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v6.8
  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
 52static int sd_srv_version;
 53static int ts_srv_version;
 54static int hb_srv_version;
 55
 56#define SD_VER_COUNT 4
 57static 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
 65static const int ts_versions[] = {
 66	TS_VERSION,
 67	TS_VERSION_3,
 68	TS_VERSION_1
 69};
 70
 71#define HB_VER_COUNT 2
 72static const int hb_versions[] = {
 73	HB_VERSION,
 74	HB_VERSION_1
 75};
 76
 77#define FW_VER_COUNT 2
 78static 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 */
 86struct hibernate_work_context {
 87	struct work_struct work;
 88	struct hv_device *dev;
 89};
 90
 91static struct hibernate_work_context hibernate_context;
 92static bool hibernation_supported;
 93
 94static 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
106static 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
118static void shutdown_onchannelcallback(void *context);
119static struct hv_util_service util_shutdown = {
120	.util_cb = shutdown_onchannelcallback,
121	.util_init = hv_shutdown_init,
122};
123
124static int hv_timesync_init(struct hv_util_service *srv);
125static int hv_timesync_pre_suspend(void);
126static void hv_timesync_deinit(void);
127
128static void timesync_onchannelcallback(void *context);
129static 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
136static void heartbeat_onchannelcallback(void *context);
137static struct hv_util_service util_heartbeat = {
138	.util_cb = heartbeat_onchannelcallback,
139};
140
141static 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
149static 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
157static struct hv_util_service util_fcopy = {
158	.util_cb = hv_fcopy_onchannelcallback,
159	.util_init = hv_fcopy_init,
160	.util_pre_suspend = hv_fcopy_pre_suspend,
161	.util_pre_resume = hv_fcopy_pre_resume,
162	.util_deinit = hv_fcopy_deinit,
163};
164
165static void perform_shutdown(struct work_struct *dummy)
166{
167	orderly_poweroff(true);
168}
169
170static void perform_restart(struct work_struct *dummy)
171{
172	orderly_reboot();
173}
174
175/*
176 * Perform the shutdown operation in a thread context.
177 */
178static DECLARE_WORK(shutdown_work, perform_shutdown);
179
180/*
181 * Perform the restart operation in a thread context.
182 */
183static DECLARE_WORK(restart_work, perform_restart);
184
185static void shutdown_onchannelcallback(void *context)
186{
187	struct vmbus_channel *channel = context;
188	struct work_struct *work = NULL;
189	u32 recvlen;
190	u64 requestid;
 
191	u8  *shut_txf_buf = util_shutdown.recv_buffer;
192
193	struct shutdown_msg_data *shutdown_msg;
194
195	struct icmsg_hdr *icmsghdrp;
196
197	if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
198		pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
199		return;
200	}
201
202	if (!recvlen)
203		return;
 
204
205	/* Ensure recvlen is big enough to read header data */
206	if (recvlen < ICMSG_HDR) {
207		pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
208				   recvlen);
209		return;
210	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
211
212	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];
 
 
 
 
 
213
214	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
215		if (vmbus_prep_negotiate_resp(icmsghdrp,
216				shut_txf_buf, recvlen,
217				fw_versions, FW_VER_COUNT,
218				sd_versions, SD_VER_COUNT,
219				NULL, &sd_srv_version)) {
220			pr_info("Shutdown IC version %d.%d\n",
221				sd_srv_version >> 16,
222				sd_srv_version & 0xFFFF);
223		}
224	} else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
225		/* Ensure recvlen is big enough to contain shutdown_msg_data struct */
226		if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
227			pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
228					   recvlen);
229			return;
230		}
231
232		shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
 
