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 #include <linux/clockchips.h>
  31 #include <linux/ptp_clock_kernel.h>
  32 #include <asm/mshyperv.h>
  33
  34 #include "hyperv_vmbus.h"
  35
  36 #define SD_MAJOR        3
  37 #define SD_MINOR        0
  38 #define SD_VERSION      (SD_MAJOR << 16 | SD_MINOR)
  39
  40 #define SD_MAJOR_1      1
  41 #define SD_VERSION_1    (SD_MAJOR_1 << 16 | SD_MINOR)
  42
  43 #define TS_MAJOR        4
  44 #define TS_MINOR        0
  45 #define TS_VERSION      (TS_MAJOR << 16 | TS_MINOR)
  46
  47 #define TS_MAJOR_1      1
  48 #define TS_VERSION_1    (TS_MAJOR_1 << 16 | TS_MINOR)
  49
  50 #define TS_MAJOR_3      3
  51 #define TS_VERSION_3    (TS_MAJOR_3 << 16 | TS_MINOR)
  52
  53 #define HB_MAJOR        3
  54 #define HB_MINOR        0
  55 #define HB_VERSION      (HB_MAJOR << 16 | HB_MINOR)
  56
  57 #define HB_MAJOR_1      1
  58 #define HB_VERSION_1    (HB_MAJOR_1 << 16 | HB_MINOR)
  59
  60 static int sd_srv_version;
  61 static int ts_srv_version;
  62 static int hb_srv_version;
  63
  64 #define SD_VER_COUNT 2
  65 static const int sd_versions[] = {
  66         SD_VERSION,
  67         SD_VERSION_1
  68 };
  69
  70 #define TS_VER_COUNT 3
  71 static const int ts_versions[] = {
  72         TS_VERSION,
  73         TS_VERSION_3,
  74         TS_VERSION_1
  75 };
  76
  77 #define HB_VER_COUNT 2
  78 static const int hb_versions[] = {
  79         HB_VERSION,
  80         HB_VERSION_1
  81 };
  82
  83 #define FW_VER_COUNT 2
  84 static const int fw_versions[] = {
  85         UTIL_FW_VERSION,
  86         UTIL_WS2K8_FW_VERSION
  87 };
  88
  89 static void shutdown_onchannelcallback(void *context);
  90 static struct hv_util_service util_shutdown = {
  91         .util_cb = shutdown_onchannelcallback,
  92 };
  93
  94 static int hv_timesync_init(struct hv_util_service *srv);
  95 static void hv_timesync_deinit(void);
  96
  97 static void timesync_onchannelcallback(void *context);
  98 static struct hv_util_service util_timesynch = {
  99         .util_cb = timesync_onchannelcallback,
 100         .util_init = hv_timesync_init,
 101         .util_deinit = hv_timesync_deinit,
 102 };
 103
 104 static void heartbeat_onchannelcallback(void *context);
 105 static struct hv_util_service util_heartbeat = {
 106         .util_cb = heartbeat_onchannelcallback,
 107 };
 108
 109 static struct hv_util_service util_kvp = {
 110         .util_cb = hv_kvp_onchannelcallback,
 111         .util_init = hv_kvp_init,
 112         .util_deinit = hv_kvp_deinit,
 113 };
 114
 115 static struct hv_util_service util_vss = {
 116         .util_cb = hv_vss_onchannelcallback,
 117         .util_init = hv_vss_init,
 118         .util_deinit = hv_vss_deinit,
 119 };
 120
 121 static struct hv_util_service util_fcopy = {
 122         .util_cb = hv_fcopy_onchannelcallback,
 123         .util_init = hv_fcopy_init,
 124         .util_deinit = hv_fcopy_deinit,
 125 };
 126
 127 static void perform_shutdown(struct work_struct *dummy)
 128 {
 129         orderly_poweroff(true);
 130 }
 131
 132 /*
 133  * Perform the shutdown operation in a thread context.
