allow to use serial terminal as display

www/manager/Utils.js

@@ -187,7 +187,11 @@ Ext.define('PVE.Utils', { statics: {
 	std: 'Standard VGA',
 	vmware: 'VMWare compatible',
 	cirrus: 'Cirrus Logic GD5446',
-	qxl: 'SPICE'
+	qxl: 'SPICE',
+	serial0: 'Serial terminal 0',
+	serial1: 'Serial terminal 1',
+	serial2: 'Serial terminal 2',
+	serial3: 'Serial terminal 3'
     },
 
     render_kvm_language: function (value) {

www/manager/qemu/DisplayEdit.js

 Ext.define('PVE.qemu.DisplayEdit', {
     extend: 'PVE.window.Edit',
 
+    vmconfig: undefined,
+
     initComponent : function() {
 	var me = this;
 
+	var displayField;
+
+	var validateDisplay = function() {
+	    var val = displayField.getValue();
+
+	    if (me.vmconfig && val.match(/^serial\d+$/)) {
+		if (me.vmconfig[val] && me.vmconfig[val] === 'socket') {
+		    return true;
+		}
+		return "Serial interface '" + val + "' is not correctly configured.";
+	    }
+	    
+	    return true;
+	};
+
+	displayField = Ext.createWidget('DisplaySelector', {  
+	    name: 'vga',
+	    value: '',
+	    fieldLabel: gettext('Graphic card'),
+	    validator: validateDisplay
+	});
+
 	Ext.apply(me, {
 	    subject: gettext('Display'),
 	    width: 350,
-	    items: {
-		xtype: 'DisplaySelector',
-		name: 'vga',
-		value: '',
-		fieldLabel: gettext('Graphic card')
-	    }
+	    items: displayField
 	});
 
 	me.callParent();
 
-	me.load();
+	me.load({
+	    success: function(response, options) {
+		var values = response.result.data;
+
+		me.vmconfig = values;
+
+		me.setValues(values);
+	    }
+	});
     }
 });