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 perform_shutdown(struct work_struct *dummy)
  53{
  54        orderly_poweroff(true);
  55}
  56
  57/*
  58 * Perform the shutdown operation in a thread context.
  59 */
  60static DECLARE_WORK(shutdown_work, perform_shutdown);
  61
  62static 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 */
 125static 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
 140struct adj_time_work {
 141        struct work_struct work;
 142        u64     host_time;
 143};
 144
 145static 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 */
 165static 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 */
 192static 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 */
 232static 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
 269static 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
 305error:
 306        if (srv->util_deinit)
 307                srv->util_deinit();
 308error1:
 309        kfree(srv->recv_buffer);
 310        return ret;
 311}
 312
 313static 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
 325static 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
 345MODULE_DEVICE_TABLE(vmbus, id_table);
 346
 347/* The one and only one */
 348static  struct hv_driver util_drv = {
 349        .name = "hv_util",
 350        .id_table = id_table,
 351        .probe =  util_probe,
 352        .remove =  util_remove,
 353};
 354
 355static 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
 362static void exit_hyperv_utils(void)
 363{
 364        pr_info("De-Registered HyperV Utility Driver\n");
 365
 366        vmbus_driver_unregister(&util_drv);
 367}
 368
 369module_init(init_hyperv_utils);
 370module_exit(exit_hyperv_utils);
 371
 372MODULE_DESCRIPTION("Hyper-V Utilities");
 373MODULE_VERSION(HV_DRV_VERSION);
 374MODULE_LICENSE("GPL");
 375
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