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 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 * 2, 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, 4 * PAGE_SIZE, 4 * 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");