I should also add that I did compile qemu with vhost-net enabled:

# /usr/local/bin/qemu-system-x86_64 -device virtio-net-pci,?
virtio-net-pci.ioeventfd=on/off
virtio-net-pci.vectors=uint32
virtio-net-pci.indirect_desc=on/off
virtio-net-pci.csum=on/off
virtio-net-pci.guest_csum=on/off
virtio-net-pci.gso=on/off
virtio-net-pci.guest_tso4=on/off
virtio-net-pci.guest_tso6=on/off
virtio-net-pci.guest_ecn=on/off
virtio-net-pci.guest_ufo=on/off
virtio-net-pci.host_tso4=on/off
virtio-net-pci.host_tso6=on/off
virtio-net-pci.host_ecn=on/off
virtio-net-pci.host_ufo=on/off
virtio-net-pci.mrg_rxbuf=on/off
virtio-net-pci.status=on/off
virtio-net-pci.ctrl_vq=on/off
virtio-net-pci.ctrl_rx=on/off
virtio-net-pci.ctrl_vlan=on/off
virtio-net-pci.ctrl_rx_extra=on/off
virtio-net-pci.mac=macaddr
virtio-net-pci.vlan=vlan
virtio-net-pci.netdev=netdev
virtio-net-pci.bootindex=int32
virtio-net-pci.x-txtimer=uint32
virtio-net-pci.x-txburst=int32
virtio-net-pci.tx=string



On Fri, May 20, 2011 at 11:15 AM, Cal Heldenbrand <cal@fbsdata.com> wrote:
Hi everyone,

I'm trying to test out the virtio driver's "tx=bh" option, or iothread in libvirt.  When I create a machine, I get the "unsupported" error message:

# virsh create web101.xml
error: Failed to create domain from web101.xml
error: unsupported configuration: vhost-net is not supported with this QEMU binary

My interface XML looks like this:

   <interface type='bridge'>
     <mac address='52:54:00:6f:51:43'/>
     <source bridge='vnet0'/>
     <model type='virtio'/>
       <driver name='vhost' txmode='iothread'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
   </interface>


I've compiled libvirt (0.9.1) and QEMU (0.14.1) from source, but am still using my distro's kernel, 2.6.32-71.29.1.el6.x86_64.  (Scientific Linux 6)

Thanks, and please let me know if you need any more info!

--Cal