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 #define SHUTDOWN_MAJOR  3
  32 #define SHUTDOWN_MINOR  0
  33 #define SHUTDOWN_MAJOR_MINOR    (SHUTDOWN_MAJOR << 16 | SHUTDOWN_MINOR)
  34
  35 #define TIMESYNCH_MAJOR 3
  36 #define TIMESYNCH_MINOR 0
  37 #define TIMESYNCH_MAJOR_MINOR   (TIMESYNCH_MAJOR << 16 | TIMESYNCH_MINOR)
  38
  39 #define HEARTBEAT_MAJOR 3
  40 #define HEARTBEAT_MINOR 0
  41 #define HEARTBEAT_MAJOR_MINOR   (HEARTBEAT_MAJOR << 16 | HEARTBEAT_MINOR)
  42
  43 static void shutdown_onchannelcallback(void *context);
  44 static struct hv_util_service util_shutdown = {
  45         .util_cb = shutdown_onchannelcallback,
  46 };
  47
  48 static void timesync_onchannelcallback(void *context);
  49 static struct hv_util_service util_timesynch = {
  50         .util_cb = timesync_onchannelcallback,
  51 };
  52
  53 static void heartbeat_onchannelcallback(void *context);
  54 static struct hv_util_service util_heartbeat = {
  55         .util_cb = heartbeat_onchannelcallback,
  56 };
  57
  58 static struct hv_util_service util_kvp = {
  59         .util_cb = hv_kvp_onchannelcallback,
  60         .util_init = hv_kvp_init,
  61         .util_deinit = hv_kvp_deinit,
  62 };
  63
  64 static struct hv_util_service util_vss = {
  65         .util_cb = hv_vss_onchannelcallback,
  66         .util_init = hv_vss_init,
  67         .util_deinit = hv_vss_deinit,
  68 };
  69
  70 static void perform_shutdown(struct work_struct *dummy)
  71 {
  72         orderly_poweroff(true);
  73 }
  74
  75 /*
  76  * Perform the shutdown operation in a thread context.
  77  */
  78 static DECLARE_WORK(shutdown_work, perform_shutdown);
  79
  80 static void shutdown_onchannelcallback(void *context)
  81 {
  82         struct vmbus_channel *channel = context;
  83         u32 recvlen;
  84         u64 requestid;
  85         u8  execute_shutdown = false;
  86         u8  *shut_txf_buf = util_shutdown.recv_buffer;
  87
  88         struct shutdown_msg_data *shutdown_msg;
  89
  90         struct icmsg_hdr *icmsghdrp;
  91         struct icmsg_negotiate *negop = NULL;
  92
  93         vmbus_recvpacket(channel, shut_txf_buf,
  94                          PAGE_SIZE, &recvlen, &requestid);
  95
  96         if (recvlen > 0) {
  97                 icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
  98                         sizeof(struct vmbuspipe_hdr)];
  99
 100                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 101                         vmbus_prep_negotiate_resp(icmsghdrp, negop,
 102                                         shut_txf_buf, UTIL_FW_MAJOR_MINOR,
 103                                         SHUTDOWN_MAJOR_MINOR);
 104                 } else {
 105                         shutdown_msg =
 106                                 (struct shutdown_msg_data *)&shut_txf_buf[
 107                                         sizeof(struct vmbuspipe_hdr) +
 108                                         sizeof(struct icmsg_hdr)];
 109
 110                         switch (shutdown_msg->flags) {
 111                         case 0:
 112                         case 1:
 113                                 icmsghdrp->status = HV_S_OK;
 114                                 execute_shutdown = true;
 115
 116                                 pr_info("Shutdown request received -"
 117                                             " graceful shutdown initiated\n");
 118                                 break;
 119                         default:
 120                                 icmsghdrp->status = HV_E_FAIL;
 121                                 execute_shutdown = false;
 122
 123                                 pr_info("Shutdown request received -"
 124                                             " Invalid request\n");
 125                                 break;
 126                         }
 127                 }
 128
 129                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 130                         | ICMSGHDRFLAG_RESPONSE;
 131
 132                 vmbus_sendpacket(channel, shut_txf_buf,
 133                                        recvlen, requestid,
 134                                        VM_PKT_DATA_INBAND, 0);
 135         }
 136
 137         if (execute_shutdown == true)
 138                 schedule_work(&shutdown_work);
 139 }
 140
 141 /*
 142  * Set guest time to host UTC time.
