linux/drivers/hv/hv_util.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2010, Microsoft Corporation.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
*/
#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>
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
#include <linux/clockchips.h>
#include <linux/ptp_clock_kernel.h>
clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic Continue consolidating Hyper-V clock and timer code into an ISA independent Hyper-V clocksource driver. Move the existing clocksource code under drivers/hv and arch/x86 to the new clocksource driver while separating out the ISA dependencies. Update Hyper-V initialization to call initialization and cleanup routines since the Hyper-V synthetic clock is not independently enumerated in ACPI. Update Hyper-V clocksource users in KVM and VDSO to get definitions from the new include file. No behavior is changed and no new functionality is added. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: "bp@alien8.de" <bp@alien8.de> Cc: "will.deacon@arm.com" <will.deacon@arm.com> Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com> Cc: "mark.rutland@arm.com" <mark.rutland@arm.com> Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org> Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org> Cc: "olaf@aepfle.de" <olaf@aepfle.de> Cc: "apw@canonical.com" <apw@canonical.com> Cc: "jasowang@redhat.com" <jasowang@redhat.com> Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com> Cc: Sunil Muthuswamy <sunilmut@microsoft.com> Cc: KY Srinivasan <kys@microsoft.com> Cc: "sashal@kernel.org" <sashal@kernel.org> Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com> Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org> Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org> Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org> Cc: "arnd@arndb.de" <arnd@arndb.de> Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk> Cc: "ralf@linux-mips.org" <ralf@linux-mips.org> Cc: "paul.burton@mips.com" <paul.burton@mips.com> Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org> Cc: "salyzyn@android.com" <salyzyn@android.com> Cc: "pcc@google.com" <pcc@google.com> Cc: "shuah@kernel.org" <shuah@kernel.org> Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com> Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk> Cc: "huw@codeweavers.com" <huw@codeweavers.com> Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au> Cc: "pbonzini@redhat.com" <pbonzini@redhat.com> Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com> Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org> Link: https://lkml.kernel.org/r/1561955054-1838-3-git-send-email-mikelley@microsoft.com
2019-07-01 04:26:06 +00:00
#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
#define SD_MAJOR 3
#define SD_MINOR 0
#define SD_VERSION (SD_MAJOR << 16 | SD_MINOR)
#define SD_MAJOR_1 1
#define SD_VERSION_1 (SD_MAJOR_1 << 16 | SD_MINOR)
#define TS_MAJOR 4
#define TS_MINOR 0
#define TS_VERSION (TS_MAJOR << 16 | TS_MINOR)
#define TS_MAJOR_1 1
#define TS_VERSION_1 (TS_MAJOR_1 << 16 | TS_MINOR)
#define TS_MAJOR_3 3
#define TS_VERSION_3 (TS_MAJOR_3 << 16 | TS_MINOR)
#define HB_MAJOR 3
#define HB_MINOR 0
#define HB_VERSION (HB_MAJOR << 16 | HB_MINOR)
#define HB_MAJOR_1 1
#define HB_VERSION_1 (HB_MAJOR_1 << 16 | HB_MINOR)
static int sd_srv_version;
static int ts_srv_version;
static int hb_srv_version;
#define SD_VER_COUNT 2
static const int sd_versions[] = {
SD_VERSION,
SD_VERSION_1
};
#define TS_VER_COUNT 3
static const int ts_versions[] = {
TS_VERSION,
TS_VERSION_3,
TS_VERSION_1
};
#define HB_VER_COUNT 2
static const int hb_versions[] = {
HB_VERSION,
HB_VERSION_1
};
#define FW_VER_COUNT 2
static const int fw_versions[] = {
UTIL_FW_VERSION,
UTIL_WS2K8_FW_VERSION
};
static void shutdown_onchannelcallback(void *context);
static struct hv_util_service util_shutdown = {
.util_cb = shutdown_onchannelcallback,
};
static int hv_timesync_init(struct hv_util_service *srv);
static void hv_timesync_deinit(void);
static void timesync_onchannelcallback(void *context);
static struct hv_util_service util_timesynch = {
.util_cb = timesync_onchannelcallback,
.util_init = hv_timesync_init,
.util_deinit = hv_timesync_deinit,
};
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 struct hv_util_service util_vss = {
.util_cb = hv_vss_onchannelcallback,
.util_init = hv_vss_init,
.util_deinit = hv_vss_deinit,
};
static struct hv_util_service util_fcopy = {
.util_cb = hv_fcopy_onchannelcallback,
.util_init = hv_fcopy_init,
.util_deinit = hv_fcopy_deinit,
};
static void perform_shutdown(struct work_struct *dummy)
{
orderly_poweroff(true);
}
/*
* Perform the shutdown operation in a thread context.
