Verified this bug with qemu-kvm-rhev-2.6.0-3.el7.
result:
/usr/libexec/qemu-kvm -m 3G,maxmem=4G,slots=4 -smp 4 -chardev socket,id=charnet0,path=/var/run/openvswitch/vhost-user2 -netdev type=vhost-user,id=hostnet0,queues=0,chardev=charnet0 -device virtio-net-pci,mq=on,vectors=10,netdev=hostnet0,id=net0,mac=52:54:00:01:0b:12,bus=pci.0,addr=0x9,ctrl_vlan=off,status=on
qemu-kvm: -netdev type=vhost-user,id=hostnet0,queues=0,chardev=charnet0: vhost-user number of queues must be in range [1, 1024]
As queues=0 has no meaning. qemu-kvm-rhev and libvirt prevented queues=0 this setting. It makes sense.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://rhn.redhat.com/errata/RHBA-2016-2673.html