Merge tag 'usb-4.20-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
[sfrench/cifs-2.6.git] / 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 #define KVP_VER_COUNT 3
50 static const int kvp_versions[] = {
51         WIN8_SRV_VERSION,
52         WIN7_SRV_VERSION,
53         WS2008_SRV_VERSION
54 };
55
56 #define FW_VER_COUNT 2
57 static const int fw_versions[] = {
58         UTIL_FW_VERSION,
59         UTIL_WS2K8_FW_VERSION
60 };
61
62 /*
63  * Global state maintained for transaction that is being processed. For a class
64  * of integration services, including the "KVP service", the specified protocol
65  * is a "request/response" protocol which means that there can only be single
66  * outstanding transaction from the host at any given point in time. We use
67  * this to simplify memory management in this driver - we cache and process
68  * only one message at a time.
69  *
70  * While the request/response protocol is guaranteed by the host, we further
71  * ensure this by serializing packet processing in this driver - we do not
72  * read additional packets from the VMBUS until the current packet is fully
73  * handled.
74  */
75
76 static struct {
77         int state;   /* hvutil_device_state */
78         int recv_len; /* number of bytes received. */
79         struct hv_kvp_msg  *kvp_msg; /* current message */
80         struct vmbus_channel *recv_channel; /* chn we got the request */
81         u64 recv_req_id; /* request ID. */
82 } kvp_transaction;
83
84 /*
85  * This state maintains the version number registered by the daemon.
86  */
87 static int dm_reg_value;
88
89 static void kvp_send_key(struct work_struct *dummy);
90
91
92 static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
93 static void kvp_timeout_func(struct work_struct *dummy);
94 static void kvp_host_handshake_func(struct work_struct *dummy);
95 static void kvp_register(int);
96
97 static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
98 static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
99 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
100
101 static const char kvp_devname[] = "vmbus/hv_kvp";
102 static u8 *recv_buffer;
103 static struct hvutil_transport *hvt;
104 /*
105  * Register the kernel component with the user-level daemon.
106  * As part of this registration, pass the LIC version number.
107  * This number has no meaning, it satisfies the registration protocol.
108  */
109 #define HV_DRV_VERSION           "3.1"
110
111 static void kvp_poll_wrapper(void *channel)
112 {
113         /* Transaction is finished, reset the state here to avoid races. */
114         kvp_transaction.state = HVUTIL_READY;
115         tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
116 }
117
118 static void kvp_register_done(void)
119 {
120         /*
121          * If we're still negotiating with the host cancel the timeout
122          * work to not poll the channel twice.
123          */
124         pr_debug("KVP: userspace daemon registered\n");
125         cancel_delayed_work_sync(&kvp_host_handshake_work);
126         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
127 }
128
129 static void
130 kvp_register(int reg_value)
131 {
132
133         struct hv_kvp_msg *kvp_msg;
134         char *version;
135
136         kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
137
138         if (kvp_msg) {
139                 version = kvp_msg->body.kvp_register.version;
140                 kvp_msg->kvp_hdr.operation = reg_value;
141                 strcpy(version, HV_DRV_VERSION);
142
143                 hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
144                                       kvp_register_done);
145                 kfree(kvp_msg);
146         }
147 }
148
149 static void kvp_timeout_func(struct work_struct *dummy)
150 {
151         /*
152          * If the timer fires, the user-mode component has not responded;
153          * process the pending transaction.
154          */
155         kvp_respond_to_host(NULL, HV_E_FAIL);
156
157         hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
158 }
159
160 static void kvp_host_handshake_func(struct work_struct *dummy)
161 {
162         tasklet_schedule(&kvp_transaction.recv_channel->callback_event);
163 }
164
165 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
166 {
167         switch (msg->kvp_hdr.operation) {
168         case KVP_OP_REGISTER:
169                 dm_reg_value = KVP_OP_REGISTER;
170                 pr_info("KVP: IP injection functionality not available\n");
171                 pr_info("KVP: Upgrade the KVP daemon\n");
172                 break;
173         case KVP_OP_REGISTER1:
174                 dm_reg_value = KVP_OP_REGISTER1;
175                 break;
176         default:
177                 pr_info("KVP: incompatible daemon\n");
178                 pr_info("KVP: KVP version: %d, Daemon version: %d\n",
179                         KVP_OP_REGISTER1, msg->kvp_hdr.operation);
180                 return -EINVAL;
181         }
182
183         /*
184          * We have a compatible daemon; complete the handshake.
