diff --git a/docs/drvxen.html.in b/docs/drvxen.html.in
index b2f41c1763..45a9329fcf 100644
--- a/docs/drvxen.html.in
+++ b/docs/drvxen.html.in
@@ -141,6 +141,35 @@ vnclisten = "0.0.0.0"
 disk = [ "tap:aio:/var/lib/xen/images/rhel5pv.img,xvda,w", "tap:qcow:/root/qcow1-xen.img,xvdd,w" ]
 vif = [ "mac=00:16:3e:60:36:ba,bridge=virbr0,script=vif-bridge,vifname=vif5.0" ]</pre>
 
+    <h2><a id="xencommand">Pass-through of arbitrary command-line arguments
+    to the qemu device model</a></h2>
+
+    <p><span class="since">Since 6.7.0</span>, the Xen driver supports passing
+      arbitrary command-line arguments to the qemu device model used by Xen with
+      the <code>&lt;xen:commandline&gt;</code> element under <code>domain</code>.
+      In order to use command-line pass-through, an XML namespace request must be
+      issued that pulls in <code>http://libvirt.org/schemas/domain/xen/1.0</code>.
+      With the namespace in place, it is then possible to add
+      <code>&lt;xen:arg&gt;</code>sub-elements to
+      <code>&lt;xen:commandline&gt;</code> describing each argument passed to
+      the device model when starting the domain.
+    </p>
+    <p>The following example illustrates passing agruments to the QEMU device
+      model that define a floppy drive, which Xen does not support through its
+      public APIs:
+    </p>
+    <pre>
+&lt;domain type="xen" xmlns:xen="http://libvirt.org/schemas/domain/xen/1.0"&gt;
+  ...
+  &lt;xen:commandline&gt;
+    &lt;xen:arg value='-drive'/&gt;
+    &lt;xen:arg value='file=/path/to/image,format=raw,if=none,id=drive-fdc0-0-0'/&gt;
+    &lt;xen:arg value='-global'/&gt;
+    &lt;xen:arg value='isa-fdc.driveA=drive-fdc0-0-0'/&gt;
+  &lt;/xen:commandline&gt;
+&lt;/domain&gt;
+    </pre>
+
     <h2><a id="xmlconfig">Example domain XML config</a></h2>
 
     <p>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index c933c71035..0d8a0caaf6 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -87,6 +87,9 @@
         <optional>
           <ref name='bhyvecmdline'/>
         </optional>
+        <optional>
+          <ref name='xencmdline'/>
+        </optional>
       </interleave>
     </element>
   </define>
@@ -6836,6 +6839,20 @@
     </element>
   </define>
 
+  <!--
+       Optional hypervisor extensions in their own namespace:
+         Xen
+    -->
+  <define name="xencmdline">
+    <element name="commandline" ns="http://libvirt.org/schemas/domain/xen/1.0">
+      <zeroOrMore>
+        <element name="arg">
+          <attribute name='value'/>
+        </element>
+      </zeroOrMore>
+    </element>
+  </define>
+
   <!--
        Type library
     -->
diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index 7c2c015015..e7c7022b69 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -760,6 +760,13 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
         libxl_get_required_shadow_memory(b_info->max_memkb,
                                          b_info->max_vcpus);
 
+    if (def->namespaceData) {
+        libxlDomainXmlNsDefPtr nsdata = def->namespaceData;
+
+        if (nsdata->num_args > 0)
+            b_info->extra = g_strdupv(nsdata->args);
+    }
+
     return 0;
 }
 
@@ -2513,5 +2520,6 @@ libxlCreateXMLConf(libxlDriverPrivatePtr driver)
     libxlDomainDefParserConfig.priv = driver;
     return virDomainXMLOptionNew(&libxlDomainDefParserConfig,
                                  &libxlDomainXMLPrivateDataCallbacks,
-                                 NULL, NULL, NULL);
+                                 &libxlDriverDomainXMLNamespace,
+                                 NULL, NULL);
 }
diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
index b057a9e4ba..fc652df61e 100644
--- a/src/libxl/libxl_conf.h
+++ b/src/libxl/libxl_conf.h
@@ -168,6 +168,14 @@ struct _libxlSavefileHeader {
     uint32_t unused[10];
 };
 
