Bug 890652

Created attachment 669855 [details]
Guest XML

I am using Oz to build an image on Amazon EC2. I need to use libvirt/qemu with emulation because EC2 doesn't do nested virtualization.

I'm using latest Fedora 17. I've updated Oz to the latest upstream version, all other packages are unmodified.

When building an image, Oz bails out with the following error:

Traceback (most recent call last):
  File "/usr/bin/oz-install", line 7, in <module>
    execfile(__file__)
  File "/home/ec2-user/oz/oz-install", line 146, in <module>
    libvirt_xml = guest.install(timeout, force_download)
  File "/home/ec2-user/oz/oz/Guest.py", line 1534, in install
    return self._do_install(timeout, force, 0)
  File "/home/ec2-user/oz/oz/Guest.py", line 1515, in _do_install
    dom = self.libvirt_conn.createXML(xml, 0)
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 2420, in createXML
    if ret is None:raise libvirtError('virDomainCreateXML() failed', conn=self)
libvirt.libvirtError: internal error process exited while connecting to monitor: qemu-system-x86_64: -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23: vhost-net support is not compiled in
qemu-system-x86_64: -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23: vhost-net requested but could not be initialized
qemu-system-x86_64: -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23: Device 'tap' could not be initialized

I've also reported this to Oz upstream under this issue:

https://github.com/clalancette/oz/issues/47

However I think this is a libvirt bug. I haven't fully diagonized this but it appears that qemu-system-x86_64 is built without vhost support. However, libvirtd does pass a vhost=on parameter.

I've added the XML that Oz generated to create the guest.