233
234		/*
235		 * shutdown_msg->flags can be 0(shut down), 2(reboot),
236		 * or 4(hibernate). It may bitwise-OR 1, which means
237		 * performing the request by force. Linux always tries
238		 * to perform the request by force.
239		 */
240		switch (shutdown_msg->flags) {
241		case 0:
242		case 1:
243			icmsghdrp->status = HV_S_OK;
244			work = &shutdown_work;
245			pr_info("Shutdown request received - graceful shutdown initiated\n");
246			break;
247		case 2:
248		case 3:
249			icmsghdrp->status = HV_S_OK;
250			work = &restart_work;
251			pr_info("Restart request received - graceful restart initiated\n");
252			break;
253		case 4:
254		case 5:
255			pr_info("Hibernation request received\n");
256			icmsghdrp->status = hibernation_supported ?
257				HV_S_OK : HV_E_FAIL;
258			if (hibernation_supported)
259				work = &hibernate_context.work;
260			break;
261		default:
262			icmsghdrp->status = HV_E_FAIL;
263			pr_info("Shutdown request received - Invalid request\n");
264			break;
265		}
266	} else {
267		icmsghdrp->status = HV_E_FAIL;
268		pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
269				   icmsghdrp->icmsgtype);
270	}
271
272	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
273		| ICMSGHDRFLAG_RESPONSE;
274
275	vmbus_sendpacket(channel, shut_txf_buf,
276			 recvlen, requestid,
277			 VM_PKT_DATA_INBAND, 0);
278
279	if (work)
280		schedule_work(work);
281}
282
283/*
284 * Set the host time in a process context.
285 */
286static struct work_struct adj_time_work;
287
288/*
289 * The last time sample, received from the host. PTP device responds to
290 * requests by using this data and the current partition-wide time reference
291 * count.
292 */
293static struct {
294	u64				host_time;
295	u64				ref_time;
296	spinlock_t			lock;
297} host_ts;
298
299static bool timesync_implicit;
300
301module_param(timesync_implicit, bool, 0644);
302MODULE_PARM_DESC(timesync_implicit, "If set treat SAMPLE as SYNC when clock is behind");
303
304static inline u64 reftime_to_ns(u64 reftime)
305{
306	return (reftime - WLTIMEDELTA) * 100;
307}
308
309/*
310 * Hard coded threshold for host timesync delay: 600 seconds
311 */
312static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
313
314static int hv_get_adj_host_time(struct timespec64 *ts)
315{
316	u64 newtime, reftime, timediff_adj;
 
317	unsigned long flags;
318	int ret = 0;
319
320	spin_lock_irqsave(&host_ts.lock, flags);
321	reftime = hv_read_reference_counter();
322
323	/*
324	 * We need to let the caller know that last update from host
325	 * is older than the max allowable threshold. clock_gettime()
326	 * and PTP ioctl do not have a documented error that we could
327	 * return for this specific case. Use ESTALE to report this.
328	 */
329	timediff_adj = reftime - host_ts.ref_time;
330	if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
331		pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
332			     (timediff_adj * 100));
333		ret = -ESTALE;
334	}
335
336	newtime = host_ts.host_time + timediff_adj;
337	*ts = ns_to_timespec64(reftime_to_ns(newtime));
338	spin_unlock_irqrestore(&host_ts.lock, flags);
339
340	return ret;
341}
342
343static void hv_set_host_time(struct work_struct *work)
344{
 
345
346	struct timespec64 ts;
347
348	if (!hv_get_adj_host_time(&ts))
349		do_settimeofday64(&ts);
350}
351
352/*
353 * Due to a bug on Hyper-V hosts, the sync flag may not always be sent on resume.
354 * Force a sync if the guest is behind.
355 */
356static inline bool hv_implicit_sync(u64 host_time)
357{
358	struct timespec64 new_ts;
359	struct timespec64 threshold_ts;
360
361	new_ts = ns_to_timespec64(reftime_to_ns(host_time));
362	ktime_get_real_ts64(&threshold_ts);
363
364	threshold_ts.tv_sec += 5;
365
366	/*
367	 * If guest behind the host by 5 or more seconds.
368	 */
369	if (timespec64_compare(&new_ts, &threshold_ts) >= 0)
370		return true;
371
372	return false;
373}
374
375/*
376 * Synchronize time with host after reboot, restore, etc.
377 *
378 * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
379 * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
380 * message after the timesync channel is opened. Since the hv_utils module is
381 * loaded after hv_vmbus, the first message is usually missed. This bit is
382 * considered a hard request to discipline the clock.
383 *
384 * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
385 * typically used as a hint to the guest. The guest is under no obligation
386 * to discipline the clock.
387 */
388static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
389{
390	unsigned long flags;
391	u64 cur_reftime;
392
393	/*
394	 * Save the adjusted time sample from the host and the snapshot
395	 * of the current system time.
396	 */
397	spin_lock_irqsave(&host_ts.lock, flags);
398
399	cur_reftime = hv_read_reference_counter();
400	host_ts.host_time = hosttime;
401	host_ts.ref_time = cur_reftime;
402
403	/*
404	 * TimeSync v4 messages contain reference time (guest's Hyper-V
405	 * clocksource read when the time sample was generated), we can
406	 * improve the precision by adding the delta between now and the
407	 * time of generation. For older protocols we set
408	 * reftime == cur_reftime on call.
409	 */
410	host_ts.host_time += (cur_reftime - reftime);
411
412	spin_unlock_irqrestore(&host_ts.lock, flags);
413
414	/* Schedule work to do do_settimeofday64() */
415	if ((adj_flags & ICTIMESYNCFLAG_SYNC) ||
416	    (timesync_implicit && hv_implicit_sync(host_ts.host_time)))
417		schedule_work(&adj_time_work);
418}
419
420/*
421 * Time Sync Channel message handler.
422 */
423static void timesync_onchannelcallback(void *context)
424{
425	struct vmbus_channel *channel = context;
426	u32 recvlen;
427	u64 requestid;
428	struct icmsg_hdr *icmsghdrp;
429	struct ictimesync_data *timedatap;
430	struct ictimesync_ref_data *refdata;
431	u8 *time_txf_buf = util_timesynch.recv_buffer;
432
433	/*
434	 * Drain the ring buffer and use the last packet to update
435	 * host_ts
436	 */
437	while (1) {
438		int ret = vmbus_recvpacket(channel, time_txf_buf,
439					   HV_HYP_PAGE_SIZE, &recvlen,
440					   &requestid);
441		if (ret) {
442			pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
443					   ret);
444			break;
445		}
446
447		if (!recvlen)
448			break;
449
450		/* Ensure recvlen is big enough to read header data */
451		if (recvlen < ICMSG_HDR) {
452			pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
453					   recvlen);
454			break;
455		}
456
 
