On Wed, Mar 13, 2013 at 06:10:30PM +0800, address@hidden wrote:
From: Lei Li <address@hidden>
Signed-off-by: Lei Li <address@hidden>
---
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?
+ 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)