diff --git a/net/Makefile.objs b/net/Makefile.objs
index b7c22fd..ba92f73 100644
--- a/net/Makefile.objs
+++ b/net/Makefile.objs
@@ -16,3 +16,4 @@ common-obj-$(CONFIG_NETMAP) += netmap.o
 common-obj-y += filter.o
 common-obj-y += filter-buffer.o
 common-obj-y += filter-mirror.o
+common-obj-y += colo-compare.o
diff --git a/net/colo-compare.c b/net/colo-compare.c
new file mode 100644
index 0000000..dc5f70c
--- /dev/null
+++ b/net/colo-compare.c
@@ -0,0 +1,270 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu-common.h"
+#include "qapi/qmp/qerror.h"
+#include "qapi/error.h"
+#include "net/net.h"
+#include "qom/object_interfaces.h"
+#include "qemu/iov.h"
+#include "qom/object.h"
+#include "qemu/typedefs.h"
+#include "net/queue.h"
+#include "sysemu/char.h"
+#include "qemu/sockets.h"
+#include "qapi-visit.h"
+
+#define TYPE_COLO_COMPARE "colo-compare"
+#define COLO_COMPARE(obj) \
+    OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
+
+#define COMPARE_READ_LEN_MAX NET_BUFSIZE
+
+typedef struct CompareState {
+    Object parent;
+
+    char *pri_indev;
+    char *sec_indev;
+    char *outdev;
+    CharDriverState *chr_pri_in;
+    CharDriverState *chr_sec_in;
+    CharDriverState *chr_out;
+    SocketReadState pri_rs;
+    SocketReadState sec_rs;
+} CompareState;
+
+typedef struct CompareClass {
+    ObjectClass parent_class;
+} CompareClass;
+
+typedef struct CompareChardevProps {
+    bool is_socket;
+} CompareChardevProps;
+
+static char *compare_get_pri_indev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->pri_indev);
+}
+
+static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->pri_indev);
+    s->pri_indev = g_strdup(value);
+}
+
+static char *compare_get_sec_indev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->sec_indev);
+}
+
+static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->sec_indev);
+    s->sec_indev = g_strdup(value);
+}
+
+static char *compare_get_outdev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->outdev);
+}
+
+static void compare_set_outdev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->outdev);
+    s->outdev = g_strdup(value);
+}
+
+static void compare_pri_rs_finalize(SocketReadState *pri_rs)
+{
+    /* if packet_enqueue pri pkt failed we will send unsupported packet */
+}
+
+static void compare_sec_rs_finalize(SocketReadState *sec_rs)
+{
+    /* if packet_enqueue sec pkt failed we will notify trace */
+}
+
+static int compare_chardev_opts(void *opaque,
+                                const char *name, const char *value,
+                                Error **errp)
+{
+    CompareChardevProps *props = opaque;
+
+    if (strcmp(name, "backend") == 0 &&
+        strcmp(value, "socket") == 0) {
+        props->is_socket = true;
+        return 0;
+    } else if (strcmp(name, "host") == 0 ||
+              (strcmp(name, "port") == 0) ||
+              (strcmp(name, "server") == 0) ||
+              (strcmp(name, "wait") == 0) ||
+              (strcmp(name, "path") == 0)) {
+        return 0;
+    } else {
+        error_setg(errp,
+                   "COLO-compare does not support a chardev with option %s=%s",
+                   name, value);
+        return -1;
+    }
+}
+
+/*
+ * Return 0 is success.
+ * Return 1 is failed.
+ */
+static int find_and_check_chardev(CharDriverState **chr,
+                                  char *chr_name,
+                                  Error **errp)
+{
+    CompareChardevProps props;
+
+    *chr = qemu_chr_find(chr_name);
+    if (*chr == NULL) {
+        error_setg(errp, "Device '%s' not found",
+                   chr_name);
+        return 1;
+    }
+
+    memset(&props, 0, sizeof(props));
+    if (qemu_opt_foreach((*chr)->opts, compare_chardev_opts, &props, errp)) {
+        return 1;
+    }
+
+    if (!props.is_socket) {
+        error_setg(errp, "chardev \"%s\" is not a tcp socket",
+                   chr_name);
+        return 1;
+    }
+    return 0;
+}
+
+/*
+ * Called from the main thread on the primary
+ * to setup colo-compare.
