summaryrefslogtreecommitdiff
path: root/drivers/hv/hv_util.c
blob: 9c97c4065fe736e7e076894999447a2def819c24 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2010, Microsoft Corporation.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/reboot.h>
#include <linux/hyperv.h>
#include <linux/clockchips.h>
#include <linux/ptp_clock_kernel.h>
#include <asm/mshyperv.h>

#include "hyperv_vmbus.h"

#define SD_MAJOR	3
#define SD_MINOR	0
#define SD_MINOR_1	1
#define SD_MINOR_2	2
#define SD_VERSION_3_1	(SD_MAJOR << 16 | SD_MINOR_1)
#define SD_VERSION_3_2	(SD_MAJOR << 16 | SD_MINOR_2)
#define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)

#define SD_MAJOR_1	1
#define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)

#define TS_MAJOR	4
#define TS_MINOR	0
#define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)

#define TS_MAJOR_1	1
#define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)

#define TS_MAJOR_3	3
#define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)

#define HB_MAJOR	3
#define HB_MINOR	0
#define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)

#define HB_MAJOR_1	1
#define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)

static int sd_srv_version;
static int ts_srv_version;
static int hb_srv_version;

#define SD_VER_COUNT 4
static const int sd_versions[] = {
	SD_VERSION_3_2,
	SD_VERSION_3_1,
	SD_VERSION,
	SD_VERSION_1
};

#define TS_VER_COUNT 3
static const int ts_versions[] = {
	TS_VERSION,
	TS_VERSION_3,
	TS_VERSION_1
};

#define HB_VER_COUNT 2
static const int hb_versions[] = {
	HB_VERSION,
	HB_VERSION_1
};

#define FW_VER_COUNT 2
static const int fw_versions[] = {
	UTIL_FW_VERSION,
	UTIL_WS2K8_FW_VERSION
};

/*
 * Send the "hibernate" udev event in a thread context.
 */
struct hibernate_work_context {
	struct work_struct work;
	struct hv_device *dev;
};

static struct hibernate_work_context hibernate_context;
static bool hibernation_supported;

static void send_hibernate_uevent(struct work_struct *work)
{
	char *uevent_env[2] = { "EVENT=hibernate", NULL };
	struct hibernate_work_context *ctx;

	ctx = container_of(work, struct hibernate_work_context, work);

	kobject_uevent_env(&ctx->dev->device.kobj, KOBJ_CHANGE, uevent_env);

	pr_info("Sent hibernation uevent\n");
}

static int hv_shutdown_init(struct hv_util_service *srv)
{
	struct vmbus_channel *channel = srv->channel;

	INIT_WORK(&hibernate_context.work, send_hibernate_uevent);
	hibernate_context.dev = channel->device_obj;

	hibernation_supported = hv_is_hibernation_supported();

	return 0;
}

static void shutdown_onchannelcallback(void *context);
static struct hv_util_service util_shutdown = {
	.util_cb = shutdown_onchannelcallback,
	.util_init = hv_shutdown_init,
};

static int hv_timesync_init(struct hv_util_service *srv);
static int hv_timesync_pre_suspend(void);
static void hv_timesync_deinit(void);

static void timesync_onchannelcallback(void *context);
static struct hv_util_service util_timesynch = {
	.util_cb = timesync_onchannelcallback,
	.util_init = hv_timesync_init,
	.util_pre_suspend = hv_timesync_pre_suspend,
	.util_deinit = hv_timesync_deinit,
};

static void heartbeat_onchannelcallback(void *context);
static struct hv_util_service util_heartbeat = {
	.util_cb = heartbeat_onchannelcallback,
};

static struct hv_util_service util_kvp = {
	.util_cb = hv_kvp_onchannelcallback,
	.util_init = hv_kvp_init,
	.util_pre_suspend = hv_kvp_pre_suspend,
	.util_pre_resume = hv_kvp_pre_resume,
	.util_deinit = hv_kvp_deinit,
};

static struct hv_util_service util_vss = {
	.util_cb = hv_vss_onchannelcallback,
	.util_init = hv_vss_init,
	.util_pre_suspend = hv_vss_pre_suspend,
	.util_pre_resume = hv_vss_pre_resume,
	.util_deinit = hv_vss_deinit,
};

