diff --git a/misc/config_tools/schema/config.xsd b/misc/config_tools/schema/config.xsd
index 3324f2cb3..c76110d66 100644
--- a/misc/config_tools/schema/config.xsd
+++ b/misc/config_tools/schema/config.xsd
@@ -459,7 +459,7 @@ address is optional.</xs:documentation>
 	      <xs:documentation>The virtio input device setting.</xs:documentation>
 	    </xs:annotation>
 	  </xs:element>
-          <xs:element name="block" type="xs:string" minOccurs="0">
+          <xs:element name="block" type="xs:string" minOccurs="0" maxOccurs="unbounded">
             <xs:annotation acrn:views="basic">
               <xs:documentation>The virtio block device setting.
 Format: ``[blk partition:][img path]``. Example: ``/dev/sda3:./a/b.img``.</xs:documentation>