457		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
458				sizeof(struct vmbuspipe_hdr)];
459
460		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
461			if (vmbus_prep_negotiate_resp(icmsghdrp,
462						time_txf_buf, recvlen,
463						fw_versions, FW_VER_COUNT,
464						ts_versions, TS_VER_COUNT,
465						NULL, &ts_srv_version)) {
466				pr_info("TimeSync IC version %d.%d\n",
467					ts_srv_version >> 16,
468					ts_srv_version & 0xFFFF);
469			}
470		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
471			if (ts_srv_version > TS_VERSION_3) {
472				/* Ensure recvlen is big enough to read ictimesync_ref_data */
473				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
474					pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
475							   recvlen);
476					break;
477				}
478				refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
479
480				adj_guesttime(refdata->parenttime,
481						refdata->vmreferencetime,
482						refdata->flags);
483			} else {
484				/* Ensure recvlen is big enough to read ictimesync_data */
485				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
486					pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
487							   recvlen);
488					break;
489				}
490				timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
491
492				adj_guesttime(timedatap->parenttime,
493					      hv_read_reference_counter(),
494					      timedatap->flags);
495			}
496		} else {
497			icmsghdrp->status = HV_E_FAIL;
498			pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
499					   icmsghdrp->icmsgtype);
500		}
501
502		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
503			| ICMSGHDRFLAG_RESPONSE;
504
505		vmbus_sendpacket(channel, time_txf_buf,
506				 recvlen, requestid,
507				 VM_PKT_DATA_INBAND, 0);
508	}
509}
510
511/*
512 * Heartbeat functionality.
513 * Every two seconds, Hyper-V send us a heartbeat request message.
514 * we respond to this message, and Hyper-V knows we are alive.
515 */
516static void heartbeat_onchannelcallback(void *context)
517{
518	struct vmbus_channel *channel = context;
519	u32 recvlen;
520	u64 requestid;
521	struct icmsg_hdr *icmsghdrp;
522	struct heartbeat_msg_data *heartbeat_msg;
523	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
524
525	while (1) {
526
527		if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
528				     &recvlen, &requestid)) {
529			pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
530			return;
531		}
532
533		if (!recvlen)
534			break;
535
536		/* Ensure recvlen is big enough to read header data */
537		if (recvlen < ICMSG_HDR) {
538			pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
539					   recvlen);
540			break;
541		}
542
543		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
544				sizeof(struct vmbuspipe_hdr)];
545
546		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
547			if (vmbus_prep_negotiate_resp(icmsghdrp,
548					hbeat_txf_buf, recvlen,
549					fw_versions, FW_VER_COUNT,
550					hb_versions, HB_VER_COUNT,
551					NULL, &hb_srv_version)) {
552
553				pr_info("Heartbeat IC version %d.%d\n",
554					hb_srv_version >> 16,
555					hb_srv_version & 0xFFFF);
556			}
557		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
558			/*
559			 * Ensure recvlen is big enough to read seq_num. Reserved area is not
560			 * included in the check as the host may not fill it up entirely
561			 */
562			if (recvlen < ICMSG_HDR + sizeof(u64)) {
563				pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
564						   recvlen);
565				break;
566			}
567			heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
568
569			heartbeat_msg->seq_num += 1;
570		} else {
571			icmsghdrp->status = HV_E_FAIL;
572			pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
573					   icmsghdrp->icmsgtype);
574		}
575
576		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
577			| ICMSGHDRFLAG_RESPONSE;
578
579		vmbus_sendpacket(channel, hbeat_txf_buf,
580				 recvlen, requestid,
581				 VM_PKT_DATA_INBAND, 0);
582	}
583}
584
585#define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
