| Message ID | a2948dbe0f8a451b3f23fb2bc45357a0e7dc53de.1391164056.git.mprivozn@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 01/31/2014 03:29 AM, Michal Privoznik wrote: > 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($now_from_rtc) > > Signed-off-by: Michal Privoznik <mprivozn@redhat.com> > --- > diff to v1: > -Fix checkpatch.pl warnings > > qga/commands-posix.c | 41 +++++++++++++++++++++++++---------------- > qga/commands-win32.c | 34 +++++++++++++++++++++++----------- > qga/qapi-schema.json | 9 +++++---- > 3 files changed, 53 insertions(+), 31 deletions(-) Reviewed-by: Eric Blake <eblake@redhat.com> Conversion from mandatory to optional is backward-compatible. I'm not sure if it worth some sort of annotation when it was made optional; maybe: # @time: (#optional since 2.0) time of nanoseconds, relative to the # Epoch of 1970-01-01 in UTC. we don't have much precedent for that sort of change, but documenting it may make it more obvious to a user that older agents require an argument.
On 31.01.2014 19:12, Eric Blake wrote: > On 01/31/2014 03:29 AM, Michal Privoznik wrote: >> As the description to the guest-set-time states, the command is >> there to ease time synchronization after resume. If guest was >> suspended for longer period of time, its system time can go off >> so badly, that even NTP refuses to set it. That's why the command >> was invented: to give users chance to set the time (not >> necessarily 100% correct). However, there's is no real need for >> us to require users to pass an arbitrary time. Especially if we >> can read the correct value from RTC (boiling down to reading >> host's time). Hence this commit enables logic: >> >> guest-set-time() == guest-set-time($now_from_rtc) >> >> Signed-off-by: Michal Privoznik <mprivozn@redhat.com> >> --- >> diff to v1: >> -Fix checkpatch.pl warnings >> >> qga/commands-posix.c | 41 +++++++++++++++++++++++++---------------- >> qga/commands-win32.c | 34 +++++++++++++++++++++++----------- >> qga/qapi-schema.json | 9 +++++---- >> 3 files changed, 53 insertions(+), 31 deletions(-) > > Reviewed-by: Eric Blake <eblake@redhat.com> > May I kindly ask somebody to merge this? Or is 3ACKs required for the guest agent too? Thanks in advance! Michal
Quoting Michal Privoznik (2014-01-31 04:29:51) > 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> Thanks, applied to qga tree: https://github.com/mdroth/qemu/commits/qga > --- > diff to v1: > -Fix checkpatch.pl warnings > > qga/commands-posix.c | 41 +++++++++++++++++++++++++---------------- > qga/commands-win32.c | 34 +++++++++++++++++++++++----------- > qga/qapi-schema.json | 9 +++++---- > 3 files changed, 53 insertions(+), 31 deletions(-) > > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > index 8100bee..7d6665a 100644 > --- a/qga/commands-posix.c > +++ b/qga/commands-posix.c > @@ -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 +179,10 @@ 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"); > diff --git a/qga/commands-win32.c b/qga/commands-win32.c > index a6a0af2..8245f95 100644 > --- a/qga/commands-win32.c > +++ b/qga/commands-win32.c > @@ -370,25 +370,37 @@ 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); > diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json > index 245f968..80edca1 100644 > --- a/qga/qapi-schema.json > +++ b/qga/qapi-schema.json > @@ -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: > -- > 1.8.5.2
diff to v1: -Fix checkpatch.pl warnings qga/commands-posix.c | 41 +++++++++++++++++++++++++---------------- qga/commands-win32.c | 34 +++++++++++++++++++++++----------- qga/qapi-schema.json | 9 +++++---- 3 files changed, 53 insertions(+), 31 deletions(-) diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 8100bee..7d6665a 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -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 +179,10 @@ 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"); diff --git a/qga/commands-win32.c b/qga/commands-win32.c index a6a0af2..8245f95 100644 --- a/qga/commands-win32.c +++ b/qga/commands-win32.c @@ -370,25 +370,37 @@ 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); diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json index 245f968..80edca1 100644 --- a/qga/qapi-schema.json +++ b/qga/qapi-schema.json @@ -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> ---