freebsd stable - Oct 2017 - Zlog benchmark with diskinfo, Flush error: operation not supported

Hello, I just tried to run the recently added slog benchmark for
diskinfo on 11.1-Release. It works fine with ATA drives, but not with
NVMe drives. I get the following error

# diskinfo -vSw /dev/nvd0
/dev/nvd0
    512             # sectorsize
    400088457216    # mediasize in bytes (373G)
    781422768       # mediasize in sectors
    131072          # stripesize
    0               # stripeoffset
    CVFT4291009H400GGN    # Disk ident.

Synchronous random writes:
     0.5 kbytes: diskinfo: Flush error: Operation not supported


kern.geom.debugflags is of course set to 16, these drives does not
have any partitions either.
They also do not show up with camcontrol devlist.

What do work though, is creating a partition, ufs file system and
dummy file which I can then run this benchmark on.

Is this a configuration issue or a bug?

-- 
Kind Regards / Med Vennlig Hilsen

Olav Gr?n?s Gjerde

BackupBay Gjerde
Asalvegen 19
4051 SOLA
Norway
Phone: +47 918 000 59