The Relax-NG schema for domains regarding <hostdev> doesn't match what's
implemented in src/conf/domain_conf.c#virDomainHostdevDefFormat(): The
implementation only requires @type, but the schema currently either
required none or all three attributes (@mode, @type, and @managed) to be
defined together, because they are declared in the same
<optional)-section. (@managed is currently even undocumented on
<http://libvirt.org/formatdomain.html#elementsUSB>).

Thus the following minimal <hostdev>-example fails to validate:
<domain type='test'>
	<name>N</name>
	<memory>4096</memory>
	<bootloader>/bin/false</bootloader>
	<os>
		<type arch='x86_64' machine='xenpv'>linux</type>
	</os>
	<devices>
		<hostdev type='pci'>
			<source>
				<address bus='0x06' slot='0x00' function='0x0'/>
			</source>
		</hostdev>
	</devices>
</domain>

The schema is changed to match the current implementation:
1. @mode is optional (which defaults to 'subsystem')
2. @type is required
3. @managed is optional (which defaults to 'no')

Signed-off-by: Philipp Hahn <hahn@univention.de>
---
 docs/schemas/domain.rng |   14 ++++++++------
 1 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng
index 8b215f3..21c4380 100644
--- a/docs/schemas/domain.rng
+++ b/docs/schemas/domain.rng
@@ -1731,12 +1731,14 @@
             <value>capabilities</value>
           </choice>
         </attribute>
-        <attribute name="type">
-          <choice>
-            <value>usb</value>
-            <value>pci</value>
-          </choice>
-        </attribute>
+      </optional>
+      <attribute name="type">
+        <choice>
+          <value>usb</value>
+          <value>pci</value>
+        </choice>
+      </attribute>
+      <optional>
         <attribute name="managed">
           <choice>
             <value>yes</value>
-- 
1.7.1