xref: /openbmc/linux/drivers/hv/hv_util.c (revision b34081f1)
1 /*
2  * Copyright (c) 2010, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  */
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/kernel.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <linux/sysctl.h>
28 #include <linux/reboot.h>
29 #include <linux/hyperv.h>
30 
31 #define SHUTDOWN_MAJOR	3
32 #define SHUTDOWN_MINOR  0
33 #define SHUTDOWN_MAJOR_MINOR	(SHUTDOWN_MAJOR << 16 | SHUTDOWN_MINOR)
34 
35 #define TIMESYNCH_MAJOR	3
36 #define TIMESYNCH_MINOR 0
37 #define TIMESYNCH_MAJOR_MINOR	(TIMESYNCH_MAJOR << 16 | TIMESYNCH_MINOR)
38 
39 #define HEARTBEAT_MAJOR	3
40 #define HEARTBEAT_MINOR 0
41 #define HEARTBEAT_MAJOR_MINOR	(HEARTBEAT_MAJOR << 16 | HEARTBEAT_MINOR)
42 
43 static void shutdown_onchannelcallback(void *context);
44 static struct hv_util_service util_shutdown = {
45 	.util_cb = shutdown_onchannelcallback,
46 };
47 
48 static void timesync_onchannelcallback(void *context);
49 static struct hv_util_service util_timesynch = {
50 	.util_cb = timesync_onchannelcallback,
51 };
52 
53 static void heartbeat_onchannelcallback(void *context);
54 static struct hv_util_service util_heartbeat = {
55 	.util_cb = heartbeat_onchannelcallback,
56 };
57 
58 static struct hv_util_service util_kvp = {
59 	.util_cb = hv_kvp_onchannelcallback,
60 	.util_init = hv_kvp_init,
61 	.util_deinit = hv_kvp_deinit,
62 };
63 
64 static struct hv_util_service util_vss = {
65 	.util_cb = hv_vss_onchannelcallback,
66 	.util_init = hv_vss_init,
67 	.util_deinit = hv_vss_deinit,
68 };
69 
70 static void perform_shutdown(struct work_struct *dummy)
71 {
72 	orderly_poweroff(true);
73 }
74 
75 /*
76  * Perform the shutdown operation in a thread context.
77  */
78 static DECLARE_WORK(shutdown_work, perform_shutdown);
79 
80 static void shutdown_onchannelcallback(void *context)
81 {
82 	struct vmbus_channel *channel = context;
83 	u32 recvlen;
84 	u64 requestid;
85 	u8  execute_shutdown = false;
86 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
87 
88 	struct shutdown_msg_data *shutdown_msg;
89 
90 	struct icmsg_hdr *icmsghdrp;
91 	struct icmsg_negotiate *negop = NULL;
92 
93 	vmbus_recvpacket(channel, shut_txf_buf,
94 			 PAGE_SIZE, &recvlen, &requestid);
95 
96 	if (recvlen > 0) {
97 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
98 			sizeof(struct vmbuspipe_hdr)];
99 
100 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
101 			vmbus_prep_negotiate_resp(icmsghdrp, negop,
102 					shut_txf_buf, UTIL_FW_MAJOR_MINOR,
103 					SHUTDOWN_MAJOR_MINOR);
104 		} else {
105 			shutdown_msg =
106 				(struct shutdown_msg_data *)&shut_txf_buf[
107 					sizeof(struct vmbuspipe_hdr) +
108 					sizeof(struct icmsg_hdr)];
109 
110 			switch (shutdown_msg->flags) {
111 			case 0:
112 			case 1:
113 				icmsghdrp->status = HV_S_OK;
114 				execute_shutdown = true;
115 
116 				pr_info("Shutdown request received -"
117 					    " graceful shutdown initiated\n");
118 				break;
119 			default:
120 				icmsghdrp->status = HV_E_FAIL;
121 				execute_shutdown = false;
122 
123 				pr_info("Shutdown request received -"
124 					    " Invalid request\n");
125 				break;
126 			}
127 		}
128 
129 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
130 			| ICMSGHDRFLAG_RESPONSE;
131 
132 		vmbus_sendpacket(channel, shut_txf_buf,
133 				       recvlen, requestid,
134 				       VM_PKT_DATA_INBAND, 0);
135 	}
136 
137 	if (execute_shutdown == true)
138 		schedule_work(&shutdown_work);
139 }
140 
141 /*
142  * Set guest time to host UTC time.
