xref: /linux/drivers/hv/hv_util.c (revision ebf68996de0ab250c5d520eb2291ab65643e9a1e)
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_VERSION	(SD_MAJOR << 16 | SD_MINOR)
27 
28 #define SD_MAJOR_1	1
29 #define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)
30 
31 #define TS_MAJOR	4
32 #define TS_MINOR	0
33 #define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
34 
35 #define TS_MAJOR_1	1
36 #define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)
37 
38 #define TS_MAJOR_3	3
39 #define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)
40 
41 #define HB_MAJOR	3
42 #define HB_MINOR	0
43 #define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
44 
45 #define HB_MAJOR_1	1
46 #define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)
47 
48 static int sd_srv_version;
49 static int ts_srv_version;
50 static int hb_srv_version;
51 
52 #define SD_VER_COUNT 2
53 static const int sd_versions[] = {
54 	SD_VERSION,
55 	SD_VERSION_1
56 };
57 
58 #define TS_VER_COUNT 3
59 static const int ts_versions[] = {
60 	TS_VERSION,
61 	TS_VERSION_3,
62 	TS_VERSION_1
63 };
64 
65 #define HB_VER_COUNT 2
66 static const int hb_versions[] = {
67 	HB_VERSION,
68 	HB_VERSION_1
69 };
70 
71 #define FW_VER_COUNT 2
72 static const int fw_versions[] = {
73 	UTIL_FW_VERSION,
74 	UTIL_WS2K8_FW_VERSION
75 };
76 
77 static void shutdown_onchannelcallback(void *context);
78 static struct hv_util_service util_shutdown = {
79 	.util_cb = shutdown_onchannelcallback,
80 };
81 
82 static int hv_timesync_init(struct hv_util_service *srv);
83 static void hv_timesync_deinit(void);
84 
85 static void timesync_onchannelcallback(void *context);
86 static struct hv_util_service util_timesynch = {
87 	.util_cb = timesync_onchannelcallback,
88 	.util_init = hv_timesync_init,
89 	.util_deinit = hv_timesync_deinit,
90 };
91 
92 static void heartbeat_onchannelcallback(void *context);
93 static struct hv_util_service util_heartbeat = {
94 	.util_cb = heartbeat_onchannelcallback,
95 };
96 
97 static struct hv_util_service util_kvp = {
98 	.util_cb = hv_kvp_onchannelcallback,
99 	.util_init = hv_kvp_init,
100 	.util_deinit = hv_kvp_deinit,
101 };
102 
103 static struct hv_util_service util_vss = {
104 	.util_cb = hv_vss_onchannelcallback,
105 	.util_init = hv_vss_init,
106 	.util_deinit = hv_vss_deinit,
107 };
108 
109 static struct hv_util_service util_fcopy = {
110 	.util_cb = hv_fcopy_onchannelcallback,
111 	.util_init = hv_fcopy_init,
112 	.util_deinit = hv_fcopy_deinit,
113 };
114 
115 static void perform_shutdown(struct work_struct *dummy)
116 {
117 	orderly_poweroff(true);
118 }
119 
120 /*
121  * Perform the shutdown operation in a thread context.
122  */
123 static DECLARE_WORK(shutdown_work, perform_shutdown);
124 
125 static void shutdown_onchannelcallback(void *context)
126 {
127 	struct vmbus_channel *channel = context;
128 	u32 recvlen;
129 	u64 requestid;
130 	bool execute_shutdown = false;
131 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
132 
133 	struct shutdown_msg_data *shutdown_msg;
134 
135 	struct icmsg_hdr *icmsghdrp;
136 
137 	vmbus_recvpacket(channel, shut_txf_buf,
138 			 PAGE_SIZE, &recvlen, &requestid);
139 
140 	if (recvlen > 0) {
141 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
142 			sizeof(struct vmbuspipe_hdr)];
143 
144 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
145 			if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
146 					fw_versions, FW_VER_COUNT,
147 					sd_versions, SD_VER_COUNT,
148 					NULL, &sd_srv_version)) {
149 				pr_info("Shutdown IC version %d.%d\n",
150 					sd_srv_version >> 16,
151 					sd_srv_version & 0xFFFF);
152 			}
153 		} else {
154 			shutdown_msg =
155 				(struct shutdown_msg_data *)&shut_txf_buf[
156 					sizeof(struct vmbuspipe_hdr) +
157 					sizeof(struct icmsg_hdr)];
158 
159 			switch (shutdown_msg->flags) {
160 			case 0:
161 			case 1:
162 				icmsghdrp->status = HV_S_OK;
163 				execute_shutdown = true;
164 
165 				pr_info("Shutdown request received -"
166 					    " graceful shutdown initiated\n");
167 				break;
168 			default:
169 				icmsghdrp->status = HV_E_FAIL;
170 				execute_shutdown = false;
171 
172 				pr_info("Shutdown request received -"
173 					    " Invalid request\n");
174 				break;
175 			}
176 		}
177 
178 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
179 			| ICMSGHDRFLAG_RESPONSE;
180 
181 		vmbus_sendpacket(channel, shut_txf_buf,
182 				       recvlen, requestid,
183 				       VM_PKT_DATA_INBAND, 0);
184 	}
185 
186 	if (execute_shutdown == true)
187 		schedule_work(&shutdown_work);
188 }
189 
190 /*
191  * Set the host time in a process context.
