Merge tag 'char-misc-4.20-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...
[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                 /* fallthrough */
357
358         case KVP_OP_GET_IP_INFO:
359                 utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
360                                 MAX_ADAPTER_ID_SIZE,
361                                 UTF16_LITTLE_ENDIAN,
362                                 (__u8 *)out->body.kvp_ip_val.adapter_id,
363                                 MAX_ADAPTER_ID_SIZE);
364
365                 out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
366         }
367 }
368
369
370
371
372 static void
373 kvp_send_key(struct work_struct *dummy)
374 {
375         struct hv_kvp_msg *message;
376         struct hv_kvp_msg *in_msg;
377         __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
378         __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
379         __u32 val32;
380         __u64 val64;
381         int rc;
382
383         /* The transaction state is wrong. */
384         if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
385                 return;
386
387         message = kzalloc(sizeof(*message), GFP_KERNEL);
388         if (!message)
389                 return;
390
391         message->kvp_hdr.operation = operation;
392         message->kvp_hdr.pool = pool;
393         in_msg = kvp_transaction.kvp_msg;
394
395         /*
396          * The key/value strings sent from the host are encoded in
397          * in utf16; convert it to utf8 strings.
398          * The host assures us that the utf16 strings will not exceed
399          * the max lengths specified. We will however, reserve room
400          * for the string terminating character - in the utf16s_utf8s()
401          * function we limit the size of the buffer where the converted
402          * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to guarantee
403          * that the strings can be properly terminated!
404          */
405
406         switch (message->kvp_hdr.operation) {
407         case KVP_OP_SET_IP_INFO:
408                 process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
409                 break;
410         case KVP_OP_GET_IP_INFO:
411                 /*
412                  * We only need to pass on the info of operation, adapter_id
413                  * and addr_family to the userland kvp daemon.
414                  */
415                 process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
416                 break;
417         case KVP_OP_SET:
418                 switch (in_msg->body.kvp_set.data.value_type) {
419                 case REG_SZ:
420                         /*
421                          * The value is a string - utf16 encoding.
422                          */
423                         message->body.kvp_set.data.value_size =
424                                 utf16s_to_utf8s(
425                                 (wchar_t *)in_msg->body.kvp_set.data.value,
426                                 in_msg->body.kvp_set.data.value_size,
427                                 UTF16_LITTLE_ENDIAN,
428                                 message->body.kvp_set.data.value,
429                                 HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
430                         break;
431
432                 case REG_U32:
433                         /*
434                          * The value is a 32 bit scalar.
435                          * We save this as a utf8 string.
436                          */
437                         val32 = in_msg->body.kvp_set.data.value_u32;
438                         message->body.kvp_set.data.value_size =
439                                 sprintf(message->body.kvp_set.data.value,
440                                         "%d", val32) + 1;
441                         break;
442
443                 case REG_U64:
444                         /*
445                          * The value is a 64 bit scalar.
446                          * We save this as a utf8 string.
447                          */
448                         val64 = in_msg->body.kvp_set.data.value_u64;
449                         message->body.kvp_set.data.value_size =
450                                 sprintf(message->body.kvp_set.data.value,
451                                         "%llu", val64) + 1;
452                         break;
453
454                 }
455
456                 /*
457                  * The key is always a string - utf16 encoding.
458                  */
459                 message->body.kvp_set.data.key_size =
460                         utf16s_to_utf8s(
461                         (wchar_t *)in_msg->body.kvp_set.data.key,
462                         in_msg->body.kvp_set.data.key_size,
463                         UTF16_LITTLE_ENDIAN,
464                         message->body.kvp_set.data.key,
465                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
466
467                 break;
468
469         case KVP_OP_GET:
470                 message->body.kvp_get.data.key_size =
471                         utf16s_to_utf8s(
472                         (wchar_t *)in_msg->body.kvp_get.data.key,
473                         in_msg->body.kvp_get.data.key_size,
474                         UTF16_LITTLE_ENDIAN,
475                         message->body.kvp_get.data.key,
476                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
477                 break;
478
479         case KVP_OP_DELETE:
480                 message->body.kvp_delete.key_size =
481                         utf16s_to_utf8s(
482                         (wchar_t *)in_msg->body.kvp_delete.key,
483                         in_msg->body.kvp_delete.key_size,
484                         UTF16_LITTLE_ENDIAN,
485                         message->body.kvp_delete.key,
486                         HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
487                 break;
488
489         case KVP_OP_ENUMERATE:
490                 message->body.kvp_enum_data.index =
491                         in_msg->body.kvp_enum_data.index;
492                 break;
493         }
494
495         kvp_transaction.state = HVUTIL_USERSPACE_REQ;
496         rc = hvutil_transport_send(hvt, message, sizeof(*message), NULL);
497         if (rc) {
498                 pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
499                 if (cancel_delayed_work_sync(&kvp_timeout_work)) {
500                         kvp_respond_to_host(message, HV_E_FAIL);
501                         kvp_transaction.state = HVUTIL_READY;
502                 }
503         }
504
505         kfree(message);
506 }
507
508 /*
509  * Send a response back to the host.