143  */
144 static inline void do_adj_guesttime(u64 hosttime)
145 {
146 	s64 host_tns;
147 	struct timespec host_ts;
148 
149 	host_tns = (hosttime - WLTIMEDELTA) * 100;
150 	host_ts = ns_to_timespec(host_tns);
151 
152 	do_settimeofday(&host_ts);
153 }
154 
155 /*
156  * Set the host time in a process context.
157  */
158 
159 struct adj_time_work {
160 	struct work_struct work;
161 	u64	host_time;
162 };
163 
164 static void hv_set_host_time(struct work_struct *work)
165 {
166 	struct adj_time_work	*wrk;
167 
168 	wrk = container_of(work, struct adj_time_work, work);
169 	do_adj_guesttime(wrk->host_time);
170 	kfree(wrk);
171 }
172 
173 /*
174  * Synchronize time with host after reboot, restore, etc.
175  *
176  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
177  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
178  * message after the timesync channel is opened. Since the hv_utils module is
179  * loaded after hv_vmbus, the first message is usually missed. The other
180  * thing is, systime is automatically set to emulated hardware clock which may
181  * not be UTC time or in the same time zone. So, to override these effects, we
182  * use the first 50 time samples for initial system time setting.
183  */
184 static inline void adj_guesttime(u64 hosttime, u8 flags)
185 {
186 	struct adj_time_work    *wrk;
187 	static s32 scnt = 50;
188 
189 	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
190 	if (wrk == NULL)
191 		return;
192 
193 	wrk->host_time = hosttime;
194 	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
195 		INIT_WORK(&wrk->work, hv_set_host_time);
196 		schedule_work(&wrk->work);
197 		return;
198 	}
199 
200 	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
201 		scnt--;
202 		INIT_WORK(&wrk->work, hv_set_host_time);
203 		schedule_work(&wrk->work);
204 	} else
205 		kfree(wrk);
206 }
207 
208 /*
209  * Time Sync Channel message handler.
210  */
211 static void timesync_onchannelcallback(void *context)
212 {
213 	struct vmbus_channel *channel = context;
214 	u32 recvlen;
215 	u64 requestid;
216 	struct icmsg_hdr *icmsghdrp;
217 	struct ictimesync_data *timedatap;
218 	u8 *time_txf_buf = util_timesynch.recv_buffer;
219 
220 	vmbus_recvpacket(channel, time_txf_buf,
221 			 PAGE_SIZE, &recvlen, &requestid);
222 
223 	if (recvlen > 0) {
224 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
225 				sizeof(struct vmbuspipe_hdr)];
226 
227 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
228 			vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
229 						UTIL_FW_MAJOR_MINOR,
230 						TIMESYNCH_MAJOR_MINOR);
231 		} else {
232 			timedatap = (struct ictimesync_data *)&time_txf_buf[
233 				sizeof(struct vmbuspipe_hdr) +
234 				sizeof(struct icmsg_hdr)];
235 			adj_guesttime(timedatap->parenttime, timedatap->flags);
236 		}
237 
238 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
239 			| ICMSGHDRFLAG_RESPONSE;
240 
241 		vmbus_sendpacket(channel, time_txf_buf,
242 				recvlen, requestid,
243 				VM_PKT_DATA_INBAND, 0);
244 	}
245 }
246 
247 /*
248  * Heartbeat functionality.
249  * Every two seconds, Hyper-V send us a heartbeat request message.
250  * we respond to this message, and Hyper-V knows we are alive.