185          */
186         pr_debug("KVP: userspace daemon ver. %d connected\n",
187                  msg->kvp_hdr.operation);
188         kvp_register(dm_reg_value);
189
190         return 0;
191 }
192
193
194 /*
195  * Callback when data is received from user mode.
196  */
197
198 static int kvp_on_msg(void *msg, int len)
199 {
200         struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
201         struct hv_kvp_msg_enumerate *data;
202         int     error = 0;
203
204         if (len < sizeof(*message))
205                 return -EINVAL;
206
207         /*
208          * If we are negotiating the version information
209          * with the daemon; handle that first.
210          */
211
212         if (kvp_transaction.state < HVUTIL_READY) {
213                 return kvp_handle_handshake(message);
214         }
215
216         /* We didn't send anything to userspace so the reply is spurious */
217         if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
218                 return -EINVAL;
219
220         kvp_transaction.state = HVUTIL_USERSPACE_RECV;
221
222         /*
223          * Based on the version of the daemon, we propagate errors from the
224          * daemon differently.
225          */
226
227         data = &message->body.kvp_enum_data;
228
229         switch (dm_reg_value) {
230         case KVP_OP_REGISTER:
231                 /*
232                  * Null string is used to pass back error condition.
233                  */
234                 if (data->data.key[0] == 0)
235                         error = HV_S_CONT;
236                 break;
237
238         case KVP_OP_REGISTER1:
239                 /*
240                  * We use the message header information from
241                  * the user level daemon to transmit errors.
242                  */
243                 error = message->error;
244                 break;
245         }
246
247         /*
248          * Complete the transaction by forwarding the key value
249          * to the host. But first, cancel the timeout.
250          */
251         if (cancel_delayed_work_sync(&kvp_timeout_work)) {
252                 kvp_respond_to_host(message, error);
253                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
254         }
255
256         return 0;
257 }
258
259
260 static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
261 {
262         struct hv_kvp_msg *in = in_msg;
263         struct hv_kvp_ip_msg *out = out_msg;
264         int len;
265
266         switch (op) {
267         case KVP_OP_GET_IP_INFO:
268                 /*
269                  * Transform all parameters into utf16 encoding.
270                  */
271                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
272                                 strlen((char *)in->body.kvp_ip_val.ip_addr),
273                                 UTF16_HOST_ENDIAN,
274                                 (wchar_t *)out->kvp_ip_val.ip_addr,
275                                 MAX_IP_ADDR_SIZE);
276                 if (len < 0)
277                         return len;
278
279                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
280                                 strlen((char *)in->body.kvp_ip_val.sub_net),
281                                 UTF16_HOST_ENDIAN,
282                                 (wchar_t *)out->kvp_ip_val.sub_net,
283                                 MAX_IP_ADDR_SIZE);
284                 if (len < 0)
285                         return len;
286
287                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
288                                 strlen((char *)in->body.kvp_ip_val.gate_way),
289                                 UTF16_HOST_ENDIAN,
290                                 (wchar_t *)out->kvp_ip_val.gate_way,
291                                 MAX_GATEWAY_SIZE);
292                 if (len < 0)
293                         return len;
294
295                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
296                                 strlen((char *)in->body.kvp_ip_val.dns_addr),
297                                 UTF16_HOST_ENDIAN,
298                                 (wchar_t *)out->kvp_ip_val.dns_addr,
299                                 MAX_IP_ADDR_SIZE);
300                 if (len < 0)
301                         return len;
302
303                 len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
304                                 strlen((char *)in->body.kvp_ip_val.adapter_id),
305                                 UTF16_HOST_ENDIAN,
306                                 (wchar_t *)out->kvp_ip_val.adapter_id,
307                                 MAX_ADAPTER_ID_SIZE);
308                 if (len < 0)
309                         return len;
310
311                 out->kvp_ip_val.dhcp_enabled =
312                         in->body.kvp_ip_val.dhcp_enabled;
313                 out->kvp_ip_val.addr_family =
314                         in->body.kvp_ip_val.addr_family;
315         }
316
317         return 0;
318 }
319
320 static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
321 {
322         struct hv_kvp_ip_msg *in = in_msg;
323         struct hv_kvp_msg *out = out_msg;
324
325         switch (op) {
326         case KVP_OP_SET_IP_INFO:
327                 /*
328                  * Transform all parameters into utf8 encoding.