 134  */
 135 static DECLARE_WORK(shutdown_work, perform_shutdown);
 136
 137 static void shutdown_onchannelcallback(void *context)
 138 {
 139         struct vmbus_channel *channel = context;
 140         u32 recvlen;
 141         u64 requestid;
 142         bool execute_shutdown = false;
 143         u8  *shut_txf_buf = util_shutdown.recv_buffer;
 144
 145         struct shutdown_msg_data *shutdown_msg;
 146
 147         struct icmsg_hdr *icmsghdrp;
 148
 149         vmbus_recvpacket(channel, shut_txf_buf,
 150                          PAGE_SIZE, &recvlen, &requestid);
 151
 152         if (recvlen > 0) {
 153                 icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
 154                         sizeof(struct vmbuspipe_hdr)];
 155
 156                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 157                         if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
 158                                         fw_versions, FW_VER_COUNT,
 159                                         sd_versions, SD_VER_COUNT,
 160                                         NULL, &sd_srv_version)) {
 161                                 pr_info("Shutdown IC version %d.%d\n",
 162                                         sd_srv_version >> 16,
 163                                         sd_srv_version & 0xFFFF);
 164                         }
 165                 } else {
 166                         shutdown_msg =
 167                                 (struct shutdown_msg_data *)&shut_txf_buf[
 168                                         sizeof(struct vmbuspipe_hdr) +
 169                                         sizeof(struct icmsg_hdr)];
 170
 171                         switch (shutdown_msg->flags) {
 172                         case 0:
 173                         case 1:
 174                                 icmsghdrp->status = HV_S_OK;
 175                                 execute_shutdown = true;
 176
 177                                 pr_info("Shutdown request received -"
 178                                             " graceful shutdown initiated\n");
 179                                 break;
 180                         default:
 181                                 icmsghdrp->status = HV_E_FAIL;
 182                                 execute_shutdown = false;
 183
 184                                 pr_info("Shutdown request received -"
 185                                             " Invalid request\n");
 186                                 break;
 187                         }
 188                 }
 189
 190                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 191                         | ICMSGHDRFLAG_RESPONSE;
 192
 193                 vmbus_sendpacket(channel, shut_txf_buf,
 194                                        recvlen, requestid,
 195                                        VM_PKT_DATA_INBAND, 0);
 196         }
 197
 198         if (execute_shutdown == true)
 199                 schedule_work(&shutdown_work);
 200 }
 201
 202 /*
 203  * Set the host time in a process context.
 204  */
 205
 206 struct adj_time_work {
 207         struct work_struct work;
 208         u64     host_time;
 209         u64     ref_time;
 210         u8      flags;
 211 };
 212
 213 static void hv_set_host_time(struct work_struct *work)
 214 {
 215         struct adj_time_work *wrk;
 216         struct timespec64 host_ts;
 217         u64 reftime, newtime;
 218
 219         wrk = container_of(work, struct adj_time_work, work);
 220
 221         reftime = hyperv_cs->read(hyperv_cs);
 222         newtime = wrk->host_time + (reftime - wrk->ref_time);
 223         host_ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
 224
 225         do_settimeofday64(&host_ts);
 226 }
 227
 228 /*
 229  * Synchronize time with host after reboot, restore, etc.
 230  *
 231  * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
 232  * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
 233  * message after the timesync channel is opened. Since the hv_utils module is
 234  * loaded after hv_vmbus, the first message is usually missed. This bit is
 235  * considered a hard request to discipline the clock.
 236  *
 237  * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
 238  * typically used as a hint to the guest. The guest is under no obligation
 239  * to discipline the clock.
 240  */
 241 static struct adj_time_work  wrk;
 242
 243 /*
 244  * The last time sample, received from the host. PTP device responds to
 245  * requests by using this data and the current partition-wide time reference
 246  * count.
 247  */
 248 static struct {
 249         u64                             host_time;
 250         u64                             ref_time;
 251         struct system_time_snapshot     snap;
 252         spinlock_t                      lock;
 253 } host_ts;
 254
 255 static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
 256 {
 257         unsigned long flags;
 258         u64 cur_reftime;
 259
 260         /*
 261          * This check is safe since we are executing in the
 262          * interrupt context and time synch messages are always
 263          * delivered on the same CPU.
 264          */
 265         if (adj_flags & ICTIMESYNCFLAG_SYNC) {
 266                 /* Queue a job to do do_settimeofday64() */
 267                 if (work_pending(&wrk.work))
 268                         return;
 269
 270                 wrk.host_time = hosttime;
 271                 wrk.ref_time = reftime;
 272                 wrk.flags = adj_flags;
 273                 schedule_work(&wrk.work);
 274         } else {
 275                 /*
 276                  * Save the adjusted time sample from the host and the snapshot
 277                  * of the current system time for PTP device.