251  */
252 static void heartbeat_onchannelcallback(void *context)
253 {
254 	struct vmbus_channel *channel = context;
255 	u32 recvlen;
256 	u64 requestid;
257 	struct icmsg_hdr *icmsghdrp;
258 	struct heartbeat_msg_data *heartbeat_msg;
259 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
260 
261 	vmbus_recvpacket(channel, hbeat_txf_buf,
262 			 PAGE_SIZE, &recvlen, &requestid);
263 
264 	if (recvlen > 0) {
265 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
266 				sizeof(struct vmbuspipe_hdr)];
267 
268 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
269 			vmbus_prep_negotiate_resp(icmsghdrp, NULL,
270 				hbeat_txf_buf, UTIL_FW_MAJOR_MINOR,
271 				HEARTBEAT_MAJOR_MINOR);
272 		} else {
273 			heartbeat_msg =
274 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
275 					sizeof(struct vmbuspipe_hdr) +
276 					sizeof(struct icmsg_hdr)];
277 
278 			heartbeat_msg->seq_num += 1;
279 		}
280 
281 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
282 			| ICMSGHDRFLAG_RESPONSE;
283 
284 		vmbus_sendpacket(channel, hbeat_txf_buf,
285 				       recvlen, requestid,
286 				       VM_PKT_DATA_INBAND, 0);
287 	}
288 }
289 
290 static int util_probe(struct hv_device *dev,
291 			const struct hv_vmbus_device_id *dev_id)
292 {
293 	struct hv_util_service *srv =
294 		(struct hv_util_service *)dev_id->driver_data;
295 	int ret;
296 
297 	srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
298 	if (!srv->recv_buffer)
299 		return -ENOMEM;
300 	if (srv->util_init) {
301 		ret = srv->util_init(srv);
302 		if (ret) {
303 			ret = -ENODEV;
304 			goto error1;
305 		}
306 	}
307 
308 	/*
309 	 * The set of services managed by the util driver are not performance
310 	 * critical and do not need batched reading. Furthermore, some services
311 	 * such as KVP can only handle one message from the host at a time.
312 	 * Turn off batched reading for all util drivers before we open the
313 	 * channel.
314 	 */
315 
316 	set_channel_read_state(dev->channel, false);
317 
318 	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
319 			srv->util_cb, dev->channel);
320 	if (ret)
321 		goto error;
322 
323 	hv_set_drvdata(dev, srv);
324 	return 0;
325 
326 error:
327 	if (srv->util_deinit)
328 		srv->util_deinit();
329 error1:
330 	kfree(srv->recv_buffer);
331 	return ret;
332 }
333 
334 static int util_remove(struct hv_device *dev)
335 {
336 	struct hv_util_service *srv = hv_get_drvdata(dev);
337 
338 	vmbus_close(dev->channel);
339 	if (srv->util_deinit)
340 		srv->util_deinit();
341 	kfree(srv->recv_buffer);
342 
343 	return 0;
344 }
345 
346 static const struct hv_vmbus_device_id id_table[] = {
347 	/* Shutdown guid */
348 	{ HV_SHUTDOWN_GUID,
349 	  .driver_data = (unsigned long)&util_shutdown
350 	},
351 	/* Time synch guid */
352 	{ HV_TS_GUID,
353 	  .driver_data = (unsigned long)&util_timesynch
354 	},
355 	/* Heartbeat guid */
356 	{ HV_HEART_BEAT_GUID,
357 	  .driver_data = (unsigned long)&util_heartbeat
358 	},
359 	/* KVP guid */
360 	{ HV_KVP_GUID,
361 	  .driver_data = (unsigned long)&util_kvp
362 	},
363 	/* VSS GUID */
364 	{ HV_VSS_GUID,
365 	  .driver_data = (unsigned long)&util_vss
366 	},
367 	{ },
368 };
369 
370 MODULE_DEVICE_TABLE(vmbus, id_table);
371 
372 /* The one and only one */
373 static  struct hv_driver util_drv = {
374 	.name = "hv_util",
375 	.id_table = id_table,
376 	.probe =  util_probe,
377 	.remove =  util_remove,
378 };
379 
380 static int __init init_hyperv_utils(void)
381 {
382 	pr_info("Registering HyperV Utility Driver\n");
383 
384 	return vmbus_driver_register(&util_drv);
385 }
386 
387 static void exit_hyperv_utils(void)
388 {
389 	pr_info("De-Registered HyperV Utility Driver\n");
390 
391 	vmbus_driver_unregister(&util_drv);
392 }
393 
394 module_init(init_hyperv_utils);
395 module_exit(exit_hyperv_utils);
396 
397 MODULE_DESCRIPTION("Hyper-V Utilities");
398 MODULE_LICENSE("GPL");
399