+ */
+static void colo_compare_complete(UserCreatable *uc, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(uc);
+
+    if (!s->pri_indev || !s->sec_indev || !s->outdev) {
+        error_setg(errp, "colo compare needs 'primary_in' ,"
+                   "'secondary_in','outdev' property set");
+        return;
+    } else if (!strcmp(s->pri_indev, s->outdev) ||
+               !strcmp(s->sec_indev, s->outdev) ||
+               !strcmp(s->pri_indev, s->sec_indev)) {
+        error_setg(errp, "'indev' and 'outdev' could not be same "
+                   "for compare module");
+        return;
+    }
+
+    if (find_and_check_chardev(&s->chr_pri_in, s->pri_indev, errp)) {
+        return;
+    }
+
+    if (find_and_check_chardev(&s->chr_sec_in, s->sec_indev, errp)) {
+        return;
+    }
+
+    if (find_and_check_chardev(&s->chr_out, s->outdev, errp)) {
+        return;
+    }
+
+    qemu_chr_fe_claim_no_fail(s->chr_pri_in);
+
+    qemu_chr_fe_claim_no_fail(s->chr_sec_in);
+
+    qemu_chr_fe_claim_no_fail(s->chr_out);
+
+    net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize);
+    net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize);
+
+    return;
+}
+
+static void colo_compare_class_init(ObjectClass *oc, void *data)
+{
+    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+    ucc->complete = colo_compare_complete;
+}
+
+static void colo_compare_init(Object *obj)
+{
+    object_property_add_str(obj, "primary_in",
+                            compare_get_pri_indev, compare_set_pri_indev,
+                            NULL);
+    object_property_add_str(obj, "secondary_in",
+                            compare_get_sec_indev, compare_set_sec_indev,
+                            NULL);
+    object_property_add_str(obj, "outdev",
+                            compare_get_outdev, compare_set_outdev,
+                            NULL);
+}
+
+static void colo_compare_finalize(Object *obj)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    if (s->chr_pri_in) {
+        qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
+        qemu_chr_fe_release(s->chr_pri_in);
+    }
+    if (s->chr_sec_in) {
+        qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
+        qemu_chr_fe_release(s->chr_sec_in);
+    }
+    if (s->chr_out) {
+        qemu_chr_fe_release(s->chr_out);
+    }
+
+    g_free(s->pri_indev);
+    g_free(s->sec_indev);
+    g_free(s->outdev);
+}
+
+static const TypeInfo colo_compare_info = {
+    .name = TYPE_COLO_COMPARE,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(CompareState),
+    .instance_init = colo_compare_init,
+    .instance_finalize = colo_compare_finalize,
+    .class_size = sizeof(CompareClass),
+    .class_init = colo_compare_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void register_types(void)
+{
+    type_register_static(&colo_compare_info);
+}
+
+type_init(register_types);
diff --git a/qemu-options.hx b/qemu-options.hx
index 0b621bb..d0ed69a 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3894,6 +3894,45 @@ Dump the network traffic on netdev @var{dev} to the file specified by
 The file format is libpcap, so it can be analyzed with tools such as tcpdump
 or Wireshark.
 
+@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},
+outdev=@var{chardevid}
+
+Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
+secondary packet. If the packets are same, we will output primary
+packet to outdev@var{chardevid}, else we will notify colo-frame
+do checkpoint and send primary packet to outdev@var{chardevid}.
+
+we must use it with the help of filter-mirror and filter-redirector.
+
+@example
+
+primary:
+-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
+-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
+-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
+-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
+-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
+-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
+-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
+-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
+-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
+-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
+-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
+-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0
+
+secondary:
+-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
+-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
+-chardev socket,id=red0,host=3.3.3.3,port=9003
+-chardev socket,id=red1,host=3.3.3.3,port=9004
+-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
+-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
+
+@end example
+
+If you want to know the detail of above command line, you can read
+the colo-compare git log.
+
 @item -object secret,id=@var{id},data=@var{string},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
 @item -object secret,id=@var{id},file=@var{filename},format=@var{raw|base64}[,keyid=@var{secretid},iv=@var{string}]
 
diff --git a/vl.c b/vl.c
index 215a6f9..7dadb9e 100644
--- a/vl.c
+++ b/vl.c
@@ -2845,7 +2845,8 @@ static bool object_create_initial(const char *type)
     if (g_str_equal(type, "filter-buffer") ||
         g_str_equal(type, "filter-dump") ||
         g_str_equal(type, "filter-mirror") ||
-        g_str_equal(type, "filter-redirector")) {
+        g_str_equal(type, "filter-redirector") ||
+        g_str_equal(type, "colo-compare")) {
         return false;
     }
 
