xref: /openbmc/linux/drivers/hv/hv_util.c (revision 1ab142d4)
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, shut_txf_buf);
74 		} else {
75 			shutdown_msg =
76 				(struct shutdown_msg_data *)&shut_txf_buf[
77 					sizeof(struct vmbuspipe_hdr) +
78 					sizeof(struct icmsg_hdr)];
79 
80 			switch (shutdown_msg->flags) {
81 			case 0:
82 			case 1:
83 				icmsghdrp->status = HV_S_OK;
84 				execute_shutdown = true;
85 
86 				pr_info("Shutdown request received -"
87 					    " graceful shutdown initiated\n");
88 				break;
89 			default:
90 				icmsghdrp->status = HV_E_FAIL;
91 				execute_shutdown = false;
92 
93 				pr_info("Shutdown request received -"
94 					    " Invalid request\n");
95 				break;
96 			}
97 		}
98 
99 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
100 			| ICMSGHDRFLAG_RESPONSE;
101 
102 		vmbus_sendpacket(channel, shut_txf_buf,
103 				       recvlen, requestid,
104 				       VM_PKT_DATA_INBAND, 0);
105 	}
106 
107 	if (execute_shutdown == true)
108 		orderly_poweroff(true);
109 }
110 
111 /*
112  * Set guest time to host UTC time.
113  */
114 static inline void do_adj_guesttime(u64 hosttime)
115 {
116 	s64 host_tns;
117 	struct timespec host_ts;
118 
119 	host_tns = (hosttime - WLTIMEDELTA) * 100;
120 	host_ts = ns_to_timespec(host_tns);
121 
122 	do_settimeofday(&host_ts);
123 }
124 
125 /*
126  * Set the host time in a process context.
127  */
128 
129 struct adj_time_work {
130 	struct work_struct work;
131 	u64	host_time;
132 };
133 
134 static void hv_set_host_time(struct work_struct *work)
135 {
136 	struct adj_time_work	*wrk;
137 
138 	wrk = container_of(work, struct adj_time_work, work);
139 	do_adj_guesttime(wrk->host_time);
140 	kfree(wrk);
141 }
142 
143 /*
144  * Synchronize time with host after reboot, restore, etc.
145  *
146  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
147  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
148  * message after the timesync channel is opened. Since the hv_utils module is
149  * loaded after hv_vmbus, the first message is usually missed. The other
150  * thing is, systime is automatically set to emulated hardware clock which may
151  * not be UTC time or in the same time zone. So, to override these effects, we
152  * use the first 50 time samples for initial system time setting.
153  */
154 static inline void adj_guesttime(u64 hosttime, u8 flags)
155 {
156 	struct adj_time_work    *wrk;
157 	static s32 scnt = 50;
158 
159 	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
160 	if (wrk == NULL)
161 		return;
162 
163 	wrk->host_time = hosttime;
164 	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
165 		INIT_WORK(&wrk->work, hv_set_host_time);
166 		schedule_work(&wrk->work);
167 		return;
168 	}
169 
170 	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
171 		scnt--;
172 		INIT_WORK(&wrk->work, hv_set_host_time);
173 		schedule_work(&wrk->work);
174 	} else
175 		kfree(wrk);
176 }
177 
178 /*
179  * Time Sync Channel message handler.
180  */
181 static void timesync_onchannelcallback(void *context)
182 {
183 	struct vmbus_channel *channel = context;
184 	u32 recvlen;
185 	u64 requestid;
186 	struct icmsg_hdr *icmsghdrp;
187 	struct ictimesync_data *timedatap;
188 	u8 *time_txf_buf = util_timesynch.recv_buffer;
189 
190 	vmbus_recvpacket(channel, time_txf_buf,
191 			 PAGE_SIZE, &recvlen, &requestid);
192 
193 	if (recvlen > 0) {
194 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
195 				sizeof(struct vmbuspipe_hdr)];
196 
197 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
198 			vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf);
199 		} else {
200 			timedatap = (struct ictimesync_data *)&time_txf_buf[
201 				sizeof(struct vmbuspipe_hdr) +
202 				sizeof(struct icmsg_hdr)];
203 			adj_guesttime(timedatap->parenttime, timedatap->flags);
204 		}
205 
206 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
207 			| ICMSGHDRFLAG_RESPONSE;
208 
209 		vmbus_sendpacket(channel, time_txf_buf,
210 				recvlen, requestid,
211 				VM_PKT_DATA_INBAND, 0);
212 	}
213 }
214 
215 /*
216  * Heartbeat functionality.
217  * Every two seconds, Hyper-V send us a heartbeat request message.
218  * we respond to this message, and Hyper-V knows we are alive.
