Add virtio-related options to rng devices

https://bugzilla.redhat.com/show_bug.cgi?id=1283251

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>

docs/formatdomain.html.in

@@ -7064,6 +7064,17 @@ qemu-kvm -net nic,model=? /dev/null
           </dd>
         </dl>
       </dd>
+      <dt><code>driver</code></dt>
+      <dd>
+        The subelement <code>driver</code> can be used to tune the device:
+        <dl>
+          <dt>virtio options</dt>
+          <dd>
+          <a href="#elementsVirtio">Virtio-specific options</a> can also be
+          set. (<span class="since">Since 3.5.0</span>)
+          </dd>
+        </dl>
+      </dd>
 
     </dl>
 

docs/schemas/domaincommon.rng

@@ -4965,6 +4965,11 @@
       </attribute>
       <interleave>
         <ref name="rng-backend"/>
+        <optional>
+          <element name="driver">
+            <ref name="virtioOptions"/>
+          </element>
+        </optional>
         <optional>
           <ref name="rng-rate"/>
         </optional>

src/conf/domain_conf.c

@@ -12949,6 +12949,9 @@ virDomainRNGDefParseXML(virDomainXMLOptionPtr xmlopt,
     if (virDomainDeviceInfoParseXML(node, NULL, &def->info, flags) < 0)
         goto error;
 
+    if (virDomainVirtioOptionsParseXML(ctxt, &def->virtio) < 0)
+        goto error;
+
  cleanup:
     VIR_FREE(model);
     VIR_FREE(backend);
@@ -19663,6 +19666,10 @@ virDomainRNGDefCheckABIStability(virDomainRNGDefPtr src,
         return false;
     }
 
+    if (src->virtio && dst->virtio &&
+        !virDomainVirtioOptionsCheckABIStability(src->virtio, dst->virtio))
+        return false;
+
     if (!virDomainDeviceInfoCheckABIStability(&src->info, &dst->info))
         return false;
 
@@ -23176,6 +23183,7 @@ virDomainRNGDefFormat(virBufferPtr buf,
 {
     const char *model = virDomainRNGModelTypeToString(def->model);
     const char *backend = virDomainRNGBackendTypeToString(def->backend);
+    virBuffer driverBuf = VIR_BUFFER_INITIALIZER;
 
     virBufferAsprintf(buf, "<rng model='%s'>\n", model);
     virBufferAdjustIndent(buf, 2);
@@ -23204,6 +23212,16 @@ virDomainRNGDefFormat(virBufferPtr buf,
         break;
     }
 
+    virDomainVirtioOptionsFormat(&driverBuf, def->virtio);
+    if (virBufferCheckError(&driverBuf) < 0)
+        return -1;
+
+    if (virBufferUse(&driverBuf)) {
+        virBufferAddLit(buf, "<driver");
+        virBufferAddBuffer(buf, &driverBuf);
+        virBufferAddLit(buf, "/>\n");
+    }
+
     if (virDomainDeviceInfoNeedsFormat(&def->info, flags)) {
         if (virDomainDeviceInfoFormat(buf, &def->info, flags) < 0)
             return -1;
@@ -23232,6 +23250,7 @@ virDomainRNGDefFree(virDomainRNGDefPtr def)
     }
 
     virDomainDeviceInfoClear(&def->info);
+    VIR_FREE(def->virtio);
     VIR_FREE(def);
 }
 

src/conf/domain_conf.h

@@ -2020,6 +2020,7 @@ struct _virDomainRNGDef {
     } source;
 
     virDomainDeviceInfo info;
+    virDomainVirtioOptionsPtr virtio;
 };
 
 typedef enum {

tests/qemuxml2argvdata/qemuxml2argv-virtio-options.xml

@@ -80,6 +80,7 @@
     </memballoon>
     <rng model='virtio'>
       <backend model='random'>/dev/random</backend>
+      <driver iommu='on' ats='on'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x0d' function='0x0'/>
     </rng>
   </devices>