Vhost example application hangs QEMU

["Nicolson Ken (ニコルソン ケン)" <ken.nicolson@jp.panasonic.com>]

Looking at the page https://doc.dpdk.org/guides-22.11/sample_app_ug/vhost.html I first use the Virtual Machine Manager GUI to initially set up Ubuntu 22.04.

Note: I disabled AppArmor as that caused a separate problem trying to create /tmp/sock0

Next, I add the flags to the config (note I need server**=on**, and net9 to prevent duplicate IDs):

 virt-xml ubuntu22.04 --edit --confirm --qemu-commandline="-chardev socket,id=char1,path=/tmp/sock0,server=on \
    -netdev type=vhost-user,id=hostnet9,chardev=char1  \
    -device virtio-net-pci,netdev=hostnet9,id=net9,mac=52:54:00:00:00:14"  --connect qemu:///system

The XML looks OK, so I then do:

 virsh start ubuntu22.04

However, this hangs, and Ctrl-C gets me back to the command line, where I can do this:

  virsh list --all
  Id   Name          State
 ------------------------------
  10   ubuntu22.04   paused

 virsh shutdown ubuntu22.04 
 error: Failed to shutdown domain 'ubuntu22.04'
 error: Timed out during operation: cannot acquire state change lock (held by monitor=remoteDispatchDomainCreate)

Only a reboot can reset the situation. What is missing, or where am I going wrong?

Thanks,
Ken