 143  */
 144 static inline void do_adj_guesttime(u64 hosttime)
 145 {
 146         s64 host_tns;
 147         struct timespec host_ts;
 148
 149         host_tns = (hosttime - WLTIMEDELTA) * 100;
 150         host_ts = ns_to_timespec(host_tns);
 151
 152         do_settimeofday(&host_ts);
 153 }
 154
 155 /*
 156  * Set the host time in a process context.
 157  */
 158
 159 struct adj_time_work {
 160         struct work_struct work;
 161         u64     host_time;
 162 };
 163
 164 static void hv_set_host_time(struct work_struct *work)
 165 {
 166         struct adj_time_work    *wrk;
 167
 168         wrk = container_of(work, struct adj_time_work, work);
 169         do_adj_guesttime(wrk->host_time);
 170         kfree(wrk);
 171 }
 172
 173 /*
 174  * Synchronize time with host after reboot, restore, etc.
 175  *
 176  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
 177  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
 178  * message after the timesync channel is opened. Since the hv_utils module is
 179  * loaded after hv_vmbus, the first message is usually missed. The other
 180  * thing is, systime is automatically set to emulated hardware clock which may
 181  * not be UTC time or in the same time zone. So, to override these effects, we
 182  * use the first 50 time samples for initial system time setting.
 183  */
 184 static inline void adj_guesttime(u64 hosttime, u8 flags)
 185 {
 186         struct adj_time_work    *wrk;
 187         static s32 scnt = 50;
 188
 189         wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
 190         if (wrk == NULL)
 191                 return;
 192
 193         wrk->host_time = hosttime;
 194         if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
 195                 INIT_WORK(&wrk->work, hv_set_host_time);
 196                 schedule_work(&wrk->work);
 197                 return;
 198         }
 199
 200         if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
 201                 scnt--;
 202                 INIT_WORK(&wrk->work, hv_set_host_time);
 203                 schedule_work(&wrk->work);
 204         } else
 205                 kfree(wrk);
 206 }
 207
 208 /*
 209  * Time Sync Channel message handler.
 210  */
 211 static void timesync_onchannelcallback(void *context)
 212 {
 213         struct vmbus_channel *channel = context;
 214         u32 recvlen;
 215         u64 requestid;
 216         struct icmsg_hdr *icmsghdrp;
 217         struct ictimesync_data *timedatap;
 218         u8 *time_txf_buf = util_timesynch.recv_buffer;
 219
 220         vmbus_recvpacket(channel, time_txf_buf,
 221                          PAGE_SIZE, &recvlen, &requestid);
 222
 223         if (recvlen > 0) {
 224                 icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
 225                                 sizeof(struct vmbuspipe_hdr)];
 226
 227                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 228                         vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
 229                                                 UTIL_FW_MAJOR_MINOR,
 230                                                 TIMESYNCH_MAJOR_MINOR);
 231                 } else {
 232                         timedatap = (struct ictimesync_data *)&time_txf_buf[
 233                                 sizeof(struct vmbuspipe_hdr) +
 234                                 sizeof(struct icmsg_hdr)];
 235                         adj_guesttime(timedatap->parenttime, timedatap->flags);
 236                 }
 237
 238                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 239                         | ICMSGHDRFLAG_RESPONSE;
 240
 241                 vmbus_sendpacket(channel, time_txf_buf,
 242                                 recvlen, requestid,
 243                                 VM_PKT_DATA_INBAND, 0);
 244         }
 245 }
 246
 247 /*
 248  * Heartbeat functionality.
 249  * Every two seconds, Hyper-V send us a heartbeat request message.
 250  * we respond to this message, and Hyper-V knows we are alive.