 278                  */
 279                 spin_lock_irqsave(&host_ts.lock, flags);
 280
 281                 cur_reftime = hyperv_cs->read(hyperv_cs);
 282                 host_ts.host_time = hosttime;
 283                 host_ts.ref_time = cur_reftime;
 284                 ktime_get_snapshot(&host_ts.snap);
 285
 286                 /*
 287                  * TimeSync v4 messages contain reference time (guest's Hyper-V
 288                  * clocksource read when the time sample was generated), we can
 289                  * improve the precision by adding the delta between now and the
 290                  * time of generation.
 291                  */
 292                 if (ts_srv_version > TS_VERSION_3)
 293                         host_ts.host_time += (cur_reftime - reftime);
 294
 295                 spin_unlock_irqrestore(&host_ts.lock, flags);
 296         }
 297 }
 298
 299 /*
 300  * Time Sync Channel message handler.
 301  */
 302 static void timesync_onchannelcallback(void *context)
 303 {
 304         struct vmbus_channel *channel = context;
 305         u32 recvlen;
 306         u64 requestid;
 307         struct icmsg_hdr *icmsghdrp;
 308         struct ictimesync_data *timedatap;
 309         struct ictimesync_ref_data *refdata;
 310         u8 *time_txf_buf = util_timesynch.recv_buffer;
 311
 312         vmbus_recvpacket(channel, time_txf_buf,
 313                          PAGE_SIZE, &recvlen, &requestid);
 314
 315         if (recvlen > 0) {
 316                 icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
 317                                 sizeof(struct vmbuspipe_hdr)];
 318
 319                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 320                         if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
 321                                                 fw_versions, FW_VER_COUNT,
 322                                                 ts_versions, TS_VER_COUNT,
 323                                                 NULL, &ts_srv_version)) {
 324                                 pr_info("TimeSync IC version %d.%d\n",
 325                                         ts_srv_version >> 16,
 326                                         ts_srv_version & 0xFFFF);
 327                         }
 328                 } else {
 329                         if (ts_srv_version > TS_VERSION_3) {
 330                                 refdata = (struct ictimesync_ref_data *)
 331                                         &time_txf_buf[
 332                                         sizeof(struct vmbuspipe_hdr) +
 333                                         sizeof(struct icmsg_hdr)];
 334
 335                                 adj_guesttime(refdata->parenttime,
 336                                                 refdata->vmreferencetime,
 337                                                 refdata->flags);
 338                         } else {
 339                                 timedatap = (struct ictimesync_data *)
 340                                         &time_txf_buf[
 341                                         sizeof(struct vmbuspipe_hdr) +
 342                                         sizeof(struct icmsg_hdr)];
 343                                 adj_guesttime(timedatap->parenttime,
 344                                                 0,
 345                                                 timedatap->flags);
 346                         }
 347                 }
 348
 349                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 350                         | ICMSGHDRFLAG_RESPONSE;
 351
 352                 vmbus_sendpacket(channel, time_txf_buf,
 353                                 recvlen, requestid,
 354                                 VM_PKT_DATA_INBAND, 0);
 355         }
 356 }
 357
 358 /*
 359  * Heartbeat functionality.
 360  * Every two seconds, Hyper-V send us a heartbeat request message.
 361  * we respond to this message, and Hyper-V knows we are alive.
