[libvirt] [PATCH] macvtap: libvirtd forgot macvtap device name during a shutdown/restart cycle

[Stefan Berger]

During a shutdown/restart cycle libvirtd forgot the macvtap device name 
that it had created on behalf of a VM so that a stale macvtap device 
remained on the host when the VM terminated. Libvirtd has to actively 
tear down a macvtap device and it uses its name for identifying which 
device to tear down.

The solution is to not blank out the <target dev='...'/> completely, but 
only blank it out on VMs that are not active. So, if a VM is active, the 
device name makes it into the XML and is also being parsed. If a VM is 
not active, the device name is discarded.

Signed-off-by: Stefan Berger <stefanb at us.ibm.com>

---
  src/conf/domain_conf.c |    5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

Index: libvirt-acl/src/conf/domain_conf.c
===================================================================
--- libvirt-acl.orig/src/conf/domain_conf.c
+++ libvirt-acl/src/conf/domain_conf.c
@@ -2343,7 +2343,8 @@ virDomainNetDefParseXML(virCapsPtr caps,
          def->data.direct.linkdev = dev;
          dev = NULL;

-        VIR_FREE(ifname);
+        if ((flags & VIR_DOMAIN_XML_INACTIVE))
+            VIR_FREE(ifname);

          break;

@@ -5801,6 +5802,8 @@ virDomainNetDefFormat(virBufferPtr buf,
          virBufferAddLit(buf, "/>\n");
          virVirtualPortProfileFormat(buf, 
&def->data.direct.virtPortProfile,
                                      "      ");
+        if ((flags & VIR_DOMAIN_XML_INACTIVE))
+            VIR_FREE(def->ifname);
          break;

      case VIR_DOMAIN_NET_TYPE_USER: