On 03/01/2013 02:33 AM, Lei Li wrote: > Signed-off-by: Lei Li <li...@linux.vnet.ibm.com> > --- > qga/commands-posix.c | 55 > ++++++++++++++++++++++++++++++++++++++++++++++++++++ > qga/qapi-schema.json | 27 ++++++++++++++++++++++++++ > 2 files changed, 82 insertions(+) > > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > index f159e25..e246a0d 100644 > --- a/qga/commands-posix.c > +++ b/qga/commands-posix.c > @@ -135,6 +135,61 @@ int64_t qmp_guest_get_time(Error **errp) > return time_ns; > } > > +void qmp_guest_set_time(int64_t time_ns, Error **errp) > +{ > + int ret; > + int status; > + pid_t pid; > + Error *local_err = NULL; > + struct timeval tv; > + > + /* year-2038 will overflow in case time_t is 32bit */ > + if ((sizeof(time_t) <= 4) && ((unsigned long) time_ns & (1ul << 31))) {
Wrong. If 'unsigned long' and 'time_t' are both 32 bits, but time_ns is 0x1000000000000000, then the cast truncates to 0 and you don't report overflow. Conversely, if time_ns is 0x80000000, you report overflow, even though this value fits in 32-bit time_t after you do division from nanoseconds back to seconds. What you WANT is: if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) { > + error_setg_errno(errp, errno, "Invalid time %ld for overflow", > + time_ns); That wording sounds awkward. Worse, errno is NOT set to anything sane, so you do NOT want error_setg_errno. And %ld is wrong for int64_t on 32-bit platforms. How about: error_setg(errp, "Time %" PRI64D " is too large", time_ns); > +++ b/qga/qapi-schema.json > @@ -99,6 +99,33 @@ > 'returns': 'int' } > > ## > +# @guest-set-time: > +# > +# Set guest time. > +# > +# Right now, when a guest is paused or migrated to a file s/Right now, when/When/ > +# then loaded from that file, the guest OS has no idea that > +# there was a big gap in the time. Depending on how long > +# the gap was, NTP might not be able to resynchronize the > +# guest. > +# > +# This command tries to set guest time based on the information > +# from host or an absolute value given by management app, and > +# set the Hardware Clock to the current System Time. This > +# will make it easier for a guest to resynchronize without > +# waiting for NTP. > +# > +# @time: time of nanoseconds, relative to the Epoch of > +# 1970-01-01 in UTC/GMT. drop '/GMT' > +# > +# Returns: Nothing on success. > +# > +# Since: 1.5 > +## > +{ 'command': 'guest-set-time', > + 'data': { 'time': 'int' } } > + > +## > # @GuestAgentCommandInfo: > # > # Information about guest agent commands. > -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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