 362  */
 363 static void heartbeat_onchannelcallback(void *context)
 364 {
 365         struct vmbus_channel *channel = context;
 366         u32 recvlen;
 367         u64 requestid;
 368         struct icmsg_hdr *icmsghdrp;
 369         struct heartbeat_msg_data *heartbeat_msg;
 370         u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
 371
 372         while (1) {
 373
 374                 vmbus_recvpacket(channel, hbeat_txf_buf,
 375                                  PAGE_SIZE, &recvlen, &requestid);
 376
 377                 if (!recvlen)
 378                         break;
 379
 380                 icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
 381                                 sizeof(struct vmbuspipe_hdr)];
 382
 383                 if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
 384                         if (vmbus_prep_negotiate_resp(icmsghdrp,
 385                                         hbeat_txf_buf,
 386                                         fw_versions, FW_VER_COUNT,
 387                                         hb_versions, HB_VER_COUNT,
 388                                         NULL, &hb_srv_version)) {
 389
 390                                 pr_info("Heartbeat IC version %d.%d\n",
 391                                         hb_srv_version >> 16,
 392                                         hb_srv_version & 0xFFFF);
 393                         }
 394                 } else {
 395                         heartbeat_msg =
 396                                 (struct heartbeat_msg_data *)&hbeat_txf_buf[
 397                                         sizeof(struct vmbuspipe_hdr) +
 398                                         sizeof(struct icmsg_hdr)];
 399
 400                         heartbeat_msg->seq_num += 1;
 401                 }
 402
 403                 icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 404                         | ICMSGHDRFLAG_RESPONSE;
 405
 406                 vmbus_sendpacket(channel, hbeat_txf_buf,
 407                                        recvlen, requestid,
 408                                        VM_PKT_DATA_INBAND, 0);
 409         }
 410 }
 411
 412 static int util_probe(struct hv_device *dev,
 413                         const struct hv_vmbus_device_id *dev_id)
 414 {
 415         struct hv_util_service *srv =
 416                 (struct hv_util_service *)dev_id->driver_data;
 417         int ret;
 418
 419         srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
 420         if (!srv->recv_buffer)
 421                 return -ENOMEM;
 422         srv->channel = dev->channel;
 423         if (srv->util_init) {
 424                 ret = srv->util_init(srv);
 425                 if (ret) {
 426                         ret = -ENODEV;
 427                         goto error1;
 428                 }
 429         }
 430
 431         /*
 432          * The set of services managed by the util driver are not performance
 433          * critical and do not need batched reading. Furthermore, some services
 434          * such as KVP can only handle one message from the host at a time.
 435          * Turn off batched reading for all util drivers before we open the
 436          * channel.
 437          */
 438         set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
 439
 440         hv_set_drvdata(dev, srv);
 441
 442         ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
 443                         srv->util_cb, dev->channel);
 444         if (ret)
 445                 goto error;
 446
 447         return 0;
 448
 449 error:
 450         if (srv->util_deinit)
 451                 srv->util_deinit();
 452 error1:
 453         kfree(srv->recv_buffer);
 454         return ret;
 455 }
 456
 457 static int util_remove(struct hv_device *dev)
 458 {
 459         struct hv_util_service *srv = hv_get_drvdata(dev);
 460
 461         if (srv->util_deinit)
 462                 srv->util_deinit();
 463         vmbus_close(dev->channel);
 464         kfree(srv->recv_buffer);
 465
 466         return 0;
 467 }
 468
 469 static const struct hv_vmbus_device_id id_table[] = {
 470         /* Shutdown guid */
 471         { HV_SHUTDOWN_GUID,
 472           .driver_data = (unsigned long)&util_shutdown
 473         },
 474         /* Time synch guid */
 475         { HV_TS_GUID,
 476           .driver_data = (unsigned long)&util_timesynch
 477         },
 478         /* Heartbeat guid */
 479         { HV_HEART_BEAT_GUID,
 480           .driver_data = (unsigned long)&util_heartbeat
 481         },
 482         /* KVP guid */
 483         { HV_KVP_GUID,
 484           .driver_data = (unsigned long)&util_kvp
 485         },
 486         /* VSS GUID */
 487         { HV_VSS_GUID,
 488           .driver_data = (unsigned long)&util_vss
