xref: /linux/drivers/hv/hv_util.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2010, Microsoft Corporation.
4  *
5  * Authors:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  *   Hank Janssen  <hjanssen@microsoft.com>
8  */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/sysctl.h>
16 #include <linux/reboot.h>
17 #include <linux/hyperv.h>
18 #include <linux/clockchips.h>
19 #include <linux/ptp_clock_kernel.h>
20 #include <asm/mshyperv.h>
21 
22 #include "hyperv_vmbus.h"
23 
24 #define SD_MAJOR	3
25 #define SD_MINOR	0
26 #define SD_MINOR_1	1
27 #define SD_MINOR_2	2
28 #define SD_VERSION_3_1	(SD_MAJOR << 16 | SD_MINOR_1)
29 #define SD_VERSION_3_2	(SD_MAJOR << 16 | SD_MINOR_2)
30 #define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)
31 
32 #define SD_MAJOR_1	1
33 #define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)
34 
35 #define TS_MAJOR	4
36 #define TS_MINOR	0
37 #define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
38 
39 #define TS_MAJOR_1	1
40 #define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)
41 
42 #define TS_MAJOR_3	3
43 #define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)
44 
45 #define HB_MAJOR	3
46 #define HB_MINOR	0
47 #define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
48 
49 #define HB_MAJOR_1	1
50 #define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)
51 
52 static int sd_srv_version;
53 static int ts_srv_version;
54 static int hb_srv_version;
55 
56 #define SD_VER_COUNT 4
57 static const int sd_versions[] = {
58 	SD_VERSION_3_2,
59 	SD_VERSION_3_1,
60 	SD_VERSION,
61 	SD_VERSION_1
62 };
63 
64 #define TS_VER_COUNT 3
65 static const int ts_versions[] = {
66 	TS_VERSION,
67 	TS_VERSION_3,
68 	TS_VERSION_1
69 };
70 
71 #define HB_VER_COUNT 2
72 static const int hb_versions[] = {
73 	HB_VERSION,
74 	HB_VERSION_1
75 };
76 
77 #define FW_VER_COUNT 2
78 static const int fw_versions[] = {
79 	UTIL_FW_VERSION,
80 	UTIL_WS2K8_FW_VERSION
81 };
82 
83 /*
84  * Send the "hibernate" udev event in a thread context.
85  */
86 struct hibernate_work_context {
87 	struct work_struct work;
88 	struct hv_device *dev;
89 };
90 
91 static struct hibernate_work_context hibernate_context;
92 static bool hibernation_supported;
93 
94 static void send_hibernate_uevent(struct work_struct *work)
95 {
96 	char *uevent_env[2] = { "EVENT=hibernate", NULL };
97 	struct hibernate_work_context *ctx;
98 
99 	ctx = container_of(work, struct hibernate_work_context, work);
100 
101 	kobject_uevent_env(&ctx->dev->device.kobj, KOBJ_CHANGE, uevent_env);
102 
103 	pr_info("Sent hibernation uevent\n");
104 }
105 
106 static int hv_shutdown_init(struct hv_util_service *srv)
107 {
108 	struct vmbus_channel *channel = srv->channel;
109 
110 	INIT_WORK(&hibernate_context.work, send_hibernate_uevent);
111 	hibernate_context.dev = channel->device_obj;
112 
113 	hibernation_supported = hv_is_hibernation_supported();
114 
115 	return 0;
116 }
117 
118 static void shutdown_onchannelcallback(void *context);
119 static struct hv_util_service util_shutdown = {
120 	.util_cb = shutdown_onchannelcallback,
121 	.util_init = hv_shutdown_init,
122 };
123 
124 static int hv_timesync_init(struct hv_util_service *srv);
125 static int hv_timesync_pre_suspend(void);
126 static void hv_timesync_deinit(void);
127 
128 static void timesync_onchannelcallback(void *context);
129 static struct hv_util_service util_timesynch = {
130 	.util_cb = timesync_onchannelcallback,
131 	.util_init = hv_timesync_init,
132 	.util_pre_suspend = hv_timesync_pre_suspend,
133 	.util_deinit = hv_timesync_deinit,
134 };
135 
136 static void heartbeat_onchannelcallback(void *context);
137 static struct hv_util_service util_heartbeat = {
138 	.util_cb = heartbeat_onchannelcallback,
139 };
140 
141 static struct hv_util_service util_kvp = {
142 	.util_cb = hv_kvp_onchannelcallback,
143 	.util_init = hv_kvp_init,
144 	.util_pre_suspend = hv_kvp_pre_suspend,
145 	.util_pre_resume = hv_kvp_pre_resume,
146 	.util_deinit = hv_kvp_deinit,
147 };
148 
149 static struct hv_util_service util_vss = {
150 	.util_cb = hv_vss_onchannelcallback,
151 	.util_init = hv_vss_init,
152 	.util_pre_suspend = hv_vss_pre_suspend,
153 	.util_pre_resume = hv_vss_pre_resume,
154 	.util_deinit = hv_vss_deinit,
155 };
156 
157 static void perform_shutdown(struct work_struct *dummy)
158 {
159 	orderly_poweroff(true);
160 }
161 
162 static void perform_restart(struct work_struct *dummy)
163 {
164 	orderly_reboot();
165 }
166 
167 /*
168  * Perform the shutdown operation in a thread context.