586#define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
587
588static int util_probe(struct hv_device *dev,
589			const struct hv_vmbus_device_id *dev_id)
590{
591	struct hv_util_service *srv =
592		(struct hv_util_service *)dev_id->driver_data;
593	int ret;
594
595	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
596	if (!srv->recv_buffer)
597		return -ENOMEM;
598	srv->channel = dev->channel;
599	if (srv->util_init) {
600		ret = srv->util_init(srv);
601		if (ret) {
602			ret = -ENODEV;
603			goto error1;
604		}
605	}
606
607	/*
608	 * The set of services managed by the util driver are not performance
609	 * critical and do not need batched reading. Furthermore, some services
610	 * such as KVP can only handle one message from the host at a time.
611	 * Turn off batched reading for all util drivers before we open the
612	 * channel.
613	 */
614	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
615
616	hv_set_drvdata(dev, srv);
617
618	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
619			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
620			 dev->channel);
621	if (ret)
622		goto error;
623
624	return 0;
625
626error:
627	if (srv->util_deinit)
628		srv->util_deinit();
629error1:
630	kfree(srv->recv_buffer);
631	return ret;
632}
633
634static void util_remove(struct hv_device *dev)
635{
636	struct hv_util_service *srv = hv_get_drvdata(dev);
637
638	if (srv->util_deinit)
639		srv->util_deinit();
640	vmbus_close(dev->channel);
641	kfree(srv->recv_buffer);
642}
643
644/*
645 * When we're in util_suspend(), all the userspace processes have been frozen
646 * (refer to hibernate() -> freeze_processes()). The userspace is thawed only
647 * after the whole resume procedure, including util_resume(), finishes.
648 */
649static int util_suspend(struct hv_device *dev)
650{
651	struct hv_util_service *srv = hv_get_drvdata(dev);
652	int ret = 0;
653
654	if (srv->util_pre_suspend) {
655		ret = srv->util_pre_suspend();
656		if (ret)
657			return ret;
658	}
659
660	vmbus_close(dev->channel);
661
662	return 0;
663}
664
665static int util_resume(struct hv_device *dev)
666{
667	struct hv_util_service *srv = hv_get_drvdata(dev);
668	int ret = 0;
669
670	if (srv->util_pre_resume) {
671		ret = srv->util_pre_resume();
672		if (ret)
673			return ret;
674	}
675
676	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
677			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
678			 dev->channel);
679	return ret;
680}
681
682static const struct hv_vmbus_device_id id_table[] = {
683	/* Shutdown guid */
684	{ HV_SHUTDOWN_GUID,
685	  .driver_data = (unsigned long)&util_shutdown
686	},
687	/* Time synch guid */
688	{ HV_TS_GUID,
689	  .driver_data = (unsigned long)&util_timesynch
690	},
691	/* Heartbeat guid */
692	{ HV_HEART_BEAT_GUID,
693	  .driver_data = (unsigned long)&util_heartbeat
694	},
695	/* KVP guid */
696	{ HV_KVP_GUID,
697	  .driver_data = (unsigned long)&util_kvp
698	},
699	/* VSS GUID */
700	{ HV_VSS_GUID,
701	  .driver_data = (unsigned long)&util_vss
702	},
703	/* File copy GUID */
704	{ HV_FCOPY_GUID,
705	  .driver_data = (unsigned long)&util_fcopy
706	},
707	{ },
708};
709
710MODULE_DEVICE_TABLE(vmbus, id_table);
711
712/* The one and only one */
713static  struct hv_driver util_drv = {
714	.name = "hv_utils",
715	.id_table = id_table,
716	.probe =  util_probe,
717	.remove =  util_remove,
718	.suspend = util_suspend,
719	.resume =  util_resume,
720	.driver = {
721		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
722	},
723};
724
725static int hv_ptp_enable(struct ptp_clock_info *info,
726			 struct ptp_clock_request *request, int on)
727{
728	return -EOPNOTSUPP;
729}
730
731static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
732{
733	return -EOPNOTSUPP;
734}
735
736static int hv_ptp_adjfine(struct ptp_clock_info *ptp, long delta)
737{
738	return -EOPNOTSUPP;
739}
740static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
741{
742	return -EOPNOTSUPP;
743}
744
745static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
746{
747	return hv_get_adj_host_time(ts);
 
