diff --git a/virttest/qemu_devices/qcontainer.py b/virttest/qemu_devices/qcontainer.py
index bce972f9e2..cab5d0aa3f 100644
--- a/virttest/qemu_devices/qcontainer.py
+++ b/virttest/qemu_devices/qcontainer.py
@@ -1990,6 +1990,9 @@ def chardev_define_by_params(self, chardev_id, params, file_name=None):
             chardev_param.update(
                 {'debug': params.get('chardev_debug'),
                  'name': params.get('chardev_name')})
+        elif 'ringbuf' in backend:
+            chardev_param.update(
+                {'ringbuf_write_size': int(params.get('ringbuf_write_size'))})
         return qdevices.CharDevice(chardev_param, chardev_id)
 
     def cdroms_define_by_params(self, name, image_params, media=None,
diff --git a/virttest/qemu_devices/qdevices.py b/virttest/qemu_devices/qdevices.py
index 5a9e11f0d8..26e373af08 100644
--- a/virttest/qemu_devices/qdevices.py
+++ b/virttest/qemu_devices/qdevices.py
@@ -1294,6 +1294,9 @@ def get_supported_options(self, backend):
             special_opts = ["host", "port", "localaddr",
                             "localport", "ipv4", "ipv6"]
 
+        elif backend == 'ringbuf':
+            special_opts = ["ringbuf_write_size"]
+
         return set(common_opts + special_opts)
 
     def format_params(self, params):
@@ -1364,6 +1367,11 @@ def get_qmp_args(self):
             args["backend"]["data"] = {"device": self.get_param("path")}
             return args
 
+        if self.params.get("backend") in "ringbuf":
+            args["backend"]["data"] = {
+                "size": self.get_param("ringbuf_write_size")}
+            return args
+
         raise DeviceError("chardev '%s' not support hotplug" %
                           self.params.get("backend"))