xref: /freebsd/sys/dev/hyperv/utilities/hv_kvp.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*-
2  * Copyright (c) 2014 Microsoft Corp.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /*
28  *	Author:	Sainath Varanasi.
29  *	Date:	4/2012
30  *	Email:	bsdic@microsoft.com
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/conf.h>
39 #include <sys/uio.h>
40 #include <sys/bus.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/module.h>
44 #include <sys/reboot.h>
45 #include <sys/lock.h>
46 #include <sys/taskqueue.h>
47 #include <sys/sysctl.h>
48 #include <sys/poll.h>
49 #include <sys/proc.h>
50 #include <sys/kthread.h>
51 #include <sys/syscallsubr.h>
52 #include <sys/sysproto.h>
53 #include <sys/un.h>
54 #include <sys/endian.h>
55 #include <sys/_null.h>
56 #include <sys/signal.h>
57 #include <sys/syslog.h>
58 #include <sys/mutex.h>
59 #include <net/if_arp.h>
60 
61 #include <dev/hyperv/include/hyperv.h>
62 #include <dev/hyperv/netvsc/hv_net_vsc.h>
63 
64 #include "unicode.h"
65 #include "hv_kvp.h"
66 
67 /* hv_kvp defines */
68 #define BUFFERSIZE	sizeof(struct hv_kvp_msg)
69 #define KVP_SUCCESS	0
70 #define KVP_ERROR	1
71 #define kvp_hdr		hdr.kvp_hdr
72 
73 /* hv_kvp debug control */
74 static int hv_kvp_log = 0;
75 SYSCTL_INT(_dev, OID_AUTO, hv_kvp_log, CTLFLAG_RW, &hv_kvp_log, 0,
76 	"hv_kvp log");
77 
78 #define	hv_kvp_log_error(...)	do {				\
79 	if (hv_kvp_log > 0)				\
80 		log(LOG_ERR, "hv_kvp: " __VA_ARGS__);	\
81 } while (0)
82 
83 #define	hv_kvp_log_info(...) do {				\
84 	if (hv_kvp_log > 1)				\
85 		log(LOG_INFO, "hv_kvp: " __VA_ARGS__);		\
86 } while (0)
87 
88 /* character device prototypes */
89 static d_open_t		hv_kvp_dev_open;
90 static d_close_t	hv_kvp_dev_close;
91 static d_read_t		hv_kvp_dev_daemon_read;
92 static d_write_t	hv_kvp_dev_daemon_write;
93 static d_poll_t		hv_kvp_dev_daemon_poll;
94 
95 /* hv_kvp prototypes */
96 static int	hv_kvp_req_in_progress(void);
97 static void	hv_kvp_transaction_init(uint32_t, hv_vmbus_channel *, uint64_t, uint8_t *);
98 static void	hv_kvp_send_msg_to_daemon(void);
99 static void	hv_kvp_process_request(void *context);
100 
101 /* hv_kvp character device structure */
102 static struct cdevsw hv_kvp_cdevsw =
103 {
104 	.d_version	= D_VERSION,
105 	.d_open		= hv_kvp_dev_open,
106 	.d_close	= hv_kvp_dev_close,
107 	.d_read		= hv_kvp_dev_daemon_read,
108 	.d_write	= hv_kvp_dev_daemon_write,
109 	.d_poll		= hv_kvp_dev_daemon_poll,
110 	.d_name		= "hv_kvp_dev",
111 };
112 static struct cdev *hv_kvp_dev;
113 static struct hv_kvp_msg *hv_kvp_dev_buf;
114 struct proc *daemon_task;
115 
116 /*
117  * Global state to track and synchronize multiple
118  * KVP transaction requests from the host.
119  */
120 static struct {
121 
122 	/* Pre-allocated work item for queue */
123 	hv_work_item		work_item;
124 
125 	/* Unless specified the pending mutex should be
126 	 * used to alter the values of the following paramters:
127 	 * 1. req_in_progress
128 	 * 2. req_timed_out
129 	 * 3. pending_reqs.
