welcome to communities
yes this is possible. SDW does allow hyperV guest VM to connect to host iscsi and map luns directly (Passthrough disk)
Snapmanagers use SDW in backend so this is possible.
VHD or passthrough disk on the host
You can now expose a host disk to the guest without even putting a volume on it using a passthrough disk. Hyper-V will let you “bypass” the host’s file system and access a disk directly. This raw disk, which is not limited to 2040 GB in size, can be a physical HD on the host or a logical unit on a SAN. To make sure the host and the guest are not trying to use the disk at the same time, Hyper-V requires the disk to be in the offline state on the host. This is referred to as LUN passthrough, if the disk being exposed to the guest is a LUN on a SAN from the host perspective. With passthrough disks you will lose some nice, VHD-related features, like VHD snapshots, dynamically expanding VHDs and differencing VHDs.
Got it from ---> http://blogs.technet.com/b/josebda/archive/2008/02/06/storage-options-for-windows-server-2008-s-hyper-v.aspx
hope this helps
-srinivas
