Current upstream has a rhel5.4 os dictionary entry that can be selected in virt-manager or via virt-install --os-variant. Users no longer need to use virtio26 to enable virtio support for RHEL guests. This change should be backported to 5.5:
This should also be release noted, if the 'virtio26/Generic virtio' value was ever added to the docs.
Created attachment 378626 [details]
Add RHEL5.4 osdict entry (and RHEL6, and F12)
This is built in python-virtinst-0_400_3-7_el5
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.