130 	 */
131 	struct mtx		pending_mutex;
132 
133 	/* To track if transaction is active or not */
134 	boolean_t		req_in_progress;
135 	/* Tracks if daemon did not reply back in time */
136 	boolean_t		req_timed_out;
137 	/* Tracks if daemon is serving a request currently */
138 	boolean_t		daemon_busy;
139 	/* Count of KVP requests from Hyper-V. */
140 	uint64_t		pending_reqs;
141 
142 
143 	/* Length of host message */
144 	uint32_t		host_msg_len;
145 
146 	/* Pointer to channel */
147 	hv_vmbus_channel	*channelp;
148 
149 	/* Host message id */
150 	uint64_t		host_msg_id;
151 
152 	/* Current kvp message from the host */
153 	struct hv_kvp_msg	*host_kvp_msg;
154 
155 	 /* Current kvp message for daemon */
156 	struct hv_kvp_msg	daemon_kvp_msg;
157 
158 	/* Rcv buffer for communicating with the host*/
159 	uint8_t			*rcv_buf;
160 
161 	/* Device semaphore to control communication */
162 	struct sema		dev_sema;
163 
164 	/* Indicates if daemon registered with driver */
165 	boolean_t		register_done;
166 
167 	/* Character device status */
168 	boolean_t		dev_accessed;
169 } kvp_globals;
170 
171 /* global vars */
172 MALLOC_DECLARE(M_HV_KVP_DEV_BUF);
173 MALLOC_DEFINE(M_HV_KVP_DEV_BUF, "hv_kvp_dev buffer", "buffer for hv_kvp_dev module");
174 
175 /*
176  * hv_kvp low level functions
177  */
178 
179 /*
180  * Check if kvp transaction is in progres
181  */
182 static int
183 hv_kvp_req_in_progress(void)
184 {
185 
186 	return (kvp_globals.req_in_progress);
187 }
188 
189 
190 /*
191  * This routine is called whenever a message is received from the host
192  */
193 static void
194 hv_kvp_transaction_init(uint32_t rcv_len, hv_vmbus_channel *rcv_channel,
195 			uint64_t request_id, uint8_t *rcv_buf)
196 {
197 
198 	/* Store all the relevant message details in the global structure */
199 	/* Do not need to use mutex for req_in_progress here */
200 	kvp_globals.req_in_progress = true;
201 	kvp_globals.host_msg_len = rcv_len;
202 	kvp_globals.channelp = rcv_channel;
203 	kvp_globals.host_msg_id = request_id;
204 	kvp_globals.rcv_buf = rcv_buf;
205 	kvp_globals.host_kvp_msg = (struct hv_kvp_msg *)&rcv_buf[
206 		sizeof(struct hv_vmbus_pipe_hdr) +
207 		sizeof(struct hv_vmbus_icmsg_hdr)];
208 }
209 
210 
211 /*
212  * hv_kvp - version neogtiation function
213  */
214 static void
215 hv_kvp_negotiate_version(struct hv_vmbus_icmsg_hdr *icmsghdrp,
216 			 struct hv_vmbus_icmsg_negotiate *negop,
217 			 uint8_t *buf)
218 {
219 	int icframe_vercnt;
220 	int icmsg_vercnt;
221 
222 	icmsghdrp->icmsgsize = 0x10;
223 
224 	negop = (struct hv_vmbus_icmsg_negotiate *)&buf[
225 		sizeof(struct hv_vmbus_pipe_hdr) +
226 		sizeof(struct hv_vmbus_icmsg_hdr)];
227 	icframe_vercnt = negop->icframe_vercnt;
228 	icmsg_vercnt = negop->icmsg_vercnt;
229 
230 	/*
231 	 * Select the framework version number we will support
232 	 */
233 	if ((icframe_vercnt >= 2) && (negop->icversion_data[1].major == 3)) {
234 		icframe_vercnt = 3;
235 		if (icmsg_vercnt >= 2)
236 			icmsg_vercnt = 4;
237 		else
238 			icmsg_vercnt = 3;
239 	} else {
240 		icframe_vercnt = 1;
241 		icmsg_vercnt = 1;
242 	}
243 
244 	negop->icframe_vercnt = 1;
245 	negop->icmsg_vercnt = 1;
246 	negop->icversion_data[0].major = icframe_vercnt;
247 	negop->icversion_data[0].minor = 0;
248 	negop->icversion_data[1].major = icmsg_vercnt;
249 	negop->icversion_data[1].minor = 0;
250 }
251 
252 
253 /*
254  * Convert ip related info in umsg from utf8 to utf16 and store in hmsg
255  */
256 static int
257 hv_kvp_convert_utf8_ipinfo_to_utf16(struct hv_kvp_msg *umsg,
258 				    struct hv_kvp_ip_msg *host_ip_msg)
259 {
260 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
261 	int UNUSED_FLAG = 1;
262 
263 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
264 	    MAX_IP_ADDR_SIZE,
265 	    (char *)umsg->body.kvp_ip_val.ip_addr,
266 	    strlen((char *)umsg->body.kvp_ip_val.ip_addr),
267 	    UNUSED_FLAG,
268 	    &err_ip);
269 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
270 	    MAX_IP_ADDR_SIZE,
271 	    (char *)umsg->body.kvp_ip_val.sub_net,
272 	    strlen((char *)umsg->body.kvp_ip_val.sub_net),
273 	    UNUSED_FLAG,
274 	    &err_subnet);
275 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
276 	    MAX_GATEWAY_SIZE,
277 	    (char *)umsg->body.kvp_ip_val.gate_way,
278 	    strlen((char *)umsg->body.kvp_ip_val.gate_way),