*/
static DECLARE_WORK(shutdown_work, perform_shutdown);
static void shutdown_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
u32 recvlen;
u64 requestid;
bool execute_shutdown = false;
u8 *shut_txf_buf = util_shutdown.recv_buffer;
struct shutdown_msg_data *shutdown_msg;
struct icmsg_hdr *icmsghdrp;
vmbus_recvpacket(channel, shut_txf_buf,
HV_HYP_PAGE_SIZE, &recvlen, &requestid);
if (recvlen > 0) {
icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
if (vmbus_prep_negotiate_resp(icmsghdrp, shut_txf_buf,
fw_versions, FW_VER_COUNT,
sd_versions, SD_VER_COUNT,
NULL, &sd_srv_version)) {
pr_info("Shutdown IC version %d.%d\n",
sd_srv_version >> 16,
sd_srv_version & 0xFFFF);
}
} 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)
schedule_work(&shutdown_work);
}
/*
* Set the host time in a process context.
*/
static struct work_struct adj_time_work;
/*
* The last time sample, received from the host. PTP device responds to
* requests by using this data and the current partition-wide time reference
* count.
*/
static struct {
u64 host_time;
u64 ref_time;
spinlock_t lock;
} host_ts;
static struct timespec64 hv_get_adj_host_time(void)
{
struct timespec64 ts;
u64 newtime, reftime;
unsigned long flags;
spin_lock_irqsave(&host_ts.lock, flags);
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
reftime = hyperv_cs->read(hyperv_cs);
newtime = host_ts.host_time + (reftime - host_ts.ref_time);
ts = ns_to_timespec64((newtime - WLTIMEDELTA) * 100);
spin_unlock_irqrestore(&host_ts.lock, flags);
return ts;
}
static void hv_set_host_time(struct work_struct *work)
{
struct timespec64 ts = hv_get_adj_host_time();
do_settimeofday64(&ts);
}
/*
* 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. This bit is
* considered a hard request to discipline the clock.
*
* ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
* typically used as a hint to the guest. The guest is under no obligation
* to discipline the clock.
*/
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
{
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
unsigned long flags;
u64 cur_reftime;
/*
* Save the adjusted time sample from the host and the snapshot
* of the current system time.
*/
spin_lock_irqsave(&host_ts.lock, flags);
cur_reftime = hyperv_cs->read(hyperv_cs);
host_ts.host_time = hosttime;
host_ts.ref_time = cur_reftime;
/*
* TimeSync v4 messages contain reference time (guest's Hyper-V
* clocksource read when the time sample was generated), we can
* improve the precision by adding the delta between now and the
* time of generation. For older protocols we set
* reftime == cur_reftime on call.
*/
host_ts.host_time += (cur_reftime - reftime);
spin_unlock_irqrestore(&host_ts.lock, flags);
/* Schedule work to do do_settimeofday64() */
if (adj_flags & ICTIMESYNCFLAG_SYNC)
schedule_work(&adj_time_work);
}
/*
* 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;
struct ictimesync_ref_data *refdata;
u8 *time_txf_buf = util_timesynch.recv_buffer;
vmbus_recvpacket(channel, time_txf_buf,
HV_HYP_PAGE_SIZE, &recvlen, &requestid);
if (recvlen > 0) {
icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
if (vmbus_prep_negotiate_resp(icmsghdrp, time_txf_buf,
fw_versions, FW_VER_COUNT,
ts_versions, TS_VER_COUNT,
NULL, &ts_srv_version)) {
pr_info("TimeSync IC version %d.%d\n",
ts_srv_version >> 16,
ts_srv_version & 0xFFFF);
}
} else {
if (ts_srv_version > TS_VERSION_3) {
refdata = (struct ictimesync_ref_data *)
&time_txf_buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
adj_guesttime(refdata->parenttime,
refdata->vmreferencetime,
refdata->flags);
} else {
timedatap = (struct ictimesync_data *)
&time_txf_buf[
sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
adj_guesttime(timedatap->parenttime,
hyperv_cs->read(hyperv_cs),
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;
while (1) {
vmbus_recvpacket(channel, hbeat_txf_buf,
HV_HYP_PAGE_SIZE, &recvlen, &requestid);
if (!recvlen)
break;
icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
if (vmbus_prep_negotiate_resp(icmsghdrp,
hbeat_txf_buf,
fw_versions, FW_VER_COUNT,
hb_versions, HB_VER_COUNT,
NULL, &hb_srv_version)) {
pr_info("Heartbeat IC version %d.%d\n",
hb_srv_version >> 16,
hb_srv_version & 0xFFFF);
}
} 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(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
if (!srv->recv_buffer)
return -ENOMEM;
srv->channel = dev->channel;
if (srv->util_init) {
ret = srv->util_init(srv);
if (ret) {
ret = -ENODEV;
goto error1;
}
}
/*
* The set of services managed by the util driver 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.
