hv_util.c

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/*
 * Copyright (c) 2010, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <[email protected]>
 *   Hank Janssen  <[email protected]>
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/reboot.h>
#include <linux/hyperv.h>

static void shutdown_onchannelcallback(void *context);
static struct hv_util_service util_shutdown = {
    .util_cb = shutdown_onchannelcallback,
};

static void timesync_onchannelcallback(void *context);
static struct hv_util_service util_timesynch = {
    .util_cb = timesync_onchannelcallback,
};

static void heartbeat_onchannelcallback(void *context);
static struct hv_util_service util_heartbeat = {
    .util_cb = heartbeat_onchannelcallback,
};

static struct hv_util_service util_kvp = {
    .util_cb = hv_kvp_onchannelcallback,
    .util_init = hv_kvp_init,
    .util_deinit = hv_kvp_deinit,
};

static void shutdown_onchannelcallback(void *context)
{
    struct vmbus_channel *channel = context;
    u32 recvlen;
    u64 requestid;
    u8  execute_shutdown = false;
    u8  *shut_txf_buf = util_shutdown.recv_buffer;

    struct shutdown_msg_data *shutdown_msg;

    struct icmsg_hdr *icmsghdrp;
    struct icmsg_negotiate *negop = NULL;

    vmbus_recvpacket(channel, shut_txf_buf,
             PAGE_SIZE, &recvlen, &requestid);

    if (recvlen > 0) {
        icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
            sizeof(struct vmbuspipe_hdr)];

        if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
            vmbus_prep_negotiate_resp(icmsghdrp, negop,
                    shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
        } else {
            shutdown_msg =
                (struct shutdown_msg_data *)&shut_txf_buf[
                    sizeof(struct vmbuspipe_hdr) +
                    sizeof(struct icmsg_hdr)];

            switch (shutdown_msg->flags) {
            case 0:
            case 1:
                icmsghdrp->status = HV_S_OK;
                execute_shutdown = true;

                pr_info("Shutdown request received -"
                        " graceful shutdown initiated\n");
                break;
            default:
                icmsghdrp->status = HV_E_FAIL;
                execute_shutdown = false;

                pr_info("Shutdown request received -"
                        " Invalid request\n");
                break;
            }
        }

        icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
            | ICMSGHDRFLAG_RESPONSE;

        vmbus_sendpacket(channel, shut_txf_buf,
                       recvlen, requestid,
                       VM_PKT_DATA_INBAND, 0);
    }

    if (execute_shutdown == true)
        orderly_poweroff(true);
}

/*
 * Set guest time to host UTC time.
 */
static inline void do_adj_guesttime(u64 hosttime)
{
    s64 host_tns;
    struct timespec host_ts;

    host_tns = (hosttime - WLTIMEDELTA) * 100;
    host_ts = ns_to_timespec(host_tns);

    do_settimeofday(&host_ts);
}

/*
 * Set the host time in a process context.
 */

struct adj_time_work {
    struct work_struct work;
    u64 host_time;
};

static void hv_set_host_time(struct work_struct *work)
{
    struct adj_time_work    *wrk;

    wrk = container_of(work, struct adj_time_work, work);
    do_adj_guesttime(wrk->host_time);
    kfree(wrk);
}

/*
 * Synchronize time with host after reboot, restore, etc.
 *
 * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
 * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
 * message after the timesync channel is opened. Since the hv_utils module is
 * loaded after hv_vmbus, the first message is usually missed. The other
 * thing is, systime is automatically set to emulated hardware clock which may
 * not be UTC time or in the same time zone. So, to override these effects, we
 * use the first 50 time samples for initial system time setting.
 */
static inline void adj_guesttime(u64 hosttime, u8 flags)
{
    struct adj_time_work    *wrk;
    static s32 scnt = 50;

    wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
    if (wrk == NULL)
        return;

    wrk->host_time = hosttime;
    if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
        INIT_WORK(&wrk->work, hv_set_host_time);
        schedule_work(&wrk->work);
        return;
    }

    if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
        scnt--;
        INIT_WORK(&wrk->work, hv_set_host_time);
        schedule_work(&wrk->work);
    } else
        kfree(wrk);
}

