freebsd-dev/sys/dev/hyperv/utilities/hv_util.c

/*-
 * Copyright (c) 2014 Microsoft Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD$
 */

/*
 * A common driver for all hyper-V util services.
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/reboot.h>
#include <sys/timetc.h>
#include <sys/syscallsubr.h>

#include <dev/hyperv/include/hyperv.h>
#include "hv_kvp.h"

/* Time Sync data */
typedef struct {
	uint64_t data;
} time_sync_data;

static void hv_shutdown_cb(void *context);
static void hv_heartbeat_cb(void *context);
static void hv_timesync_cb(void *context);

static int hv_timesync_init(hv_vmbus_service *serv);
static int hv_timesync_uninit(hv_vmbus_service *serv);
static void hv_set_host_time(void *context, int pending);

/*
 * Note: GUID codes below are predefined by the host hypervisor
 * (Hyper-V and Azure)interface and required for correct operation.
 */
hv_vmbus_service service_table[] = {
	/* Shutdown Service */
	{ .guid.data = {0x31, 0x60, 0x0B, 0X0E, 0x13, 0x52, 0x34, 0x49,
			0x81, 0x8B, 0x38, 0XD9, 0x0C, 0xED, 0x39, 0xDB},
	  .name  = "Hyper-V Shutdown Service\n",
	  .enabled = TRUE,
	  .callback = hv_shutdown_cb,
	},

        /* Time Synch Service */
        { .guid.data = {0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
			0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf},
	  .name = "Hyper-V Time Synch Service\n",
	  .enabled = TRUE,
	  .init = hv_timesync_init,
	  .callback = hv_timesync_cb,
	  .uninit = hv_timesync_uninit,
	},

        /* Heartbeat Service */
        { .guid.data = {0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e,
			0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d},
	  .name = "Hyper-V Heartbeat Service\n",
	  .enabled = TRUE,
  	  .callback = hv_heartbeat_cb,
	},

        /* KVP (Key Value Pair) Service */
        { .guid.data = {0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d,
			0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6},
	  .name = "Hyper-V KVP Service\n",
	  .enabled = TRUE,
	  .init = hv_kvp_init,
	  .callback = hv_kvp_callback,
	},
};

/*
 * Receive buffer pointers. There is one buffer per utility service. The
 * buffer is allocated during attach().
 */
uint8_t *receive_buffer[HV_MAX_UTIL_SERVICES];

static boolean_t destroyed_kvp = FALSE;

struct hv_ictimesync_data {
	uint64_t    parenttime;
	uint64_t    childtime;
	uint64_t    roundtriptime;
	uint8_t     flags;
} __packed;

static int
hv_timesync_init(hv_vmbus_service *serv)
{
	void *time_msg = malloc(sizeof(time_sync_data), M_DEVBUF, M_WAITOK);
	TASK_INIT(&serv->task, 1, hv_set_host_time, time_msg);
	return (0);
}

static int
hv_timesync_uninit(hv_vmbus_service *serv)
{
	taskqueue_drain(taskqueue_thread, &serv->task);
	free(serv->task.ta_context, M_DEVBUF);
	return (0);
}

static void
hv_negotiate_version(
	struct hv_vmbus_icmsg_hdr*		icmsghdrp,
	struct hv_vmbus_icmsg_negotiate*	negop,
	uint8_t*				buf)
{
	icmsghdrp->icmsgsize = 0x10;

	negop = (struct hv_vmbus_icmsg_negotiate *)&buf[
		sizeof(struct hv_vmbus_pipe_hdr) +
		sizeof(struct hv_vmbus_icmsg_hdr)];

	if (negop->icframe_vercnt >= 2 &&
	    negop->icversion_data[1].major == 3) {
		negop->icversion_data[0].major = 3;
		negop->icversion_data[0].minor = 0;
		negop->icversion_data[1].major = 3;
		negop->icversion_data[1].minor = 0;
	} else {
		negop->icversion_data[0].major = 1;
		negop->icversion_data[0].minor = 0;
		negop->icversion_data[1].major = 1;
		negop->icversion_data[1].minor = 0;
	}

	negop->icframe_vercnt = 1;
	negop->icmsg_vercnt = 1;
}


/**
 * Set host time based on time sync message from host
 */
static void
hv_set_host_time(void *context, int pending)
{
	time_sync_data* time_msg = (time_sync_data*) context;
	uint64_t hosttime = time_msg->data;
	struct timespec guest_ts, host_ts;
	uint64_t host_tns;
	int64_t diff;
	int error;

	host_tns = (hosttime - HV_WLTIMEDELTA) * 100;
	host_ts.tv_sec = (time_t)(host_tns/HV_NANO_SEC_PER_SEC);
	host_ts.tv_nsec = (long)(host_tns%HV_NANO_SEC_PER_SEC);

	nanotime(&guest_ts);

	diff = (int64_t)host_ts.tv_sec - (int64_t)guest_ts.tv_sec;

