Yanqiu Zhang reported [1] that when a vlan is defined with a single vlan id and native mode set to tagged, the vlan was not setup correctly using the standard Linux bridge functionality. This is due a conflict between the XML validation and the bridge functionality. The XML validation will allow a single vlan id to be configured with native mode set to tagged without setting the vlan mode to trunked. If the vlan is explicitly set to "trunk='no'" then the validation will correctly reject the configuration. Rather than force the user to specify "trunk='yes'", update the code to infer trunk='yes' if a single vlan id is configured with native mode set to a non-default value. It already infers trunk='yes' if more than one vlan id is specified. Reported-by: Yanqiu Zhang <yanqzhan(a)redhat.com&gt; Closes: https://gitlab.com/libvirt/libvirt/-/issues/767 [1] Signed-off-by: Leigh Brown <leigh(a)solinno.co.uk&gt; --- src/conf/netdev_vlan_conf.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/src/conf/netdev_vlan_conf.c b/src/conf/netdev_vlan_conf.c index 1ac66aec54..300d0d8e86 100644 --- a/src/conf/netdev_vlan_conf.c +++ b/src/conf/netdev_vlan_conf.c @@ -87,12 +87,13 @@ virNetDevVlanParse(xmlNodePtr node, xmlXPathContextPtr ctxt, virNetDevVlan *def) def->nTags = nTags; - /* now that we know how many tags there are, look for an explicit - * trunk setting. + /* In case the trunk attribute is not specified, infer it from + * the number of tags or use of native vlan mode. */ - if (nTags > 1) + if (nTags > 1 || def->nativeMode != 0) def->trunk = true; + /* Look for and validate an explicit trunk setting. */ ctxt->node = node; if ((trunk = virXPathString("string(./@trunk)", ctxt)) != NULL) { def->trunk = STRCASEEQ(trunk, "yes"); -- 2.49.0