[libvirt] Libvirt iSCSI APIs

Hi All, I am interested in extending libvirt APIs to support iSCSI operations such as: add/remove targets, list targets, list remote LUNs, rescan luns etc. The intention is to provide an interface that external programs can hook to manage iSCSI storage devices on a given hypervisor(I would be adding interfaces for ESX first). Looking at the libvirt.c interface for storage driver I'm unable find routines that can be overridden for specific hypervisor. Googling lead to a nice blog presentation that provisions VMs on remote LUN(s) for KVM but uses virish. (http://berrange.com/tags/iscsi/). My question is; is this as per design not to expose iSCSI related APIs? Will an extention to libvirt.c (_virStorageDriver) so that every hypervisor can implement it is acceptable? Please correct me if I am missing something serious here. Thanks! Ata