
Fixes bug 1154731 that stated the iso support was broken. There were several issues around a vdis list without a 'root' disk. Because the ISO boot was HVM, only 0-3 devices will work, so, the devices used have been re-ordered to ensure ISOs can be read by a HVM guest without PV tools. Once PV tools are present, a HVM guest will be able to access an ephemeral or swap disk. Change-Id: I4b57f70301a4256fa975323d7964fde19e8d4508