 
748}
749
750static struct ptp_clock_info ptp_hyperv_info = {
751	.name		= "hyperv",
752	.enable         = hv_ptp_enable,
753	.adjtime        = hv_ptp_adjtime,
754	.adjfine        = hv_ptp_adjfine,
755	.gettime64      = hv_ptp_gettime,
756	.settime64      = hv_ptp_settime,
757	.owner		= THIS_MODULE,
758};
759
760static struct ptp_clock *hv_ptp_clock;
761
762static int hv_timesync_init(struct hv_util_service *srv)
763{
 
 
 
 
764	spin_lock_init(&host_ts.lock);
765
766	INIT_WORK(&adj_time_work, hv_set_host_time);
767
768	/*
769	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
770	 * disabled but the driver is still useful without the PTP device
771	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
772	 */
773	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
774	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
775		pr_err("cannot register PTP clock: %d\n",
776		       PTR_ERR_OR_ZERO(hv_ptp_clock));
777		hv_ptp_clock = NULL;
778	}
779
780	return 0;
781}
782
783static void hv_timesync_cancel_work(void)
784{
785	cancel_work_sync(&adj_time_work);
786}
787
788static int hv_timesync_pre_suspend(void)
789{
790	hv_timesync_cancel_work();
791	return 0;
792}
793
794static void hv_timesync_deinit(void)
795{
796	if (hv_ptp_clock)
797		ptp_clock_unregister(hv_ptp_clock);
798
799	hv_timesync_cancel_work();
800}
801
802static int __init init_hyperv_utils(void)
803{
804	pr_info("Registering HyperV Utility Driver\n");
805
806	return vmbus_driver_register(&util_drv);
807}
808
809static void exit_hyperv_utils(void)
810{
811	pr_info("De-Registered HyperV Utility Driver\n");
812
813	vmbus_driver_unregister(&util_drv);
814}
815
816module_init(init_hyperv_utils);
817module_exit(exit_hyperv_utils);
818
819MODULE_DESCRIPTION("Hyper-V Utilities");
820MODULE_LICENSE("GPL");
v5.4
  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 <clocksource/hyperv_timer.h>
 21#include <asm/mshyperv.h>
 22
 23#include "hyperv_vmbus.h"
 24
 25#define SD_MAJOR	3
 26#define SD_MINOR	0
 
 
 
 
 27#define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)
 28
 29#define SD_MAJOR_1	1
 30#define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)
 31
 32#define TS_MAJOR	4
 33#define TS_MINOR	0
 34#define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
 35
 36#define TS_MAJOR_1	1
 37#define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)
 38
 39#define TS_MAJOR_3	3
 40#define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)
 41
 42#define HB_MAJOR	3
 43#define HB_MINOR	0
 44#define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
 45
 46#define HB_MAJOR_1	1
 47#define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)
 48
 49static int sd_srv_version;
 50static int ts_srv_version;
 51static int hb_srv_version;
 52
 53#define SD_VER_COUNT 2
 54static const int sd_versions[] = {
 
 
 55	SD_VERSION,
 56	SD_VERSION_1
 57};
 58
 59#define TS_VER_COUNT 3
 60static const int ts_versions[] = {
 61	TS_VERSION,
 62	TS_VERSION_3,
 63	TS_VERSION_1
 64};
 65
 66#define HB_VER_COUNT 2
 67static const int hb_versions[] = {
 68	HB_VERSION,
 69	HB_VERSION_1
 70};
 71
 72#define FW_VER_COUNT 2
 73static const int fw_versions[] = {
 74	UTIL_FW_VERSION,
 75	UTIL_WS2K8_FW_VERSION
 76};
 77
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 78static void shutdown_onchannelcallback(void *context);
 79static struct hv_util_service util_shutdown = {
 80	.util_cb = shutdown_onchannelcallback,
 
 81};
 82
 83static int hv_timesync_init(struct hv_util_service *srv);
 
 84static void hv_timesync_deinit(void);
 85
 86static void timesync_onchannelcallback(void *context);
 87static struct hv_util_service util_timesynch = {
 88	.util_cb = timesync_onchannelcallback,
 89	.util_init = hv_timesync_init,
 
 90	.util_deinit = hv_timesync_deinit,
 91};
 92
 93static void heartbeat_onchannelcallback(void *context);
 94static struct hv_util_service util_heartbeat = {
 95	.util_cb = heartbeat_onchannelcallback,
 96};
 97
 98static struct hv_util_service util_kvp = {
 99	.util_cb = hv_kvp_onchannelcallback,
100	.util_init = hv_kvp_init,
 
 
101	.util_deinit = hv_kvp_deinit,
102};
103
104static struct hv_util_service util_vss = {
105	.util_cb = hv_vss_onchannelcallback,
106	.util_init = hv_vss_init,
 
 
107	.util_deinit = hv_vss_deinit,
108};
109
110static struct hv_util_service util_fcopy = {
111	.util_cb = hv_fcopy_onchannelcallback,
112	.util_init = hv_fcopy_init,
 