192  */
193 static struct work_struct adj_time_work;
194 
195 /*
196  * The last time sample, received from the host. PTP device responds to
197  * requests by using this data and the current partition-wide time reference
198  * count.
199  */
200 static struct {
201 	u64				host_time;
202 	u64				ref_time;
203 	spinlock_t			lock;
204 } host_ts;
205 
206 static struct timespec64 hv_get_adj_host_time(void)
207 {
208 	struct timespec64 ts;
209 	u64 newtime, reftime;
210 	unsigned long flags;
211 
212 	spin_lock_irqsave(&host_ts.lock, flags);
213 	reftime = hyperv_cs->read(hyperv_cs);
214 	newtime = host_ts.host_time + (reftime - host_ts.ref_time);
215 	ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
216 	spin_unlock_irqrestore(&host_ts.lock, flags);
217 
218 	return ts;
219 }
220 
221 static void hv_set_host_time(struct work_struct *work)
222 {
223 	struct timespec64 ts = hv_get_adj_host_time();
224 
225 	do_settimeofday64(&ts);
226 }
227 
228 /*
229  * Synchronize time with host after reboot, restore, etc.
230  *
231  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
232  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
233  * message after the timesync channel is opened. Since the hv_utils module is
234  * loaded after hv_vmbus, the first message is usually missed. This bit is
235  * considered a hard request to discipline the clock.
236  *
237  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
238  * typically used as a hint to the guest. The guest is under no obligation
239  * to discipline the clock.
240  */
241 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
242 {
243 	unsigned long flags;
244 	u64 cur_reftime;
245 
246 	/*
247 	 * Save the adjusted time sample from the host and the snapshot
248 	 * of the current system time.
249 	 */
250 	spin_lock_irqsave(&host_ts.lock, flags);
251 
252 	cur_reftime = hyperv_cs->read(hyperv_cs);
253 	host_ts.host_time = hosttime;
254 	host_ts.ref_time = cur_reftime;
255 
256 	/*
257 	 * TimeSync v4 messages contain reference time (guest's Hyper-V
258 	 * clocksource read when the time sample was generated), we can
259 	 * improve the precision by adding the delta between now and the
260 	 * time of generation. For older protocols we set
261 	 * reftime == cur_reftime on call.
262 	 */
263 	host_ts.host_time += (cur_reftime - reftime);
264 
265 	spin_unlock_irqrestore(&host_ts.lock, flags);
266 
267 	/* Schedule work to do do_settimeofday64() */
268 	if (adj_flags & ICTIMESYNCFLAG_SYNC)
269 		schedule_work(&adj_time_work);
270 }
271 
272 /*
273  * Time Sync Channel message handler.