219  */
220 static void heartbeat_onchannelcallback(void *context)
221 {
222 	struct vmbus_channel *channel = context;
223 	u32 recvlen;
224 	u64 requestid;
225 	struct icmsg_hdr *icmsghdrp;
226 	struct heartbeat_msg_data *heartbeat_msg;
227 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
228 
229 	vmbus_recvpacket(channel, hbeat_txf_buf,
230 			 PAGE_SIZE, &recvlen, &requestid);
231 
232 	if (recvlen > 0) {
233 		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
234 				sizeof(struct vmbuspipe_hdr)];
235 
236 		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
237 			vmbus_prep_negotiate_resp(icmsghdrp, NULL, hbeat_txf_buf);
238 		} else {
239 			heartbeat_msg =
240 				(struct heartbeat_msg_data *)&hbeat_txf_buf[
241 					sizeof(struct vmbuspipe_hdr) +
242 					sizeof(struct icmsg_hdr)];
243 
244 			heartbeat_msg->seq_num += 1;
245 		}
246 
247 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
248 			| ICMSGHDRFLAG_RESPONSE;
249 
250 		vmbus_sendpacket(channel, hbeat_txf_buf,
251 				       recvlen, requestid,
252 				       VM_PKT_DATA_INBAND, 0);
253 	}
254 }
255 
256 static int util_probe(struct hv_device *dev,
257 			const struct hv_vmbus_device_id *dev_id)
258 {
259 	struct hv_util_service *srv =
260 		(struct hv_util_service *)dev_id->driver_data;
261 	int ret;
262 
263 	srv->recv_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
264 	if (!srv->recv_buffer)
265 		return -ENOMEM;
266 	if (srv->util_init) {
267 		ret = srv->util_init(srv);
268 		if (ret) {
269 			ret = -ENODEV;
270 			goto error1;
271 		}
272 	}
273 
274 	ret = vmbus_open(dev->channel, 2 * PAGE_SIZE, 2 * PAGE_SIZE, NULL, 0,
275 			srv->util_cb, dev->channel);
276 	if (ret)
277 		goto error;
278 
279 	hv_set_drvdata(dev, srv);
280 	return 0;
281 
282 error:
283 	if (srv->util_deinit)
284 		srv->util_deinit();
285 error1:
286 	kfree(srv->recv_buffer);
287 	return ret;
288 }
289 
290 static int util_remove(struct hv_device *dev)
291 {
292 	struct hv_util_service *srv = hv_get_drvdata(dev);
293 
294 	vmbus_close(dev->channel);
295 	if (srv->util_deinit)
296 		srv->util_deinit();
297 	kfree(srv->recv_buffer);
298 
299 	return 0;
300 }
301 
302 static const struct hv_vmbus_device_id id_table[] = {
303 	/* Shutdown guid */
304 	{ VMBUS_DEVICE(0x31, 0x60, 0x0B, 0X0E, 0x13, 0x52, 0x34, 0x49,
305 		       0x81, 0x8B, 0x38, 0XD9, 0x0C, 0xED, 0x39, 0xDB)
306 	  .driver_data = (unsigned long)&util_shutdown },
307 	/* Time synch guid */
308 	{ VMBUS_DEVICE(0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
309 		       0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf)
310 	  .driver_data = (unsigned long)&util_timesynch },
311 	/* Heartbeat guid */
312 	{ VMBUS_DEVICE(0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e,
313 		       0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d)
314 	  .driver_data = (unsigned long)&util_heartbeat },
315 	/* KVP guid */
316 	{ VMBUS_DEVICE(0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
317 		       0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6)
318 	  .driver_data = (unsigned long)&util_kvp },
319 	{ },
320 };
321 
322 MODULE_DEVICE_TABLE(vmbus, id_table);
323 
324 /* The one and only one */
325 static  struct hv_driver util_drv = {
326 	.name = "hv_util",
327 	.id_table = id_table,
328 	.probe =  util_probe,
329 	.remove =  util_remove,
330 };
331 
332 static int __init init_hyperv_utils(void)
333 {
334 	pr_info("Registering HyperV Utility Driver\n");
335 
336 	return vmbus_driver_register(&util_drv);
337 }
338 
339 static void exit_hyperv_utils(void)
340 {
341 	pr_info("De-Registered HyperV Utility Driver\n");
342 
343 	vmbus_driver_unregister(&util_drv);
344 }
345 
346 module_init(init_hyperv_utils);
347 module_exit(exit_hyperv_utils);
348 
349 MODULE_DESCRIPTION("Hyper-V Utilities");
350 MODULE_VERSION(HV_DRV_VERSION);
351 MODULE_LICENSE("GPL");
352