169  */
170 static DECLARE_WORK(shutdown_work, perform_shutdown);
171 
172 /*
173  * Perform the restart operation in a thread context.
174  */
175 static DECLARE_WORK(restart_work, perform_restart);
176 
177 static void shutdown_onchannelcallback(void *context)
178 {
179 	struct vmbus_channel *channel = context;
180 	struct work_struct *work = NULL;
181 	u32 recvlen;
182 	u64 requestid;
183 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
184 
185 	struct shutdown_msg_data *shutdown_msg;
186 
187 	struct icmsg_hdr *icmsghdrp;
188 
189 	if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
190 		pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
191 		return;
192 	}
193 
194 	if (!recvlen)
195 		return;
196 
197 	/* Ensure recvlen is big enough to read header data */
198 	if (recvlen < ICMSG_HDR) {
199 		pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
200 				   recvlen);
201 		return;
202 	}
203 
204 	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];
205 
206 	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
207 		if (vmbus_prep_negotiate_resp(icmsghdrp,
208 				shut_txf_buf, recvlen,
209 				fw_versions, FW_VER_COUNT,
210 				sd_versions, SD_VER_COUNT,
211 				NULL, &sd_srv_version)) {
212 			pr_info("Shutdown IC version %d.%d\n",
213 				sd_srv_version >> 16,
214 				sd_srv_version & 0xFFFF);
215 		}
216 	} else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
217 		/* Ensure recvlen is big enough to contain shutdown_msg_data struct */
218 		if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
219 			pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
220 					   recvlen);
221 			return;
222 		}
223 
224 		shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
225 
226 		/*
227 		 * shutdown_msg->flags can be 0(shut down), 2(reboot),
228 		 * or 4(hibernate). It may bitwise-OR 1, which means
229 		 * performing the request by force. Linux always tries
230 		 * to perform the request by force.
231 		 */
232 		switch (shutdown_msg->flags) {
233 		case 0:
234 		case 1:
235 			icmsghdrp->status = HV_S_OK;
236 			work = &shutdown_work;
237 			pr_info("Shutdown request received - graceful shutdown initiated\n");
238 			break;
239 		case 2:
240 		case 3:
241 			icmsghdrp->status = HV_S_OK;
242 			work = &restart_work;
243 			pr_info("Restart request received - graceful restart initiated\n");
244 			break;
245 		case 4:
246 		case 5:
247 			pr_info("Hibernation request received\n");
248 			icmsghdrp->status = hibernation_supported ?
249 				HV_S_OK : HV_E_FAIL;
250 			if (hibernation_supported)
251 				work = &hibernate_context.work;
252 			break;
253 		default:
254 			icmsghdrp->status = HV_E_FAIL;
255 			pr_info("Shutdown request received - Invalid request\n");
256 			break;
257 		}
258 	} else {
259 		icmsghdrp->status = HV_E_FAIL;
260 		pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
261 				   icmsghdrp->icmsgtype);
262 	}
263 
264 	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
265 		| ICMSGHDRFLAG_RESPONSE;
266 
267 	vmbus_sendpacket(channel, shut_txf_buf,
268 			 recvlen, requestid,
269 			 VM_PKT_DATA_INBAND, 0);
270 
271 	if (work)
272 		schedule_work(work);
273 }
274 
275 /*
276  * Set the host time in a process context.