510  */
511
512 static void
513 kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
514 {
515         struct hv_kvp_msg  *kvp_msg;
516         struct hv_kvp_exchg_msg_value  *kvp_data;
517         char    *key_name;
518         char    *value;
519         struct icmsg_hdr *icmsghdrp;
520         int     keylen = 0;
521         int     valuelen = 0;
522         u32     buf_len;
523         struct vmbus_channel *channel;
524         u64     req_id;
525         int ret;
526
527         /*
528          * Copy the global state for completing the transaction. Note that
529          * only one transaction can be active at a time.
530          */
531
532         buf_len = kvp_transaction.recv_len;
533         channel = kvp_transaction.recv_channel;
534         req_id = kvp_transaction.recv_req_id;
535
536         icmsghdrp = (struct icmsg_hdr *)
537                         &recv_buffer[sizeof(struct vmbuspipe_hdr)];
538
539         if (channel->onchannel_callback == NULL)
540                 /*
541                  * We have raced with util driver being unloaded;
542                  * silently return.
543                  */
544                 return;
545
546         icmsghdrp->status = error;
547
548         /*
549          * If the error parameter is set, terminate the host's enumeration
550          * on this pool.
551          */
552         if (error) {
553                 /*
554                  * Something failed or we have timed out;
555                  * terminate the current host-side iteration.
556                  */
557                 goto response_done;
558         }
559
560         kvp_msg = (struct hv_kvp_msg *)
561                         &recv_buffer[sizeof(struct vmbuspipe_hdr) +
562                         sizeof(struct icmsg_hdr)];
563
564         switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
565         case KVP_OP_GET_IP_INFO:
566                 ret = process_ob_ipinfo(msg_to_host,
567                                  (struct hv_kvp_ip_msg *)kvp_msg,
568                                  KVP_OP_GET_IP_INFO);
569                 if (ret < 0)
570                         icmsghdrp->status = HV_E_FAIL;
571
572                 goto response_done;
573         case KVP_OP_SET_IP_INFO:
574                 goto response_done;
575         case KVP_OP_GET:
576                 kvp_data = &kvp_msg->body.kvp_get.data;
577                 goto copy_value;
578
579         case KVP_OP_SET:
580         case KVP_OP_DELETE:
581                 goto response_done;
582
583         default:
584                 break;
585         }
586
587         kvp_data = &kvp_msg->body.kvp_enum_data.data;
588         key_name = msg_to_host->body.kvp_enum_data.data.key;
589
590         /*
591          * The windows host expects the key/value pair to be encoded
592          * in utf16. Ensure that the key/value size reported to the host
593          * will be less than or equal to the MAX size (including the
594          * terminating character).
595          */
596         keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
597                                 (wchar_t *) kvp_data->key,
598                                 (HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
599         kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
600
601 copy_value:
602         value = msg_to_host->body.kvp_enum_data.data.value;
603         valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
604                                 (wchar_t *) kvp_data->value,
605                                 (HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
606         kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
607
608         /*
609          * If the utf8s to utf16s conversion failed; notify host
610          * of the error.
611          */
612         if ((keylen < 0) || (valuelen < 0))
613                 icmsghdrp->status = HV_E_FAIL;
614
615         kvp_data->value_type = REG_SZ; /* all our values are strings */
616
617 response_done:
618         icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
619
620         vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
621                                 VM_PKT_DATA_INBAND, 0);
622 }
623
624 /*
625  * This callback is invoked when we get a KVP message from the host.
626  * The host ensures that only one KVP transaction can be active at a time.
627  * KVP implementation in Linux needs to forward the key to a user-mde
628  * component to retrieve the corresponding value. Consequently, we cannot
629  * respond to the host in the context of this callback. Since the host
630  * guarantees that at most only one transaction can be active at a time,
631  * we stash away the transaction state in a set of global variables.
