I'm the tech PM in charge of NVMeoF for IBM Ceph - here's some info on how to pull the nvme-cli and configure the target:
https://docs.ceph.com/en/squid/rbd/nvmeof-target-configure/

Make sure you create a subsystem with appropriate masking access to NQNs, NVMe/TCP listener, RBD pool and image, and map the RBD image to an NVMeoF namespace. The build is iterative, and missing a step can prove problematic.

nvmeof is currently available and usable in both reef and squid, was previewed in quincy iirc. just not a part of cephadm currently. cephadm integration is coming as previously mentioned (potentially Tentacle), but in squid the above is best used.

Feel free to reach out if you need help on any of the above - we're actively working on simplifying workflow (squid has all of this in the dashboard, hopefully it's easier as a PoC). Cheers - Mike Burkhart