329                  */
330                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
331                                 MAX_IP_ADDR_SIZE,
332                                 UTF16_LITTLE_ENDIAN,
333                                 (__u8 *)out->body.kvp_ip_val.ip_addr,
334                                 MAX_IP_ADDR_SIZE);
335
336                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
337                                 MAX_IP_ADDR_SIZE,
338                                 UTF16_LITTLE_ENDIAN,
339                                 (__u8 *)out->body.kvp_ip_val.sub_net,
340                                 MAX_IP_ADDR_SIZE);
341
342                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
343                                 MAX_GATEWAY_SIZE,
344                                 UTF16_LITTLE_ENDIAN,
345                                 (__u8 *)out->body.kvp_ip_val.gate_way,
346                                 MAX_GATEWAY_SIZE);
347
348                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
349                                 MAX_IP_ADDR_SIZE,
350                                 UTF16_LITTLE_ENDIAN,
351                                 (__u8 *)out->body.kvp_ip_val.dns_addr,
352                                 MAX_IP_ADDR_SIZE);
353
354                 out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
355
356                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
357                                 MAX_ADAPTER_ID_SIZE,
358                                 UTF16_LITTLE_ENDIAN,
359                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
360                                 MAX_ADAPTER_ID_SIZE);
361
362                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
363         }
364 }
365
366
367
368
369 static void
370 kvp_send_key(struct work_struct *dummy)
371 {
372         struct hv_kvp_msg *message;
373         struct hv_kvp_msg *in_msg;
374         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
375         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
376         __u32 val32;
377         __u64 val64;
378         int rc;
379
380         /* The transaction state is wrong. */
381         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
382                 return;
383
384         message = kzalloc(sizeof(*message), GFP_KERNEL);
385         if (!message)
386                 return;
387
388         message->kvp_hdr.operation = operation;
389         message->kvp_hdr.pool = pool;
390         in_msg = kvp_transaction.kvp_msg;
391
392         /*
393          * The key/value strings sent from the host are encoded in
394          * in utf16; convert it to utf8 strings.
395          * The host assures us that the utf16 strings will not exceed
396          * the max lengths specified. We will however, reserve room
397          * for the string terminating character - in the utf16s_utf8s()
398          * function we limit the size of the buffer where the converted
399          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to guarantee
400          * that the strings can be properly terminated!
401          */
402
403         switch (message->kvp_hdr.operation) {
404         case KVP_OP_SET_IP_INFO:
405                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
406                 break;
407         case KVP_OP_GET_IP_INFO:
408                 /* We only need to pass on message->kvp_hdr.operation.  */
409                 break;
410         case KVP_OP_SET:
411                 switch (in_msg->body.kvp_set.data.value_type) {
412                 case REG_SZ:
413                         /*
414                          * The value is a string - utf16 encoding.
415                          */
416                         message->body.kvp_set.data.value_size =
417                                 utf16s_to_utf8s(
418                                 (wchar_t *)in_msg->body.kvp_set.data.value,
419                                 in_msg->body.kvp_set.data.value_size,
420                                 UTF16_LITTLE_ENDIAN,
421                                 message->body.kvp_set.data.value,
422                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
423                         break;
424
425                 case REG_U32:
426                         /*
427                          * The value is a 32 bit scalar.
428                          * We save this as a utf8 string.
429                          */
430                         val32 = in_msg->body.kvp_set.data.value_u32;
431                         message->body.kvp_set.data.value_size =
432                                 sprintf(message->body.kvp_set.data.value,
433                                         "%d", val32) + 1;
434                         break;
435
436                 case REG_U64:
437                         /*
438                          * The value is a 64 bit scalar.
439                          * We save this as a utf8 string.