 489         },
 490         /* File copy GUID */
 491         { HV_FCOPY_GUID,
 492           .driver_data = (unsigned long)&util_fcopy
 493         },
 494         { },
 495 };
 496
 497 MODULE_DEVICE_TABLE(vmbus, id_table);
 498
 499 /* The one and only one */
 500 static  struct hv_driver util_drv = {
 501         .name = "hv_util",
 502         .id_table = id_table,
 503         .probe =  util_probe,
 504         .remove =  util_remove,
 505 };
 506
 507 static int hv_ptp_enable(struct ptp_clock_info *info,
 508                          struct ptp_clock_request *request, int on)
 509 {
 510         return -EOPNOTSUPP;
 511 }
 512
 513 static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
 514 {
 515         return -EOPNOTSUPP;
 516 }
 517
 518 static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
 519 {
 520         return -EOPNOTSUPP;
 521 }
 522 static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 523 {
 524         return -EOPNOTSUPP;
 525 }
 526
 527 static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
 528 {
 529         unsigned long flags;
 530         u64 newtime, reftime;
 531
 532         spin_lock_irqsave(&host_ts.lock, flags);
 533         reftime = hyperv_cs->read(hyperv_cs);
 534         newtime = host_ts.host_time + (reftime - host_ts.ref_time);
 535         *ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
 536         spin_unlock_irqrestore(&host_ts.lock, flags);
 537
 538         return 0;
 539 }
 540
 541 static int hv_ptp_get_syncdevicetime(ktime_t *device,
 542                                      struct system_counterval_t *system,
 543                                      void *ctx)
 544 {
 545         system->cs = hyperv_cs;
 546         system->cycles = host_ts.ref_time;
 547         *device = ns_to_ktime((host_ts.host_time - WLTIMEDELTA) * 100);
 548
 549         return 0;
 550 }
 551
 552 static int hv_ptp_getcrosststamp(struct ptp_clock_info *ptp,
 553                                  struct system_device_crosststamp *xtstamp)
 554 {
 555         unsigned long flags;
 556         int ret;
 557
 558         spin_lock_irqsave(&host_ts.lock, flags);
 559
 560         /*
 561          * host_ts contains the last time sample from the host and the snapshot
 562          * of system time. We don't need to calculate the time delta between
 563          * the reception and now as get_device_system_crosststamp() does the
 564          * required interpolation.
 565          */
 566         ret = get_device_system_crosststamp(hv_ptp_get_syncdevicetime,
 567                                             NULL, &host_ts.snap, xtstamp);
 568
 569         spin_unlock_irqrestore(&host_ts.lock, flags);
 570
 571         return ret;
 572 }
 573
 574 static struct ptp_clock_info ptp_hyperv_info = {
 575         .name           = "hyperv",
 576         .enable         = hv_ptp_enable,
 577         .adjtime        = hv_ptp_adjtime,
 578         .adjfreq        = hv_ptp_adjfreq,
 579         .gettime64      = hv_ptp_gettime,
 580         .getcrosststamp = hv_ptp_getcrosststamp,
 581         .settime64      = hv_ptp_settime,
 582         .owner          = THIS_MODULE,
 583 };
 584
 585 static struct ptp_clock *hv_ptp_clock;
 586
 587 static int hv_timesync_init(struct hv_util_service *srv)
 588 {
 589         /* TimeSync requires Hyper-V clocksource. */
 590         if (!hyperv_cs)
 591                 return -ENODEV;
 592
 593         spin_lock_init(&host_ts.lock);
 594
 595         INIT_WORK(&wrk.work, hv_set_host_time);
 596
 597         /*
 598          * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
 599          * disabled but the driver is still useful without the PTP device
 600          * as it still handles the ICTIMESYNCFLAG_SYNC case.
 601          */
 602         hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
 603         if (IS_ERR_OR_NULL(hv_ptp_clock)) {
 604                 pr_err("cannot register PTP clock: %ld\n",
 605                        PTR_ERR(hv_ptp_clock));
 606                 hv_ptp_clock = NULL;
 607         }
 608
 609         return 0;
 610 }
 611
 612 static void hv_timesync_deinit(void)
 613 {
 614         if (hv_ptp_clock)
 615                 ptp_clock_unregister(hv_ptp_clock);
 616         cancel_work_sync(&wrk.work);
 617 }
 618
 619 static int __init init_hyperv_utils(void)
 620 {
 621         pr_info("Registering HyperV Utility Driver\n");
 622
 623         return vmbus_driver_register(&util_drv);
 624 }
 625
 626 static void exit_hyperv_utils(void)
 627 {
 628         pr_info("De-Registered HyperV Utility Driver\n");
 629
 630         vmbus_driver_unregister(&util_drv);
 631 }
 632
 633 module_init(init_hyperv_utils);
 634 module_exit(exit_hyperv_utils);
 635
 636 MODULE_DESCRIPTION("Hyper-V Utilities");
 637 MODULE_LICENSE("GPL");