The Linux SCSI Target Wiki
Vmware ESX v4.x has been tested with LIO-Target v3.x with virtual (IBLOCK, FILEIO) TCM storage objects. Using export of physical (pSCSI) TCM storage objects will work as well given that the underlying SCSI LLD supports SPC-2 RESERVE/RELEASE and T10 WWN for ESX MPIO.
ESX 4.x Reservations
Note that ESX v4.x does not use SPC-3 and above Persistent_Reservations for controlling I_T Nexus access to a LUN, but uses legacy SPC-2 RESERVE/RELEASE for writing metadata to a VMFS enabled LUN.
ESX 4.x Multipath
Note that ESX 4.x does not use SPC-3 and above ALUA for multipath, but the legacy SPC-2 MPIO using T10 world wide unique naming to determine multiple paths to the same LUN.
ESX 4.x LUN provisioning
By default, ESX v4.x uses Thin Provisioning and will call SPC-2 RESERVE/RELEASE as new blocks are written to update it's VMFS metadata. Think Provisioning (where the VMFS metadata is setup during mkfs time) can also be enabled. See the "Thin Provisioning" section on pages 116 through 118 in VMware's "ESX Configuration Guide", ESX 4.0, EN-000106-00, retrieved from vsp_40_esx_server_config.pdf
Note that Vmware ESX v3.x is currently not supported because it depends upon Task Management Function WARM_RESET.