274  */
275 static void timesync_onchannelcallback(void *context)
276 {
277 	struct vmbus_channel *channel = context;
278 	u32 recvlen;
279 	u64 requestid;
280 	struct icmsg_hdr *icmsghdrp;
281 	struct ictimesync_data *timedatap;
282 	struct ictimesync_ref_data *refdata;
283 	u8 *time_txf_buf = util_timesynch.recv_buffer;
284 
285 	vmbus_recvpacket(channel, time_txf_buf,
286 			 PAGE_SIZE, &recvlen, &requestid);
287 
288 	if (recvlen > 0) {
289 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
290 				sizeof(struct vmbuspipe_hdr)];
291 
292 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
293 			if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
294 						fw_versions, FW_VER_COUNT,
295 						ts_versions, TS_VER_COUNT,
296 						NULL, &ts_srv_version)) {
297 				pr_info("TimeSync IC version %d.%d\n",
298 					ts_srv_version >> 16,
299 					ts_srv_version & 0xFFFF);
300 			}
301 		} else {
302 			if (ts_srv_version > TS_VERSION_3) {
303 				refdata = (struct ictimesync_ref_data *)
304 					&time_txf_buf[
305 					sizeof(struct vmbuspipe_hdr) +
306 					sizeof(struct icmsg_hdr)];
307 
308 				adj_guesttime(refdata->parenttime,
309 						refdata->vmreferencetime,
310 						refdata->flags);
311 			} else {
312 				timedatap = (struct ictimesync_data *)
313 					&time_txf_buf[
314 					sizeof(struct vmbuspipe_hdr) +
315 					sizeof(struct icmsg_hdr)];
316 				adj_guesttime(timedatap->parenttime,
317 					      hyperv_cs->read(hyperv_cs),
318 					      timedatap->flags);
319 			}
320 		}
321 
322 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
323 			| ICMSGHDRFLAG_RESPONSE;
324 
325 		vmbus_sendpacket(channel, time_txf_buf,
326 				recvlen, requestid,
327 				VM_PKT_DATA_INBAND, 0);
328 	}
329 }
330 
331 /*
332  * Heartbeat functionality.
333  * Every two seconds, Hyper-V send us a heartbeat request message.
334  * we respond to this message, and Hyper-V knows we are alive.
335  */
336 static void heartbeat_onchannelcallback(void *context)
337 {
338 	struct vmbus_channel *channel = context;
339 	u32 recvlen;
340 	u64 requestid;
341 	struct icmsg_hdr *icmsghdrp;
342 	struct heartbeat_msg_data *heartbeat_msg;
343 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
344 
345 	while (1) {
346 
347 		vmbus_recvpacket(channel, hbeat_txf_buf,
348 				 PAGE_SIZE, &recvlen, &requestid);
349 
350 		if (!recvlen)
351 			break;
352 
353 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
354 				sizeof(struct vmbuspipe_hdr)];
355 
356 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
357 			if (vmbus_prep_negotiate_resp(icmsghdrp,
358 					hbeat_txf_buf,
359 					fw_versions, FW_VER_COUNT,
360 					hb_versions, HB_VER_COUNT,
361 					NULL, &hb_srv_version)) {
362 
363 				pr_info("Heartbeat IC version %d.%d\n",
364 					hb_srv_version >> 16,
365 					hb_srv_version & 0xFFFF);
366 			}
367 		} else {
368 			heartbeat_msg =
369 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
370 					sizeof(struct vmbuspipe_hdr) +
371 					sizeof(struct icmsg_hdr)];
372 
373 			heartbeat_msg->seq_num += 1;
374 		}
375 
376 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
377 			| ICMSGHDRFLAG_RESPONSE;
378 
379 		vmbus_sendpacket(channel, hbeat_txf_buf,
380 				       recvlen, requestid,
381 				       VM_PKT_DATA_INBAND, 0);
382 	}
383 }
384 
385 static int util_probe(struct hv_device *dev,
386 			const struct hv_vmbus_device_id *dev_id)
387 {
388 	struct hv_util_service *srv =
389 		(struct hv_util_service *)dev_id->driver_data;
390 	int ret;
391 
392 	srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
393 	if (!srv->recv_buffer)
394 		return -ENOMEM;
395 	srv->channel = dev->channel;
396 	if (srv->util_init) {
397 		ret = srv->util_init(srv);
398 		if (ret) {
399 			ret = -ENODEV;
400 			goto error1;
401 		}
402 	}
403 
404 	/*
405 	 * The set of services managed by the util driver are not performance
406 	 * critical and do not need batched reading. Furthermore, some services
407 	 * such as KVP can only handle one message from the host at a time.
408 	 * Turn off batched reading for all util drivers before we open the
409 	 * channel.