279 	    UNUSED_FLAG,
280 	    &err_gway);
281 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
282 	    MAX_IP_ADDR_SIZE,
283 	    (char *)umsg->body.kvp_ip_val.dns_addr,
284 	    strlen((char *)umsg->body.kvp_ip_val.dns_addr),
285 	    UNUSED_FLAG,
286 	    &err_dns);
287 	utf8_to_utf16((uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
288 	    MAX_IP_ADDR_SIZE,
289 	    (char *)umsg->body.kvp_ip_val.adapter_id,
290 	    strlen((char *)umsg->body.kvp_ip_val.adapter_id),
291 	    UNUSED_FLAG,
292 	    &err_adap);
293 
294 	host_ip_msg->kvp_ip_val.dhcp_enabled = umsg->body.kvp_ip_val.dhcp_enabled;
295 	host_ip_msg->kvp_ip_val.addr_family = umsg->body.kvp_ip_val.addr_family;
296 
297 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
298 }
299 
300 
301 /*
302  * Convert ip related info in hmsg from utf16 to utf8 and store in umsg
303  */
304 static int
305 hv_kvp_convert_utf16_ipinfo_to_utf8(struct hv_kvp_ip_msg *host_ip_msg,
306 				    struct hv_kvp_msg *umsg)
307 {
308 	int err_ip, err_subnet, err_gway, err_dns, err_adap;
309 	int UNUSED_FLAG = 1;
310 	int guid_index;
311 	struct hv_device *hv_dev;       /* GUID Data Structure */
312 	hn_softc_t *sc;                 /* hn softc structure  */
313 	char if_name[4];
314 	unsigned char guid_instance[40];
315 	char *guid_data = NULL;
316 	char buf[39];
317 
318 	struct guid_extract {
319 		char	a1[2];
320 		char	a2[2];
321 		char	a3[2];
322 		char	a4[2];
323 		char	b1[2];
324 		char	b2[2];
325 		char	c1[2];
326 		char	c2[2];
327 		char	d[4];
328 		char	e[12];
329 	};
330 
331 	struct guid_extract *id;
332 	device_t *devs;
333 	int devcnt;
334 
335 	/* IP Address */
336 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.ip_addr,
337 	    MAX_IP_ADDR_SIZE,
338 	    (uint16_t *)host_ip_msg->kvp_ip_val.ip_addr,
339 	    MAX_IP_ADDR_SIZE,
340 	    UNUSED_FLAG,
341 	    &err_ip);
342 
343 	/* Adapter ID : GUID */
344 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
345 	    MAX_ADAPTER_ID_SIZE,
346 	    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
347 	    MAX_ADAPTER_ID_SIZE,
348 	    UNUSED_FLAG,
349 	    &err_adap);
350 
351 	if (devclass_get_devices(devclass_find("hn"), &devs, &devcnt) == 0) {
352 		for (devcnt = devcnt - 1; devcnt >= 0; devcnt--) {
353 			sc = device_get_softc(devs[devcnt]);
354 
355 			/* Trying to find GUID of Network Device */
356 			hv_dev = sc->hn_dev_obj;
357 
358 			for (guid_index = 0; guid_index < 16; guid_index++) {
359 				sprintf(&guid_instance[guid_index * 2], "%02x",
360 				    hv_dev->device_id.data[guid_index]);
361 			}
362 
363 			guid_data = (char *)guid_instance;
364 			id = (struct guid_extract *)guid_data;
365 			snprintf(buf, sizeof(buf), "{%.2s%.2s%.2s%.2s-%.2s%.2s-%.2s%.2s-%.4s-%s}",
366 			    id->a4, id->a3, id->a2, id->a1,
367 			    id->b2, id->b1, id->c2, id->c1, id->d, id->e);
368 			guid_data = NULL;
369 			sprintf(if_name, "%s%d", "hn", device_get_unit(devs[devcnt]));
370 
371 			if (strncmp(buf, (char *)umsg->body.kvp_ip_val.adapter_id, 39) == 0) {
372 				strcpy((char *)umsg->body.kvp_ip_val.adapter_id, if_name);
373 				break;
374 			}
375 		}
376 		free(devs, M_TEMP);
377 	}
378 
379 	/* Address Family , DHCP , SUBNET, Gateway, DNS */
380 	umsg->kvp_hdr.operation = host_ip_msg->operation;
381 	umsg->body.kvp_ip_val.addr_family = host_ip_msg->kvp_ip_val.addr_family;
382 	umsg->body.kvp_ip_val.dhcp_enabled = host_ip_msg->kvp_ip_val.dhcp_enabled;
383 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.sub_net, MAX_IP_ADDR_SIZE,
384 	    (uint16_t *)host_ip_msg->kvp_ip_val.sub_net,
385 	    MAX_IP_ADDR_SIZE,
386 	    UNUSED_FLAG,
387 	    &err_subnet);
388 
389 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.gate_way, MAX_GATEWAY_SIZE,
390 	    (uint16_t *)host_ip_msg->kvp_ip_val.gate_way,
391 	    MAX_GATEWAY_SIZE,
392 	    UNUSED_FLAG,
393 	    &err_gway);
394 
395 	utf16_to_utf8((char *)umsg->body.kvp_ip_val.dns_addr, MAX_IP_ADDR_SIZE,
396 	    (uint16_t *)host_ip_msg->kvp_ip_val.dns_addr,
397 	    MAX_IP_ADDR_SIZE,
398 	    UNUSED_FLAG,
399 	    &err_dns);
400 
401 	return (err_ip | err_subnet | err_gway | err_dns | err_adap);
402 }
403 
404 
405 /*
406  * Prepare a user kvp msg based on host kvp msg (utf16 to utf8)
407  * Ensure utf16_utf8 takes care of the additional string terminating char!!
