qmp: support command 'chardev-remove'

So that caller can remove hotremove chardev via qmp

Signed-off-by: Liu Xiaodong <xiaodong.liu@intel.com>

qemu/qmp.go

@@ -946,6 +946,17 @@ func (q *QMP) ExecuteBlockdevDel(ctx context.Context, blockdevID string) error {
 	return q.executeCommand(ctx, "x-blockdev-del", args, nil)
 }
 
+// ExecuteChardevDel deletes a char device by sending a chardev-remove command.
+// chardevID is the id of the char device to be deleted. Typically, this will
+// match the id passed to ExecuteCharDevUnixSocketAdd. It must be a valid QMP id.
+func (q *QMP) ExecuteChardevDel(ctx context.Context, chardevID string) error {
+	args := map[string]interface{}{
+		"id": chardevID,
+	}
+
+	return q.executeCommand(ctx, "chardev-remove", args, nil)
+}
+
 // ExecuteNetdevAdd adds a Net device to a QEMU instance
 // using the netdev_add command. netdevID is the id of the device to add.
 // Must be valid QMP identifier.

qemu/qmp_test.go

@@ -638,6 +638,28 @@ func TestQMPBlockdevDel(t *testing.T) {
 	<-disconnectedCh
 }
 
+// Checks that the chardev-remove command is correctly sent.
+//
+// We start a QMPLoop, send the chardev-remove command and stop the loop.
+//
+// The chardev-remove command should be correctly sent and the QMP loop should
+// exit gracefully.
+func TestQMPChardevDel(t *testing.T) {
+	connectedCh := make(chan *QMPVersion)
+	disconnectedCh := make(chan struct{})
+	buf := newQMPTestCommandBuffer(t)
+	buf.AddCommand("chardev-remove", nil, "return", nil)
+	cfg := QMPConfig{Logger: qmpTestLogger{}}
+	q := startQMPLoop(buf, cfg, connectedCh, disconnectedCh)
+	q.version = checkVersion(t, connectedCh)
+	err := q.ExecuteChardevDel(context.Background(), "chardev-0")
+	if err != nil {
+		t.Fatalf("Unexpected error %v", err)
+	}
+	q.Shutdown()
+	<-disconnectedCh
+}
+
 // Checks that the device_del command is correctly sent.
 //
 // We start a QMPLoop, send the device_del command and wait for it to complete.