion(&release_event);
 728         /*
 729          * When this driver loads, the user level daemon that
 730          * processes the host requests may not yet be running.
 731          * Defer processing channel callbacks until the daemon
 732          * has registered.
 733          */
 734         kvp_transaction.state = HVUTIL_DEVICE_INIT;
 735
 736         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
 737                                     kvp_on_msg, kvp_on_reset);
 738         if (!hvt)
 739                 return -EFAULT;
 740
 741         return 0;
 742 }
 743
 744 void hv_kvp_deinit(void)
 745 {
 746         kvp_transaction.state = HVUTIL_DEVICE_DYING;
 747         cancel_delayed_work_sync(&kvp_host_handshake_work);
 748         cancel_delayed_work_sync(&kvp_timeout_work);
 749         cancel_work_sync(&kvp_sendkey_work);
 750         hvutil_transport_destroy(hvt);
 751         wait_for_completion(&release_event);
 752 }