static struct hv_util_service util_fcopy = {
	.util_cb = hv_fcopy_onchannelcallback,
	.util_init = hv_fcopy_init,
	.util_pre_suspend = hv_fcopy_pre_suspend,
	.util_pre_resume = hv_fcopy_pre_resume,
	.util_deinit = hv_fcopy_deinit,
};

static void perform_shutdown(struct work_struct *dummy)
{
	orderly_poweroff(true);
}

static void perform_restart(struct work_struct *dummy)
{
	orderly_reboot();
}

/*
 * Perform the shutdown operation in a thread context.
 */
static DECLARE_WORK(shutdown_work, perform_shutdown);

/*
 * Perform the restart operation in a thread context.
 */
static DECLARE_WORK(restart_work, perform_restart);

static void shutdown_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	struct work_struct *work = NULL;
	u32 recvlen;
	u64 requestid;
	u8  *shut_txf_buf = util_shutdown.recv_buffer;

	struct shutdown_msg_data *shutdown_msg;

	struct icmsg_hdr *icmsghdrp;

	if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
		pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
		return;
	}

	if (!recvlen)
		return;

	/* Ensure recvlen is big enough to read header data */
	if (recvlen < ICMSG_HDR) {
		pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
				   recvlen);
		return;
	}

	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];

	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
		if (vmbus_prep_negotiate_resp(icmsghdrp,
				shut_txf_buf, recvlen,
				fw_versions, FW_VER_COUNT,
				sd_versions, SD_VER_COUNT,
				NULL, &sd_srv_version)) {
			pr_info("Shutdown IC version %d.%d\n",
				sd_srv_version >> 16,
				sd_srv_version & 0xFFFF);
		}
	} else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
		/* Ensure recvlen is big enough to contain shutdown_msg_data struct */
		if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
			pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
					   recvlen);
			return;
		}

		shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];

		/*
		 * shutdown_msg->flags can be 0(shut down), 2(reboot),
		 * or 4(hibernate). It may bitwise-OR 1, which means
		 * performing the request by force. Linux always tries
		 * to perform the request by force.
		 */
		switch (shutdown_msg->flags) {
		case 0:
		case 1:
			icmsghdrp->status = HV_S_OK;
			work = &shutdown_work;
			pr_info("Shutdown request received - graceful shutdown initiated\n");
			break;
		case 2:
		case 3:
			icmsghdrp->status = HV_S_OK;
			work = &restart_work;
			pr_info("Restart request received - graceful restart initiated\n");
			break;
		case 4:
		case 5:
			pr_info("Hibernation request received\n");
			icmsghdrp->status = hibernation_supported ?
				HV_S_OK : HV_E_FAIL;
			if (hibernation_supported)
				work = &hibernate_context.work;
			break;
		default:
			icmsghdrp->status = HV_E_FAIL;
			pr_info("Shutdown request received - Invalid request\n");
			break;
		}
	} else {
		icmsghdrp->status = HV_E_FAIL;
		pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
				   icmsghdrp->icmsgtype);
	}

	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
		| ICMSGHDRFLAG_RESPONSE;

	vmbus_sendpacket(channel, shut_txf_buf,
			 recvlen, requestid,
			 VM_PKT_DATA_INBAND, 0);

	if (work)
		schedule_work(work);
}

/*
 * Set the host time in a process context.
 */
static struct work_struct adj_time_work;

/*
 * The last time sample, received from the host. PTP device responds to
 * requests by using this data and the current partition-wide time reference
 * count.
 */
static struct {
	u64				host_time;
	u64				ref_time;
	spinlock_t			lock;
} host_ts;

static bool timesync_implicit;

module_param(timesync_implicit, bool, 0644);
MODULE_PARM_DESC(timesync_implicit, "If set treat SAMPLE as SYNC when clock is behind");

static inline u64 reftime_to_ns(u64 reftime)
{
	return (reftime - WLTIMEDELTA) * 100;
}

/*
 * Hard coded threshold for host timesync delay: 600 seconds
 */
static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;

static int hv_get_adj_host_time(struct timespec64 *ts)
{
	u64 newtime, reftime, timediff_adj;
	unsigned long flags;
	int ret = 0;

	spin_lock_irqsave(&host_ts.lock, flags);
	reftime = hv_read_reference_counter();

