Created attachment 660639 [details]
Virtual machine definition.

With a rarely encountered combination of configuration parameters, a virtual
machine using the network installer tries and fails to bring up the Red Hat
Virtio Network Device, which is not exactly functional.  

My virtual machine, emulated by  qemu-kvm-2.3.1-9.1.x86_64 and monitored by
libvirt-daemon-1.2.18.1-3.2.x86_64, boots from
openSUSE-Leap-42.1-NET-x86_64.iso .  The failure is similar if the main action
is update, install, or rescue system.  
* F4, source selection, I scrolled to Network Configuration, and picked Manual.
 I gave it the VM's IPv4 address/CIDR but left the gateway, DNS and search
domain blank.  This is because I was doing something special with an enterprise
mirror.  
* If I leave the network configuration at the default, the bug does not appear.
 It starts a DHCP client on eth0 by itself and eventually uses the SuSE
servers.  
* Scroll to the main action and press Enter.  
* It got the kernel and installer initrd off the ISO,  System startup was
uneventful until it tried to start up the network, but it failed to open the
SuSE repo URL.  
* Don't try to fix it; just hit Back, pick language and keyboard, Start
Installation.  
* Scroll down to Network Setup and press Enter.  Tell it to not keep the
messed-up configuration.  
* Bug: the network device is set to Red Hat Virtio Network Device (null).
* Workaround: Change to eth0.
* You're back to the Start Installation menu.  Wait 10-15 seconds; it should
ask: automatic configuration by DHCP?  Answer what's appropriate for your net
(usually Yes).  
* Back to Start Installation menu again.  Pick the main action.  The
installation will use the network successfully, and will ask for the enterprise
mirror's URL when appropriate.  

I've never seen similar behavior on a real machine.  qemu-kvm is the only
emulator that I've used.  I have 2 VM's with almost identical configurations,
and both fail equally.  It fails the same way every time I try to boot from the
ISO with the network in Manual.  The bug appears if the host OS version is 42.1
or 13.1 (qemu-1.6.2-4.8.1.x86_64).