410 	 */
411 	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
412 
413 	hv_set_drvdata(dev, srv);
414 
415 	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
416 			srv->util_cb, dev->channel);
417 	if (ret)
418 		goto error;
419 
420 	return 0;
421 
422 error:
423 	if (srv->util_deinit)
424 		srv->util_deinit();
425 error1:
426 	kfree(srv->recv_buffer);
427 	return ret;
428 }
429 
430 static int util_remove(struct hv_device *dev)
431 {
432 	struct hv_util_service *srv = hv_get_drvdata(dev);
433 
434 	if (srv->util_deinit)
435 		srv->util_deinit();
436 	vmbus_close(dev->channel);
437 	kfree(srv->recv_buffer);
438 
439 	return 0;
440 }
441 
442 static const struct hv_vmbus_device_id id_table[] = {
443 	/* Shutdown guid */
444 	{ HV_SHUTDOWN_GUID,
445 	  .driver_data = (unsigned long)&util_shutdown
446 	},
447 	/* Time synch guid */
448 	{ HV_TS_GUID,
449 	  .driver_data = (unsigned long)&util_timesynch
450 	},
451 	/* Heartbeat guid */
452 	{ HV_HEART_BEAT_GUID,
453 	  .driver_data = (unsigned long)&util_heartbeat
454 	},
455 	/* KVP guid */
456 	{ HV_KVP_GUID,
457 	  .driver_data = (unsigned long)&util_kvp
458 	},
459 	/* VSS GUID */
460 	{ HV_VSS_GUID,
461 	  .driver_data = (unsigned long)&util_vss
462 	},
463 	/* File copy GUID */
464 	{ HV_FCOPY_GUID,
465 	  .driver_data = (unsigned long)&util_fcopy
466 	},
467 	{ },
468 };
469 
470 MODULE_DEVICE_TABLE(vmbus, id_table);
471 
472 /* The one and only one */
473 static  struct hv_driver util_drv = {
474 	.name = "hv_utils",
475 	.id_table = id_table,
476 	.probe =  util_probe,
477 	.remove =  util_remove,
478 	.driver = {
479 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
480 	},
481 };
482 
483 static int hv_ptp_enable(struct ptp_clock_info *info,
484 			 struct ptp_clock_request *request, int on)
485 {
486 	return -EOPNOTSUPP;
487 }
488 
489 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
490 {
491 	return -EOPNOTSUPP;
492 }
493 
494 static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
495 {
496 	return -EOPNOTSUPP;
497 }
498 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
499 {
500 	return -EOPNOTSUPP;
501 }
502 
503 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
504 {
505 	*ts = hv_get_adj_host_time();
506 
507 	return 0;
508 }
509 
510 static struct ptp_clock_info ptp_hyperv_info = {
511 	.name		= "hyperv",
512 	.enable         = hv_ptp_enable,
513 	.adjtime        = hv_ptp_adjtime,
514 	.adjfreq        = hv_ptp_adjfreq,
515 	.gettime64      = hv_ptp_gettime,
516 	.settime64      = hv_ptp_settime,
517 	.owner		= THIS_MODULE,
518 };
519 
520 static struct ptp_clock *hv_ptp_clock;
521 
522 static int hv_timesync_init(struct hv_util_service *srv)
523 {
524 	/* TimeSync requires Hyper-V clocksource. */
525 	if (!hyperv_cs)
526 		return -ENODEV;
527 
528 	spin_lock_init(&host_ts.lock);
529 
530 	INIT_WORK(&adj_time_work, hv_set_host_time);
531 
532 	/*
533 	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
534 	 * disabled but the driver is still useful without the PTP device
535 	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
536 	 */
537 	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
538 	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
539 		pr_err("cannot register PTP clock: %ld\n",
540 		       PTR_ERR(hv_ptp_clock));
541 		hv_ptp_clock = NULL;
542 	}
543 
544 	return 0;
545 }
546 
547 static void hv_timesync_deinit(void)
548 {
549 	if (hv_ptp_clock)
550 		ptp_clock_unregister(hv_ptp_clock);
551 	cancel_work_sync(&adj_time_work);
552 }
553 
554 static int __init init_hyperv_utils(void)
555 {
556 	pr_info("Registering HyperV Utility Driver\n");
557 
558 	return vmbus_driver_register(&util_drv);
559 }
560 
561 static void exit_hyperv_utils(void)
562 {
563 	pr_info("De-Registered HyperV Utility Driver\n");
564 
565 	vmbus_driver_unregister(&util_drv);
566 }
567 
568 module_init(init_hyperv_utils);
569 module_exit(exit_hyperv_utils);
570 
571 MODULE_DESCRIPTION("Hyper-V Utilities");
572 MODULE_LICENSE("GPL");
573