408  */
409 static void
410 hv_kvp_convert_hostmsg_to_usermsg(void)
411 {
412 	int utf_err = 0;
413 	uint32_t value_type;
414 	struct hv_kvp_ip_msg *host_ip_msg = (struct hv_kvp_ip_msg *)
415 		kvp_globals.host_kvp_msg;
416 
417 	struct hv_kvp_msg *hmsg = kvp_globals.host_kvp_msg;
418 	struct hv_kvp_msg *umsg = &kvp_globals.daemon_kvp_msg;
419 
420 	memset(umsg, 0, sizeof(struct hv_kvp_msg));
421 
422 	umsg->kvp_hdr.operation = hmsg->kvp_hdr.operation;
423 	umsg->kvp_hdr.pool = hmsg->kvp_hdr.pool;
424 
425 	switch (umsg->kvp_hdr.operation) {
426 	case HV_KVP_OP_SET_IP_INFO:
427 		hv_kvp_convert_utf16_ipinfo_to_utf8(host_ip_msg, umsg);
428 		break;
429 
430 	case HV_KVP_OP_GET_IP_INFO:
431 		utf16_to_utf8((char *)umsg->body.kvp_ip_val.adapter_id,
432 		    MAX_ADAPTER_ID_SIZE,
433 		    (uint16_t *)host_ip_msg->kvp_ip_val.adapter_id,
434 		    MAX_ADAPTER_ID_SIZE, 1, &utf_err);
435 
436 		umsg->body.kvp_ip_val.addr_family =
437 		    host_ip_msg->kvp_ip_val.addr_family;
438 		break;
439 
440 	case HV_KVP_OP_SET:
441 		value_type = hmsg->body.kvp_set.data.value_type;
442 
443 		switch (value_type) {
444 		case HV_REG_SZ:
445 			umsg->body.kvp_set.data.value_size =
446 			    utf16_to_utf8(
447 				(char *)umsg->body.kvp_set.data.msg_value.value,
448 				HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1,
449 				(uint16_t *)hmsg->body.kvp_set.data.msg_value.value,
450 				hmsg->body.kvp_set.data.value_size,
451 				1, &utf_err);
452 			/* utf8 encoding */
453 			umsg->body.kvp_set.data.value_size =
454 			    umsg->body.kvp_set.data.value_size / 2;
455 			break;
456 
457 		case HV_REG_U32:
458 			umsg->body.kvp_set.data.value_size =
459 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%d",
460 				hmsg->body.kvp_set.data.msg_value.value_u32) + 1;
461 			break;
462 
463 		case HV_REG_U64:
464 			umsg->body.kvp_set.data.value_size =
465 			    sprintf(umsg->body.kvp_set.data.msg_value.value, "%llu",
466 				(unsigned long long)
467 				hmsg->body.kvp_set.data.msg_value.value_u64) + 1;
468 			break;
469 		}
470 
471 		umsg->body.kvp_set.data.key_size =
472 		    utf16_to_utf8(
473 			umsg->body.kvp_set.data.key,
474 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
475 			(uint16_t *)hmsg->body.kvp_set.data.key,
476 			hmsg->body.kvp_set.data.key_size,
477 			1, &utf_err);
478 
479 		/* utf8 encoding */
480 		umsg->body.kvp_set.data.key_size =
481 		    umsg->body.kvp_set.data.key_size / 2;
482 		break;
483 
484 	case HV_KVP_OP_GET:
485 		umsg->body.kvp_get.data.key_size =
486 		    utf16_to_utf8(umsg->body.kvp_get.data.key,
487 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
488 			(uint16_t *)hmsg->body.kvp_get.data.key,
489 			hmsg->body.kvp_get.data.key_size,
490 			1, &utf_err);
491 		/* utf8 encoding */
492 		umsg->body.kvp_get.data.key_size =
493 		    umsg->body.kvp_get.data.key_size / 2;
494 		break;
495 
496 	case HV_KVP_OP_DELETE:
497 		umsg->body.kvp_delete.key_size =
498 		    utf16_to_utf8(umsg->body.kvp_delete.key,
