freebsd-dev/sys/dev/hyperv/utilities/hv_timesync.c
Sepherosa Ziehau f1d33c25fa hyperv/ic: Cleanup driver glue.
MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8849
2016-12-20 07:34:44 +00:00

246 lines
6.7 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <dev/hyperv/include/hyperv.h>
#include <dev/hyperv/include/vmbus.h>
#include <dev/hyperv/utilities/vmbus_icreg.h>
#include <dev/hyperv/utilities/vmbus_icvar.h>
#define VMBUS_TIMESYNC_FWVER_MAJOR 3
#define VMBUS_TIMESYNC_FWVER \
VMBUS_IC_VERSION(VMBUS_TIMESYNC_FWVER_MAJOR, 0)
#define VMBUS_TIMESYNC_MSGVER_MAJOR 4
#define VMBUS_TIMESYNC_MSGVER \
VMBUS_IC_VERSION(VMBUS_TIMESYNC_MSGVER_MAJOR, 0)
#define VMBUS_TIMESYNC_DORTT(sc) \
((sc)->ic_msgver >= VMBUS_IC_VERSION(4, 0) && \
(hyperv_features & CPUID_HV_MSR_TIME_REFCNT))
static int vmbus_timesync_probe(device_t);
static int vmbus_timesync_attach(device_t);
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
};
static device_method_t vmbus_timesync_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, vmbus_timesync_probe),
DEVMETHOD(device_attach, vmbus_timesync_attach),
DEVMETHOD(device_detach, vmbus_ic_detach),
DEVMETHOD_END
};
static driver_t vmbus_timesync_driver = {
"hvtimesync",
vmbus_timesync_methods,
sizeof(struct vmbus_ic_softc)
};
static devclass_t vmbus_timesync_devclass;
DRIVER_MODULE(hv_timesync, vmbus, vmbus_timesync_driver,
vmbus_timesync_devclass, NULL, NULL);
MODULE_VERSION(hv_timesync, 1);
MODULE_DEPEND(hv_timesync, vmbus, 1, 1, 1);
SYSCTL_NODE(_hw, OID_AUTO, hvtimesync, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
"Hyper-V timesync interface");
static int vmbus_ts_ignore_sync = 0;
SYSCTL_INT(_hw_hvtimesync, OID_AUTO, ignore_sync, CTLFLAG_RWTUN,
&vmbus_ts_ignore_sync, 0, "Ignore the sync request.");
/*
* Trigger sample sync when drift exceeds threshold (ms).
* Ignore the sample request when set to 0.
*/
static int vmbus_ts_sample_thresh = 100;
SYSCTL_INT(_hw_hvtimesync, OID_AUTO, sample_thresh, CTLFLAG_RWTUN,
&vmbus_ts_sample_thresh, 0,
"Threshold that makes sample request trigger the sync (unit: ms).");
static int vmbus_ts_sample_verbose = 0;
SYSCTL_INT(_hw_hvtimesync, OID_AUTO, sample_verbose, CTLFLAG_RWTUN,
&vmbus_ts_sample_verbose, 0, "Increase sample request verbosity.");
static void
vmbus_timesync(struct vmbus_ic_softc *sc, uint64_t hvtime, uint64_t sent_tc,
uint8_t tsflags)
{
struct timespec vm_ts;
uint64_t hv_ns, vm_ns, rtt = 0;
if (VMBUS_TIMESYNC_DORTT(sc))
rtt = rdmsr(MSR_HV_TIME_REF_COUNT) - sent_tc;
hv_ns = (hvtime - VMBUS_ICMSG_TS_BASE + rtt) * HYPERV_TIMER_NS_FACTOR;
nanotime(&vm_ts);
vm_ns = (vm_ts.tv_sec * NANOSEC) + vm_ts.tv_nsec;
if ((tsflags & VMBUS_ICMSG_TS_FLAG_SYNC) && !vmbus_ts_ignore_sync) {
struct timespec hv_ts;
if (bootverbose) {
device_printf(sc->ic_dev, "apply sync request, "
"hv: %ju, vm: %ju\n",
(uintmax_t)hv_ns, (uintmax_t)vm_ns);
}
hv_ts.tv_sec = hv_ns / NANOSEC;
hv_ts.tv_nsec = hv_ns % NANOSEC;
kern_clock_settime(curthread, CLOCK_REALTIME, &hv_ts);
/* Done! */
return;
}
if ((tsflags & VMBUS_ICMSG_TS_FLAG_SAMPLE) &&
vmbus_ts_sample_thresh > 0) {
int64_t diff;
if (vmbus_ts_sample_verbose) {
device_printf(sc->ic_dev, "sample request, "
"hv: %ju, vm: %ju\n",
(uintmax_t)hv_ns, (uintmax_t)vm_ns);
}
if (hv_ns > vm_ns)
diff = hv_ns - vm_ns;
else
diff = vm_ns - hv_ns;
/* nanosec -> millisec */
diff /= 1000000;
if (diff > vmbus_ts_sample_thresh) {
struct timespec hv_ts;
if (bootverbose) {
device_printf(sc->ic_dev,
"apply sample request, hv: %ju, vm: %ju\n",
(uintmax_t)hv_ns, (uintmax_t)vm_ns);
}
hv_ts.tv_sec = hv_ns / NANOSEC;
hv_ts.tv_nsec = hv_ns % NANOSEC;
kern_clock_settime(curthread, CLOCK_REALTIME, &hv_ts);
}
/* Done */
return;
}
}
static void
vmbus_timesync_cb(struct vmbus_channel *chan, void *xsc)
{
struct vmbus_ic_softc *sc = xsc;
struct vmbus_icmsg_hdr *hdr;
const struct vmbus_icmsg_timesync *msg;
int dlen, error;
uint64_t xactid;
void *data;
/*
* Receive request.
*/
data = sc->ic_buf;
dlen = sc->ic_buflen;
error = vmbus_chan_recv(chan, data, &dlen, &xactid);
KASSERT(error != ENOBUFS, ("icbuf is not large enough"));
if (error)
return;
if (dlen < sizeof(*hdr)) {
device_printf(sc->ic_dev, "invalid data len %d\n", dlen);
return;
}
hdr = data;
/*
* Update request, which will be echoed back as response.
*/
switch (hdr->ic_type) {
case VMBUS_ICMSG_TYPE_NEGOTIATE:
error = vmbus_ic_negomsg(sc, data, &dlen,
VMBUS_TIMESYNC_FWVER, VMBUS_TIMESYNC_MSGVER);
if (error)
return;
if (VMBUS_TIMESYNC_DORTT(sc))
device_printf(sc->ic_dev, "RTT\n");
break;
case VMBUS_ICMSG_TYPE_TIMESYNC:
if (dlen < sizeof(*msg)) {
device_printf(sc->ic_dev, "invalid timesync len %d\n",
dlen);
return;
}
msg = data;
vmbus_timesync(sc, msg->ic_hvtime, msg->ic_sent_tc,
msg->ic_tsflags);
break;
default:
device_printf(sc->ic_dev, "got 0x%08x icmsg\n", hdr->ic_type);
break;
}
/*
* Send response by echoing the request back.
*/
vmbus_ic_sendresp(sc, chan, data, dlen, xactid);
}
static int
vmbus_timesync_probe(device_t dev)
{
return (vmbus_ic_probe(dev, vmbus_timesync_descs));
}
static int
vmbus_timesync_attach(device_t dev)
{
return (vmbus_ic_attach(dev, vmbus_timesync_cb));
}