Drivers: hv: Add a new driver to support host initiated backup
[linux-3.10.git] / drivers / hv / hv_util.c
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 struct hv_util_service util_vss = {
53         .util_cb = hv_vss_onchannelcallback,
54         .util_init = hv_vss_init,
55         .util_deinit = hv_vss_deinit,
56 };
57
58 static void perform_shutdown(struct work_struct *dummy)
59 {
60         orderly_poweroff(true);
61 }
62
63 /*
64  * Perform the shutdown operation in a thread context.
65  */
66 static DECLARE_WORK(shutdown_work, perform_shutdown);
67
68 static void shutdown_onchannelcallback(void *context)
69 {
70         struct vmbus_channel *channel = context;
71         u32 recvlen;
72         u64 requestid;
73         u8  execute_shutdown = false;
74         u8  *shut_txf_buf = util_shutdown.recv_buffer;
75
76         struct shutdown_msg_data *shutdown_msg;
77
78         struct icmsg_hdr *icmsghdrp;
79         struct icmsg_negotiate *negop = NULL;
80
81         vmbus_recvpacket(channel, shut_txf_buf,
82                          PAGE_SIZE, &recvlen, &requestid);
83
84         if (recvlen > 0) {
85                 icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
86                         sizeof(struct vmbuspipe_hdr)];
87
88                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
89                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
90                                         shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
91                 } else {
92                         shutdown_msg =
93                                 (struct shutdown_msg_data *)&shut_txf_buf[
94                                         sizeof(struct vmbuspipe_hdr) +
95                                         sizeof(struct icmsg_hdr)];
96
97                         switch (shutdown_msg->flags) {
98                         case 0:
99                         case 1:
100                                 icmsghdrp->status = HV_S_OK;
101                                 execute_shutdown = true;
102
103                                 pr_info("Shutdown request received -"
104                                             " graceful shutdown initiated\n");
105                                 break;
106                         default:
107                                 icmsghdrp->status = HV_E_FAIL;
108                                 execute_shutdown = false;
109
110                                 pr_info("Shutdown request received -"
111                                             " Invalid request\n");
112                                 break;
113                         }
114                 }
115
116                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
117                         | ICMSGHDRFLAG_RESPONSE;
118
119                 vmbus_sendpacket(channel, shut_txf_buf,
120                                        recvlen, requestid,
121                                        VM_PKT_DATA_INBAND, 0);
122         }
123
124         if (execute_shutdown == true)
125                 schedule_work(&shutdown_work);
126 }
127
128 /*
129  * Set guest time to host UTC time.
130  */
131 static inline void do_adj_guesttime(u64 hosttime)
132 {
133         s64 host_tns;
134         struct timespec host_ts;
135
136         host_tns = (hosttime - WLTIMEDELTA) * 100;
137         host_ts = ns_to_timespec(host_tns);
138
139         do_settimeofday(&host_ts);
140 }
141
142 /*
143  * Set the host time in a process context.
144  */
145
146 struct adj_time_work {
147         struct work_struct work;
148         u64     host_time;
149 };
150
151 static void hv_set_host_time(struct work_struct *work)
152 {
153         struct adj_time_work    *wrk;
154
155         wrk = container_of(work, struct adj_time_work, work);
156         do_adj_guesttime(wrk->host_time);
157         kfree(wrk);
158 }
159
160 /*
161  * Synchronize time with host after reboot, restore, etc.
162  *
163  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
164  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
165  * message after the timesync channel is opened. Since the hv_utils module is
166  * loaded after hv_vmbus, the first message is usually missed. The other
167  * thing is, systime is automatically set to emulated hardware clock which may
168  * not be UTC time or in the same time zone. So, to override these effects, we
169  * use the first 50 time samples for initial system time setting.
170  */
171 static inline void adj_guesttime(u64 hosttime, u8 flags)
172 {
173         struct adj_time_work    *wrk;
174         static s32 scnt = 50;
175
176         wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
177         if (wrk == NULL)
178                 return;
179
180         wrk->host_time = hosttime;
181         if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
182                 INIT_WORK(&wrk->work, hv_set_host_time);
183                 schedule_work(&wrk->work);
184                 return;
185         }
186
187         if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
188                 scnt--;
189                 INIT_WORK(&wrk->work, hv_set_host_time);
190                 schedule_work(&wrk->work);
191         } else
192                 kfree(wrk);
193 }
194
195 /*
196  * Time Sync Channel message handler.
197  */
198 static void timesync_onchannelcallback(void *context)
199 {
200         struct vmbus_channel *channel = context;
201         u32 recvlen;
202         u64 requestid;
203         struct icmsg_hdr *icmsghdrp;
204         struct ictimesync_data *timedatap;
205         u8 *time_txf_buf = util_timesynch.recv_buffer;
206
207         vmbus_recvpacket(channel, time_txf_buf,
208                          PAGE_SIZE, &recvlen, &requestid);
209
210         if (recvlen > 0) {
211                 icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
212                                 sizeof(struct vmbuspipe_hdr)];
213
214                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
215                         vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
216                                                 MAX_SRV_VER, MAX_SRV_VER);
217                 } else {
218                         timedatap = (struct ictimesync_data *)&time_txf_buf[
219                                 sizeof(struct vmbuspipe_hdr) +
220                                 sizeof(struct icmsg_hdr)];
221                         adj_guesttime(timedatap->parenttime, timedatap->flags);
222                 }
223
224                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
225                         | ICMSGHDRFLAG_RESPONSE;
226
227                 vmbus_sendpacket(channel, time_txf_buf,
228                                 recvlen, requestid,
229                                 VM_PKT_DATA_INBAND, 0);
230         }
231 }
232
233 /*
234  * Heartbeat functionality.
