diff --git a/freeclock-add-qmp-command-to-get-time-offset-of-vm-i.patch b/freeclock-add-qmp-command-to-get-time-offset-of-vm-i.patch
new file mode 100644
index 0000000..e16b514
--- /dev/null
+++ b/freeclock-add-qmp-command-to-get-time-offset-of-vm-i.patch
@@ -0,0 +1,125 @@
+From 124d427a1fdae2d1eeed433093ec4ab78b81237e Mon Sep 17 00:00:00 2001
+From: "shenghualong@huawei.com" <shenghualong@huawei.com>
+Date: Thu, 10 Feb 2022 11:11:37 +0800
+Subject: [PATCH] freeclock: add qmp command to get time offset of vm in
+ seconds
+
+When setting the system time in VM, a RTC_CHANGE event will be reported.
+However, if libvirt is restarted while the event is be reporting, the
+event will be lost and we will get the old time (not the time we set in
+VM) after rebooting the VM.
+
+We save the delta time in QEMU and add a rtc-date-diff qmp to get the
+delta time so that libvirt can get the latest time in VM according to
+the qmp after libvirt is restarted.
+
+Signed-off-by: Peng Liang <liangpeng10@huawei.com>
+Signed-off-by: zhangxinhao <zhangxinhao1@huawei.com>
+---
+ include/qemu-common.h |  4 +++-
+ monitor/qmp-cmds.c    |  5 +++++
+ qapi/misc.json        |  9 +++++++++
+ qapi/pragma.json      |  3 ++-
+ softmmu/rtc.c         | 13 ++++++++++++-
+ 5 files changed, 31 insertions(+), 3 deletions(-)
+
+diff --git a/include/qemu-common.h b/include/qemu-common.h
+index 73bcf763ed..9ed8832152 100644
+--- a/include/qemu-common.h
++++ b/include/qemu-common.h
+@@ -27,7 +27,9 @@ int qemu_main(int argc, char **argv, char **envp);
+ #endif
+ 
+ void qemu_get_timedate(struct tm *tm, int offset);
+-int qemu_timedate_diff(struct tm *tm);
++time_t qemu_timedate_diff(struct tm *tm);
++time_t get_rtc_date_diff(void);
++void set_rtc_date_diff(time_t diff);
+ 
+ void *qemu_oom_check(void *ptr);
+ 
+diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
+index 343353e27a..98868cee03 100644
+--- a/monitor/qmp-cmds.c
++++ b/monitor/qmp-cmds.c
+@@ -466,3 +466,8 @@ HumanReadableText *qmp_x_query_irq(Error **errp)
+ 
+     return human_readable_text_from_str(buf);
+ }
++
++int64_t qmp_query_rtc_date_diff(Error **errp)
++{
++    return get_rtc_date_diff();
++}
+diff --git a/qapi/misc.json b/qapi/misc.json
+index 358548abe1..5b6d653682 100644
+--- a/qapi/misc.json
++++ b/qapi/misc.json
+@@ -527,3 +527,12 @@
+  'data': { '*option': 'str' },
+  'returns': ['CommandLineOptionInfo'],
+  'allow-preconfig': true }
++
++##
++# @query-rtc-date-diff:
++#
++# get vm's time offset
++#
++# Since: 2.8
++##
++{ 'command': 'query-rtc-date-diff', 'returns': 'int64' }
+diff --git a/qapi/pragma.json b/qapi/pragma.json
+index 3bc0335d1f..b37f6de445 100644
+--- a/qapi/pragma.json
++++ b/qapi/pragma.json
+@@ -26,7 +26,8 @@
+         'qom-get',
+         'query-tpm-models',
+         'query-tpm-types',
+-        'ringbuf-read' ],
++        'ringbuf-read',
++        'query-rtc-date-diff' ],
+     # Externally visible types whose member names may use uppercase
+     'member-name-exceptions': [     # visible in:
+         'ACPISlotType',             # query-acpi-ospm-status
+diff --git a/softmmu/rtc.c b/softmmu/rtc.c
+index 5632684fc9..57bb8bba7c 100644
+--- a/softmmu/rtc.c
++++ b/softmmu/rtc.c
+@@ -43,6 +43,7 @@ static time_t rtc_ref_start_datetime;
+ static int rtc_realtime_clock_offset; /* used only with QEMU_CLOCK_REALTIME */
+ static int rtc_host_datetime_offset = -1; /* valid & used only with
+                                              RTC_BASE_DATETIME */
++static time_t rtc_date_diff = 0;
+ QEMUClockType rtc_clock;
+ /***********************************************************/
+ /* RTC reference time/date access */
+@@ -84,7 +85,7 @@ void qemu_get_timedate(struct tm *tm, int offset)
+     }
+ }
+ 
+-int qemu_timedate_diff(struct tm *tm)
++time_t qemu_timedate_diff(struct tm *tm)
+ {
+     time_t seconds;
+ 
+@@ -107,6 +108,16 @@ int qemu_timedate_diff(struct tm *tm)
+     return seconds - qemu_ref_timedate(QEMU_CLOCK_HOST);
+ }
+ 
++time_t get_rtc_date_diff(void)
++{
++    return rtc_date_diff;
++}
++
++void set_rtc_date_diff(time_t diff)
++{
++    rtc_date_diff = diff;
++}
++
+ static void configure_rtc_base_datetime(const char *startdate)
+ {
+     time_t rtc_start_datetime;
+-- 
+2.27.0
+