xref: /openbmc/linux/drivers/hv/hv_util.c (revision 97da55fc)
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 static void shutdown_onchannelcallback(void *context);
32 static struct hv_util_service util_shutdown = {
33 	.util_cb = shutdown_onchannelcallback,
34 };
35 
36 static void timesync_onchannelcallback(void *context);
37 static struct hv_util_service util_timesynch = {
38 	.util_cb = timesync_onchannelcallback,
39 };
40 
41 static void heartbeat_onchannelcallback(void *context);
42 static struct hv_util_service util_heartbeat = {
43 	.util_cb = heartbeat_onchannelcallback,
44 };
45 
46 static struct hv_util_service util_kvp = {
47 	.util_cb = hv_kvp_onchannelcallback,
48 	.util_init = hv_kvp_init,
49 	.util_deinit = hv_kvp_deinit,
50 };
51 
52 static void perform_shutdown(struct work_struct *dummy)
53 {
54 	orderly_poweroff(true);
55 }
56 
57 /*
58  * Perform the shutdown operation in a thread context.
59  */
60 static DECLARE_WORK(shutdown_work, perform_shutdown);
61 
62 static void shutdown_onchannelcallback(void *context)
63 {
64 	struct vmbus_channel *channel = context;
65 	u32 recvlen;
66 	u64 requestid;
67 	u8  execute_shutdown = false;
68 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
69 
70 	struct shutdown_msg_data *shutdown_msg;
71 
72 	struct icmsg_hdr *icmsghdrp;
73 	struct icmsg_negotiate *negop = NULL;
74 
75 	vmbus_recvpacket(channel, shut_txf_buf,
76 			 PAGE_SIZE, &recvlen, &requestid);
77 
78 	if (recvlen > 0) {
79 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
80 			sizeof(struct vmbuspipe_hdr)];
81 
82 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
83 			vmbus_prep_negotiate_resp(icmsghdrp, negop,
84 					shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
85 		} else {
86 			shutdown_msg =
87 				(struct shutdown_msg_data *)&shut_txf_buf[
88 					sizeof(struct vmbuspipe_hdr) +
89 					sizeof(struct icmsg_hdr)];
90 
91 			switch (shutdown_msg->flags) {
92 			case 0:
93 			case 1:
94 				icmsghdrp->status = HV_S_OK;
95 				execute_shutdown = true;
96 
97 				pr_info("Shutdown request received -"
98 					    " graceful shutdown initiated\n");
99 				break;
100 			default:
101 				icmsghdrp->status = HV_E_FAIL;
102 				execute_shutdown = false;
103 
104 				pr_info("Shutdown request received -"
105 					    " Invalid request\n");
106 				break;
107 			}
108 		}
109 
110 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
111 			| ICMSGHDRFLAG_RESPONSE;
112 
113 		vmbus_sendpacket(channel, shut_txf_buf,
114 				       recvlen, requestid,
115 				       VM_PKT_DATA_INBAND, 0);
116 	}
117 
118 	if (execute_shutdown == true)
119 		schedule_work(&shutdown_work);
120 }
121 
122 /*
123  * Set guest time to host UTC time.
124  */
125 static inline void do_adj_guesttime(u64 hosttime)
126 {
127 	s64 host_tns;
128 	struct timespec host_ts;
129 
130 	host_tns = (hosttime - WLTIMEDELTA) * 100;
131 	host_ts = ns_to_timespec(host_tns);
132 
133 	do_settimeofday(&host_ts);
134 }
135 
136 /*
137  * Set the host time in a process context.
138  */
139 
140 struct adj_time_work {
141 	struct work_struct work;
142 	u64	host_time;
143 };
144 
145 static void hv_set_host_time(struct work_struct *work)
146 {
147 	struct adj_time_work	*wrk;
148 
149 	wrk = container_of(work, struct adj_time_work, work);
150 	do_adj_guesttime(wrk->host_time);
151 	kfree(wrk);
152 }
153 
154 /*
155  * Synchronize time with host after reboot, restore, etc.
156  *
157  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
158  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
159  * message after the timesync channel is opened. Since the hv_utils module is
160  * loaded after hv_vmbus, the first message is usually missed. The other
161  * thing is, systime is automatically set to emulated hardware clock which may
162  * not be UTC time or in the same time zone. So, to override these effects, we
163  * use the first 50 time samples for initial system time setting.
164  */
165 static inline void adj_guesttime(u64 hosttime, u8 flags)
166 {
167 	struct adj_time_work    *wrk;
168 	static s32 scnt = 50;
169 
170 	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
171 	if (wrk == NULL)
172 		return;
173 
174 	wrk->host_time = hosttime;
175 	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
176 		INIT_WORK(&wrk->work, hv_set_host_time);
177 		schedule_work(&wrk->work);
178 		return;
179 	}
180 
181 	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
182 		scnt--;
183 		INIT_WORK(&wrk->work, hv_set_host_time);
184 		schedule_work(&wrk->work);
185 	} else
186 		kfree(wrk);
187 }
188 
189 /*
190  * Time Sync Channel message handler.
