>From d8f029819dcf2bf266e93661cf3c2f1503504835 Mon Sep 17 00:00:00 2001
From: Dan Kenigsberg <address@hidden>
Date: Sun, 27 Apr 2008 18:10:00 +0300
Subject: [PATCH] read current rtc offset (guest vs. host) from the monitor.
 this allows management software to notice rtc changes from the guest.

---
 console.h        |    5 +++++
 hw/mc146818rtc.c |    5 +++++
 hw/pc.c          |    6 ++++++
 monitor.c        |    4 ++++
 vl.c             |   12 ++++++++++++
 5 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/console.h b/console.h
index c7f29f5..44d0dad 100644
--- a/console.h
+++ b/console.h
@@ -149,6 +149,11 @@ int vnc_display_open(DisplayState *ds, const char *display);
 int vnc_display_password(DisplayState *ds, const char *password);
 void do_info_vnc(void);
 
+#if defined(TARGET_I386)
+/* pc.c */
+void do_info_timeoffset(void);
+#endif
+
 /* curses.c */
 void curses_display_init(DisplayState *ds, int full_screen);
 
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c
index 30bb044..3294363 100644
--- a/hw/mc146818rtc.c
+++ b/hw/mc146818rtc.c
@@ -487,6 +487,11 @@ RTCState *rtc_init(int base, qemu_irq irq)
     return s;
 }
 
+int rtc_get_timeoffset(RTCState *s)
+{
+    return qemu_timedate_offset(&s->current_tm);
+}
+
 /* Memory mapped interface */
 static uint32_t cmos_mm_readb (void *opaque, target_phys_addr_t addr)
 {
diff --git a/hw/pc.c b/hw/pc.c
index 44a021b..ff440c7 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -50,6 +50,12 @@ static PITState *pit;
 static IOAPICState *ioapic;
 static PCIDevice *i440fx_state;
 
+void do_info_timeoffset(void)
+{
+    int rtc_get_timeoffset(RTCState *s);
+    term_printf("now%+d\n", rtc_get_timeoffset(rtc_state));
+}
+
 static void ioport80_write(void *opaque, uint32_t addr, uint32_t data)
 {
 }
diff --git a/monitor.c b/monitor.c
index 574973d..76817e1 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1406,6 +1406,10 @@ static term_cmd_t info_cmds[] = {
       "", "show which guest mouse is receiving events" },
     { "vnc", "", do_info_vnc,
       "", "show the vnc server status"},
+#if defined(TARGET_I386)
+    { "timeoffset", "", do_info_timeoffset,
+      "", "show how much the VM real time clock differ from host time" },
+#endif
     { "name", "", do_info_name,
       "", "show the current VM name" },
 #if defined(TARGET_PPC)
diff --git a/vl.c b/vl.c
index 34d8e68..c3c575c 100644
--- a/vl.c
+++ b/vl.c
@@ -1595,6 +1595,18 @@ int qemu_timedate_diff(struct tm *tm)
     return seconds - time(NULL);
 }
 
+int qemu_timedate_offset(struct tm *tm)
+{
+    time_t seconds;
+
+    if (rtc_utc)
+        seconds = mktimegm(tm);
+    else
+        seconds = mktime(tm);
+
+    return seconds - time(NULL);
+}
+
 /***********************************************************/
 /* character device */
 
-- 
1.5.4.5