linux-stable/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>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
#define SD_MAJOR 3
#define SD_MINOR 0
#define SD_MINOR_1 1
#define SD_MINOR_2 2
#define SD_VERSION_3_1 (SD_MAJOR << 16 | SD_MINOR_1)
#define SD_VERSION_3_2 (SD_MAJOR << 16 | SD_MINOR_2)
#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 4
static const int sd_versions[] = {
SD_VERSION_3_2,
SD_VERSION_3_1,
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
};
/*
* Send the "hibernate" udev event in a thread context.
*/
struct hibernate_work_context {
struct work_struct work;
struct hv_device *dev;
};
static struct hibernate_work_context hibernate_context;
static bool hibernation_supported;
static void send_hibernate_uevent(struct work_struct *work)
{
char *uevent_env[2] = { "EVENT=hibernate", NULL };
struct hibernate_work_context *ctx;
ctx = container_of(work, struct hibernate_work_context, work);
kobject_uevent_env(&ctx->dev->device.kobj, KOBJ_CHANGE, uevent_env);
pr_info("Sent hibernation uevent\n");
}
static int hv_shutdown_init(struct hv_util_service *srv)
{
struct vmbus_channel *channel = srv->channel;
INIT_WORK(&hibernate_context.work, send_hibernate_uevent);
hibernate_context.dev = channel->device_obj;
hibernation_supported = hv_is_hibernation_supported();
return 0;
}
static void shutdown_onchannelcallback(void *context);
static struct hv_util_service util_shutdown = {
.util_cb = shutdown_onchannelcallback,
.util_init = hv_shutdown_init,
};
static int hv_timesync_init(struct hv_util_service *srv);
static int hv_timesync_pre_suspend(void);
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_pre_suspend = hv_timesync_pre_suspend,
.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_pre_suspend = hv_kvp_pre_suspend,
.util_pre_resume = hv_kvp_pre_resume,
.util_deinit = hv_kvp_deinit,
};
static struct hv_util_service util_vss = {
.util_cb = hv_vss_onchannelcallback,
.util_init = hv_vss_init,
.util_pre_suspend = hv_vss_pre_suspend,
.util_pre_resume = hv_vss_pre_resume,
.util_deinit = hv_vss_deinit,
};
static struct hv_util_service util_fcopy = {
.util_cb = hv_fcopy_onchannelcallback,
.util_init = hv_fcopy_init,
.util_pre_suspend = hv_fcopy_pre_suspend,
.util_pre_resume = hv_fcopy_pre_resume,
.util_deinit = hv_fcopy_deinit,
};
static void perform_shutdown(struct work_struct *dummy)
{
orderly_poweroff(true);
}
static void perform_restart(struct work_struct *dummy)
{
orderly_reboot();
}
/*
* Perform the shutdown operation in a thread context.
*/
static DECLARE_WORK(shutdown_work, perform_shutdown);
/*
* Perform the restart operation in a thread context.
*/
static DECLARE_WORK(restart_work, perform_restart);
static void shutdown_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
struct work_struct *work = NULL;
u32 recvlen;
u64 requestid;
u8 *shut_txf_buf = util_shutdown.recv_buffer;
struct shutdown_msg_data *shutdown_msg;
struct icmsg_hdr *icmsghdrp;
if (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
return;
}
if (!recvlen)
return;
/* Ensure recvlen is big enough to read header data */
if (recvlen < ICMSG_HDR) {
pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
recvlen);
return;
}
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, recvlen,
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 if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
/* Ensure recvlen is big enough to contain shutdown_msg_data struct */
if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
recvlen);
return;
}
shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
/*
* shutdown_msg->flags can be 0(shut down), 2(reboot),
* or 4(hibernate). It may bitwise-OR 1, which means
* performing the request by force. Linux always tries
* to perform the request by force.
*/
switch (shutdown_msg->flags) {
case 0:
case 1:
icmsghdrp->status = HV_S_OK;
work = &shutdown_work;
pr_info("Shutdown request received - graceful shutdown initiated\n");
break;
case 2:
case 3:
icmsghdrp->status = HV_S_OK;
work = &restart_work;
pr_info("Restart request received - graceful restart initiated\n");
break;
case 4:
case 5:
pr_info("Hibernation request received\n");
icmsghdrp->status = hibernation_supported ?