	/*
	 * If host differs by 5 seconds then make the guest catch up
	 */
	if (diff > 5 || diff < -5) {
		error = kern_clock_settime(curthread, CLOCK_REALTIME,
		    &host_ts);
	}
}

/**
 * @brief 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 hv_adj_guesttime(uint64_t hosttime, uint8_t flags)
{
	time_sync_data* time_msg = service_table[HV_TIME_SYNCH].task.ta_context;

	time_msg->data = hosttime;

	if (((flags & HV_ICTIMESYNCFLAG_SYNC) != 0) ||
		((flags & HV_ICTIMESYNCFLAG_SAMPLE) != 0)) {
		taskqueue_enqueue(taskqueue_thread, &service_table[HV_TIME_SYNCH].task);
	}
}

/**
 * Time Sync Channel message handler
 */
static void
hv_timesync_cb(void *context)
{
	hv_vmbus_channel*	channel = context;
	hv_vmbus_icmsg_hdr*	icmsghdrp;
	uint32_t		recvlen;
	uint64_t		requestId;
	int			ret;
	uint8_t*		time_buf;
	struct hv_ictimesync_data* timedatap;

	time_buf = receive_buffer[HV_TIME_SYNCH];

	ret = hv_vmbus_channel_recv_packet(channel, time_buf,
					    PAGE_SIZE, &recvlen, &requestId);

	if ((ret == 0) && recvlen > 0) {
	    icmsghdrp = (struct hv_vmbus_icmsg_hdr *) &time_buf[
		sizeof(struct hv_vmbus_pipe_hdr)];

	    if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
		hv_negotiate_version(icmsghdrp, NULL, time_buf);
	    } else {
		timedatap = (struct hv_ictimesync_data *) &time_buf[
		    sizeof(struct hv_vmbus_pipe_hdr) +
			sizeof(struct hv_vmbus_icmsg_hdr)];
		hv_adj_guesttime(timedatap->parenttime, timedatap->flags);
	    }

	    icmsghdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION
		| HV_ICMSGHDRFLAG_RESPONSE;

	    hv_vmbus_channel_send_packet(channel, time_buf,
		recvlen, requestId,
		HV_VMBUS_PACKET_TYPE_DATA_IN_BAND, 0);
	}
}

/**
 * Shutdown
 */
static void
hv_shutdown_cb(void *context)
{
	uint8_t*		buf;
	hv_vmbus_channel*		channel = context;
	uint8_t			execute_shutdown = 0;
	hv_vmbus_icmsg_hdr*		icmsghdrp;
	uint32_t		recv_len;
	uint64_t		request_id;
	int				ret;
	hv_vmbus_shutdown_msg_data*	shutdown_msg;

	buf = receive_buffer[HV_SHUT_DOWN];

	ret = hv_vmbus_channel_recv_packet(channel, buf, PAGE_SIZE,
					    &recv_len, &request_id);

	if ((ret == 0) && recv_len > 0) {

	    icmsghdrp = (struct hv_vmbus_icmsg_hdr *)
		&buf[sizeof(struct hv_vmbus_pipe_hdr)];

	    if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
		hv_negotiate_version(icmsghdrp, NULL, buf);

	    } else {
		shutdown_msg =
		    (struct hv_vmbus_shutdown_msg_data *)
		    &buf[sizeof(struct hv_vmbus_pipe_hdr) +
			sizeof(struct hv_vmbus_icmsg_hdr)];

		switch (shutdown_msg->flags) {
		    case 0:
		    case 1:
			icmsghdrp->status = HV_S_OK;
			execute_shutdown = 1;
			if(bootverbose)
			    printf("Shutdown request received -"
				    " graceful shutdown initiated\n");
			break;
		    default:
			icmsghdrp->status = HV_E_FAIL;
			execute_shutdown = 0;
			printf("Shutdown request received -"
			    " Invalid request\n");
			break;
		    }
	    }

	    icmsghdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION |
				 HV_ICMSGHDRFLAG_RESPONSE;

	    hv_vmbus_channel_send_packet(channel, buf,
					recv_len, request_id,
					HV_VMBUS_PACKET_TYPE_DATA_IN_BAND, 0);
	}

	if (execute_shutdown)
	    shutdown_nice(RB_POWEROFF);
}

/**
 * Process heartbeat message
 */
static void
hv_heartbeat_cb(void *context)
{
	uint8_t*		buf;
	hv_vmbus_channel*	channel = context;
	uint32_t		recvlen;
	uint64_t		requestid;
	int			ret;

	struct hv_vmbus_heartbeat_msg_data*	heartbeat_msg;
	struct hv_vmbus_icmsg_hdr*		icmsghdrp;

	buf = receive_buffer[HV_HEART_BEAT];

	ret = hv_vmbus_channel_recv_packet(channel, buf, PAGE_SIZE, &recvlen,
					    &requestid);

	if ((ret == 0) && recvlen > 0) {

	    icmsghdrp = (struct hv_vmbus_icmsg_hdr *)
		&buf[sizeof(struct hv_vmbus_pipe_hdr)];

	    if (icmsghdrp->icmsgtype == HV_ICMSGTYPE_NEGOTIATE) {
		hv_negotiate_version(icmsghdrp, NULL, buf);