499 			HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1,
500 			(uint16_t *)hmsg->body.kvp_delete.key,
501 			hmsg->body.kvp_delete.key_size,
502 			1, &utf_err);
503 		/* utf8 encoding */
504 		umsg->body.kvp_delete.key_size =
505 		    umsg->body.kvp_delete.key_size / 2;
506 		break;
507 
508 	case HV_KVP_OP_ENUMERATE:
509 		umsg->body.kvp_enum_data.index =
510 		    hmsg->body.kvp_enum_data.index;
511 		break;
512 
513 	default:
514 		hv_kvp_log_info("%s: daemon_kvp_msg: Invalid operation : %d\n",
515 		    __func__, umsg->kvp_hdr.operation);
516 	}
517 }
518 
519 
520 /*
521  * Prepare a host kvp msg based on user kvp msg (utf8 to utf16)
522  */
523 static int
524 hv_kvp_convert_usermsg_to_hostmsg(void)
525 {
526 	int hkey_len = 0, hvalue_len = 0, utf_err = 0;
527 	struct hv_kvp_exchg_msg_value *host_exchg_data;
528 	char *key_name, *value;
529 
530 	struct hv_kvp_msg *umsg = &kvp_globals.daemon_kvp_msg;
531 	struct hv_kvp_msg *hmsg = kvp_globals.host_kvp_msg;
532 	struct hv_kvp_ip_msg *host_ip_msg = (struct hv_kvp_ip_msg *)hmsg;
533 
534 	switch (hmsg->kvp_hdr.operation) {
535 	case HV_KVP_OP_GET_IP_INFO:
536 		return (hv_kvp_convert_utf8_ipinfo_to_utf16(umsg, host_ip_msg));
537 
538 	case HV_KVP_OP_SET_IP_INFO:
539 	case HV_KVP_OP_SET:
540 	case HV_KVP_OP_DELETE:
541 		return (KVP_SUCCESS);
542 
543 	case HV_KVP_OP_ENUMERATE:
544 		host_exchg_data = &hmsg->body.kvp_enum_data.data;
545 		key_name = umsg->body.kvp_enum_data.data.key;
546 		hkey_len = utf8_to_utf16((uint16_t *)host_exchg_data->key,
547 				((HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2),
548 				key_name, strlen(key_name),
549 				1, &utf_err);
550 		/* utf16 encoding */
551 		host_exchg_data->key_size = 2 * (hkey_len + 1);
552 		value = umsg->body.kvp_enum_data.data.msg_value.value;
553 		hvalue_len = utf8_to_utf16(
554 				(uint16_t *)host_exchg_data->msg_value.value,
555 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
556 				value, strlen(value),
557 				1, &utf_err);
558 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
559 		host_exchg_data->value_type = HV_REG_SZ;
560 
561 		if ((hkey_len < 0) || (hvalue_len < 0))
562 			return (HV_KVP_E_FAIL);
563 
564 		return (KVP_SUCCESS);
565 
566 	case HV_KVP_OP_GET:
567 		host_exchg_data = &hmsg->body.kvp_get.data;
568 		value = umsg->body.kvp_get.data.msg_value.value;
569 		hvalue_len = utf8_to_utf16(
570 				(uint16_t *)host_exchg_data->msg_value.value,
571 				((HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2),
572 				value, strlen(value),
573 				1, &utf_err);
574 		/* Convert value size to uft16 */
575 		host_exchg_data->value_size = 2 * (hvalue_len + 1);
576 		/* Use values by string */
577 		host_exchg_data->value_type = HV_REG_SZ;
578 
579 		if ((hkey_len < 0) || (hvalue_len < 0))
580 			return (HV_KVP_E_FAIL);
581 
582 		return (KVP_SUCCESS);
583 
584 	default:
585 		return (HV_KVP_E_FAIL);
586 	}
587 }
588 
589 
590 /*
591  * Send the response back to the host.