	/*
	 * We need to let the caller know that last update from host
	 * is older than the max allowable threshold. clock_gettime()
	 * and PTP ioctl do not have a documented error that we could
	 * return for this specific case. Use ESTALE to report this.
	 */
	timediff_adj = reftime - host_ts.ref_time;
	if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
		pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
			     (timediff_adj * 100));
		ret = -ESTALE;
	}

	newtime = host_ts.host_time + timediff_adj;
	*ts = ns_to_timespec64(reftime_to_ns(newtime));
	spin_unlock_irqrestore(&host_ts.lock, flags);

	return ret;
}

static void hv_set_host_time(struct work_struct *work)
{

	struct timespec64 ts;

	if (!hv_get_adj_host_time(&ts))
		do_settimeofday64(&ts);
}

/*
 * Due to a bug on Hyper-V hosts, the sync flag may not always be sent on resume.
 * Force a sync if the guest is behind.
 */
static inline bool hv_implicit_sync(u64 host_time)
{
	struct timespec64 new_ts;
	struct timespec64 threshold_ts;

	new_ts = ns_to_timespec64(reftime_to_ns(host_time));
	ktime_get_real_ts64(&threshold_ts);

	threshold_ts.tv_sec += 5;

	/*
	 * If guest behind the host by 5 or more seconds.
	 */
	if (timespec64_compare(&new_ts, &threshold_ts) >= 0)
		return true;

	return false;
}

/*
 * Synchronize time with host after reboot, restore, etc.
 *
 * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
 * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
 * message after the timesync channel is opened. Since the hv_utils module is
 * loaded after hv_vmbus, the first message is usually missed. This bit is
 * considered a hard request to discipline the clock.
 *
 * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
 * typically used as a hint to the guest. The guest is under no obligation
 * to discipline the clock.
 */
static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
{
	unsigned long flags;
	u64 cur_reftime;

	/*
	 * Save the adjusted time sample from the host and the snapshot
	 * of the current system time.
	 */
	spin_lock_irqsave(&host_ts.lock, flags);

	cur_reftime = hv_read_reference_counter();
	host_ts.host_time = hosttime;
	host_ts.ref_time = cur_reftime;

	/*
	 * TimeSync v4 messages contain reference time (guest's Hyper-V
	 * clocksource read when the time sample was generated), we can
	 * improve the precision by adding the delta between now and the
	 * time of generation. For older protocols we set
	 * reftime == cur_reftime on call.
	 */
	host_ts.host_time += (cur_reftime - reftime);

	spin_unlock_irqrestore(&host_ts.lock, flags);

	/* Schedule work to do do_settimeofday64() */
	if ((adj_flags & ICTIMESYNCFLAG_SYNC) ||
	    (timesync_implicit && hv_implicit_sync(host_ts.host_time)))
		schedule_work(&adj_time_work);
}

/*
 * Time Sync Channel message handler.
 */
static void timesync_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct icmsg_hdr *icmsghdrp;
	struct ictimesync_data *timedatap;
	struct ictimesync_ref_data *refdata;
	u8 *time_txf_buf = util_timesynch.recv_buffer;

	/*
	 * Drain the ring buffer and use the last packet to update
	 * host_ts
	 */
	while (1) {
		int ret = vmbus_recvpacket(channel, time_txf_buf,
					   HV_HYP_PAGE_SIZE, &recvlen,
					   &requestid);
		if (ret) {
			pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
					   ret);
			break;
		}

		if (!recvlen)
			break;

		/* Ensure recvlen is big enough to read header data */
		if (recvlen < ICMSG_HDR) {
			pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
					   recvlen);
			break;
		}

		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
				sizeof(struct vmbuspipe_hdr)];