277  */
278 static struct work_struct adj_time_work;
279 
280 /*
281  * The last time sample, received from the host. PTP device responds to
282  * requests by using this data and the current partition-wide time reference
283  * count.
284  */
285 static struct {
286 	u64				host_time;
287 	u64				ref_time;
288 	spinlock_t			lock;
289 } host_ts;
290 
291 static bool timesync_implicit;
292 
293 module_param(timesync_implicit, bool, 0644);
294 MODULE_PARM_DESC(timesync_implicit, "If set treat SAMPLE as SYNC when clock is behind");
295 
296 static inline u64 reftime_to_ns(u64 reftime)
297 {
298 	return (reftime - WLTIMEDELTA) * 100;
299 }
300 
301 /*
302  * Hard coded threshold for host timesync delay: 600 seconds
303  */
304 static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
305 
306 static int hv_get_adj_host_time(struct timespec64 *ts)
307 {
308 	u64 newtime, reftime, timediff_adj;
309 	unsigned long flags;
310 	int ret = 0;
311 
312 	spin_lock_irqsave(&host_ts.lock, flags);
313 	reftime = hv_read_reference_counter();
314 
315 	/*
316 	 * We need to let the caller know that last update from host
317 	 * is older than the max allowable threshold. clock_gettime()
318 	 * and PTP ioctl do not have a documented error that we could
319 	 * return for this specific case. Use ESTALE to report this.
320 	 */
321 	timediff_adj = reftime - host_ts.ref_time;
322 	if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
323 		pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
324 			     (timediff_adj * 100));
325 		ret = -ESTALE;
326 	}
327 
328 	newtime = host_ts.host_time + timediff_adj;
329 	*ts = ns_to_timespec64(reftime_to_ns(newtime));
330 	spin_unlock_irqrestore(&host_ts.lock, flags);
331 
332 	return ret;
333 }
334 
335 static void hv_set_host_time(struct work_struct *work)
336 {
337 
338 	struct timespec64 ts;
339 
340 	if (!hv_get_adj_host_time(&ts))
341 		do_settimeofday64(&ts);
342 }
343 
344 /*
345  * Due to a bug on Hyper-V hosts, the sync flag may not always be sent on resume.
346  * Force a sync if the guest is behind.
347  */
348 static inline bool hv_implicit_sync(u64 host_time)
349 {
350 	struct timespec64 new_ts;
351 	struct timespec64 threshold_ts;
352 
353 	new_ts = ns_to_timespec64(reftime_to_ns(host_time));
354 	ktime_get_real_ts64(&threshold_ts);
355 
356 	threshold_ts.tv_sec += 5;
357 
358 	/*
359 	 * If guest behind the host by 5 or more seconds.
360 	 */
361 	if (timespec64_compare(&new_ts, &threshold_ts) >= 0)
362 		return true;
363 
364 	return false;
365 }
366 
367 /*
368  * Synchronize time with host after reboot, restore, etc.
369  *
370  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
371  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
372  * message after the timesync channel is opened. Since the hv_utils module is
373  * loaded after hv_vmbus, the first message is usually missed. This bit is
374  * considered a hard request to discipline the clock.
375  *
376  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
377  * typically used as a hint to the guest. The guest is under no obligation
378  * to discipline the clock.
379  */
380 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
381 {
382 	unsigned long flags;
383 	u64 cur_reftime;
384 
385 	/*
386 	 * Save the adjusted time sample from the host and the snapshot
387 	 * of the current system time.
388 	 */
389 	spin_lock_irqsave(&host_ts.lock, flags);
390 
391 	cur_reftime = hv_read_reference_counter();
392 	host_ts.host_time = hosttime;
393 	host_ts.ref_time = cur_reftime;
394 
395 	/*
396 	 * TimeSync v4 messages contain reference time (guest's Hyper-V
397 	 * clocksource read when the time sample was generated), we can
398 	 * improve the precision by adding the delta between now and the
399 	 * time of generation. For older protocols we set
400 	 * reftime == cur_reftime on call.
