conf: add support for Direct Mode for Hyper-V Synthetic timers

Support 'Direct Mode' for Hyper-V Synthetic Timers in domain config.
Make it 'stimer' enlightenment option as it is not a separate thing.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>

docs/formatdomain.html.in

@@ -2033,7 +2033,9 @@
     <vpindex state='on'/>
     <runtime state='on'/>
     <synic state='on'/>
-    <stimer state='on'/>
+    <stimer state='on'>
+      <direct state='on'/>
+    </stimer>
     <reset state='on'/>
     <vendor_id state='on' value='KVM Hv'/>
     <frequencies state='on'/>
@@ -2149,9 +2151,9 @@
         </tr>
         <tr>
           <td>stimer</td>
-          <td>Enable SynIC timers</td>
-          <td>on, off</td>
-          <td><span class="since">1.3.3 (QEMU 2.6)</span></td>
+          <td>Enable SynIC timers, optionally with Direct Mode support</td>
+          <td>on, off; direct - on,off</td>
+          <td><span class="since">1.3.3 (QEMU 2.6), direct mode 5.7.0 (QEMU 4.1)</span></td>
         </tr>
         <tr>
           <td>reset</td>

docs/schemas/domaincommon.rng

@@ -5907,7 +5907,7 @@
         </optional>
         <optional>
           <element name="stimer">
-            <ref name="featurestate"/>
+            <ref name="stimer"/>
           </element>
         </optional>
         <optional>
@@ -5956,6 +5956,20 @@
     </element>
   </define>
 
+  <!-- Hyper-V stimer features -->
+  <define name="stimer">
+    <interleave>
+      <optional>
+        <ref name="featurestate"/>
+      </optional>
+      <optional>
+        <element name="direct">
+          <ref name="featurestate"/>
+        </element>
+      </optional>
+    </interleave>
+  </define>
+
   <!-- Optional KVM features -->
   <define name="kvm">
     <element name="kvm">