+
+typedef struct _libxlDomainXmlNsDef libxlDomainXmlNsDef;
+typedef libxlDomainXmlNsDef *libxlDomainXmlNsDefPtr;
+struct _libxlDomainXmlNsDef {
+    size_t num_args;
+    char **args;
+};
+
 libxlDriverConfigPtr
 libxlDriverConfigNew(void);
 int
diff --git a/src/libxl/libxl_domain.c b/src/libxl/libxl_domain.c
index d9fcde4364..de2059fa24 100644
--- a/src/libxl/libxl_domain.c
+++ b/src/libxl/libxl_domain.c
@@ -1573,3 +1573,85 @@ libxlDomainDefCheckABIStability(libxlDriverPrivatePtr driver,
     virDomainDefFree(migratableDefDst);
     return ret;
 }
+
+
+static void
+libxlDomainDefNamespaceFree(void *nsdata)
+{
+    libxlDomainXmlNsDefPtr def = nsdata;
+
+    if (!def)
+        return;
+
+    g_strfreev(def->args);
+    g_free(def);
+}
+
+
+static int
+libxlDomainDefNamespaceParse(xmlXPathContextPtr ctxt,
+                             void **data)
+{
+    libxlDomainXmlNsDefPtr nsdata = NULL;
+    g_autofree xmlNodePtr *nodes = NULL;
+    ssize_t nnodes;
+    size_t i;
+    int ret = -1;
+
+    if ((nnodes = virXPathNodeSet("./xen:commandline/xen:arg", ctxt, &nodes)) < 0)
+        return -1;
+
+    if (nnodes == 0)
+        return 0;
+
+    nsdata = g_new0(libxlDomainXmlNsDef, 1);
+    nsdata->args = g_new0(char *, nnodes + 1);
+
+    for (i = 0; i < nnodes; i++) {
+        if (!(nsdata->args[nsdata->num_args++] = virXMLPropString(nodes[i], "value"))) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("No device model command-line argument specified"));
+            goto cleanup;
+        }
+    }
+
+    *data = g_steal_pointer(&nsdata);
+    ret = 0;
+
+ cleanup:
+    libxlDomainDefNamespaceFree(nsdata);
+    return ret;
+}
+
+
+static int
+libxlDomainDefNamespaceFormatXML(virBufferPtr buf,
+                                 void *nsdata)
+{
+    libxlDomainXmlNsDefPtr cmd = nsdata;
+    size_t i;
+
+    if (!cmd->num_args)
+        return 0;
+
+    virBufferAddLit(buf, "<xen:commandline>\n");
+    virBufferAdjustIndent(buf, 2);
+
+    for (i = 0; i < cmd->num_args; i++)
+        virBufferEscapeString(buf, "<xen:arg value='%s'/>\n",
+                              cmd->args[i]);
+
+    virBufferAdjustIndent(buf, -2);
+    virBufferAddLit(buf, "</xen:commandline>\n");
+
+    return 0;
+}
+
+
+virXMLNamespace libxlDriverDomainXMLNamespace = {
+    .parse = libxlDomainDefNamespaceParse,
+    .free = libxlDomainDefNamespaceFree,
+    .format = libxlDomainDefNamespaceFormatXML,
+    .prefix = "xen",
+    .uri = "http://libvirt.org/schemas/domain/xen/1.0",
+};
diff --git a/src/libxl/libxl_domain.h b/src/libxl/libxl_domain.h
index 7e28093722..00682546e0 100644
--- a/src/libxl/libxl_domain.h
+++ b/src/libxl/libxl_domain.h
@@ -77,6 +77,7 @@ struct _libxlDomainObjPrivate {
 
 extern virDomainXMLPrivateDataCallbacks libxlDomainXMLPrivateDataCallbacks;
 extern virDomainDefParserConfig libxlDomainDefParserConfig;
+extern virXMLNamespace libxlDriverDomainXMLNamespace;
 extern const struct libxl_event_hooks ev_hooks;
 
 int