8:47 a.m.
This patch documents XML elements used for (basic) support of virtual
RNG devices.
In the devices section in the domain XML users may specify:
For the default 'random' backend:
<devices>
<rng model='virtio'>
<backend model='random'>/dev/urandom</backend>
</rng>
</devices>
For the slightly more advanced EGD backend:
<devices>
<rng model='virtio'>
<backend model='egd' type='udp'>
<!-- this is a definition of a character device -->
<source mode='bind' service='1234'/>
<source mode='connect' host='1.2.3.4'
service='1234'/>
<!-- or other valid character device configuration -->
</backend>
</rng>
</devices>
For the planned random daemon/pool:
<devices>
<rng model='virtio'>
<backend model='pool' pool='poolname'>class</backend>
</devices>
to enable the RNG device for guests.
---
Notes:
Version 2:
- ACKed, no change, unfortunately doesn't make sense to push alone
docs/formatdomain.html.in | 69 +++++++++++++++++++++++++++++++++++++++++++
docs/schemas/domaincommon.rng | 32 ++++++++++++++++++++
2 files changed, 101 insertions(+)
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index ffcc33e..e8cd086 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -4278,6 +4278,75 @@ qemu-kvm -net nic,model=? /dev/null
</ul>
</dd>
</dl>
+ <h4><a name="elementsRng">Random number generator
device</a></h4>
+
+ <p>
+ The virtual random number generator device allows the host to pass
+ through entropy to guest operating systems.
+ <span class="since">Since 1.0.3</span>
+ </p>
+
+ <p>
+ Example: usage of the RNG device:
+ </p>
+<pre>
+ ...
+ <devices>
+ <rng model='virtio'>
+ <backend model='random'>/dev/random</backend>
+ <!-- OR -->
+ <backend model='egd' type='udp'>
+ <source mode='bind' service='1234'>
+ <source mode='connect' host='1.2.3.4'
service='1234'>
+ </backend>
+ </rng>
+ </devices>
+ ...
+</pre>
+ <dl>
+ <dt><code>model</code></dt>
+ <dd>
+ <p>
+ The required <code>model</code> attribute specifies what type
+ of RNG device is provided. Valid values are specific to
+ the virtualization platform:
+ </p>
+ <ul>
+ <li>'virtio' — supported by qemu and virtio-rng kernel
module</li>
+ </ul>
+ </dd>
+ <dt><code>backend</code></dt>
+ <dd>
+ <p>
+ The <code>backend</code> element specifies the source of entropy
+ to be used for the doimain. The source model is configured using the
+ <code>model</code> attribute. Supported source models are:
+ </p>
+ <ul>
+ <li>'random' — /dev/random (default) or similar device
as source</li>
+ <li>'egd' — a EGD protocol backend. </li>
+ </ul>
+ </dd>
+ <dt><code>backend type='random'</code></dt>
+ <dd>
+ <p>
+ This backend type expects a non-blocking character device as input.
+ Examples of such devices are /dev/random and /dev/urandom. The file
+ name is specified as contents of the <code>backend</code> element.
+ When no file name is specified the hypervisor default is used.
+ </p>
+ </dd>
+ <dt><code>backend type='egd'</code></dt>
+ <dd>
+ <p>
+ This backend connects to a source using the EGD protocol.
+ The source is specified as a character device. Refer to
+ <a href='#elementsCharHostInterface'>character device host
interface</a>
+ for more information.
+ </p>
+ </dd>
+
+ </dl>
<h3><a name="seclabel">Security label</a></h3>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 63be4aa..8330a50 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -3126,6 +3126,7 @@
<ref name="hub"/>
<ref name="redirdev"/>
<ref name="redirfilter"/>
+ <ref name="rng"/>
</choice>
</zeroOrMore>
<optional>
@@ -3514,6 +3515,37 @@
</element>
</define>
+ <define name="rng">
+ <element name="rng">
+ <attribute name="model">
+ <choice>
+ <value>virtio</value>
+ </choice>
+ </attribute>
+ <ref name="rng-backend"/>
+ </element>
+ </define>
+
+ <define name="rng-backend">
+ <element name="backend">
+ <choice>
+ <group>
+ <attribute name="model">
+ <value>random</value>
+ </attribute>
+ <ref name="filePath"/>
+ </group>
+ <group>
+ <attribute name="model">
+ <value>egd</value>
+ </attribute>
+ <ref name="qemucdevSrcType"/>
+ <ref name="qemucdevSrcDef"/>
+ </group>
+ </choice>
+ </element>
+ </define>
+
<define name="usbmaster">
<element name="master">
<attribute name="startport">
--
1.8.1.1