COLO-compare: Add new parameter to communicate with remote colo-frame

We add the "notify_dev=chardevID" parameter. After that colo-compare can connect with
remote(currently just for Xen, KVM-COLO didn't need it.) colo-frame through chardev socket,
it can notify remote(Xen) colo-frame to handle checkpoint event.

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/colo-compare.c

@@ -83,6 +83,7 @@ typedef struct CompareState {
     char *pri_indev;
     char *sec_indev;
     char *outdev;
+    char *notify_dev;
     CharBackend chr_pri_in;
     CharBackend chr_sec_in;
     CharBackend chr_out;
@@ -897,6 +898,21 @@ static void compare_set_vnet_hdr(Object *obj,
     s->vnet_hdr = value;
 }
 
+static char *compare_get_notify_dev(Object *obj, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    return g_strdup(s->notify_dev);
+}
+
+static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+
+    g_free(s->notify_dev);
+    s->notify_dev = g_strdup(value);
+}
+
 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
 {
     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
@@ -1057,6 +1073,10 @@ static void colo_compare_init(Object *obj)
                             (Object **)&s->iothread,
                             object_property_allow_set_link,
                             OBJ_PROP_LINK_STRONG, NULL);
+    /* This parameter just for Xen COLO */
+    object_property_add_str(obj, "notify_dev",
+                            compare_get_notify_dev, compare_set_notify_dev,
+                            NULL);
 
     s->vnet_hdr = false;
     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
@@ -1103,6 +1123,7 @@ static void colo_compare_finalize(Object *obj)
     g_free(s->pri_indev);
     g_free(s->sec_indev);
     g_free(s->outdev);
+    g_free(s->notify_dev);
 }
 
 static const TypeInfo colo_compare_info = {

qemu-options.hx

@@ -4477,7 +4477,7 @@ 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},iothread=@var{id}[,vnet_hdr_support]
+@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support][,notify_dev=@var{id}]
 
 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
@@ -4486,11 +4486,15 @@ do checkpoint and send primary packet to outdev@var{chardevid}.
 In order to improve efficiency, we need to put the task of comparison
 in another thread. If it has the vnet_hdr_support flag, colo compare
 will send/recv packet with vnet_hdr_len.
+If you want to use Xen COLO, will need the notify_dev to notify Xen
+colo-frame to do checkpoint.
 
 we must use it with the help of filter-mirror and filter-redirector.
 
 @example
 
+KVM COLO
+
 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
@@ -4514,6 +4518,33 @@ secondary:
 -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
 
+
+Xen COLO
+
+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
+-chardev socket,id=notify_way,host=3.3.3.3,port=9009,server,nowait
+-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 iothread,id=iothread1
+-object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,notify_dev=nofity_way,iothread=iothread1
+
+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