		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
			if (vmbus_prep_negotiate_resp(icmsghdrp,
						time_txf_buf, recvlen,
						fw_versions, FW_VER_COUNT,
						ts_versions, TS_VER_COUNT,
						NULL, &ts_srv_version)) {
				pr_info("TimeSync IC version %d.%d\n",
					ts_srv_version >> 16,
					ts_srv_version & 0xFFFF);
			}
		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
			if (ts_srv_version > TS_VERSION_3) {
				/* Ensure recvlen is big enough to read ictimesync_ref_data */
				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
					pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
							   recvlen);
					break;
				}
				refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];

				adj_guesttime(refdata->parenttime,
						refdata->vmreferencetime,
						refdata->flags);
			} else {
				/* Ensure recvlen is big enough to read ictimesync_data */
				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
					pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
							   recvlen);
					break;
				}
				timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];

				adj_guesttime(timedatap->parenttime,
					      hv_read_reference_counter(),
					      timedatap->flags);
			}
		} else {
			icmsghdrp->status = HV_E_FAIL;
			pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
					   icmsghdrp->icmsgtype);
		}

		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
			| ICMSGHDRFLAG_RESPONSE;

		vmbus_sendpacket(channel, time_txf_buf,
				 recvlen, requestid,
				 VM_PKT_DATA_INBAND, 0);
	}
}

/*
 * Heartbeat functionality.
 * Every two seconds, Hyper-V send us a heartbeat request message.
 * we respond to this message, and Hyper-V knows we are alive.
 */
static void heartbeat_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct icmsg_hdr *icmsghdrp;
	struct heartbeat_msg_data *heartbeat_msg;
	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;

	while (1) {

		if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
				     &recvlen, &requestid)) {
			pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
			return;
		}

		if (!recvlen)
			break;

		/* Ensure recvlen is big enough to read header data */
		if (recvlen < ICMSG_HDR) {
			pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
					   recvlen);
			break;
		}

		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
				sizeof(struct vmbuspipe_hdr)];

		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
			if (vmbus_prep_negotiate_resp(icmsghdrp,
					hbeat_txf_buf, recvlen,
					fw_versions, FW_VER_COUNT,
					hb_versions, HB_VER_COUNT,
					NULL, &hb_srv_version)) {

				pr_info("Heartbeat IC version %d.%d\n",
					hb_srv_version >> 16,
					hb_srv_version & 0xFFFF);
			}
		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
			/*
			 * Ensure recvlen is big enough to read seq_num. Reserved area is not
			 * included in the check as the host may not fill it up entirely
			 */
			if (recvlen < ICMSG_HDR + sizeof(u64)) {
				pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
						   recvlen);
				break;
			}
			heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];

			heartbeat_msg->seq_num += 1;
		} else {
			icmsghdrp->status = HV_E_FAIL;
			pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
					   icmsghdrp->icmsgtype);
		}

		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
			| ICMSGHDRFLAG_RESPONSE;

		vmbus_sendpacket(channel, hbeat_txf_buf,
				 recvlen, requestid,
				 VM_PKT_DATA_INBAND, 0);
	}
}

#define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
#define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)

static int util_probe(struct hv_device *dev,
			const struct hv_vmbus_device_id *dev_id)
{
	struct hv_util_service *srv =
		(struct hv_util_service *)dev_id->driver_data;
	int ret;

	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
	if (!srv->recv_buffer)
		return -ENOMEM;
	srv->channel = dev->channel;
	if (srv->util_init) {
		ret = srv->util_init(srv);
		if (ret) {
			ret = -ENODEV;
			goto error1;
		}
	}

	/*
	 * The set of services managed by the util driver are not performance
	 * critical and do not need batched reading. Furthermore, some services
	 * such as KVP can only handle one message from the host at a time.
	 * Turn off batched reading for all util drivers before we open the
	 * channel.
	 */
	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);

	hv_set_drvdata(dev, srv);

	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
			 dev->channel);
	if (ret)
		goto error;

	return 0;

error:
	if (srv->util_deinit)
		srv->util_deinit();
error1:
	kfree(srv->recv_buffer);
	return ret;
}

static void util_remove(struct hv_device *dev)
{
	struct hv_util_service *srv = hv_get_drvdata(dev);

	if (srv->util_deinit)
		srv->util_deinit();
	vmbus_close(dev->channel);
	kfree(srv->recv_buffer);
}

