Re: [RFC PATCH v3 00/11] NVMeTCP Offload ULP and QEDN Device Driver

On Fri, 12 Feb 2021 at 20:06, Chris Leech wrote:

On Sun, Feb 07, 2021 at 08:13:13PM +0200, Shai Malin wrote:

quoted

Queue Initialization:
=====================
The nvme-tcp-offload ULP module shall register with the existing
nvmf_transport_ops (.name = "tcp_offload"), nvme_ctrl_ops and blk_mq_ops.
The nvme-tcp-offload vendor driver shall register to nvme-tcp-offload ULP
with the following ops:
 - claim_dev() - in order to resolve the route to the target according to
                 the net_dev.
 - create_queue() - in order to create offloaded nvme-tcp queue.

The nvme-tcp-offload ULP module shall manage all the controller level
functionalities, call claim_dev and based on the return values shall call
the relevant module create_queue in order to create the admin queue and
the IO queues.

Hi Shai,

How well does this claim_dev approach work with multipathing?  Is it
expected that providing HOST_TRADDR is sufficient control over which
offload device will be used with multiple valid paths to the controller?

- Chris

Hi Chris,

The nvme-tcp-offload multipath behaves the same as the non-offloaded
nvme-tcp. The HOST_TRADDR is sufficient to control which offload device
will be used with multiple valid paths.

- Shai