HV_S_OK : HV_E_FAIL;
if (hibernation_supported)
work = &hibernate_context.work;
break;
default:
icmsghdrp->status = HV_E_FAIL;
pr_info("Shutdown request received - Invalid request\n");
break;
}
} else {
icmsghdrp->status = HV_E_FAIL;
pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
icmsghdrp->icmsgtype);
}
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE;
vmbus_sendpacket(channel, shut_txf_buf,
recvlen, requestid,
VM_PKT_DATA_INBAND, 0);
if (work)
schedule_work(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 inline u64 reftime_to_ns(u64 reftime)
{
return (reftime - WLTIMEDELTA) * 100;
}
/*
* Hard coded threshold for host timesync delay: 600 seconds
*/
static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
static int hv_get_adj_host_time(struct timespec64 *ts)
{
u64 newtime, reftime, timediff_adj;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&host_ts.lock, flags);
reftime = hv_read_reference_counter();
/*
* We need to let the caller know that last update from host
* is older than the max allowable threshold. clock_gettime()
* and PTP ioctl do not have a documented error that we could
* return for this specific case. Use ESTALE to report this.
*/
timediff_adj = reftime - host_ts.ref_time;
if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
(timediff_adj * 100));
ret = -ESTALE;
}
newtime = host_ts.host_time + timediff_adj;
*ts = ns_to_timespec64(reftime_to_ns(newtime));
spin_unlock_irqrestore(&host_ts.lock, flags);
return ret;
}
static void hv_set_host_time(struct work_struct *work)
{
struct timespec64 ts;
if (!hv_get_adj_host_time(&ts))
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 = hv_read_reference_counter();
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;
/*
* Drain the ring buffer and use the last packet to update
* host_ts
*/
while (1) {
int ret = vmbus_recvpacket(channel, time_txf_buf,
HV_HYP_PAGE_SIZE, &recvlen,
&requestid);
if (ret) {
pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
ret);
break;
}
if (!recvlen)
break;
/* Ensure recvlen is big enough to read header data */
if (recvlen < ICMSG_HDR) {
pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
recvlen);
break;
}
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, recvlen,
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 (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
if (ts_srv_version > TS_VERSION_3) {
/* Ensure recvlen is big enough to read ictimesync_ref_data */
if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
recvlen);
break;
}
refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
adj_guesttime(refdata->parenttime,
refdata->vmreferencetime,
refdata->flags);
} else {
/* Ensure recvlen is big enough to read ictimesync_data */
if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
recvlen);
break;
}
timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
adj_guesttime(timedatap->parenttime,
hv_read_reference_counter(),
timedatap->flags);
}
} else {
icmsghdrp->status = HV_E_FAIL;
pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
icmsghdrp->icmsgtype);
}
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) {
if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
&recvlen, &requestid)) {
pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
return;
}
if (!recvlen)
break;
/* Ensure recvlen is big enough to read header data */
if (recvlen < ICMSG_HDR) {
pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
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, recvlen,
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 if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
/*
* Ensure recvlen is big enough to read seq_num. Reserved area is not
* included in the check as the host may not fill it up entirely
*/
if (recvlen < ICMSG_HDR + sizeof(u64)) {
pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
recvlen);
break;
}
heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
heartbeat_msg->seq_num += 1;
} else {
icmsghdrp->status = HV_E_FAIL;
pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
icmsghdrp->icmsgtype);
}
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE;
vmbus_sendpacket(channel, hbeat_txf_buf,
recvlen, requestid,
VM_PKT_DATA_INBAND, 0);
}
}
#define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
#define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
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, HV_UTIL_RING_SEND_SIZE,
HV_UTIL_RING_RECV_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;
}
/*
* When we're in util_suspend(), all the userspace processes have been frozen
* (refer to hibernate() -> freeze_processes()). The userspace is thawed only
* after the whole resume procedure, including util_resume(), finishes.
*/
static int util_suspend(struct hv_device *dev)
{
struct hv_util_service *srv = hv_get_drvdata(dev);
int ret = 0;
if (srv->util_pre_suspend) {
ret = srv->util_pre_suspend();
if (ret)
return ret;
}
vmbus_close(dev->channel);
return 0;
}
static int util_resume(struct hv_device *dev)
{
struct hv_util_service *srv = hv_get_drvdata(dev);
int ret = 0;
if (srv->util_pre_resume) {
ret = srv->util_pre_resume();
if (ret)
return ret;
}
ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
dev->channel);
return ret;
}
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,
.suspend = util_suspend,
.resume = util_resume,
.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)
{
return hv_get_adj_host_time(ts);
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 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)
{
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: %d\n",
PTR_ERR_OR_ZERO(hv_ptp_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
hv_ptp_clock = NULL;
}
return 0;
}
static void hv_timesync_cancel_work(void)
{
cancel_work_sync(&adj_time_work);
}
static int hv_timesync_pre_suspend(void)
{
hv_timesync_cancel_work();
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);
hv_timesync_cancel_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");