freebsd-dev/sys/dev/hyperv/utilities/hv_timesync.c
Sepherosa Ziehau c4b78a2628 hyperv/util: Factor out helper for IC device_probe DEVMETHOD
MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D7530
2016-08-17 08:38:49 +00:00

219 lines
6.4 KiB
C

/*-
* Copyright (c) 2014,2016 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 <sys/systm.h>
#include <sys/taskqueue.h>
#include <dev/hyperv/include/hyperv.h>
#include <dev/hyperv/include/vmbus.h>
#include <dev/hyperv/utilities/hv_utilreg.h>
#include "hv_util.h"
#include "vmbus_if.h"
#define HV_WLTIMEDELTA 116444736000000000L /* in 100ns unit */
#define HV_ICTIMESYNCFLAG_PROBE 0
#define HV_ICTIMESYNCFLAG_SYNC 1
#define HV_ICTIMESYNCFLAG_SAMPLE 2
#define HV_NANO_SEC_PER_SEC 1000000000
/* Time Sync data */
typedef struct {
uint64_t data;
} time_sync_data;
static const struct vmbus_ic_desc vmbus_timesync_descs[] = {
{
.ic_guid = { .hv_guid = {
0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf } },
.ic_desc = "Hyper-V Timesync"
},
VMBUS_IC_DESC_END
};
struct hv_ictimesync_data {
uint64_t parenttime;
uint64_t childtime;
uint64_t roundtriptime;
uint8_t flags;
} __packed;
typedef struct hv_timesync_sc {
hv_util_sc util_sc;
struct task task;
time_sync_data time_msg;
} hv_timesync_sc;
/**
* Set host time based on time sync message from host
*/
static void
hv_set_host_time(void *context, int pending)
{
hv_timesync_sc *softc = (hv_timesync_sc*)context;
uint64_t hosttime = softc->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(hv_timesync_sc *sc, uint64_t hosttime, uint8_t flags)
{
sc->time_msg.data = hosttime;
if (((flags & HV_ICTIMESYNCFLAG_SYNC) != 0) ||
((flags & HV_ICTIMESYNCFLAG_SAMPLE) != 0)) {
taskqueue_enqueue(taskqueue_thread, &sc->task);
}
}
/**
* Time Sync Channel message handler
*/
static void
hv_timesync_cb(struct vmbus_channel *channel, void *context)
{
hv_vmbus_icmsg_hdr* icmsghdrp;
uint32_t recvlen;
uint64_t requestId;
int ret;
uint8_t* time_buf;
struct hv_ictimesync_data* timedatap;
hv_timesync_sc *softc;
softc = (hv_timesync_sc*)context;
time_buf = softc->util_sc.receive_buffer;
recvlen = softc->util_sc.ic_buflen;
ret = vmbus_chan_recv(channel, time_buf, &recvlen, &requestId);
KASSERT(ret != ENOBUFS, ("hvtimesync recvbuf is not large enough"));
/* XXX check recvlen to make sure that it contains enough data */
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, 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(softc, timedatap->parenttime, timedatap->flags);
}
icmsghdrp->icflags = HV_ICMSGHDRFLAG_TRANSACTION
| HV_ICMSGHDRFLAG_RESPONSE;
vmbus_chan_send(channel, VMBUS_CHANPKT_TYPE_INBAND, 0,
time_buf, recvlen, requestId);
}
}
static int
hv_timesync_probe(device_t dev)
{
return (vmbus_ic_probe(dev, vmbus_timesync_descs));
}
static int
hv_timesync_attach(device_t dev)
{
hv_timesync_sc *softc = device_get_softc(dev);
TASK_INIT(&softc->task, 1, hv_set_host_time, softc);
return hv_util_attach(dev, hv_timesync_cb);
}
static int
hv_timesync_detach(device_t dev)
{
hv_timesync_sc *softc = device_get_softc(dev);
taskqueue_drain(taskqueue_thread, &softc->task);
return hv_util_detach(dev);
}
static device_method_t timesync_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, hv_timesync_probe),
DEVMETHOD(device_attach, hv_timesync_attach),
DEVMETHOD(device_detach, hv_timesync_detach),
{ 0, 0 }
};
static driver_t timesync_driver = { "hvtimesync", timesync_methods, sizeof(hv_timesync_sc)};
static devclass_t timesync_devclass;
DRIVER_MODULE(hv_timesync, vmbus, timesync_driver, timesync_devclass, NULL, NULL);
MODULE_VERSION(hv_timesync, 1);
MODULE_DEPEND(hv_timesync, vmbus, 1, 1, 1);