401 	 */
402 	host_ts.host_time += (cur_reftime - reftime);
403 
404 	spin_unlock_irqrestore(&host_ts.lock, flags);
405 
406 	/* Schedule work to do do_settimeofday64() */
407 	if ((adj_flags & ICTIMESYNCFLAG_SYNC) ||
408 	    (timesync_implicit && hv_implicit_sync(host_ts.host_time)))
409 		schedule_work(&adj_time_work);
410 }
411 
412 /*
413  * Time Sync Channel message handler.
414  */
415 static void timesync_onchannelcallback(void *context)
416 {
417 	struct vmbus_channel *channel = context;
418 	u32 recvlen;
419 	u64 requestid;
420 	struct icmsg_hdr *icmsghdrp;
421 	struct ictimesync_data *timedatap;
422 	struct ictimesync_ref_data *refdata;
423 	u8 *time_txf_buf = util_timesynch.recv_buffer;
424 
425 	/*
426 	 * Drain the ring buffer and use the last packet to update
427 	 * host_ts
428 	 */
429 	while (1) {
430 		int ret = vmbus_recvpacket(channel, time_txf_buf,
431 					   HV_HYP_PAGE_SIZE, &recvlen,
432 					   &requestid);
433 		if (ret) {
434 			pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
435 					   ret);
436 			break;
437 		}
438 
439 		if (!recvlen)
440 			break;
441 
442 		/* Ensure recvlen is big enough to read header data */
443 		if (recvlen < ICMSG_HDR) {
444 			pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
445 					   recvlen);
446 			break;
447 		}
448 
449 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
450 				sizeof(struct vmbuspipe_hdr)];
451 
452 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
453 			if (vmbus_prep_negotiate_resp(icmsghdrp,
454 						time_txf_buf, recvlen,
455 						fw_versions, FW_VER_COUNT,
456 						ts_versions, TS_VER_COUNT,
457 						NULL, &ts_srv_version)) {
458 				pr_info("TimeSync IC version %d.%d\n",
459 					ts_srv_version >> 16,
460 					ts_srv_version & 0xFFFF);
461 			}
462 		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
463 			if (ts_srv_version > TS_VERSION_3) {
464 				/* Ensure recvlen is big enough to read ictimesync_ref_data */
465 				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
466 					pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
467 							   recvlen);
468 					break;
469 				}
470 				refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
471 
472 				adj_guesttime(refdata->parenttime,
473 						refdata->vmreferencetime,
474 						refdata->flags);
475 			} else {
476 				/* Ensure recvlen is big enough to read ictimesync_data */
477 				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
478 					pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
479 							   recvlen);
480 					break;
481 				}
482 				timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
483 
484 				adj_guesttime(timedatap->parenttime,
485 					      hv_read_reference_counter(),
486 					      timedatap->flags);
487 			}
488 		} else {
489 			icmsghdrp->status = HV_E_FAIL;
490 			pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
491 					   icmsghdrp->icmsgtype);
492 		}
493 
494 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
495 			| ICMSGHDRFLAG_RESPONSE;
496 
497 		vmbus_sendpacket(channel, time_txf_buf,
498 				 recvlen, requestid,
499 				 VM_PKT_DATA_INBAND, 0);
500 	}
501 }
502 
503 /*
504  * Heartbeat functionality.
505  * Every two seconds, Hyper-V send us a heartbeat request message.
506  * we respond to this message, and Hyper-V knows we are alive.