592  */
593 static void
594 hv_kvp_respond_host(int error)
595 {
596 	struct hv_vmbus_icmsg_hdr *hv_icmsg_hdrp;
597 
598 	hv_icmsg_hdrp = (struct hv_vmbus_icmsg_hdr *)
599 	    &kvp_globals.rcv_buf[sizeof(struct hv_vmbus_pipe_hdr)];
600 
601 	if (error)
602 		error = HV_KVP_E_FAIL;
603 
604 	hv_icmsg_hdrp->status = error;
605 	hv_icmsg_hdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION | HV_ICMSGHDRFLAG_RESPONSE;
606 
607 	error = hv_vmbus_channel_send_packet(kvp_globals.channelp,
608 			kvp_globals.rcv_buf,
609 			kvp_globals.host_msg_len, kvp_globals.host_msg_id,
610 			HV_VMBUS_PACKET_TYPE_DATA_IN_BAND, 0);
611 
612 	if (error)
613 		hv_kvp_log_info("%s: hv_kvp_respond_host: sendpacket error:%d\n",
614 			__func__, error);
615 }
616 
617 
618 /*
619  * This is the main kvp kernel process that interacts with both user daemon
620  * and the host
621  */
622 static void
623 hv_kvp_send_msg_to_daemon(void)
624 {
625 	/* Prepare kvp_msg to be sent to user */
626 	hv_kvp_convert_hostmsg_to_usermsg();
627 
628 	/* Send the msg to user via function deamon_read - setting sema */
629 	sema_post(&kvp_globals.dev_sema);
630 }
631 
632 
633 /*
634  * Function to read the kvp request buffer from host
635  * and interact with daemon
636  */
637 static void
638 hv_kvp_process_request(void *context)
639 {
640 	uint8_t *kvp_buf;
641 	hv_vmbus_channel *channel = context;
642 	uint32_t recvlen = 0;
643 	uint64_t requestid;
644 	struct hv_vmbus_icmsg_hdr *icmsghdrp;
645 	int ret = 0;
646 	uint64_t pending_cnt = 1;
647 
648 	hv_kvp_log_info("%s: entering hv_kvp_process_request\n", __func__);
649 	kvp_buf = receive_buffer[HV_KVP];
650 	ret = hv_vmbus_channel_recv_packet(channel, kvp_buf, 2 * PAGE_SIZE,
651 		&recvlen, &requestid);
652 
653 	/*
654 	 * We start counting only after the daemon registers
655 	 * and therefore there could be requests pending in
656 	 * the VMBus that are not reflected in pending_cnt.
657 	 * Therefore we continue reading as long as either of
658 	 * the below conditions is true.
659 	 */
660 
661 	while ((pending_cnt>0) || ((ret == 0) && (recvlen > 0))) {
662 
663 		if ((ret == 0) && (recvlen>0)) {
664 
665 			icmsghdrp = (struct hv_vmbus_icmsg_hdr *)
666 					&kvp_buf[sizeof(struct hv_vmbus_pipe_hdr)];
667 
668 			hv_kvp_transaction_init(recvlen, channel, requestid, kvp_buf);
669 			if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
670 				hv_kvp_negotiate_version(icmsghdrp, NULL, kvp_buf);
671 				hv_kvp_respond_host(ret);
672 
673 				/*
674 				 * It is ok to not acquire the mutex before setting
675 				 * req_in_progress here because negotiation is the
676 				 * first thing that happens and hence there is no
677 				 * chance of a race condition.
678 				 */
679 
680 				kvp_globals.req_in_progress = false;
681 				hv_kvp_log_info("%s :version negotiated\n", __func__);
682 
683 			} else {
684 				if (!kvp_globals.daemon_busy) {
685 
686 					hv_kvp_log_info("%s: issuing qury to daemon\n", __func__);
687 					mtx_lock(&kvp_globals.pending_mutex);
688 					kvp_globals.req_timed_out = false;
689 					kvp_globals.daemon_busy = true;
690 					mtx_unlock(&kvp_globals.pending_mutex);
691 
692 					hv_kvp_send_msg_to_daemon();
693 					hv_kvp_log_info("%s: waiting for daemon\n", __func__);
694 				}
695 
696 				/* Wait 5 seconds for daemon to respond back */
697 				tsleep(&kvp_globals, 0, "kvpworkitem", 5 * hz);
698 				hv_kvp_log_info("%s: came out of wait\n", __func__);
699 			}
700 		}
701 
702 		mtx_lock(&kvp_globals.pending_mutex);
703 
704 		/* Notice that once req_timed_out is set to true
705 		 * it will remain true until the next request is
706 		 * sent to the daemon. The response from daemon
707 		 * is forwarded to host only when this flag is
708 		 * false.
709 		 */
710 		kvp_globals.req_timed_out = true;
711 
712 		/*
713 		 * Cancel request if so need be.