 
113	.util_deinit = hv_fcopy_deinit,
114};
115
116static void perform_shutdown(struct work_struct *dummy)
117{
118	orderly_poweroff(true);
119}
120
 
 
 
 
 
121/*
122 * Perform the shutdown operation in a thread context.
123 */
124static DECLARE_WORK(shutdown_work, perform_shutdown);
125
 
 
 
 
 
126static void shutdown_onchannelcallback(void *context)
127{
128	struct vmbus_channel *channel = context;
 
129	u32 recvlen;
130	u64 requestid;
131	bool execute_shutdown = false;
132	u8  *shut_txf_buf = util_shutdown.recv_buffer;
133
134	struct shutdown_msg_data *shutdown_msg;
135
136	struct icmsg_hdr *icmsghdrp;
137
138	vmbus_recvpacket(channel, shut_txf_buf,
139			 PAGE_SIZE, &recvlen, &requestid);
 
 
140
141	if (recvlen > 0) {
142		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
143			sizeof(struct vmbuspipe_hdr)];
144
145		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
146			if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
147					fw_versions, FW_VER_COUNT,
148					sd_versions, SD_VER_COUNT,
149					NULL, &sd_srv_version)) {
150				pr_info("Shutdown IC version %d.%d\n",
151					sd_srv_version >> 16,
152					sd_srv_version & 0xFFFF);
153			}
154		} else {
155			shutdown_msg =
156				(struct shutdown_msg_data *)&shut_txf_buf[
157					sizeof(struct vmbuspipe_hdr) +
158					sizeof(struct icmsg_hdr)];
159
160			switch (shutdown_msg->flags) {
161			case 0:
162			case 1:
163				icmsghdrp->status = HV_S_OK;
164				execute_shutdown = true;
165
166				pr_info("Shutdown request received -"
167					    " graceful shutdown initiated\n");
168				break;
169			default:
170				icmsghdrp->status = HV_E_FAIL;
171				execute_shutdown = false;
172
173				pr_info("Shutdown request received -"
174					    " Invalid request\n");
175				break;
176			}
 
 
 
 
 
 
 
 
 
 
 
 
177		}
178
179		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
180			| ICMSGHDRFLAG_RESPONSE;
181
182		vmbus_sendpacket(channel, shut_txf_buf,
183				       recvlen, requestid,
184				       VM_PKT_DATA_INBAND, 0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
185	}
186
187	if (execute_shutdown == true)
188		schedule_work(&shutdown_work);
 
 
 
 
 
 
 
189}
190
191/*
192 * Set the host time in a process context.
193 */
194static struct work_struct adj_time_work;
195
196/*
197 * The last time sample, received from the host. PTP device responds to
198 * requests by using this data and the current partition-wide time reference
199 * count.
200 */
201static struct {
202	u64				host_time;
203	u64				ref_time;
204	spinlock_t			lock;
205} host_ts;
206
207static struct timespec64 hv_get_adj_host_time(void)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
208{
209	struct timespec64 ts;
210	u64 newtime, reftime;
211	unsigned long flags;
 
212
213	spin_lock_irqsave(&host_ts.lock, flags);
214	reftime = hyperv_cs->read(hyperv_cs);
215	newtime = host_ts.host_time + (reftime - host_ts.ref_time);
216	ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
217	spin_unlock_irqrestore(&host_ts.lock, flags);
218
219	return ts;
220}
221
222static void hv_set_host_time(struct work_struct *work)
223{
224	struct timespec64 ts = hv_get_adj_host_time();
225
226	do_settimeofday64(&ts);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
227}
228
229/*
230 * Synchronize time with host after reboot, restore, etc.
231 *
232 * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
233 * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
234 * message after the timesync channel is opened. Since the hv_utils module is
235 * loaded after hv_vmbus, the first message is usually missed. This bit is
236 * considered a hard request to discipline the clock.
237 *
238 * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
239 * typically used as a hint to the guest. The guest is under no obligation
240 * to discipline the clock.
241 */
242static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
243{
244	unsigned long flags;
245	u64 cur_reftime;
246
247	/*
248	 * Save the adjusted time sample from the host and the snapshot
249	 * of the current system time.
250	 */
251	spin_lock_irqsave(&host_ts.lock, flags);
252
253	cur_reftime = hyperv_cs->read(hyperv_cs);
254	host_ts.host_time = hosttime;
255	host_ts.ref_time = cur_reftime;
256
257	/*
258	 * TimeSync v4 messages contain reference time (guest's Hyper-V
259	 * clocksource read when the time sample was generated), we can
260	 * improve the precision by adding the delta between now and the
261	 * time of generation. For older protocols we set
262	 * reftime == cur_reftime on call.
263	 */
264	host_ts.host_time += (cur_reftime - reftime);
265
266	spin_unlock_irqrestore(&host_ts.lock, flags);
267
268	/* Schedule work to do do_settimeofday64() */
269	if (adj_flags & ICTIMESYNCFLAG_SYNC)
 