/*
 * When we're in util_suspend(), all the userspace processes have been frozen
 * (refer to hibernate() -> freeze_processes()). The userspace is thawed only
 * after the whole resume procedure, including util_resume(), finishes.
 */
static int util_suspend(struct hv_device *dev)
{
	struct hv_util_service *srv = hv_get_drvdata(dev);
	int ret = 0;

	if (srv->util_pre_suspend) {
		ret = srv->util_pre_suspend();
		if (ret)
			return ret;
	}

	vmbus_close(dev->channel);

	return 0;
}

static int util_resume(struct hv_device *dev)
{
	struct hv_util_service *srv = hv_get_drvdata(dev);
	int ret = 0;

	if (srv->util_pre_resume) {
		ret = srv->util_pre_resume();
		if (ret)
			return ret;
	}

	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
			 dev->channel);
	return ret;
}

static const struct hv_vmbus_device_id id_table[] = {
	/* Shutdown guid */
	{ HV_SHUTDOWN_GUID,
	  .driver_data = (unsigned long)&util_shutdown
	},
	/* Time synch guid */
	{ HV_TS_GUID,
	  .driver_data = (unsigned long)&util_timesynch
	},
	/* Heartbeat guid */
	{ HV_HEART_BEAT_GUID,
	  .driver_data = (unsigned long)&util_heartbeat
	},
	/* KVP guid */
	{ HV_KVP_GUID,
	  .driver_data = (unsigned long)&util_kvp
	},
	/* VSS GUID */
	{ HV_VSS_GUID,
	  .driver_data = (unsigned long)&util_vss
	},
	/* File copy GUID */
	{ HV_FCOPY_GUID,
	  .driver_data = (unsigned long)&util_fcopy
	},
	{ },
};

MODULE_DEVICE_TABLE(vmbus, id_table);

/* The one and only one */
static  struct hv_driver util_drv = {
	.name = "hv_utils",
	.id_table = id_table,
	.probe =  util_probe,
	.remove =  util_remove,
	.suspend = util_suspend,
	.resume =  util_resume,
	.driver = {
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
};

static int hv_ptp_enable(struct ptp_clock_info *info,
			 struct ptp_clock_request *request, int on)
{
	return -EOPNOTSUPP;
}

static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
{
	return -EOPNOTSUPP;
}

static int hv_ptp_adjfine(struct ptp_clock_info *ptp, long delta)
{
	return -EOPNOTSUPP;
}
static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	return -EOPNOTSUPP;
}

static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
{
	return hv_get_adj_host_time(ts);
}

static struct ptp_clock_info ptp_hyperv_info = {
	.name		= "hyperv",
	.enable         = hv_ptp_enable,
	.adjtime        = hv_ptp_adjtime,
	.adjfine        = hv_ptp_adjfine,
	.gettime64      = hv_ptp_gettime,
	.settime64      = hv_ptp_settime,
	.owner		= THIS_MODULE,
};

static struct ptp_clock *hv_ptp_clock;

static int hv_timesync_init(struct hv_util_service *srv)
{
	spin_lock_init(&host_ts.lock);

	INIT_WORK(&adj_time_work, hv_set_host_time);

	/*
	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
	 * disabled but the driver is still useful without the PTP device
	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
	 */
	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
		pr_err("cannot register PTP clock: %d\n",
		       PTR_ERR_OR_ZERO(hv_ptp_clock));
		hv_ptp_clock = NULL;
	}

	return 0;
}

static void hv_timesync_cancel_work(void)
{
	cancel_work_sync(&adj_time_work);
}

static int hv_timesync_pre_suspend(void)
{
	hv_timesync_cancel_work();
	return 0;
}

static void hv_timesync_deinit(void)
{
	if (hv_ptp_clock)
		ptp_clock_unregister(hv_ptp_clock);

	hv_timesync_cancel_work();
}

static int __init init_hyperv_utils(void)
{
	pr_info("Registering HyperV Utility Driver\n");

	return vmbus_driver_register(&util_drv);
}

static void exit_hyperv_utils(void)
{
	pr_info("De-Registered HyperV Utility Driver\n");

	vmbus_driver_unregister(&util_drv);
}

module_init(init_hyperv_utils);
module_exit(exit_hyperv_utils);

MODULE_DESCRIPTION("Hyper-V Utilities");
MODULE_LICENSE("GPL");