@@ -142,7 +142,7 @@ int64_t qmp_guest_get_time(Error **errp)
return time_ns;
}
-void qmp_guest_set_time(int64_t time_ns, Error **errp)
+void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
{
int ret;
int status;
@@ -150,22 +150,28 @@ void qmp_guest_set_time(int64_t time_ns, Error **errp)
Error *local_err = NULL;
struct timeval tv;
- /* year-2038 will overflow in case time_t is 32bit */
- if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) {
- error_setg(errp, "Time %" PRId64 " is too large", time_ns);
- return;
+ /* If user has passed a time, validate and set it. */
+ if (has_time) {
+ /* year-2038 will overflow in case time_t is 32bit */
+ if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) {
+ error_setg(errp, "Time %" PRId64 " is too large", time_ns);
+ return;
+ }
+
+ tv.tv_sec = time_ns / 1000000000;
+ tv.tv_usec = (time_ns % 1000000000) / 1000;
+
+ ret = settimeofday(&tv, NULL);
+ if (ret < 0) {
+ error_setg_errno(errp, errno, "Failed to set time to guest");
+ return;
+ }
}
- tv.tv_sec = time_ns / 1000000000;
- tv.tv_usec = (time_ns % 1000000000) / 1000;
-
- ret = settimeofday(&tv, NULL);
- if (ret < 0) {
- error_setg_errno(errp, errno, "Failed to set time to guest");
- return;
- }
-
- /* Set the Hardware Clock to the current System Time. */
+ /* Now, if user has passed a time to set and the system time is set, we
+ * just need to synchronize the hardware clock. However, if no time was
+ * passed, user is requesting the opposite: set the system time from the
+ * hardware clock. */
pid = fork();
if (pid == 0) {
setsid();
@@ -173,7 +179,9 @@ void qmp_guest_set_time(int64_t time_ns, Error **errp)
reopen_fd_to_null(1);
reopen_fd_to_null(2);
- execle("/sbin/hwclock", "hwclock", "-w", NULL, environ);
+ /* Use '/sbin/hwclock -w' to set RTC from the system time,
+ * or '/sbin/hwclock -s' to set the system time from RTC. */
+ execle("/sbin/hwclock", "hwclock", has_time ? "-w" : "-s", NULL, environ);
_exit(EXIT_FAILURE);
} else if (pid < 0) {
error_setg_errno(errp, errno, "failed to create child process");
@@ -370,25 +370,36 @@ int64_t qmp_guest_get_time(Error **errp)
return time_ns;
}
-void qmp_guest_set_time(int64_t time_ns, Error **errp)
+void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
{
SYSTEMTIME ts;
FILETIME tf;
LONGLONG time;
- if (time_ns < 0 || time_ns / 100 > INT64_MAX - W32_FT_OFFSET) {
- error_setg(errp, "Time %" PRId64 "is invalid", time_ns);
- return;
- }
+ if (has_time) {
+ /* Okay, user passed a time to set. Validate it. */
+ if (time_ns < 0 || time_ns / 100 > INT64_MAX - W32_FT_OFFSET) {
+ error_setg(errp, "Time %" PRId64 "is invalid", time_ns);
+ return;
+ }
- time = time_ns / 100 + W32_FT_OFFSET;
+ time = time_ns / 100 + W32_FT_OFFSET;
- tf.dwLowDateTime = (DWORD) time;
- tf.dwHighDateTime = (DWORD) (time >> 32);
+ tf.dwLowDateTime = (DWORD) time;
+ tf.dwHighDateTime = (DWORD) (time >> 32);
- if (!FileTimeToSystemTime(&tf, &ts)) {
- error_setg(errp, "Failed to convert system time %d", (int)GetLastError());
- return;
+ if (!FileTimeToSystemTime(&tf, &ts)) {
+ error_setg(errp, "Failed to convert system time %d", (int)GetLastError());
+ return;
+ }
+ } else {
+ /* Otherwise read the time from RTC which contains the correct value.
+ * Hopefully. */
+ GetSystemTime(&ts);
+ if (ts.wYear < 1601 || ts.wYear > 30827) {
+ error_setg(errp, "Failed to get time");
+ return;
+ }
}
acquire_privilege(SE_SYSTEMTIME_NAME, errp);
@@ -120,17 +120,18 @@
# This command tries to set guest time to the given value,
# then sets the Hardware Clock to the current System Time.
# This will make it easier for a guest to resynchronize
-# without waiting for NTP.
+# without waiting for NTP. If no @time is specified, then
+# the time to set is read from RTC.
#
-# @time: time of nanoseconds, relative to the Epoch of
-# 1970-01-01 in UTC.
+# @time: #optional time of nanoseconds, relative to the Epoch
+# of 1970-01-01 in UTC.
#
# Returns: Nothing on success.
#
# Since: 1.5
##
{ 'command': 'guest-set-time',
- 'data': { 'time': 'int' } }
+ 'data': { '*time': 'int' } }
##
# @GuestAgentCommandInfo:
As the description to the guest-set-time states, the command is there to ease time synchronization after resume. If guest was suspended for longer period of time, its system time can go off so badly, that even NTP refuses to set it. That's why the command was invented: to give users chance to set the time (not necessarily 100% correct). However, there's is no real need for us to require users to pass an arbitrary time. Especially if we can read the correct value from RTC (boiling down to reading host's time). Hence this commit enables logic: guest-set-time() == guest-set-time($now_from_rtc) Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- Notes: I wasn't sure about enforcing Windows to fetch time from RTC. But I've found this site [1] which seems to presume that GetSystemTime() reads RTC. Although within the page you'll find GetSystemTimeAsFileTime() which is the same except returned time is in different format. That's all. 1: http://nadeausoftware.com/articles/2012/04/c_c_tip_how_measure_elapsed_real_time_benchmarking qga/commands-posix.c | 40 ++++++++++++++++++++++++---------------- qga/commands-win32.c | 33 ++++++++++++++++++++++----------- qga/qapi-schema.json | 9 +++++---- 3 files changed, 51 insertions(+), 31 deletions(-)