With DAX[0] linux already has the ability to put a filesystem (currently ext4 and xfs) on NVDIMMS and then let userspace address them through mmap while skipping the page cache indirection. I.e. you're directly byte-addressing them through the memory controller via standard memory-mapped file abstractions. Direct block device mapping of nvdimms without filesystem is also possible.

[0] https://www.kernel.org/doc/Documentation/filesystems/dax.txt