domain: save/restore the state of dbus-daemon running

This avoids trying to start a dbus-daemon when its already running.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_domain.c

@@ -2971,6 +2971,9 @@ qemuDomainObjPrivateXMLFormat(virBufferPtr buf,
                           virDomainChrTypeToString(priv->monConfig->type));
     }
 
+    if (priv->dbusDaemonRunning)
+        virBufferAddLit(buf, "<dbusDaemon/>\n");
+
     if (priv->namespaces) {
         ssize_t ns = -1;
 
@@ -3756,6 +3759,8 @@ qemuDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt,
         goto error;
     }
 
+    priv->dbusDaemonRunning = virXPathBoolean("boolean(./dbusDaemon)", ctxt) > 0;
+
     if ((node = virXPathNode("./namespaces", ctxt))) {
         xmlNodePtr next;