1 files changed, 216 insertions, 0 deletions
diff --git a/sys/dev/hyperv/utilities/hv_timesync.c b/sys/dev/hyperv/utilities/hv_timesync.c
new file mode 100644
index 0000000..d1ea904
--- /dev/null
+++ b/sys/dev/hyperv/utilities/hv_timesync.c
@@ -0,0 +1,216 @@
+/*-
+ * 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_util.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;
+
+        /* Time Synch Service */
+static hv_guid service_guid = {.data =
+	{0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49,
+	0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf } };
+
+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(void *context)
+{
+	hv_vmbus_channel*	channel;
+	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;
+	channel = softc->util_sc.hv_dev->channel;
+	time_buf = softc->util_sc.receive_buffer;
+
+	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(softc, 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);
+	}
+}
+
+static int
+hv_timesync_probe(device_t dev)
+{
+	const char *p = vmbus_get_type(dev);
+	if (!memcmp(p, &service_guid, sizeof(hv_guid))) {
+		device_set_desc(dev, "Hyper-V Time Synch Service");
+		return BUS_PROBE_DEFAULT;
+	}
+
+	return ENXIO;
+}
+
+static int
+hv_timesync_attach(device_t dev)
+{
+	hv_timesync_sc *softc = device_get_softc(dev);
+
+	softc->util_sc.callback = hv_timesync_cb;
+	TASK_INIT(&softc->task, 1, hv_set_host_time, softc);
+
+	return hv_util_attach(dev);
+}
+
+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);