440                          */
441                         val64 = in_msg->body.kvp_set.data.value_u64;
442                         message->body.kvp_set.data.value_size =
443                                 sprintf(message->body.kvp_set.data.value,
444                                         "%llu", val64) + 1;
445                         break;
446
447                 }
448
449                 break;
450
451         case KVP_OP_GET:
452                 message->body.kvp_set.data.key_size =
453                         utf16s_to_utf8s(
454                         (wchar_t *)in_msg->body.kvp_set.data.key,
455                         in_msg->body.kvp_set.data.key_size,
456                         UTF16_LITTLE_ENDIAN,
457                         message->body.kvp_set.data.key,
458                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
459                 break;
460
461         case KVP_OP_DELETE:
462                 message->body.kvp_delete.key_size =
463                         utf16s_to_utf8s(
464                         (wchar_t *)in_msg->body.kvp_delete.key,
465                         in_msg->body.kvp_delete.key_size,
466                         UTF16_LITTLE_ENDIAN,
467                         message->body.kvp_delete.key,
468                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
469                 break;
470
471         case KVP_OP_ENUMERATE:
472                 message->body.kvp_enum_data.index =
473                         in_msg->body.kvp_enum_data.index;
474                 break;
475         }
476
477         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
478         rc = hvutil_transport_send(hvt, message, sizeof(*message), NULL);
479         if (rc) {
480                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
481                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
482                         kvp_respond_to_host(message, HV_E_FAIL);
483                         kvp_transaction.state = HVUTIL_READY;
484                 }
485         }
486
487         kfree(message);
488 }
489
490 /*
491  * Send a response back to the host.
492  */
493
494 static void
495 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
496 {
497         struct hv_kvp_msg  *kvp_msg;
498         struct hv_kvp_exchg_msg_value  *kvp_data;
499         char    *key_name;
500         char    *value;
501         struct icmsg_hdr *icmsghdrp;
502         int     keylen = 0;
503         int     valuelen = 0;
504         u32     buf_len;
505         struct vmbus_channel *channel;
506         u64     req_id;
507         int ret;
508
509         /*
510          * Copy the global state for completing the transaction. Note that
511          * only one transaction can be active at a time.
512          */
513
514         buf_len = kvp_transaction.recv_len;
515         channel = kvp_transaction.recv_channel;
516         req_id = kvp_transaction.recv_req_id;
517
518         icmsghdrp = (struct icmsg_hdr *)
519                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
520
521         if (channel->onchannel_callback == NULL)
522                 /*
523                  * We have raced with util driver being unloaded;
524                  * silently return.
525                  */
526                 return;
527
528         icmsghdrp->status = error;
529
530         /*
531          * If the error parameter is set, terminate the host's enumeration
532          * on this pool.
533          */
534         if (error) {
535                 /*
536                  * Something failed or we have timed out;
537                  * terminate the current host-side iteration.
538                  */
539                 goto response_done;
540         }
541
542         kvp_msg = (struct hv_kvp_msg *)
543                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
544                         sizeof(struct icmsg_hdr)];
545
546         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
547         case KVP_OP_GET_IP_INFO:
548                 ret = process_ob_ipinfo(msg_to_host,
549                                  (struct hv_kvp_ip_msg *)kvp_msg,
550                                  KVP_OP_GET_IP_INFO);
551                 if (ret < 0)
552                         icmsghdrp->status = HV_E_FAIL;
553
554                 goto response_done;
555         case KVP_OP_SET_IP_INFO:
556                 goto response_done;
557         case KVP_OP_GET:
558                 kvp_data = &kvp_msg->body.kvp_get.data;
559                 goto copy_value;
560
561         case KVP_OP_SET:
562         case KVP_OP_DELETE:
563                 goto response_done;
564
565         default:
566                 break;
567         }
568
569         kvp_data = &kvp_msg->body.kvp_enum_data.data;
570         key_name = msg_to_host->body.kvp_enum_data.data.key;
571
572         /*
573          * The windows host expects the key/value pair to be encoded
574          * in utf16. Ensure that the key/value size reported to the host
575          * will be less than or equal to the MAX size (including the
576          * terminating character).
577          */
578         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
579                                 (wchar_t *) kvp_data->key,
580                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
581         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
582
583 copy_value:
584         value = msg_to_host->body.kvp_enum_data.data.value;
585         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
586                                 (wchar_t *) kvp_data->value,
587                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
588         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
589
590         /*
591          * If the utf8s to utf16s conversion failed; notify host
592          * of the error.
593          */
594         if ((keylen < 0) || (valuelen < 0))
595                 icmsghdrp->status = HV_E_FAIL;
596
597         kvp_data->value_type = REG_SZ; /* all our values are strings */
598
599 response_done:
600         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
601
602         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
603                                 VM_PKT_DATA_INBAND, 0);
604 }
605
606 /*
607  * This callback is invoked when we get a KVP message from the host.
608  * The host ensures that only one KVP transaction can be active at a time.
