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