Vhost needs to register memory given by guest in VFIO container to be
able to do any DMA using this memory.
Currently DPDK doesn't provide any interface to handle guest memory, so
for now lets find container fd in /proc/self/fd/ directory and provide
some VFIO internal API that finally should extend DPDK API.
Change-Id: Iee9d496367ccd61219068fc0eadc17e786ff0731
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>