235  * Every two seconds, Hyper-V send us a heartbeat request message.
236  * we respond to this message, and Hyper-V knows we are alive.
237  */
238 static void heartbeat_onchannelcallback(void *context)
239 {
240         struct vmbus_channel *channel = context;
241         u32 recvlen;
242         u64 requestid;
243         struct icmsg_hdr *icmsghdrp;
244         struct heartbeat_msg_data *heartbeat_msg;
245         u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
246
247         vmbus_recvpacket(channel, hbeat_txf_buf,
248                          PAGE_SIZE, &recvlen, &requestid);
249
250         if (recvlen > 0) {
251                 icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
252                                 sizeof(struct vmbuspipe_hdr)];
253
254                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
255                         vmbus_prep_negotiate_resp(icmsghdrp, NULL,
256                                 hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
257                 } else {
258                         heartbeat_msg =
259                                 (struct heartbeat_msg_data *)&hbeat_txf_buf[
260                                         sizeof(struct vmbuspipe_hdr) +
261                                         sizeof(struct icmsg_hdr)];
262
263                         heartbeat_msg->seq_num += 1;
264                 }
265
266                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
267                         | ICMSGHDRFLAG_RESPONSE;
268
269                 vmbus_sendpacket(channel, hbeat_txf_buf,
270                                        recvlen, requestid,
271                                        VM_PKT_DATA_INBAND, 0);
272         }
273 }
274
275 static int util_probe(struct hv_device *dev,
276                         const struct hv_vmbus_device_id *dev_id)
277 {
278         struct hv_util_service *srv =
279                 (struct hv_util_service *)dev_id->driver_data;
280         int ret;
281
282         srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
283         if (!srv->recv_buffer)
284                 return -ENOMEM;
285         if (srv->util_init) {
286                 ret = srv->util_init(srv);
287                 if (ret) {
288                         ret = -ENODEV;
289                         goto error1;
290                 }
291         }
292
293         /*
294          * The set of services managed by the util driver are not performance
295          * critical and do not need batched reading. Furthermore, some services
296          * such as KVP can only handle one message from the host at a time.
297          * Turn off batched reading for all util drivers before we open the
298          * channel.
299          */
300
301         set_channel_read_state(dev->channel, false);
302
303         ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
304                         srv->util_cb, dev->channel);
305         if (ret)
306                 goto error;
307
308         hv_set_drvdata(dev, srv);
309         return 0;
310
311 error:
312         if (srv->util_deinit)
313                 srv->util_deinit();
314 error1:
315         kfree(srv->recv_buffer);
316         return ret;
317 }
318
319 static int util_remove(struct hv_device *dev)
320 {
321         struct hv_util_service *srv = hv_get_drvdata(dev);
322
323         vmbus_close(dev->channel);
324         if (srv->util_deinit)
325                 srv->util_deinit();
326         kfree(srv->recv_buffer);
327
328         return 0;
329 }
330
331 static const struct hv_vmbus_device_id id_table[] = {
332         /* Shutdown guid */
333         { HV_SHUTDOWN_GUID,
334           .driver_data = (unsigned long)&util_shutdown
335         },
336         /* Time synch guid */
337         { HV_TS_GUID,
338           .driver_data = (unsigned long)&util_timesynch
339         },
340         /* Heartbeat guid */
341         { HV_HEART_BEAT_GUID,
342           .driver_data = (unsigned long)&util_heartbeat
343         },
344         /* KVP guid */
345         { HV_KVP_GUID,
346           .driver_data = (unsigned long)&util_kvp
347         },
348         /* VSS GUID */
349         { HV_VSS_GUID,
350           .driver_data = (unsigned long)&util_vss
351         },
352         { },
353 };
354
355 MODULE_DEVICE_TABLE(vmbus, id_table);
356
357 /* The one and only one */
358 static  struct hv_driver util_drv = {
359         .name = "hv_util",
360         .id_table = id_table,
361         .probe =  util_probe,
362         .remove =  util_remove,
363 };
364
365 static int __init init_hyperv_utils(void)
366 {
367         pr_info("Registering HyperV Utility Driver\n");
368
369         return vmbus_driver_register(&util_drv);
370 }
371
372 static void exit_hyperv_utils(void)
373 {
374         pr_info("De-Registered HyperV Utility Driver\n");
375
376         vmbus_driver_unregister(&util_drv);
377 }
378
379 module_init(init_hyperv_utils);
380 module_exit(exit_hyperv_utils);
381
382 MODULE_DESCRIPTION("Hyper-V Utilities");
383 MODULE_VERSION(HV_DRV_VERSION);
384 MODULE_LICENSE("GPL");