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

[Shai Malin]

On 5/1/21 3:18 PM, Hannes Reinecke wrote:
> 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.

I agree that we should improve the policy decision and allow additional
capabilities and it may be discussed as a new NVMe TPAR.

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

Thanks.

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