714 		 */
715 		if (hv_kvp_req_in_progress()) {
716 			hv_kvp_log_info("%s: request was still active after wait so failing\n", __func__);
717 			hv_kvp_respond_host(HV_KVP_E_FAIL);
718 			kvp_globals.req_in_progress = false;
719 		}
720 
721 		/*
722 		* Decrement pending request count and
723 		*/
724 		if (kvp_globals.pending_reqs>0) {
725 			kvp_globals.pending_reqs = kvp_globals.pending_reqs - 1;
726 		}
727 		pending_cnt = kvp_globals.pending_reqs;
728 
729 		mtx_unlock(&kvp_globals.pending_mutex);
730 
731 		/*
732 		 * Try reading next buffer
733 		 */
734 		recvlen = 0;
735 		ret = hv_vmbus_channel_recv_packet(channel, kvp_buf, 2 * PAGE_SIZE,
736 			&recvlen, &requestid);
737 		hv_kvp_log_info("%s: read: context %p, pending_cnt %ju ret =%d, recvlen=%d\n",
738 			__func__, context, pending_cnt, ret, recvlen);
739 	}
740 }
741 
742 
743 /*
744  * Callback routine that gets called whenever there is a message from host
745  */
746 void
747 hv_kvp_callback(void *context)
748 {
749 	uint64_t pending_cnt = 0;
750 
751 	if (kvp_globals.register_done == false) {
752 
753 		kvp_globals.channelp = context;
754 	} else {
755 
756 		mtx_lock(&kvp_globals.pending_mutex);
757 		kvp_globals.pending_reqs = kvp_globals.pending_reqs + 1;
758 		pending_cnt = kvp_globals.pending_reqs;
759 		mtx_unlock(&kvp_globals.pending_mutex);
760 		if (pending_cnt == 1) {
761 			hv_kvp_log_info("%s: Queuing work item\n", __func__);
762 			hv_queue_work_item(
763 					service_table[HV_KVP].work_queue,
764 					hv_kvp_process_request,
765 					context
766 					);
767 		}
768 	}
769 }
770 
771 
772 /*
773  * This function is called by the hv_kvp_init -
774  * creates character device hv_kvp_dev
775  * allocates memory to hv_kvp_dev_buf
776  *
777  */
778 static int
779 hv_kvp_dev_init(void)
780 {
781 	int error = 0;
782 
783 	/* initialize semaphore */
784 	sema_init(&kvp_globals.dev_sema, 0, "hv_kvp device semaphore");
785 	/* create character device */
786 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
787 			&hv_kvp_dev,
788 			&hv_kvp_cdevsw,
789 			0,
790 			UID_ROOT,
791 			GID_WHEEL,
792 			0640,
793 			"hv_kvp_dev");
794 
795 	if (error != 0)
796 		return (error);
797 
798 	/*
799 	 * Malloc with M_WAITOK flag will never fail.
800 	 */
801 	hv_kvp_dev_buf = malloc(sizeof(*hv_kvp_dev_buf), M_HV_KVP_DEV_BUF, M_WAITOK |
802 				M_ZERO);
803 
804 	return (0);
805 }
806 
807 
808 /*
809  * This function is called by the hv_kvp_deinit -
810  * destroy character device
811  */
812 static void
813 hv_kvp_dev_destroy(void)
814 {
815 
816         if (daemon_task != NULL) {
817 		PROC_LOCK(daemon_task);
818         	kern_psignal(daemon_task, SIGKILL);
819 		PROC_UNLOCK(daemon_task);
820 	}
821 
822 	destroy_dev(hv_kvp_dev);
823 	free(hv_kvp_dev_buf, M_HV_KVP_DEV_BUF);
824 	return;
825 }
826 
827 
828 static int
829 hv_kvp_dev_open(struct cdev *dev, int oflags, int devtype,
830 				struct thread *td)
831 {
832 
833 	hv_kvp_log_info("%s: Opened device \"hv_kvp_device\" successfully.\n", __func__);
834 	if (kvp_globals.dev_accessed)
835 		return (-EBUSY);
836 
837 	daemon_task = curproc;
838 	kvp_globals.dev_accessed = true;
839 	kvp_globals.daemon_busy = false;
840 	return (0);
841 }
842 
843 
844 static int
845 hv_kvp_dev_close(struct cdev *dev __unused, int fflag __unused, int devtype __unused,
846 				 struct thread *td __unused)
847 {
848 
849 	hv_kvp_log_info("%s: Closing device \"hv_kvp_device\".\n", __func__);
850 	kvp_globals.dev_accessed = false;
851 	kvp_globals.register_done = false;
852 	return (0);
853 }
854 
855 
856 /*
857  * hv_kvp_daemon read invokes this function
858  * acts as a send to daemon
859  */
860 static int
