linux/drivers/hv/hv_util.c
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   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
  31static void shutdown_onchannelcallback(void *context);
  32static struct hv_util_service util_shutdown = {
  33        .util_cb = shutdown_onchannelcallback,
  34};
  35
  36static void timesync_onchannelcallback(void *context);
  37static struct hv_util_service util_timesynch = {
  38        .util_cb = timesync_onchannelcallback,
  39};
  40
  41static void heartbeat_onchannelcallback(void *context);
  42static struct hv_util_service util_heartbeat = {
  43        .util_cb = heartbeat_onchannelcallback,
  44};
  45
  46static 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
  52static 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 */
 115static 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
 130struct adj_time_work {
 131        struct work_struct work;
 132        u64     host_time;
 133};
 134
 135static 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 */
 155static 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 */
 182static 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 */
 222static 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
 259static 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, 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, 2 * PAGE_SIZE, 2 * 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
 285error:
 286        if (srv->util_deinit)
 287                srv->util_deinit();
 288error1:
 289        kfree(srv->recv_buffer);
 290        return ret;
 291}
 292
 293static 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
 305static 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
 325MODULE_DEVICE_TABLE(vmbus, id_table);
 326
 327/* The one and only one */
 328static  struct hv_driver util_drv = {
 329        .name = "hv_util",
 330        .id_table = id_table,
 331        .probe =  util_probe,
 332        .remove =  util_remove,
 333};
 334
 335static 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
 342static void exit_hyperv_utils(void)
 343{
 344        pr_info("De-Registered HyperV Utility Driver\n");
 345
 346        vmbus_driver_unregister(&util_drv);
 347}
 348
 349module_init(init_hyperv_utils);
 350module_exit(exit_hyperv_utils);
 351
 352MODULE_DESCRIPTION("Hyper-V Utilities");
 353MODULE_VERSION(HV_DRV_VERSION);
 354MODULE_LICENSE("GPL");
 355
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