632  */
633
634 void hv_kvp_onchannelcallback(void *context)
635 {
636         struct vmbus_channel *channel = context;
637         u32 recvlen;
638         u64 requestid;
639
640         struct hv_kvp_msg *kvp_msg;
641
642         struct icmsg_hdr *icmsghdrp;
643         int kvp_srv_version;
644         static enum {NEGO_NOT_STARTED,
645                      NEGO_IN_PROGRESS,
646                      NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
647
648         if (kvp_transaction.state < HVUTIL_READY) {
649                 /*
650                  * If userspace daemon is not connected and host is asking
651                  * us to negotiate we need to delay to not lose messages.
652                  * This is important for Failover IP setting.
653                  */
654                 if (host_negotiatied == NEGO_NOT_STARTED) {
655                         host_negotiatied = NEGO_IN_PROGRESS;
656                         schedule_delayed_work(&kvp_host_handshake_work,
657                                       HV_UTIL_NEGO_TIMEOUT * HZ);
658                 }
659                 return;
660         }
661         if (kvp_transaction.state > HVUTIL_READY)
662                 return;
663
664         vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
665                          &requestid);
666
667         if (recvlen > 0) {
668                 icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
669                         sizeof(struct vmbuspipe_hdr)];
670
671                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
672                         if (vmbus_prep_negotiate_resp(icmsghdrp,
673                                  recv_buffer, fw_versions, FW_VER_COUNT,
674                                  kvp_versions, KVP_VER_COUNT,
675                                  NULL, &kvp_srv_version)) {
676                                 pr_info("KVP IC version %d.%d\n",
677                                         kvp_srv_version >> 16,
678                                         kvp_srv_version & 0xFFFF);
679                         }
680                 } else {
681                         kvp_msg = (struct hv_kvp_msg *)&recv_buffer[
682                                 sizeof(struct vmbuspipe_hdr) +
683                                 sizeof(struct icmsg_hdr)];
684
685                         /*
686                          * Stash away this global state for completing the
687                          * transaction; note transactions are serialized.
688                          */
689
690                         kvp_transaction.recv_len = recvlen;
691                         kvp_transaction.recv_req_id = requestid;
692                         kvp_transaction.kvp_msg = kvp_msg;
693
694                         if (kvp_transaction.state < HVUTIL_READY) {
695                                 /* Userspace is not registered yet */
696                                 kvp_respond_to_host(NULL, HV_E_FAIL);
697                                 return;
698                         }
699                         kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
700
701                         /*
702                          * Get the information from the
703                          * user-mode component.
704                          * component. This transaction will be
705                          * completed when we get the value from
706                          * the user-mode component.
707                          * Set a timeout to deal with
708                          * user-mode not responding.
709                          */
710                         schedule_work(&kvp_sendkey_work);
711                         schedule_delayed_work(&kvp_timeout_work,
712                                               HV_UTIL_TIMEOUT * HZ);
713
714                         return;
715
716                 }
717
718                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
719                         | ICMSGHDRFLAG_RESPONSE;
720
721                 vmbus_sendpacket(channel, recv_buffer,
722                                        recvlen, requestid,
723                                        VM_PKT_DATA_INBAND, 0);
724
725                 host_negotiatied = NEGO_FINISHED;
726                 hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
727         }
728
729 }
730
731 static void kvp_on_reset(void)
732 {
733         if (cancel_delayed_work_sync(&kvp_timeout_work))
734                 kvp_respond_to_host(NULL, HV_E_FAIL);
735         kvp_transaction.state = HVUTIL_DEVICE_INIT;
736 }
737
738 int
739 hv_kvp_init(struct hv_util_service *srv)
740 {
741         recv_buffer = srv->recv_buffer;
742         kvp_transaction.recv_channel = srv->channel;
743
744         /*
745          * When this driver loads, the user level daemon that
746          * processes the host requests may not yet be running.
747          * Defer processing channel callbacks until the daemon
748          * has registered.
749          */
750         kvp_transaction.state = HVUTIL_DEVICE_INIT;
751
752         hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
753                                     kvp_on_msg, kvp_on_reset);
754         if (!hvt)
755                 return -EFAULT;
756
757         return 0;
758 }
759
760 void hv_kvp_deinit(void)
761 {
762         kvp_transaction.state = HVUTIL_DEVICE_DYING;
763         cancel_delayed_work_sync(&kvp_host_handshake_work);
764         cancel_delayed_work_sync(&kvp_timeout_work);
765         cancel_work_sync(&kvp_sendkey_work);
766         hvutil_transport_destroy(hvt);
767 }