	    } else {
		heartbeat_msg =
		    (struct hv_vmbus_heartbeat_msg_data *)
			&buf[sizeof(struct hv_vmbus_pipe_hdr) +
			     sizeof(struct hv_vmbus_icmsg_hdr)];

		heartbeat_msg->seq_num += 1;
	    }

	    icmsghdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION |
				 HV_ICMSGHDRFLAG_RESPONSE;

	    hv_vmbus_channel_send_packet(channel, buf, recvlen, requestid,
		HV_VMBUS_PACKET_TYPE_DATA_IN_BAND, 0);
	}
}


static int
hv_util_probe(device_t dev)
{
	int i;
	int rtn_value = ENXIO;

	for (i = 0; i < HV_MAX_UTIL_SERVICES; i++) {
	    const char *p = vmbus_get_type(dev);
	    if (service_table[i].enabled && !memcmp(p, &service_table[i].guid, sizeof(hv_guid))) {
		device_set_softc(dev, (void *) (&service_table[i]));
		rtn_value = BUS_PROBE_DEFAULT;
	    }
	}

	return rtn_value;
}

static int
hv_util_attach(device_t dev)
{
	struct hv_device*		hv_dev;
	struct hv_vmbus_service*	service;
	int				ret;
	size_t				receive_buffer_offset;

	hv_dev = vmbus_get_devctx(dev);
	service = device_get_softc(dev);
	receive_buffer_offset = service - &service_table[0];
	device_printf(dev, "Hyper-V Service attaching: %s\n", service->name);
	receive_buffer[receive_buffer_offset] =
		malloc(4 * PAGE_SIZE, M_DEVBUF, M_WAITOK | M_ZERO);

	if (service->init != NULL) {
	    ret = service->init(service);
	    if (ret) {
		ret = ENODEV;
		goto error0;
	    }
	}

	/*
	 * These services are not performance critical and do not need
	 * batched reading. Furthermore, some services such as KVP can
	 * only handle one message from the host at a time.
	 * Turn off batched reading for all util drivers before we open the
	 * channel.
	 */
	hv_set_channel_read_state(hv_dev->channel, FALSE);

	ret = hv_vmbus_channel_open(hv_dev->channel, 4 * PAGE_SIZE,
		    4 * PAGE_SIZE, NULL, 0,
		    service->callback, hv_dev->channel);

	if (ret)
	    goto error0;

	return (0);

	error0:

	    free(receive_buffer[receive_buffer_offset], M_DEVBUF);
	    receive_buffer[receive_buffer_offset] = NULL;

	return (ret);
}

static int
hv_util_detach(device_t dev)
{
	struct hv_device*		hv_dev;
	struct hv_vmbus_service*	service;
	size_t				receive_buffer_offset;

	if (!destroyed_kvp) {
		hv_kvp_deinit();
		destroyed_kvp = TRUE;
	}

	hv_dev = vmbus_get_devctx(dev);

	hv_vmbus_channel_close(hv_dev->channel);
	service = device_get_softc(dev);
	receive_buffer_offset = service - &service_table[0];

	if (service->uninit != NULL)
	    service->uninit(service);

	free(receive_buffer[receive_buffer_offset], M_DEVBUF);
	receive_buffer[receive_buffer_offset] = NULL;
	return (0);
}

static int
hv_util_modevent(module_t mod, int event, void *arg)
{
	switch (event) {
        case MOD_LOAD:
                break;
        case MOD_UNLOAD:
		break;
	default:
		break;
        }
        return (0);
}

static device_method_t util_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe, hv_util_probe),
	DEVMETHOD(device_attach, hv_util_attach),
	DEVMETHOD(device_detach, hv_util_detach),
	DEVMETHOD(device_shutdown, bus_generic_shutdown),
	{ 0, 0 } }
;

static driver_t util_driver = { "hyperv-utils", util_methods, 0 };

static devclass_t util_devclass;

DRIVER_MODULE(hv_utils, vmbus, util_driver, util_devclass, hv_util_modevent, 0);
MODULE_VERSION(hv_utils, 1);
MODULE_DEPEND(hv_utils, vmbus, 1, 1, 1);