Support for Disk Geometry Override

A hypervisor may allow to override the disk geometry of drives.
Qemu, as an example with cyls=,heads=,secs=[,trans=].
This patch extends the domain config to allow the specification of
disk geometry with libvirt.

Signed-off-by: J.B. Joret <jb@linux.vnet.ibm.com>
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 8e0748977..d87ca6b7f 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -1224,6 +1224,12 @@
       <target dev='sda' bus='scsi'/>
       <address type='drive' controller='0' bus='0' target='3' unit='0'/>
     </disk>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/sda'/>
+      <geometry cyls='16383' heads='16' secs='63' trans='lba'/>
+      <target dev='hda' bus='ide'/>
+    </disk>
   </devices>
   ...</pre>
 
@@ -1571,6 +1577,25 @@
         associated with the Ceph secret
         object.  <span class="since">libvirt 0.9.7</span>
       </dd>
+      <dt><code>geometry</code></dt>
+      <dd>The optional <code>geometry</code> element provides the
+        ability to override geometry settings. This mostly useful for
+        S390 DASD-disks or older DOS-disks.  <span class="since">0.10.0</span>
+        <dl>
+          <dt><code>cyls</code></dt>
+          <dd>The <code>cyls</code> attribute is the
+            number of cylinders. </dd>
+          <dt><code>heads</code></dt>
+          <dd>The <code>heads</code> attribute is the
+            number of heads. </dd>
+          <dt><code>secs</code></dt>
+          <dd>The <code>secs</code> attribute is the
+            number of sectors per track. </dd>
+          <dt><code>trans</code></dt>
+          <dd>The optional <code>trans</code> attribute is the
+            BIOS-Translation-Modus (none, lba or auto)</dd>
+        </dl>
+      </dd>
     </dl>
 
     <h4><a name="elementsFilesystems">Filesystems</a></h4>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 401b76ba8..8a1782ac7 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -866,6 +866,9 @@
       <optional>
         <ref name="address"/>
       </optional>
+      <optional>
+        <ref name="geometry"/>
+      </optional>
     </interleave>
   </define>
   <define name="snapshot">
@@ -1068,6 +1071,28 @@
       </optional>
     </element>
   </define>
+  <define name="geometry">
+    <element name="geometry">
+      <attribute name="cyls">
+        <data type="integer"/>
+      </attribute>
+      <attribute name="heads">
+        <data type="integer"/>
+      </attribute>
+      <attribute name="secs">
+        <data type="integer"/>
+      </attribute>
+      <optional>
+        <attribute name="trans">
+          <choice>
+            <value>auto</value>
+            <value>none</value>
+            <value>lba</value>
+          </choice>
+        </attribute>
+      </optional>
+    </element>
+  </define>
   <!--
       Disk may use a special driver for access.
     -->