Real PC lets its user set the real-time-clock and store it on CMOS,
which advances the clock even when the PC is offline.
This patch will allow doing the same with VM:
- Before shutting a VM down, use the monitor's info timeoffset to see
how much (in seconds) does the rtc differ from the host clock.
- Store this offset somewhere.
- Use it next time with -startdate now+offset.
Dan.
diff --git a/console.h b/console.h
index 1ac74fa..3e1ac56 100644
--- a/console.h
+++ b/console.h
@@ -124,6 +124,8 @@ int vnc_display_open(DisplayState *ds, const char *display);
int vnc_display_password(DisplayState *ds, const char *password);
void do_info_vnc(void);
+void do_info_timeoffset(void);
+
/* x_keymap.c */
extern uint8_t _translate_keycode(const int key);
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c
index c1d5956..246535a 100644
--- a/hw/mc146818rtc.c
+++ b/hw/mc146818rtc.c
@@ -397,16 +397,12 @@ static void rtc_set_date_from_host(RTCState *s)
int val;
/* set the CMOS date */
- if (rtc_start_date == -1) {
- time(&ti);
- if (rtc_utc)
- tm = gmtime(&ti);
- else
- tm = localtime(&ti);
- } else {
- ti = rtc_start_date;
+ ti = rtc_start_date;
+ if (rtc_utc)
tm = gmtime(&ti);
- }
+ else
+ tm = localtime(&ti);
+
rtc_set_date(s, tm);
val = to_bcd(s, (tm->tm_year / 100) + 19);
@@ -603,3 +599,19 @@ RTCState *rtc_mm_init(target_phys_addr_t base, int
it_shift, qemu_irq irq)
register_savevm("mc146818rtc", base, 1, rtc_save, rtc_load, s);
return s;
}
+
+int rtc_get_timeoffset(RTCState *s)
+{
+ time_t ti, rtc_ti;
+
+ rtc_set_time(s);
+
+ if (rtc_utc)
+ rtc_ti = timegm(&s->current_tm);
+ else
+ rtc_ti = mktime(&s->current_tm);
+
+ time(&ti);
+
+ return rtc_ti - ti;
+}
diff --git a/hw/pc.c b/hw/pc.c
index 7049c44..bf60ca6 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -48,6 +48,12 @@ 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 4a9e8bb..bc2870e 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1370,6 +1370,8 @@ static term_cmd_t info_cmds[] = {
"", "show which guest mouse is receiving events" },
{ "vnc", "", do_info_vnc,
"", "show the vnc server status"},
+ { "timeoffset", "", do_info_timeoffset,
+ "", "show how much the VM real time clock differ from host time" },
{ "name", "", do_info_name,
"", "show the current VM name" },
#if defined(TARGET_PPC)
diff --git a/sysemu.h b/sysemu.h
index d54f115..5a10518 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -72,7 +72,7 @@ void do_info_slirp(void);
extern int ram_size;
extern int bios_size;
extern int rtc_utc;
-extern int rtc_start_date;
+extern time_t rtc_start_date;
extern int cirrus_vga_enabled;
extern int vmsvga_enabled;
extern int graphic_width;
diff --git a/vl.c b/vl.c
index 6f83740..bed1402 100644
--- a/vl.c
+++ b/vl.c
@@ -183,7 +183,7 @@ int nb_nics;
NICInfo nd_table[MAX_NICS];
int vm_running;
int rtc_utc = 1;
-int rtc_start_date = -1; /* -1 means now */
+time_t rtc_start_date;
int cirrus_vga_enabled = 1;
int vmsvga_enabled = 0;
#ifdef TARGET_SPARC
@@ -7709,6 +7709,8 @@ int main(int argc, char **argv)
nb_nics = 0;
/* default mac address of the first network interface */
+ time(&rtc_start_date); /* now is the default */
+
optind = 1;
for(;;) {
if (optind >= argc)
@@ -8168,8 +8170,21 @@ int main(int argc, char **argv)
case QEMU_OPTION_startdate:
{
struct tm tm;
- if (!strcmp(optarg, "now")) {
- rtc_start_date = -1;
+ char sign;
+ long timeoffset;
+ if (sscanf(optarg, "now%c%lu", &sign, &timeoffset) == 2) {
+ switch (sign) {
+ case '+':
+ rtc_start_date += timeoffset;
+ break;
+ case '-':
+ rtc_start_date -= timeoffset;
+ break;
+ default:
+ goto date_fail;
+ }
+ } else if (!strcmp(optarg, "now")) {
+ /* keep the default */
} else {
if (sscanf(optarg, "%d-%d-%dT%d:%d:%d",
&tm.tm_year,
