docs: add colo readme

add colo readme, refer to
http://wiki.xen.org/wiki/COLO_-_Coarse_Grain_Lock_Stepping

Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

diff --git a/docs/README.colo b/docs/README.colo
new file mode 100644 (file)
index 0000000..466eb72
--- /dev/null
+++ b/docs/README.colo
@@ -0,0 +1,9 @@
+COLO FT/HA (COarse-grain LOck-stepping Virtual Machines for Non-stop Service)
+project is a high availability solution. Both primary VM (PVM) and secondary VM
+(SVM) run in parallel. They receive the same request from client, and generate
+response in parallel too. If the response packets from PVM and SVM are
+identical, they are released immediately. Otherwise, a VM checkpoint (on demand)
+is conducted.
+
+See the website at http://wiki.xen.org/wiki/COLO_-_Coarse_Grain_Lock_Stepping
+for details.