conf: introduce support for Fibre Channel VMID

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>

docs/formatdomain.rst

@@ -1221,6 +1221,27 @@ Resource partitions are currently supported by the QEMU and LXC drivers, which
 map partition paths to cgroups directories, in all mounted controllers.
 :since:`Since 1.0.5`
 
+Fibre Channel VMID
+-------------------
+
+The FC SAN can provide various QoS levels and access control depending on the
+VMID. It can also collect telemetry data at per-VM level which can be used
+to enhance the IO performance of the VM. This can be configured by using
+the ``appid`` attribute of ``fibrechannel`` element. The attribute contains
+single string (max 128 bytes) and it is used by kernel to create VMID.
+
+::
+
+   ...
+   <resource>
+     <fibrechannel appid='userProvidedID'/>
+   </resource>
+   ...
+
+Using this feature requires Fibre Channel capable HW, kernel compiled with
+option ``CONFIG_BLK_CGROUP_FC_APPID`` and ``nvme_fc`` kernel module loaded.
+:since:`Since 7.7.0`
+
 :anchor:`<a id="elementsCPU"/>`
 
 CPU model and topology

docs/schemas/domaincommon.rng

@@ -576,6 +576,17 @@
     </element>
   </define>
 
+  <define name="fibrechannel">
+    <element name="fibrechannel">
+      <attribute name="appid">
+        <data type="string">
+          <!-- All printable characters -->
+          <param name="pattern">[&#x20;-&#x7E;]{1,128}</param>
+        </data>
+      </attribute>
+    </element>
+  </define>
+
   <!--
       The Identifiers can be:
       - an optional id attribute with a number on the domain element
@@ -1177,6 +1188,9 @@
           <ref name="absFilePath"/>
         </element>
       </optional>
+      <optional>
+        <ref name="fibrechannel"/>
+      </optional>
     </element>
   </define>