*/
set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
hv_set_drvdata(dev, srv);
ret = vmbus_open(dev->channel, 4 * HV_HYP_PAGE_SIZE,
4 * HV_HYP_PAGE_SIZE, NULL, 0, srv->util_cb,
dev->channel);
if (ret)
goto error;
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);
if (srv->util_deinit)
srv->util_deinit();
vmbus_close(dev->channel);
kfree(srv->recv_buffer);
return 0;
}
static const struct hv_vmbus_device_id id_table[] = {
/* Shutdown guid */
{ HV_SHUTDOWN_GUID,
.driver_data = (unsigned long)&util_shutdown
},
/* Time synch guid */
{ HV_TS_GUID,
.driver_data = (unsigned long)&util_timesynch
},
/* Heartbeat guid */
{ HV_HEART_BEAT_GUID,
.driver_data = (unsigned long)&util_heartbeat
},
/* KVP guid */
{ HV_KVP_GUID,
.driver_data = (unsigned long)&util_kvp
},
/* VSS GUID */
{ HV_VSS_GUID,
.driver_data = (unsigned long)&util_vss
},
/* File copy GUID */
{ HV_FCOPY_GUID,
.driver_data = (unsigned long)&util_fcopy
},
{ },
};
MODULE_DEVICE_TABLE(vmbus, id_table);
/* The one and only one */
static struct hv_driver util_drv = {
.name = "hv_utils",
.id_table = id_table,
.probe = util_probe,
.remove = util_remove,
.driver = {
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
};
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
static int hv_ptp_enable(struct ptp_clock_info *info,
struct ptp_clock_request *request, int on)
{
return -EOPNOTSUPP;
}
static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
{
return -EOPNOTSUPP;
}
static int hv_ptp_adjfreq(struct ptp_clock_info *ptp, s32 delta)
{
return -EOPNOTSUPP;
}
static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
return -EOPNOTSUPP;
}
static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
{
*ts = hv_get_adj_host_time();
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
return 0;
}
static struct ptp_clock_info ptp_hyperv_info = {
.name = "hyperv",
.enable = hv_ptp_enable,
.adjtime = hv_ptp_adjtime,
.adjfreq = hv_ptp_adjfreq,
.gettime64 = hv_ptp_gettime,
.settime64 = hv_ptp_settime,
.owner = THIS_MODULE,
};
static struct ptp_clock *hv_ptp_clock;
static int hv_timesync_init(struct hv_util_service *srv)
{
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
/* TimeSync requires Hyper-V clocksource. */
if (!hyperv_cs)
return -ENODEV;
spin_lock_init(&host_ts.lock);
INIT_WORK(&adj_time_work, hv_set_host_time);
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
/*
* ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
* disabled but the driver is still useful without the PTP device
* as it still handles the ICTIMESYNCFLAG_SYNC case.
*/
hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
if (IS_ERR_OR_NULL(hv_ptp_clock)) {
pr_err("cannot register PTP clock: %ld\n",
PTR_ERR(hv_ptp_clock));
hv_ptp_clock = NULL;
}
return 0;
}
static void hv_timesync_deinit(void)
{
hv_utils: implement Hyper-V PTP source With TimeSync version 4 protocol support we started updating system time continuously through the whole lifetime of Hyper-V guests. Every 5 seconds there is a time sample from the host which triggers do_settimeofday[64](). While the time from the host is very accurate such adjustments may cause issues: - Time is jumping forward and backward, some applications may misbehave. - In case an NTP server runs in parallel and uses something else for time sync (network, PTP,...) system time will never converge. - Systemd starts annoying you by printing "Time has been changed" every 5 seconds to the system log. Instead of doing in-kernel time adjustments offload the work to an NTP client by exposing TimeSync messages as a PTP device. Users may now decide what they want to use as a source. I tested the solution with chrony, the config was: refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0 The result I'm seeing is accurate enough, the time delta between the guest and the host is almost always within [-10us, +10us], the in-kernel solution was giving us comparable results. I also tried implementing PPS device instead of PTP by using not currently used Hyper-V synthetic timers (we use only one of four for clockevent) but with PPS source only chrony wasn't able to give me the required accuracy, the delta often more that 100us. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 16:57:14 +00:00
if (hv_ptp_clock)
ptp_clock_unregister(hv_ptp_clock);
cancel_work_sync(&adj_time_work);
}
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_LICENSE("GPL");