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");