507  */
508 static void heartbeat_onchannelcallback(void *context)
509 {
510 	struct vmbus_channel *channel = context;
511 	u32 recvlen;
512 	u64 requestid;
513 	struct icmsg_hdr *icmsghdrp;
514 	struct heartbeat_msg_data *heartbeat_msg;
515 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
516 
517 	while (1) {
518 
519 		if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
520 				     &recvlen, &requestid)) {
521 			pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
522 			return;
523 		}
524 
525 		if (!recvlen)
526 			break;
527 
528 		/* Ensure recvlen is big enough to read header data */
529 		if (recvlen < ICMSG_HDR) {
530 			pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
531 					   recvlen);
532 			break;
533 		}
534 
535 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
536 				sizeof(struct vmbuspipe_hdr)];
537 
538 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
539 			if (vmbus_prep_negotiate_resp(icmsghdrp,
540 					hbeat_txf_buf, recvlen,
541 					fw_versions, FW_VER_COUNT,
542 					hb_versions, HB_VER_COUNT,
543 					NULL, &hb_srv_version)) {
544 
545 				pr_info("Heartbeat IC version %d.%d\n",
546 					hb_srv_version >> 16,
547 					hb_srv_version & 0xFFFF);
548 			}
549 		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
550 			/*
551 			 * Ensure recvlen is big enough to read seq_num. Reserved area is not
552 			 * included in the check as the host may not fill it up entirely
553 			 */
554 			if (recvlen < ICMSG_HDR + sizeof(u64)) {
555 				pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
556 						   recvlen);
557 				break;
558 			}
559 			heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
560 
561 			heartbeat_msg->seq_num += 1;
562 		} else {
563 			icmsghdrp->status = HV_E_FAIL;
564 			pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
565 					   icmsghdrp->icmsgtype);
566 		}
567 
568 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
569 			| ICMSGHDRFLAG_RESPONSE;
570 
571 		vmbus_sendpacket(channel, hbeat_txf_buf,
572 				 recvlen, requestid,
573 				 VM_PKT_DATA_INBAND, 0);
574 	}
575 }
576 
577 #define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
578 #define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
579 
580 static int util_probe(struct hv_device *dev,
581 			const struct hv_vmbus_device_id *dev_id)
582 {
583 	struct hv_util_service *srv =
584 		(struct hv_util_service *)dev_id->driver_data;
585 	int ret;
586 
587 	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
588 	if (!srv->recv_buffer)
589 		return -ENOMEM;
590 	srv->channel = dev->channel;
591 	if (srv->util_init) {
592 		ret = srv->util_init(srv);
593 		if (ret) {
594 			ret = -ENODEV;
595 			goto error1;
596 		}
597 	}
598 
599 	/*
600 	 * The set of services managed by the util driver are not performance
601 	 * critical and do not need batched reading. Furthermore, some services
602 	 * such as KVP can only handle one message from the host at a time.
603 	 * Turn off batched reading for all util drivers before we open the
604 	 * channel.
605 	 */
606 	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
607 
608 	hv_set_drvdata(dev, srv);
609 
610 	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
611 			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
612 			 dev->channel);
613 	if (ret)
614 		goto error;
615 
616 	return 0;
617 
618 error:
619 	if (srv->util_deinit)
620 		srv->util_deinit();
621 error1:
622 	kfree(srv->recv_buffer);
623 	return ret;
624 }
625 
626 static void util_remove(struct hv_device *dev)
627 {
628 	struct hv_util_service *srv = hv_get_drvdata(dev);
629 
630 	if (srv->util_deinit)
631 		srv->util_deinit();
632 	vmbus_close(dev->channel);
633 	kfree(srv->recv_buffer);
634 }
635 
636 /*
637  * When we're in util_suspend(), all the userspace processes have been frozen
638  * (refer to hibernate() -> freeze_processes()). The userspace is thawed only
639  * after the whole resume procedure, including util_resume(), finishes.
