Misc XML schema fixes for libxl

The libxlxml2domconfigdata directory was not covered in the RNG schema
tests. This hid a few bugs in both the libxl XML files and the RNG
schema itself.
Reviewed-by: NJim Fehlig <jfehlig@suse.com>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

docs/schemas/domaincommon.rng

@@ -1169,7 +1169,7 @@
       <optional>
         <element name="bootloader">
           <choice>
-            <ref name="absFilePath"/>
+            <text/>
             <empty/>
           </choice>
         </element>
@@ -2764,6 +2764,7 @@
                 <choice>
                   <value>kvm</value>
                   <value>vfio</value>
+                  <value>xen</value>
                 </choice>
               </attribute>
             </group>

tests/libxlxml2domconfigdata/basic-hvm.xml

@@ -8,7 +8,7 @@
   <on_poweroff>destroy</on_poweroff>
   <on_reboot>restart</on_reboot>
   <on_crash>destroy</on_crash>
-  <clock sync='utc'/>
+  <clock offset='utc'/>
   <os>
     <type>hvm</type>
     <loader>/usr/lib/xen/boot/hvmloader</loader>

tests/libxlxml2domconfigdata/vnuma-hvm.xml

@@ -8,7 +8,7 @@
   <on_poweroff>destroy</on_poweroff>
   <on_reboot>restart</on_reboot>
   <on_crash>destroy</on_crash>
-  <clock sync='utc'/>
+  <clock offset='utc'/>
   <os>
     <type>hvm</type>
     <loader>/usr/lib/xen/boot/hvmloader</loader>

tests/virschematest.c

@@ -221,7 +221,7 @@ mymain(void)
                 "qemuxml2argvdata", "sexpr2xmldata", "xmconfigdata",
                 "xml2sexprdata", "qemuxml2xmloutdata", "lxcxml2xmldata",
                 "lxcxml2xmloutdata", "bhyvexml2argvdata", "genericxml2xmlindata",
-                "genericxml2xmloutdata", "xlconfigdata",
+                "genericxml2xmloutdata", "xlconfigdata", "libxlxml2domconfigdata",
                 "qemuhotplugtestdomains");
     DO_TEST_DIR("domaincaps.rng", "domaincapsschemadata");
     DO_TEST_DIR("domainsnapshot.rng", "domainsnapshotxml2xmlin",