Re: [dpdk-dev] [20.11, PATCH v2] baseband/fpga_5gnr_fec: add companion PF config App

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Hi Nicolas,

On 7/16/20 10:20 PM, Nicolas Chautru wrote:
> Adding companion application to configure HW Device from the PF.
> Then the device can be accessed through BBDEV from VF (or PF).
> 
> Signed-off-by: Nicolas Chautru <nicolas.chautru@intel.com>
> ---
>  doc/guides/bbdevs/fpga_5gnr_fec.rst                |  80 +++--
>  .../baseband/fpga_5gnr_fec/pf_config_app/Makefile  |  36 +++
>  .../fpga_5gnr_fec/pf_config_app/config_app.c       | 333 +++++++++++++++++++
>  .../pf_config_app/fpga_5gnr_cfg_app.c              | 351 +++++++++++++++++++++
>  .../pf_config_app/fpga_5gnr_cfg_app.h              | 102 ++++++
>  .../pf_config_app/fpga_5gnr_cfg_parser.c           | 187 +++++++++++
>  .../pf_config_app/fpga_5gnr_config.cfg             |  18 ++
>  7 files changed, 1087 insertions(+), 20 deletions(-)
>  create mode 100644 drivers/baseband/fpga_5gnr_fec/pf_config_app/Makefile
>  create mode 100644 drivers/baseband/fpga_5gnr_fec/pf_config_app/config_app.c
>  create mode 100644 drivers/baseband/fpga_5gnr_fec/pf_config_app/fpga_5gnr_cfg_app.c
>  create mode 100644 drivers/baseband/fpga_5gnr_fec/pf_config_app/fpga_5gnr_cfg_app.h
>  create mode 100644 drivers/baseband/fpga_5gnr_fec/pf_config_app/fpga_5gnr_cfg_parser.c
>  create mode 100644 drivers/baseband/fpga_5gnr_fec/pf_config_app/fpga_5gnr_config.cfg

I think having the pf_config_app in the driver directory is not a good
idea, this is not the place for applications.

Also, it is not integrated in the DPDK build system, so it cannot
benefit from the CI. Having an external dependency that is not packaged
in distributions will not help to have it integrated in the build
system.

I see some alternatives:
1. Move it in another directory in the main DPDK repo, but it is not a
DPDK example, not a dev tool and not a build tool, so it would need a
new directory.
2. Create a BBDEV tools repository on dpdk.org (It would require
techboard approval).
3. Host it in a dedicated repository on Intel's github
4. Move it into some Intel FPGA tools repository

I think option 3 would be the best to get it packaged into
distributions as it has no build dependency with any DPDK library.
You could maybe add inih library as a git sub-repository within this
repo. Other advantage is you wouldn't depend on DPDK release cycles to
get fixes merged.

Regarding the tool itself, I understand from the commit message that the
tool has a dependency on the BBDEV PMD version, but the tool run on the
host while the PMD driver is used in the guest/container. So having it
in the driver directory will not really help, as host DPDK (if any) and
guest DPDK may come from different parties.

One question I have is whether this is the tool itself that has a
dependency on the PMD, or just the config file?

Regards,
Maxime