861 hv_kvp_dev_daemon_read(struct cdev *dev __unused, struct uio *uio, int ioflag __unused)
862 {
863 	size_t amt;
864 	int error = 0;
865 
866 	/* Check hv_kvp daemon registration status*/
867 	if (!kvp_globals.register_done)
868 		return (KVP_ERROR);
869 
870 	sema_wait(&kvp_globals.dev_sema);
871 
872 	memcpy(hv_kvp_dev_buf, &kvp_globals.daemon_kvp_msg, sizeof(struct hv_kvp_msg));
873 
874 	amt = MIN(uio->uio_resid, uio->uio_offset >= BUFFERSIZE + 1 ? 0 :
875 		BUFFERSIZE + 1 - uio->uio_offset);
876 
877 	if ((error = uiomove(hv_kvp_dev_buf, amt, uio)) != 0)
878 		hv_kvp_log_info("%s: hv_kvp uiomove read failed!\n", __func__);
879 
880 	return (error);
881 }
882 
883 
884 /*
885  * hv_kvp_daemon write invokes this function
886  * acts as a recieve from daemon
887  */
888 static int
889 hv_kvp_dev_daemon_write(struct cdev *dev __unused, struct uio *uio, int ioflag __unused)
890 {
891 	size_t amt;
892 	int error = 0;
893 
894 	uio->uio_offset = 0;
895 
896 	amt = MIN(uio->uio_resid, BUFFERSIZE);
897 	error = uiomove(hv_kvp_dev_buf, amt, uio);
898 
899 	if (error != 0)
900 		return (error);
901 
902 	memcpy(&kvp_globals.daemon_kvp_msg, hv_kvp_dev_buf, sizeof(struct hv_kvp_msg));
903 
904 	if (kvp_globals.register_done == false) {
905 		if (kvp_globals.daemon_kvp_msg.kvp_hdr.operation == HV_KVP_OP_REGISTER) {
906 
907 			kvp_globals.register_done = true;
908 			if (kvp_globals.channelp) {
909 
910 				hv_kvp_callback(kvp_globals.channelp);
911 			}
912 		}
913 		else {
914 			hv_kvp_log_info("%s, KVP Registration Failed\n", __func__);
915 			return (KVP_ERROR);
916 		}
917 	} else {
918 
919 		mtx_lock(&kvp_globals.pending_mutex);
920 
921 		if(!kvp_globals.req_timed_out) {
922 
923 			hv_kvp_convert_usermsg_to_hostmsg();
924 			hv_kvp_respond_host(KVP_SUCCESS);
925 			wakeup(&kvp_globals);
926 			kvp_globals.req_in_progress = false;
927 		}
928 
929 		kvp_globals.daemon_busy = false;
930 		mtx_unlock(&kvp_globals.pending_mutex);
931 	}
932 
933 	return (error);
934 }
935 
936 
937 /*
938  * hv_kvp_daemon poll invokes this function to check if data is available
939  * for daemon to read.
940  */
941 static int
942 hv_kvp_dev_daemon_poll(struct cdev *dev __unused, int events, struct thread *td  __unused)
943 {
944 	int revents = 0;
945 
946 	mtx_lock(&kvp_globals.pending_mutex);
947 	/*
948 	 * We check global flag daemon_busy for the data availiability for
949 	 * userland to read. Deamon_busy is set to true before driver has data
950 	 * for daemon to read. It is set to false after daemon sends
951 	 * then response back to driver.
952 	 */
953 	if (kvp_globals.daemon_busy == true)
954 		revents = POLLIN;
955 	mtx_unlock(&kvp_globals.pending_mutex);
956 
957 	return (revents);
958 }
959 
960 
961 /*
962  * hv_kvp initialization function
963  * called from hv_util service.
964  *
965  */
966 int
967 hv_kvp_init(hv_vmbus_service *srv)
968 {
969 	int error = 0;
970 	hv_work_queue *work_queue = NULL;
971 
972 	memset(&kvp_globals, 0, sizeof(kvp_globals));
973 
974 	work_queue = hv_work_queue_create("KVP Service");
975 	if (work_queue == NULL) {
976 		hv_kvp_log_info("%s: Work queue alloc failed\n", __func__);
977 		error = ENOMEM;
978 		hv_kvp_log_error("%s: ENOMEM\n", __func__);
979 		goto Finish;
980 	}
981 	srv->work_queue = work_queue;
982 
983 	error = hv_kvp_dev_init();
984 	mtx_init(&kvp_globals.pending_mutex, "hv-kvp pending mutex",
985 		       	NULL, MTX_DEF);
986 	kvp_globals.pending_reqs = 0;
987 
988 
989 Finish:
990 	return (error);
991 }
992 
993 
994 void
995 hv_kvp_deinit(void)
996 {
997 	hv_kvp_dev_destroy();
998 	mtx_destroy(&kvp_globals.pending_mutex);
999 
1000 	return;
1001 }
1002