Re: [PATCH v4] doc: document NIC features

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 07/07/2017 08:21 PM, Ferruh Yigit wrote:
> Document NIC features, add more information about them and add more
> implementation related support.
>
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> Signed-off-by: John McNamara <john.mcnamara@intel.com>

Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>

Few minor questions/notes below.

> ---
> Cc: Olivier Matz <olivier.matz@6wind.com>
>
> v4:
> * Apply review comments from Andrew Rybchenko
> * Add tags to the information, to clarify in, out, related data.
>
> v3:
> * received updates from John, Thanks!
>
> v2:
> * Add more details, mbuf and API fields
> * Formatting added
>
> TODO:
> - Not all features all fully documented, need help from community
>
> - Instead of having a new file, it would be nice to auto generate this
> file from defaults.ini, and perhaps add extra information as comment to
> that file.
>
> - Some features are implementing eth_dev_ops and some are updates in
> Rx/Tx path. These features can be grouped together.
>
> - A link from overview file per feature would be nice.
> ---
>   doc/guides/nics/overview.rst          |   4 +
>   doc/guides/nics/overview_features.rst | 858 ++++++++++++++++++++++++++++++++++
>   2 files changed, 862 insertions(+)
>   create mode 100644 doc/guides/nics/overview_features.rst

<...>

> +.. _nic_features_rss_hash:
> +
> +RSS hash
> +--------
> +
> +Supports RSS hashing on RX.
> +
> +* **[uses]     user config**: ``dev_conf.rxmode.mq_mode`` = ``ETH_MQ_RX_RSS_FLAG``.
> +* **[provides] mbuf**: ``mbuf.ol_flags:PKT_RX_RSS_H()ASH``, ``mbuf.rss``.

Is it indented that dev_info.flow_type_rss_offloads not mentioned here?

<...>

> +
> +.. _nic_features_inner_l3_checksum:
> +
> +Inner L3 checksum
> +-----------------
> +
> +Supports inner packet L3 checksum.
> +
> +
> +.. _nic_features_inner_l4_checksum:
> +
> +Inner L4 checksum
> +-----------------
> +
> +Supports inner packet L4 checksum.
> +

As I understand outer checksum (PKT_RX_EIP_CKSUM_BAD for Rx) and 
IPv4/IPv6 flags and
offload capabilities should be mentioned here. If ourter flags are set, 
it means that usual checksum
flags corresponds to inner packet.

<...>

> +
> +.. _nic_features_rx_descriptor_status:
> +
> +Rx descriptor status
> +--------------------
> +
> +Supports check the status of a Rx descriptor. When ``rx_descriptor_status`` is
> +used, status can be "Available", "Done" or "Unavailable". When
> +``rx_descriptor_done`` is used, status can be "DD bit is set" or "DD bit is
> +not set".
> +
> +* **[implements] eth_dev_ops**: ``rx_descriptor_status``.
> +* **[related]    API**: ``rte_eth_rx_descriptor_status()``.
> +* **[implements] eth_dev_ops**: ``rx_descriptor_done``.
> +* **[related]    API**: ``rte_eth_rx_descriptor_done()``.

I'm not sure if _done API should be mentioned here. If yes, may be 
status of the _done
API should be highlighted (as far as I remember it was ideas to remove it).

<...>

> +
> +.. _nic_features_bsd_nic_uio:
> +
> +BSD nic_uio
> +-----------
> +
> +BSD ``nic_uio`` module supported.
> +
> +
> +.. _nic_features_linux_uio:
> +
> +Linux UIO
> +---------
> +
> +Works with ``igb_uio`` kernel module.
> +
> +
> +.. _nic_features_linux_vfio:
> +
> +Linux VFIO
> +----------
> +
> +Works with ``vfio-pci`` kernel module.

Should we mention that PMD provides RTE_PMD_REGISTER_KMOD_DEP with 
corresponding kernel module listed.

<...>