270		schedule_work(&adj_time_work);
271}
272
273/*
274 * Time Sync Channel message handler.
275 */
276static void timesync_onchannelcallback(void *context)
277{
278	struct vmbus_channel *channel = context;
279	u32 recvlen;
280	u64 requestid;
281	struct icmsg_hdr *icmsghdrp;
282	struct ictimesync_data *timedatap;
283	struct ictimesync_ref_data *refdata;
284	u8 *time_txf_buf = util_timesynch.recv_buffer;
285
286	vmbus_recvpacket(channel, time_txf_buf,
287			 PAGE_SIZE, &recvlen, &requestid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
288
289	if (recvlen > 0) {
290		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
291				sizeof(struct vmbuspipe_hdr)];
292
293		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
294			if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
 
295						fw_versions, FW_VER_COUNT,
296						ts_versions, TS_VER_COUNT,
297						NULL, &ts_srv_version)) {
298				pr_info("TimeSync IC version %d.%d\n",
299					ts_srv_version >> 16,
300					ts_srv_version & 0xFFFF);
301			}
302		} else {
303			if (ts_srv_version > TS_VERSION_3) {
304				refdata = (struct ictimesync_ref_data *)
305					&time_txf_buf[
306					sizeof(struct vmbuspipe_hdr) +
307					sizeof(struct icmsg_hdr)];
 
 
 
308
309				adj_guesttime(refdata->parenttime,
310						refdata->vmreferencetime,
311						refdata->flags);
312			} else {
313				timedatap = (struct ictimesync_data *)
314					&time_txf_buf[
315					sizeof(struct vmbuspipe_hdr) +
316					sizeof(struct icmsg_hdr)];
 
 
 
 
317				adj_guesttime(timedatap->parenttime,
318					      hyperv_cs->read(hyperv_cs),
319					      timedatap->flags);
320			}
 
 
 
 
321		}
322
323		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
324			| ICMSGHDRFLAG_RESPONSE;
325
326		vmbus_sendpacket(channel, time_txf_buf,
327				recvlen, requestid,
328				VM_PKT_DATA_INBAND, 0);
329	}
330}
331
332/*
333 * Heartbeat functionality.
334 * Every two seconds, Hyper-V send us a heartbeat request message.
335 * we respond to this message, and Hyper-V knows we are alive.
336 */
337static void heartbeat_onchannelcallback(void *context)
338{
339	struct vmbus_channel *channel = context;
340	u32 recvlen;
341	u64 requestid;
342	struct icmsg_hdr *icmsghdrp;
343	struct heartbeat_msg_data *heartbeat_msg;
344	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
345
346	while (1) {
347
348		vmbus_recvpacket(channel, hbeat_txf_buf,
349				 PAGE_SIZE, &recvlen, &requestid);
 
 
 
350
351		if (!recvlen)
352			break;
353
 
 
 
 
 
 
 
354		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
355				sizeof(struct vmbuspipe_hdr)];
356
357		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
358			if (vmbus_prep_negotiate_resp(icmsghdrp,
359					hbeat_txf_buf,
360					fw_versions, FW_VER_COUNT,
361					hb_versions, HB_VER_COUNT,
362					NULL, &hb_srv_version)) {
363
364				pr_info("Heartbeat IC version %d.%d\n",
365					hb_srv_version >> 16,
366					hb_srv_version & 0xFFFF);
367			}
368		} else {
369			heartbeat_msg =
370				(struct heartbeat_msg_data *)&hbeat_txf_buf[
371					sizeof(struct vmbuspipe_hdr) +
372					sizeof(struct icmsg_hdr)];
 
 
 
 
 
 
373
374			heartbeat_msg->seq_num += 1;
 
 
 
 
375		}
376
377		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
378			| ICMSGHDRFLAG_RESPONSE;
379
380		vmbus_sendpacket(channel, hbeat_txf_buf,
381				       recvlen, requestid,
382				       VM_PKT_DATA_INBAND, 0);
383	}
384}
385
 
 
 
386static int util_probe(struct hv_device *dev,
387			const struct hv_vmbus_device_id *dev_id)
388{
389	struct hv_util_service *srv =
390		(struct hv_util_service *)dev_id->driver_data;
391	int ret;
392
393	srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
394	if (!srv->recv_buffer)
395		return -ENOMEM;
396	srv->channel = dev->channel;
397	if (srv->util_init) {
398		ret = srv->util_init(srv);
399		if (ret) {
400			ret = -ENODEV;
401			goto error1;
402		}
403	}
404
405	/*
406	 * The set of services managed by the util driver are not performance
407	 * critical and do not need batched reading. Furthermore, some services
408	 * such as KVP can only handle one message from the host at a time.
409	 * Turn off batched reading for all util drivers before we open the
410	 * channel.
411	 */
412	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
413
414	hv_set_drvdata(dev, srv);
415
416	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
417			srv->util_cb, dev->channel);
 