640  */
641 static int util_suspend(struct hv_device *dev)
642 {
643 	struct hv_util_service *srv = hv_get_drvdata(dev);
644 	int ret = 0;
645 
646 	if (srv->util_pre_suspend) {
647 		ret = srv->util_pre_suspend();
648 		if (ret)
649 			return ret;
650 	}
651 
652 	vmbus_close(dev->channel);
653 
654 	return 0;
655 }
656 
657 static int util_resume(struct hv_device *dev)
658 {
659 	struct hv_util_service *srv = hv_get_drvdata(dev);
660 	int ret = 0;
661 
662 	if (srv->util_pre_resume) {
663 		ret = srv->util_pre_resume();
664 		if (ret)
665 			return ret;
666 	}
667 
668 	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
669 			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
670 			 dev->channel);
671 	return ret;
672 }
673 
674 static const struct hv_vmbus_device_id id_table[] = {
675 	/* Shutdown guid */
676 	{ HV_SHUTDOWN_GUID,
677 	  .driver_data = (unsigned long)&util_shutdown
678 	},
679 	/* Time synch guid */
680 	{ HV_TS_GUID,
681 	  .driver_data = (unsigned long)&util_timesynch
682 	},
683 	/* Heartbeat guid */
684 	{ HV_HEART_BEAT_GUID,
685 	  .driver_data = (unsigned long)&util_heartbeat
686 	},
687 	/* KVP guid */
688 	{ HV_KVP_GUID,
689 	  .driver_data = (unsigned long)&util_kvp
690 	},
691 	/* VSS GUID */
692 	{ HV_VSS_GUID,
693 	  .driver_data = (unsigned long)&util_vss
694 	},
695 	{ },
696 };
697 
698 MODULE_DEVICE_TABLE(vmbus, id_table);
699 
700 /* The one and only one */
701 static  struct hv_driver util_drv = {
702 	.name = "hv_utils",
703 	.id_table = id_table,
704 	.probe =  util_probe,
705 	.remove =  util_remove,
706 	.suspend = util_suspend,
707 	.resume =  util_resume,
708 	.driver = {
709 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
710 	},
711 };
712 
713 static int hv_ptp_enable(struct ptp_clock_info *info,
714 			 struct ptp_clock_request *request, int on)
715 {
716 	return -EOPNOTSUPP;
717 }
718 
719 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
720 {
721 	return -EOPNOTSUPP;
722 }
723 
724 static int hv_ptp_adjfine(struct ptp_clock_info *ptp, long delta)
725 {
726 	return -EOPNOTSUPP;
727 }
728 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
729 {
730 	return -EOPNOTSUPP;
731 }
732 
733 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
734 {
735 	return hv_get_adj_host_time(ts);
736 }
737 
738 static struct ptp_clock_info ptp_hyperv_info = {
739 	.name		= "hyperv",
740 	.enable         = hv_ptp_enable,
741 	.adjtime        = hv_ptp_adjtime,
742 	.adjfine        = hv_ptp_adjfine,
743 	.gettime64      = hv_ptp_gettime,
744 	.settime64      = hv_ptp_settime,
745 	.owner		= THIS_MODULE,
746 };
747 
748 static struct ptp_clock *hv_ptp_clock;
749 
750 static int hv_timesync_init(struct hv_util_service *srv)
751 {
752 	spin_lock_init(&host_ts.lock);
753 
754 	INIT_WORK(&adj_time_work, hv_set_host_time);
755 
756 	/*
757 	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
758 	 * disabled but the driver is still useful without the PTP device
759 	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
760 	 */
761 	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
762 	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
763 		pr_err("cannot register PTP clock: %d\n",
764 		       PTR_ERR_OR_ZERO(hv_ptp_clock));
765 		hv_ptp_clock = NULL;
766 	}
767 
768 	return 0;
769 }
770 
771 static void hv_timesync_cancel_work(void)
772 {
773 	cancel_work_sync(&adj_time_work);
774 }
775 
776 static int hv_timesync_pre_suspend(void)
777 {
778 	hv_timesync_cancel_work();
779 	return 0;
780 }
781 
782 static void hv_timesync_deinit(void)
783 {
784 	if (hv_ptp_clock)
785 		ptp_clock_unregister(hv_ptp_clock);
786 
787 	hv_timesync_cancel_work();
788 }
789 
790 static int __init init_hyperv_utils(void)
791 {
792 	pr_info("Registering HyperV Utility Driver\n");
793 
794 	return vmbus_driver_register(&util_drv);
795 }
796 
797 static void exit_hyperv_utils(void)
798 {
799 	pr_info("De-Registered HyperV Utility Driver\n");
800 
801 	vmbus_driver_unregister(&util_drv);
802 }
803 
804 module_init(init_hyperv_utils);
805 module_exit(exit_hyperv_utils);
806 
807 MODULE_DESCRIPTION("Hyper-V Utilities");
808 MODULE_LICENSE("GPL");
809