commit 56945e1374bd254148643d76a98fba9be67fba15
Author: Chunyan Liu <cyliu@suse.com>
Date:   Thu Sep 17 01:15:22 2015 -0400

    libxl: fix AttachDeviceConfig on hostdev type
    
    After attach-device a <hostdev> with --config, new device doesn't
    show up in dumpxml and in guest.
    
    To fix that, set dev->data.hostdev = NULL after work so that the
    pointer is not freed, since vmdef has the pointer and still need it.
    
    Signed-off-by: Chunyan Liu <cyliu@suse.com>

Index: libvirt-1.2.19/src/libxl/libxl_driver.c
===================================================================
--- libvirt-1.2.19.orig/src/libxl/libxl_driver.c
+++ libvirt-1.2.19/src/libxl/libxl_driver.c
@@ -3311,6 +3311,7 @@ libxlDomainAttachDeviceConfig(virDomainD
 
             if (virDomainHostdevInsert(vmdef, hostdev) < 0)
                 return -1;
+            dev->data.hostdev = NULL;
             break;
 
         default: