xref: /openbmc/linux/drivers/hv/hv_util.c (revision 95e9fd10)
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 shutdown_onchannelcallback(void *context)
53 {
54 	struct vmbus_channel *channel = context;
55 	u32 recvlen;
56 	u64 requestid;
57 	u8  execute_shutdown = false;
58 	u8  *shut_txf_buf = util_shutdown.recv_buffer;
59 
60 	struct shutdown_msg_data *shutdown_msg;
61 
62 	struct icmsg_hdr *icmsghdrp;
63 	struct icmsg_negotiate *negop = NULL;
64 
65 	vmbus_recvpacket(channel, shut_txf_buf,
66 			 PAGE_SIZE, &recvlen, &requestid);
67 
68 	if (recvlen > 0) {
69 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
70 			sizeof(struct vmbuspipe_hdr)];
71 
72 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
73 			vmbus_prep_negotiate_resp(icmsghdrp, negop,
74 					shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
75 		} else {
76 			shutdown_msg =
77 				(struct shutdown_msg_data *)&shut_txf_buf[
78 					sizeof(struct vmbuspipe_hdr) +
79 					sizeof(struct icmsg_hdr)];
80 
81 			switch (shutdown_msg->flags) {
82 			case 0:
83 			case 1:
84 				icmsghdrp->status = HV_S_OK;
85 				execute_shutdown = true;
86 
87 				pr_info("Shutdown request received -"
88 					    " graceful shutdown initiated\n");
89 				break;
90 			default:
91 				icmsghdrp->status = HV_E_FAIL;
92 				execute_shutdown = false;
93 
94 				pr_info("Shutdown request received -"
95 					    " Invalid request\n");
96 				break;
97 			}
98 		}
99 
100 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
101 			| ICMSGHDRFLAG_RESPONSE;
102 
103 		vmbus_sendpacket(channel, shut_txf_buf,
104 				       recvlen, requestid,
105 				       VM_PKT_DATA_INBAND, 0);
106 	}
107 
108 	if (execute_shutdown == true)
109 		orderly_poweroff(true);
110 }
111 
112 /*
113  * Set guest time to host UTC time.
114  */
115 static inline void do_adj_guesttime(u64 hosttime)
116 {
117 	s64 host_tns;
118 	struct timespec host_ts;
119 
120 	host_tns = (hosttime - WLTIMEDELTA) * 100;
121 	host_ts = ns_to_timespec(host_tns);
122 
123 	do_settimeofday(&host_ts);
124 }
125 
126 /*
127  * Set the host time in a process context.
128  */
129 
130 struct adj_time_work {
131 	struct work_struct work;
132 	u64	host_time;
133 };
134 
135 static void hv_set_host_time(struct work_struct *work)
136 {
137 	struct adj_time_work	*wrk;
138 
139 	wrk = container_of(work, struct adj_time_work, work);
140 	do_adj_guesttime(wrk->host_time);
141 	kfree(wrk);
142 }
143 
144 /*
145  * Synchronize time with host after reboot, restore, etc.
146  *
147  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
148  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
149  * message after the timesync channel is opened. Since the hv_utils module is
150  * loaded after hv_vmbus, the first message is usually missed. The other
151  * thing is, systime is automatically set to emulated hardware clock which may
152  * not be UTC time or in the same time zone. So, to override these effects, we
153  * use the first 50 time samples for initial system time setting.
154  */
155 static inline void adj_guesttime(u64 hosttime, u8 flags)
156 {
157 	struct adj_time_work    *wrk;
158 	static s32 scnt = 50;
159 
160 	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
161 	if (wrk == NULL)
162 		return;
163 
164 	wrk->host_time = hosttime;
165 	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
166 		INIT_WORK(&wrk->work, hv_set_host_time);
167 		schedule_work(&wrk->work);
168 		return;
169 	}
170 
171 	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
172 		scnt--;
173 		INIT_WORK(&wrk->work, hv_set_host_time);
174 		schedule_work(&wrk->work);
175 	} else
176 		kfree(wrk);
177 }
178 
179 /*
180  * Time Sync Channel message handler.
181  */
182 static void timesync_onchannelcallback(void *context)
183 {
184 	struct vmbus_channel *channel = context;
185 	u32 recvlen;
186 	u64 requestid;
187 	struct icmsg_hdr *icmsghdrp;
188 	struct ictimesync_data *timedatap;
189 	u8 *time_txf_buf = util_timesynch.recv_buffer;
190 
191 	vmbus_recvpacket(channel, time_txf_buf,
192 			 PAGE_SIZE, &recvlen, &requestid);
193 
194 	if (recvlen > 0) {
195 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
196 				sizeof(struct vmbuspipe_hdr)];
197 
198 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
199 			vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
200 						MAX_SRV_VER, MAX_SRV_VER);
201 		} else {
202 			timedatap = (struct ictimesync_data *)&time_txf_buf[
203 				sizeof(struct vmbuspipe_hdr) +
204 				sizeof(struct icmsg_hdr)];
205 			adj_guesttime(timedatap->parenttime, timedatap->flags);
206 		}
207 
208 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
209 			| ICMSGHDRFLAG_RESPONSE;
210 
211 		vmbus_sendpacket(channel, time_txf_buf,
212 				recvlen, requestid,
213 				VM_PKT_DATA_INBAND, 0);
214 	}
215 }
216 
217 /*
218  * Heartbeat functionality.