609  * KVP implementation in Linux needs to forward the key to a user-mde
610  * component to retrieve the corresponding value. Consequently, we cannot
611  * respond to the host in the context of this callback. Since the host
612  * guarantees that at most only one transaction can be active at a time,
613  * we stash away the transaction state in a set of global variables.
614  */
615
616 void hv_kvp_onchannelcallback(void *context)
617 {
618         struct vmbus_channel *channel = context;
619         u32 recvlen;
620         u64 requestid;
621
622         struct hv_kvp_msg *kvp_msg;
623
624         struct icmsg_hdr *icmsghdrp;
625         int kvp_srv_version;
626         static enum {NEGO_NOT_STARTED,
627                      NEGO_IN_PROGRESS,
628                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
629
630         if (kvp_transaction.state < HVUTIL_READY) {
631                 /*
632                  * If userspace daemon is not connected and host is asking
633                  * us to negotiate we need to delay to not lose messages.
634                  * This is important for Failover IP setting.
635                  */
636                 if (host_negotiatied == NEGO_NOT_STARTED) {
637                         host_negotiatied = NEGO_IN_PROGRESS;
638                         schedule_delayed_work(&kvp_host_handshake_work,
639                                       HV_UTIL_NEGO_TIMEOUT * HZ);
640                 }
641                 return;
642         }
643         if (kvp_transaction.state > HVUTIL_READY)
644                 return;
645
646         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
647                          &requestid);
648
649         if (recvlen > 0) {
650                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
651                         sizeof(struct vmbuspipe_hdr)];
652
653                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
654                         if (vmbus_prep_negotiate_resp(icmsghdrp,
655                                  recv_buffer, fw_versions, FW_VER_COUNT,
656                                  kvp_versions, KVP_VER_COUNT,
657                                  NULL, &kvp_srv_version)) {
658                                 pr_info("KVP IC version %d.%d\n",
659                                         kvp_srv_version >> 16,
660                                         kvp_srv_version & 0xFFFF);
661                         }
662                 } else {
663                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
664                                 sizeof(struct vmbuspipe_hdr) +
665                                 sizeof(struct icmsg_hdr)];
666
667                         /*
668                          * Stash away this global state for completing the
669                          * transaction; note transactions are serialized.
670                          */
671
672                         kvp_transaction.recv_len = recvlen;
673                         kvp_transaction.recv_req_id = requestid;
674                         kvp_transaction.kvp_msg = kvp_msg;
675
676                         if (kvp_transaction.state < HVUTIL_READY) {
677                                 /* Userspace is not registered yet */
678                                 kvp_respond_to_host(NULL, HV_E_FAIL);
679                                 return;
680                         }
681                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
682
683                         /*
684                          * Get the information from the
685                          * user-mode component.
686                          * component. This transaction will be
687                          * completed when we get the value from
688                          * the user-mode component.
689                          * Set a timeout to deal with
690                          * user-mode not responding.
691                          */
692                         schedule_work(&kvp_sendkey_work);
693                         schedule_delayed_work(&kvp_timeout_work,
694                                               HV_UTIL_TIMEOUT * HZ);
695
696                         return;
697
698                 }
699
700                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
701                         | ICMSGHDRFLAG_RESPONSE;
702
703                 vmbus_sendpacket(channel, recv_buffer,
704                                        recvlen, requestid,
705                                        VM_PKT_DATA_INBAND, 0);
706
707                 host_negotiatied = NEGO_FINISHED;
708                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
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 }
719
720 int
721 hv_kvp_init(struct hv_util_service *srv)
722 {
723         recv_buffer = srv->recv_buffer;
724         kvp_transaction.recv_channel = srv->channel;
725
726         /*
727          * When this driver loads, the user level daemon that
728          * processes the host requests may not yet be running.
729          * Defer processing channel callbacks until the daemon
730          * has registered.
731          */
732         kvp_transaction.state = HVUTIL_DEVICE_INIT;
733
734         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
735                                     kvp_on_msg, kvp_on_reset);
736         if (!hvt)
737                 return -EFAULT;
738
739         return 0;
740 }
741
742 void hv_kvp_deinit(void)
743 {
744         kvp_transaction.state = HVUTIL_DEVICE_DYING;
745         cancel_delayed_work_sync(&kvp_host_handshake_work);
746         cancel_delayed_work_sync(&kvp_timeout_work);
747         cancel_work_sync(&kvp_sendkey_work);
748         hvutil_transport_destroy(hvt);
749 }