191  */
192 static void timesync_onchannelcallback(void *context)
193 {
194 	struct vmbus_channel *channel = context;
195 	u32 recvlen;
196 	u64 requestid;
197 	struct icmsg_hdr *icmsghdrp;
198 	struct ictimesync_data *timedatap;
199 	u8 *time_txf_buf = util_timesynch.recv_buffer;
200 
201 	vmbus_recvpacket(channel, time_txf_buf,
202 			 PAGE_SIZE, &recvlen, &requestid);
203 
204 	if (recvlen > 0) {
205 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
206 				sizeof(struct vmbuspipe_hdr)];
207 
208 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
209 			vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
210 						MAX_SRV_VER, MAX_SRV_VER);
211 		} else {
212 			timedatap = (struct ictimesync_data *)&time_txf_buf[
213 				sizeof(struct vmbuspipe_hdr) +
214 				sizeof(struct icmsg_hdr)];
215 			adj_guesttime(timedatap->parenttime, timedatap->flags);
216 		}
217 
218 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
219 			| ICMSGHDRFLAG_RESPONSE;
220 
221 		vmbus_sendpacket(channel, time_txf_buf,
222 				recvlen, requestid,
223 				VM_PKT_DATA_INBAND, 0);
224 	}
225 }
226 
227 /*
228  * Heartbeat functionality.
229  * Every two seconds, Hyper-V send us a heartbeat request message.
230  * we respond to this message, and Hyper-V knows we are alive.
231  */
232 static void heartbeat_onchannelcallback(void *context)
233 {
234 	struct vmbus_channel *channel = context;
235 	u32 recvlen;
236 	u64 requestid;
237 	struct icmsg_hdr *icmsghdrp;
238 	struct heartbeat_msg_data *heartbeat_msg;
239 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
240 
241 	vmbus_recvpacket(channel, hbeat_txf_buf,
242 			 PAGE_SIZE, &recvlen, &requestid);
243 
244 	if (recvlen > 0) {
245 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
246 				sizeof(struct vmbuspipe_hdr)];
247 
248 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
249 			vmbus_prep_negotiate_resp(icmsghdrp, NULL,
250 				hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
251 		} else {
252 			heartbeat_msg =
253 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
254 					sizeof(struct vmbuspipe_hdr) +
255 					sizeof(struct icmsg_hdr)];
256 
257 			heartbeat_msg->seq_num += 1;
258 		}
259 
260 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
261 			| ICMSGHDRFLAG_RESPONSE;
262 
263 		vmbus_sendpacket(channel, hbeat_txf_buf,
264 				       recvlen, requestid,
265 				       VM_PKT_DATA_INBAND, 0);
266 	}
267 }
268 
269 static int util_probe(struct hv_device *dev,
270 			const struct hv_vmbus_device_id *dev_id)
271 {
272 	struct hv_util_service *srv =
273 		(struct hv_util_service *)dev_id->driver_data;
274 	int ret;
275 
276 	srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
277 	if (!srv->recv_buffer)
278 		return -ENOMEM;
279 	if (srv->util_init) {
280 		ret = srv->util_init(srv);
281 		if (ret) {
282 			ret = -ENODEV;
283 			goto error1;
284 		}
285 	}
286 
287 	/*
288 	 * The set of services managed by the util driver are not performance
289 	 * critical and do not need batched reading. Furthermore, some services
290 	 * such as KVP can only handle one message from the host at a time.
291 	 * Turn off batched reading for all util drivers before we open the
292 	 * channel.
293 	 */
294 
295 	set_channel_read_state(dev->channel, false);
296 
297 	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
298 			srv->util_cb, dev->channel);
299 	if (ret)
300 		goto error;
301 
302 	hv_set_drvdata(dev, srv);
303 	return 0;
304 
305 error:
306 	if (srv->util_deinit)
307 		srv->util_deinit();
308 error1:
309 	kfree(srv->recv_buffer);
310 	return ret;
311 }
312 
313 static int util_remove(struct hv_device *dev)
314 {
315 	struct hv_util_service *srv = hv_get_drvdata(dev);
316 
317 	vmbus_close(dev->channel);
318 	if (srv->util_deinit)
319 		srv->util_deinit();
320 	kfree(srv->recv_buffer);
321 
322 	return 0;
323 }
324 
325 static const struct hv_vmbus_device_id id_table[] = {
326 	/* Shutdown guid */
327 	{ HV_SHUTDOWN_GUID,
328 	  .driver_data = (unsigned long)&util_shutdown
329 	},
330 	/* Time synch guid */
331 	{ HV_TS_GUID,
332 	  .driver_data = (unsigned long)&util_timesynch
333 	},
334 	/* Heartbeat guid */
335 	{ HV_HEART_BEAT_GUID,
336 	  .driver_data = (unsigned long)&util_heartbeat
337 	},
338 	/* KVP guid */
339 	{ HV_KVP_GUID,
340 	  .driver_data = (unsigned long)&util_kvp
341 	},
342 	{ },
343 };
344 
345 MODULE_DEVICE_TABLE(vmbus, id_table);
346 
347 /* The one and only one */
348 static  struct hv_driver util_drv = {
349 	.name = "hv_util",
350 	.id_table = id_table,
351 	.probe =  util_probe,
352 	.remove =  util_remove,
353 };
354 
355 static int __init init_hyperv_utils(void)
356 {
357 	pr_info("Registering HyperV Utility Driver\n");
358 
359 	return vmbus_driver_register(&util_drv);
360 }
361 
362 static void exit_hyperv_utils(void)
363 {
364 	pr_info("De-Registered HyperV Utility Driver\n");
365 
366 	vmbus_driver_unregister(&util_drv);
367 }
368 
369 module_init(init_hyperv_utils);
370 module_exit(exit_hyperv_utils);
371 
372 MODULE_DESCRIPTION("Hyper-V Utilities");
373 MODULE_VERSION(HV_DRV_VERSION);
374 MODULE_LICENSE("GPL");
375