219  * Every two seconds, Hyper-V send us a heartbeat request message.
220  * we respond to this message, and Hyper-V knows we are alive.
221  */
222 static void heartbeat_onchannelcallback(void *context)
223 {
224 	struct vmbus_channel *channel = context;
225 	u32 recvlen;
226 	u64 requestid;
227 	struct icmsg_hdr *icmsghdrp;
228 	struct heartbeat_msg_data *heartbeat_msg;
229 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
230 
231 	vmbus_recvpacket(channel, hbeat_txf_buf,
232 			 PAGE_SIZE, &recvlen, &requestid);
233 
234 	if (recvlen > 0) {
235 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
236 				sizeof(struct vmbuspipe_hdr)];
237 
238 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
239 			vmbus_prep_negotiate_resp(icmsghdrp, NULL,
240 				hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
241 		} else {
242 			heartbeat_msg =
243 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
244 					sizeof(struct vmbuspipe_hdr) +
245 					sizeof(struct icmsg_hdr)];
246 
247 			heartbeat_msg->seq_num += 1;
248 		}
249 
250 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
251 			| ICMSGHDRFLAG_RESPONSE;
252 
253 		vmbus_sendpacket(channel, hbeat_txf_buf,
254 				       recvlen, requestid,
255 				       VM_PKT_DATA_INBAND, 0);
256 	}
257 }
258 
259 static int util_probe(struct hv_device *dev,
260 			const struct hv_vmbus_device_id *dev_id)
261 {
262 	struct hv_util_service *srv =
263 		(struct hv_util_service *)dev_id->driver_data;
264 	int ret;
265 
266 	srv->recv_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
267 	if (!srv->recv_buffer)
268 		return -ENOMEM;
269 	if (srv->util_init) {
270 		ret = srv->util_init(srv);
271 		if (ret) {
272 			ret = -ENODEV;
273 			goto error1;
274 		}
275 	}
276 
277 	ret = vmbus_open(dev->channel, 2 * PAGE_SIZE, 2 * PAGE_SIZE, NULL, 0,
278 			srv->util_cb, dev->channel);
279 	if (ret)
280 		goto error;
281 
282 	hv_set_drvdata(dev, srv);
283 	return 0;
284 
285 error:
286 	if (srv->util_deinit)
287 		srv->util_deinit();
288 error1:
289 	kfree(srv->recv_buffer);
290 	return ret;
291 }
292 
293 static int util_remove(struct hv_device *dev)
294 {
295 	struct hv_util_service *srv = hv_get_drvdata(dev);
296 
297 	vmbus_close(dev->channel);
298 	if (srv->util_deinit)
299 		srv->util_deinit();
300 	kfree(srv->recv_buffer);
301 
302 	return 0;
303 }
304 
305 static const struct hv_vmbus_device_id id_table[] = {
306 	/* Shutdown guid */
307 	{ VMBUS_DEVICE(0x31, 0x60, 0x0B, 0X0E, 0x13, 0x52, 0x34, 0x49,
308 		       0x81, 0x8B, 0x38, 0XD9, 0x0C, 0xED, 0x39, 0xDB)
309 	  .driver_data = (unsigned long)&util_shutdown },
310 	/* Time synch guid */
311 	{ VMBUS_DEVICE(0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
312 		       0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf)
313 	  .driver_data = (unsigned long)&util_timesynch },
314 	/* Heartbeat guid */
315 	{ VMBUS_DEVICE(0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e,
316 		       0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d)
317 	  .driver_data = (unsigned long)&util_heartbeat },
318 	/* KVP guid */
319 	{ VMBUS_DEVICE(0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
320 		       0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6)
321 	  .driver_data = (unsigned long)&util_kvp },
322 	{ },
323 };
324 
325 MODULE_DEVICE_TABLE(vmbus, id_table);
326 
327 /* The one and only one */
328 static  struct hv_driver util_drv = {
329 	.name = "hv_util",
330 	.id_table = id_table,
331 	.probe =  util_probe,
332 	.remove =  util_remove,
333 };
334 
335 static int __init init_hyperv_utils(void)
336 {
337 	pr_info("Registering HyperV Utility Driver\n");
338 
339 	return vmbus_driver_register(&util_drv);
340 }
341 
342 static void exit_hyperv_utils(void)
343 {
344 	pr_info("De-Registered HyperV Utility Driver\n");
345 
346 	vmbus_driver_unregister(&util_drv);
347 }
348 
349 module_init(init_hyperv_utils);
350 module_exit(exit_hyperv_utils);
351 
352 MODULE_DESCRIPTION("Hyper-V Utilities");
353 MODULE_VERSION(HV_DRV_VERSION);
354 MODULE_LICENSE("GPL");
355