On Wed, Mar 13, 2013 at 06:10:30PM +0800, li...@linux.vnet.ibm.com wrote:
> From: Lei Li <li...@linux.vnet.ibm.com>
>
> Signed-off-by: Lei Li <li...@linux.vnet.ibm.com>
> ---
> qga/commands-win32.c | 32 ++++++++++++++++++++++++++++++++
> 1 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index 7e8ecb3..0a2bb34 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -22,6 +22,12 @@
> #define SHTDN_REASON_FLAG_PLANNED 0x80000000
> #endif
>
> +/* multiple of 100 nanoseconds elapsed between windows baseline
> + (1/1/1601) and Unix Epoch (1/1/1970), accounting for leap years */
> +#define W32_FT_OFFSET (10000000ULL * 60 * 60 * 24 * \
> + (365 * (1970 - 1601) + \
> + (1970 - 1601) / 4 - 3))
> +
> static void acquire_privilege(const char *name, Error **err)
> {
> HANDLE token;
> @@ -108,6 +114,32 @@ void qmp_guest_shutdown(bool has_mode, const char *mode,
> Error **err)
> }
> }
>
> +int64_t qmp_guest_get_time(Error **errp)
> +{
> + SYSTEMTIME *ts = g_malloc0(sizeof(SYSTEMTIME));
Don't we need to free this at some point?
> + int64_t time_ns;
> + union {
> + UINT64 ns100;
> + FILETIME tf;
> + } time;
> +
> + GetSystemTime(ts);
> + if (!ts) {
> + slog("guest-get-time failed: %d", GetLastError());
GetSystemTime() does not seem to set an error that can be retrieved by
GetLastError().
> + error_setg_errno(errp, errno, "Failed to get time");
> + return -1;
> + }
> +
> + if (!SystemTimeToFileTime(ts, &time.tf)) {
> + error_setg_errno(errp, errno, "Failed to convert system time");
> + return -1;
> + }
> +
> + time_ns = (int64_t)((time.ns100 - W32_FT_OFFSET) * 100);
I'm not sure how safe this union stuff is. The documentation suggests that in
some circumstances the low/high fields in FILETIME might be padded for
64-bit alignment and that doing this type of cast could generate an
alignment fault:
http://msdn.microsoft.com/en-us/library/windows/desktop/ms724284(v=vs.85).aspx
or it might, perhaps even worse, just silently report the wrong time.
I think we should just do the math explicitly:
(((tf.dwHighDateTime << 32) | tf.dwLowDateTime) - W32_FT_OFFSET) * 100)
(or something along that line)
> +
> + return time_ns;
> +}
> +
> int64_t qmp_guest_file_open(const char *path, bool has_mode, const char
> *mode, Error **err)
> {
> error_set(err, QERR_UNSUPPORTED);
> --
> 1.7.7.6
>
