[Users] info on virtio-scsi

Hello, I had a CentOS 6.4 VM created in oVirt 3.3.0 Then I updated to 3.3.1 I created a CentOS 5.10 VM In CentOS 5.10 I built rhev-agent-2.3.16-3.el5.src.rpm In CentOS 6.4 I have ovirt-guest-agent-1.0.8-1.el6.noarch Both are configured with one virtio disk. In CentOS 5 I can add a disk and select virtio-scsi... but I can't use it because of no support in 5.x kernels. In CentOS 6.4 I'm not presented with the option virtio-scsi. What can I do to get it? Gianluca