[RFC PATCH v4 08/27] nvme-tcp-offload: Add nvme-tcp-offload - NVMeTCP HW offload ULP

[Hannes Reinecke]

On 4/29/21 9:09 PM, Shai Malin wrote:
> This patch will present the structure for the NVMeTCP offload common
> layer driver. This module is added under "drivers/nvme/host/" and future
> offload drivers which will register to it will be placed under
> "drivers/nvme/hw".
> This new driver will be enabled by the Kconfig "NVM Express over Fabrics
> TCP offload commmon layer".
> In order to support the new transport type, for host mode, no change is
> needed.
> 
> Each new vendor-specific offload driver will register to this ULP during
> its probe function, by filling out the nvme_tcp_ofld_dev->ops and
> nvme_tcp_ofld_dev->private_data and calling nvme_tcp_ofld_register_dev
> with the initialized struct.
> 
> The internal implementation:
> - tcp-offload.h:
>    Includes all common structs and ops to be used and shared by offload
>    drivers.
> 
> - tcp-offload.c:
>    Includes the init function which registers as a NVMf transport just
>    like any other transport.
> 
> Acked-by: Igor Russkikh <irusskikh at marvell.com>
> Signed-off-by: Dean Balandin <dbalandin at marvell.com>
> Signed-off-by: Prabhakar Kushwaha <pkushwaha at marvell.com>
> Signed-off-by: Omkar Kulkarni <okulkarni at marvell.com>
> Signed-off-by: Michal Kalderon <mkalderon at marvell.com>
> Signed-off-by: Ariel Elior <aelior at marvell.com>
> Signed-off-by: Shai Malin <smalin at marvell.com>
> ---
>   drivers/nvme/host/Kconfig       |  16 +++
>   drivers/nvme/host/Makefile      |   3 +
>   drivers/nvme/host/tcp-offload.c | 126 +++++++++++++++++++
>   drivers/nvme/host/tcp-offload.h | 206 ++++++++++++++++++++++++++++++++
>   4 files changed, 351 insertions(+)
>   create mode 100644 drivers/nvme/host/tcp-offload.c
>   create mode 100644 drivers/nvme/host/tcp-offload.h
> 
It will be tricky to select the correct transport eg when traversing the 
discovery log page; the discovery log page only knows about 'tcp' (not 
'tcp_offload'), so the offload won't be picked up.
But that can we worked on / fixed later on, as it's arguably a policy 
decision.

Reviewed-by: Hannes Reinecke <hare at suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare at suse.de                              +49 911 74053 688
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