/*
 * Time Sync Channel message handler.
 */
static void timesync_onchannelcallback(void *context)
{
    struct vmbus_channel *channel = context;
    u32 recvlen;
    u64 requestid;
    struct icmsg_hdr *icmsghdrp;
    struct ictimesync_data *timedatap;
    u8 *time_txf_buf = util_timesynch.recv_buffer;

    vmbus_recvpacket(channel, time_txf_buf,
             PAGE_SIZE, &recvlen, &requestid);

    if (recvlen > 0) {
        icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
                sizeof(struct vmbuspipe_hdr)];

        if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
            vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
                        MAX_SRV_VER, MAX_SRV_VER);
        } else {
            timedatap = (struct ictimesync_data *)&time_txf_buf[
                sizeof(struct vmbuspipe_hdr) +
                sizeof(struct icmsg_hdr)];
            adj_guesttime(timedatap->parenttime, timedatap->flags);
        }

        icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
            | ICMSGHDRFLAG_RESPONSE;

        vmbus_sendpacket(channel, time_txf_buf,
                recvlen, requestid,
                VM_PKT_DATA_INBAND, 0);
    }
}

/*
 * Heartbeat functionality.
 * Every two seconds, Hyper-V send us a heartbeat request message.
 * we respond to this message, and Hyper-V knows we are alive.
 */
static void heartbeat_onchannelcallback(void *context)
{
    struct vmbus_channel *channel = context;
    u32 recvlen;
    u64 requestid;
    struct icmsg_hdr *icmsghdrp;
    struct heartbeat_msg_data *heartbeat_msg;
    u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;

    vmbus_recvpacket(channel, hbeat_txf_buf,
             PAGE_SIZE, &recvlen, &requestid);

    if (recvlen > 0) {
        icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
                sizeof(struct vmbuspipe_hdr)];

        if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
            vmbus_prep_negotiate_resp(icmsghdrp, NULL,
                hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
        } else {
            heartbeat_msg =
                (struct heartbeat_msg_data *)&hbeat_txf_buf[
                    sizeof(struct vmbuspipe_hdr) +
                    sizeof(struct icmsg_hdr)];

            heartbeat_msg->seq_num += 1;
        }

        icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
            | ICMSGHDRFLAG_RESPONSE;

        vmbus_sendpacket(channel, hbeat_txf_buf,
                       recvlen, requestid,
                       VM_PKT_DATA_INBAND, 0);
    }
}

static int util_probe(struct hv_device *dev,
            const struct hv_vmbus_device_id *dev_id)
{
    struct hv_util_service *srv =
        (struct hv_util_service *)dev_id->driver_data;
    int ret;

    srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
    if (!srv->recv_buffer)
        return -ENOMEM;
    if (srv->util_init) {
        ret = srv->util_init(srv);
        if (ret) {
            ret = -ENODEV;
            goto error1;
        }
    }

    ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
            srv->util_cb, dev->channel);
    if (ret)
        goto error;

    hv_set_drvdata(dev, srv);
    return 0;

error:
    if (srv->util_deinit)
        srv->util_deinit();
error1:
    kfree(srv->recv_buffer);
    return ret;
}

static int util_remove(struct hv_device *dev)
{
    struct hv_util_service *srv = hv_get_drvdata(dev);

    vmbus_close(dev->channel);
    if (srv->util_deinit)
        srv->util_deinit();
    kfree(srv->recv_buffer);

    return 0;
}

static const struct hv_vmbus_device_id id_table[] = {
    /* Shutdown guid */
    { VMBUS_DEVICE(0x31, 0x60, 0x0B, 0X0E, 0x13, 0x52, 0x34, 0x49,
               0x81, 0x8B, 0x38, 0XD9, 0x0C, 0xED, 0x39, 0xDB)
      .driver_data = (unsigned long)&util_shutdown },
    /* Time synch guid */
    { VMBUS_DEVICE(0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
               0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf)
      .driver_data = (unsigned long)&util_timesynch },
    /* Heartbeat guid */
    { VMBUS_DEVICE(0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e,
               0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d)
      .driver_data = (unsigned long)&util_heartbeat },
    /* KVP guid */
    { VMBUS_DEVICE(0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
               0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6)
      .driver_data = (unsigned long)&util_kvp },
    { },
};

MODULE_DEVICE_TABLE(vmbus, id_table);

/* The one and only one */
static  struct hv_driver util_drv = {
    .name = "hv_util",
    .id_table = id_table,
    .probe =  util_probe,
    .remove =  util_remove,
};

static int __init init_hyperv_utils(void)
{
    pr_info("Registering HyperV Utility Driver\n");

    return vmbus_driver_register(&util_drv);
}

static void exit_hyperv_utils(void)
{
    pr_info("De-Registered HyperV Utility Driver\n");

    vmbus_driver_unregister(&util_drv);
}

module_init(init_hyperv_utils);
module_exit(exit_hyperv_utils);

MODULE_DESCRIPTION("Hyper-V Utilities");
MODULE_VERSION(HV_DRV_VERSION);
MODULE_LICENSE("GPL");