 251  */
 252 static void heartbeat_onchannelcallback(void *context)
 253 {
 254         struct vmbus_channel *channel = context;
 255         u32 recvlen;
 256         u64 requestid;
 257         struct icmsg_hdr *icmsghdrp;
 258         struct heartbeat_msg_data *heartbeat_msg;
 259         u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
 260
 261         vmbus_recvpacket(channel, hbeat_txf_buf,
 262                          PAGE_SIZE, &recvlen, &requestid);
 263
 264         if (recvlen > 0) {
 265                 icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
 266                                 sizeof(struct vmbuspipe_hdr)];
 267
 268                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 269                         vmbus_prep_negotiate_resp(icmsghdrp, NULL,
 270                                 hbeat_txf_buf, UTIL_FW_MAJOR_MINOR,
 271                                 HEARTBEAT_MAJOR_MINOR);
 272                 } else {
 273                         heartbeat_msg =
 274                                 (struct heartbeat_msg_data *)&hbeat_txf_buf[
 275                                         sizeof(struct vmbuspipe_hdr) +
 276                                         sizeof(struct icmsg_hdr)];
 277
 278                         heartbeat_msg->seq_num += 1;
 279                 }
 280
 281                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 282                         | ICMSGHDRFLAG_RESPONSE;
 283
 284                 vmbus_sendpacket(channel, hbeat_txf_buf,
 285                                        recvlen, requestid,
 286                                        VM_PKT_DATA_INBAND, 0);
 287         }
 288 }
 289
 290 static int util_probe(struct hv_device *dev,
 291                         const struct hv_vmbus_device_id *dev_id)
 292 {
 293         struct hv_util_service *srv =
 294                 (struct hv_util_service *)dev_id->driver_data;
 295         int ret;
 296
 297         srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
 298         if (!srv->recv_buffer)
 299                 return -ENOMEM;
 300         if (srv->util_init) {
 301                 ret = srv->util_init(srv);
 302                 if (ret) {
 303                         ret = -ENODEV;
 304                         goto error1;
 305                 }
 306         }
 307
 308         /*
 309          * The set of services managed by the util driver are not performance
 310          * critical and do not need batched reading. Furthermore, some services
 311          * such as KVP can only handle one message from the host at a time.
 312          * Turn off batched reading for all util drivers before we open the
 313          * channel.
 314          */
 315
 316         set_channel_read_state(dev->channel, false);
 317
 318         ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
 319                         srv->util_cb, dev->channel);
 320         if (ret)
 321                 goto error;
 322
 323         hv_set_drvdata(dev, srv);
 324         return 0;
 325
 326 error:
 327         if (srv->util_deinit)
 328                 srv->util_deinit();
 329 error1:
 330         kfree(srv->recv_buffer);
 331         return ret;
 332 }
 333
 334 static int util_remove(struct hv_device *dev)
 335 {
 336         struct hv_util_service *srv = hv_get_drvdata(dev);
 337
 338         vmbus_close(dev->channel);
 339         if (srv->util_deinit)
 340                 srv->util_deinit();
 341         kfree(srv->recv_buffer);
 342
 343         return 0;
 344 }
 345
 346 static const struct hv_vmbus_device_id id_table[] = {
 347         /* Shutdown guid */
 348         { HV_SHUTDOWN_GUID,
 349           .driver_data = (unsigned long)&util_shutdown
 350         },
 351         /* Time synch guid */
 352         { HV_TS_GUID,
 353           .driver_data = (unsigned long)&util_timesynch
 354         },
 355         /* Heartbeat guid */
 356         { HV_HEART_BEAT_GUID,
 357           .driver_data = (unsigned long)&util_heartbeat
 358         },
 359         /* KVP guid */
 360         { HV_KVP_GUID,
 361           .driver_data = (unsigned long)&util_kvp
 362         },
 363         /* VSS GUID */
 364         { HV_VSS_GUID,
 365           .driver_data = (unsigned long)&util_vss
 366         },
 367         { },
 368 };
 369
 370 MODULE_DEVICE_TABLE(vmbus, id_table);
 371
 372 /* The one and only one */
 373 static  struct hv_driver util_drv = {
 374         .name = "hv_util",
 375         .id_table = id_table,
 376         .probe =  util_probe,
 377         .remove =  util_remove,
 378 };
 379
 380 static int __init init_hyperv_utils(void)
 381 {
 382         pr_info("Registering HyperV Utility Driver\n");
 383
 384         return vmbus_driver_register(&util_drv);
 385 }
 386
 387 static void exit_hyperv_utils(void)
 388 {
 389         pr_info("De-Registered HyperV Utility Driver\n");
 390
 391         vmbus_driver_unregister(&util_drv);
 392 }
 393
 394 module_init(init_hyperv_utils);
 395 module_exit(exit_hyperv_utils);
 396
 397 MODULE_DESCRIPTION("Hyper-V Utilities");
 398 MODULE_LICENSE("GPL");