nvmf: Switch several ioctls to using nvlists

For requests that handoff queues from userspace to the kernel as well
as the request to fetch reconnect parameters from the kernel, switch
from using fla

nvmf: Switch several ioctls to using nvlists

For requests that handoff queues from userspace to the kernel as well
as the request to fetch reconnect parameters from the kernel, switch
from using flat structures to nvlists. In particular, this will
permit adding support for additional transports in the future without
breaking the ABI of the structures.

Note that this is an ABI break for the ioctls used by nvmf(4) and
nvmft(4). Since this is only present in main I did not bother
implementing compatability shims.

Inspired by: imp (suggestion on a different review)
Reviewed by: imp
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D48230

show more ...

nvmfd: A simple userspace daemon for the NVMe over Fabrics controller

This daemon can operate as a purely userspace controller exporting one
or more simulated RAM disks or local block devices as NVM

nvmfd: A simple userspace daemon for the NVMe over Fabrics controller

This daemon can operate as a purely userspace controller exporting one
or more simulated RAM disks or local block devices as NVMe namespaces
to a remote host. In this case the daemon provides a discovery
controller with a single entry for an I/O controller.

nvmfd can also offload I/O controller queue pairs to the nvmft.ko
in-kernel Fabrics controller when -K is passed. In this mode, nvmfd
still accepts connections and performs initial transport-specific
negotitation in userland. The daemon still provides a userspace-only
discovery controller with a single entry for an I/O controller.
However, queue pairs for the I/O controller are handed off to the CTL
NVMF frontend.

Eventually ctld(8) should be refactored to to provide an abstraction
for the frontend protocol and the discovery and the kernel mode of
this daemon should be merged into ctld(8). At that point this daemon
can be moved to tools/tools/nvmf as a debugging tool (mostly as sample
code for a userspace controller using libnvmf).

Reviewed by: imp
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D44731

show more ...