diff --git a/migration-dirtyrate-add-DirtyRateStatus-to-denote-ca.patch b/migration-dirtyrate-add-DirtyRateStatus-to-denote-ca.patch
new file mode 100644
index 0000000..e0ebb2a
--- /dev/null
+++ b/migration-dirtyrate-add-DirtyRateStatus-to-denote-ca.patch
@@ -0,0 +1,93 @@
+From 466b3eee340f022e53478e706e8d4dc02136b1e1 Mon Sep 17 00:00:00 2001
+From: Chuan Zheng <zhengchuan@huawei.com>
+Date: Wed, 16 Sep 2020 14:21:57 +0800
+Subject: [PATCH] migration/dirtyrate: add DirtyRateStatus to denote
+ calculation status
+
+add DirtyRateStatus to denote calculating status.
+
+Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
+Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
+Reviewed-by: Li Qiang <liq3ea@gmail.com>
+Message-Id: <1600237327-33618-3-git-send-email-zhengchuan@huawei.com>
+Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
+  atomic name fixup
+---
+ migration/dirtyrate.c | 26 ++++++++++++++++++++++++++
+ qapi/migration.json   | 17 +++++++++++++++++
+ 2 files changed, 43 insertions(+)
+
+diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
+index 29ef663acb..44a60bf10d 100644
+--- a/migration/dirtyrate.c
++++ b/migration/dirtyrate.c
+@@ -22,6 +22,19 @@
+ #include "migration.h"
+ #include "dirtyrate.h"
+ 
++static int CalculatingState = DIRTY_RATE_STATUS_UNSTARTED;
++
++static int dirtyrate_set_state(int *state, int old_state, int new_state)
++{
++    assert(new_state < DIRTY_RATE_STATUS__MAX);
++    if (atomic_cmpxchg(state, old_state, new_state) == old_state) {
++        return 0;
++    } else {
++        return -1;
++    }
++}
++
++
+ static void calculate_dirtyrate(struct DirtyRateConfig config)
+ {
+     /* todo */
+@@ -31,8 +44,21 @@ static void calculate_dirtyrate(struct DirtyRateConfig config)
+ void *get_dirtyrate_thread(void *arg)
+ {
+     struct DirtyRateConfig config = *(struct DirtyRateConfig *)arg;
++    int ret;
++
++    ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_UNSTARTED,
++                              DIRTY_RATE_STATUS_MEASURING);
++    if (ret == -1) {
++        error_report("change dirtyrate state failed.");
++        return NULL;
++    }
+ 
+     calculate_dirtyrate(config);
+ 
++    ret = dirtyrate_set_state(&CalculatingState, DIRTY_RATE_STATUS_MEASURING,
++                              DIRTY_RATE_STATUS_MEASURED);
++    if (ret == -1) {
++        error_report("change dirtyrate state failed.");
++    }
+     return NULL;
+ }
+diff --git a/qapi/migration.json b/qapi/migration.json
+index 9cfbaf8c6c..fdddde0af7 100644
+--- a/qapi/migration.json
++++ b/qapi/migration.json
+@@ -1445,3 +1445,20 @@
+ # Since: 3.0
+ ##
+ { 'command': 'migrate-pause', 'allow-oob': true }
++
++##
++# @DirtyRateStatus:
++#
++# An enumeration of dirtyrate status.
++#
++# @unstarted: the dirtyrate thread has not been started.
++#
++# @measuring: the dirtyrate thread is measuring.
++#
++# @measured: the dirtyrate thread has measured and results are available.
++#
++# Since: 5.2
++#
++##
++{ 'enum': 'DirtyRateStatus',
++  'data': [ 'unstarted', 'measuring', 'measured'] }
+-- 
+2.27.0
+