diff --git a/misc/config_tools/schema/config.xsd b/misc/config_tools/schema/config.xsd
index cfcb69238..d88212e17 100644
--- a/misc/config_tools/schema/config.xsd
+++ b/misc/config_tools/schema/config.xsd
@@ -222,7 +222,7 @@ value ``0x400000000``.</xs:documentation>
 maximum supported resource.</xs:documentation>
   </xs:annotation>
   <xs:all>
-    <xs:element name="MAX_VM_NUM" type="xs:integer" default="16">
+    <xs:element name="MAX_VM_NUM" type="MaxVMNumType" default="8">
       <xs:annotation>
         <xs:documentation>Maximum number of User VMs allowed.</xs:documentation>
       </xs:annotation>
diff --git a/misc/config_tools/schema/types.xsd b/misc/config_tools/schema/types.xsd
index d1617b025..026a6b939 100644
--- a/misc/config_tools/schema/types.xsd
+++ b/misc/config_tools/schema/types.xsd
@@ -50,6 +50,16 @@
   </xs:restriction>
 </xs:simpleType>
 
+<xs:simpleType name="MaxVMNumType">
+  <xs:annotation>
+    <xs:documentation>Integer from 1 to 8.</xs:documentation>
+  </xs:annotation>
+  <xs:restriction base="xs:integer">
+    <xs:minInclusive value="1" />
+    <xs:maxInclusive value="8" />
+  </xs:restriction>
+</xs:simpleType>
+
 <xs:simpleType name="MaxMsixTableSizeType">
   <xs:annotation>
     <xs:documentation>Either empty, or an Integer value between 1 and 2048.</xs:documentation>