418	if (ret)
419		goto error;
420
421	return 0;
422
423error:
424	if (srv->util_deinit)
425		srv->util_deinit();
426error1:
427	kfree(srv->recv_buffer);
428	return ret;
429}
430
431static int util_remove(struct hv_device *dev)
432{
433	struct hv_util_service *srv = hv_get_drvdata(dev);
434
435	if (srv->util_deinit)
436		srv->util_deinit();
437	vmbus_close(dev->channel);
438	kfree(srv->recv_buffer);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
439
440	return 0;
441}
442
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
443static const struct hv_vmbus_device_id id_table[] = {
444	/* Shutdown guid */
445	{ HV_SHUTDOWN_GUID,
446	  .driver_data = (unsigned long)&util_shutdown
447	},
448	/* Time synch guid */
449	{ HV_TS_GUID,
450	  .driver_data = (unsigned long)&util_timesynch
451	},
452	/* Heartbeat guid */
453	{ HV_HEART_BEAT_GUID,
454	  .driver_data = (unsigned long)&util_heartbeat
455	},
456	/* KVP guid */
457	{ HV_KVP_GUID,
458	  .driver_data = (unsigned long)&util_kvp
459	},
460	/* VSS GUID */
461	{ HV_VSS_GUID,
462	  .driver_data = (unsigned long)&util_vss
463	},
464	/* File copy GUID */
465	{ HV_FCOPY_GUID,
466	  .driver_data = (unsigned long)&util_fcopy
467	},
468	{ },
469};
470
471MODULE_DEVICE_TABLE(vmbus, id_table);
472
473/* The one and only one */
474static  struct hv_driver util_drv = {
475	.name = "hv_utils",
476	.id_table = id_table,
477	.probe =  util_probe,
478	.remove =  util_remove,
 
 
479	.driver = {
480		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
481	},
482};
483
484static int hv_ptp_enable(struct ptp_clock_info *info,
485			 struct ptp_clock_request *request, int on)
486{
487	return -EOPNOTSUPP;
488}
489
490static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
491{
492	return -EOPNOTSUPP;
493}
494
495static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
496{
497	return -EOPNOTSUPP;
498}
499static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
500{
501	return -EOPNOTSUPP;
502}
503
504static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
505{
506	*ts = hv_get_adj_host_time();
507
508	return 0;
509}
510
511static struct ptp_clock_info ptp_hyperv_info = {
512	.name		= "hyperv",
513	.enable         = hv_ptp_enable,
514	.adjtime        = hv_ptp_adjtime,
515	.adjfreq        = hv_ptp_adjfreq,
516	.gettime64      = hv_ptp_gettime,
517	.settime64      = hv_ptp_settime,
518	.owner		= THIS_MODULE,
519};
520
521static struct ptp_clock *hv_ptp_clock;
522
523static int hv_timesync_init(struct hv_util_service *srv)
524{
525	/* TimeSync requires Hyper-V clocksource. */
526	if (!hyperv_cs)
527		return -ENODEV;
528
529	spin_lock_init(&host_ts.lock);
530
531	INIT_WORK(&adj_time_work, hv_set_host_time);
532
533	/*
534	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
535	 * disabled but the driver is still useful without the PTP device
536	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
537	 */
538	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
539	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
540		pr_err("cannot register PTP clock: %ld\n",
541		       PTR_ERR(hv_ptp_clock));
542		hv_ptp_clock = NULL;
543	}
544
545	return 0;
546}
547
 
 
 
 
 
 
 
 
 
 
 
548static void hv_timesync_deinit(void)
549{
550	if (hv_ptp_clock)
551		ptp_clock_unregister(hv_ptp_clock);
552	cancel_work_sync(&adj_time_work);
 
553}
554
555static int __init init_hyperv_utils(void)
556{
557	pr_info("Registering HyperV Utility Driver\n");
558
559	return vmbus_driver_register(&util_drv);
560}
561
562static void exit_hyperv_utils(void)
563{
564	pr_info("De-Registered HyperV Utility Driver\n");
565
566	vmbus_driver_unregister(&util_drv);
567}
568
569module_init(init_hyperv_utils);
570module_exit(exit_hyperv_utils);
571
572MODULE_DESCRIPTION("Hyper-V Utilities");
573MODULE_LICENSE("GPL");