Ethernet IP cores in Vivado have been updated to be delivered as a core block containing both encrypted HDL and GT instances.
The previous 'core block' level is now the top level of the core. This includes transceiver instances and physical interface I/O logic. The transceiver instances, IOBs and supporting logic are still delivered as plain HDL. There is also a core level hierarchical XDC file. For more information about the block level ports, please consult the core product guide.
In Vivado 2013.3 and later tools, cores have a GUI option to include or exclude shareable logic resources in the core. This includes logic such as BUFGs, MMCM and GT COMMON blocks that can be shared between multiple cores. The shared logic layer is called the <core_name>_support.v/vhd. For more information about this option, please consult the core product guide.
Note: RXAUI added this shared logic option in Vivado Design Suite 2013.1.