[dpdk-stable] [PATCH v6] doc: add GRO limitations in prog_guide

[Ananyev, Konstantin]

> -----Original Message-----
> From: Hu, Jiayu
> Sent: Wednesday, January 16, 2019 2:14 AM
> To: dev at dpdk.org
> Cc: Ananyev, Konstantin <konstantin.ananyev at intel.com>; thomas at monjalon.net; Hu, Jiayu <jiayu.hu at intel.com>; stable at dpdk.org
> Subject: [PATCH v6] doc: add GRO limitations in prog_guide
> 
> This patch adds GRO limitations in the programmer guide.
> 
> Fixes: 2c900d09055e ("doc: add GRO guide")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
> ---
> changes in v6:
> - add VLAN limitation
> changes in v5:
> - remove fix commit 9e0b9d2ec0f4
> changes in v4:
> - update MBUF->l2_len/... requirement
> changes in v3:
> - add MBUF limitation
> changes in v2:
> - add fix commits
> - add more limitations
> 
>  doc/guides/prog_guide/generic_receive_offload_lib.rst | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/doc/guides/prog_guide/generic_receive_offload_lib.rst b/doc/guides/prog_guide/generic_receive_offload_lib.rst
> index 9c6a4d0..5b3fb91 100644
> --- a/doc/guides/prog_guide/generic_receive_offload_lib.rst
> +++ b/doc/guides/prog_guide/generic_receive_offload_lib.rst
> @@ -191,3 +191,22 @@ Header fields deciding if packets are neighbors include:
>          ignore IPv4 ID fields for the packets whose DF bit is 1.
>          Additionally, packets which have different value of DF bit can't
>          be merged.
> +
> +GRO Library Limitations
> +-----------------------
> +
> +- GRO library uses MBUF->l2_len/l3_len/l4_len/outer_l2_len/
> +  outer_l3_len/packet_type to get protocol headers for the
> +  input packet, rather than parsing the packet header. Therefore,
> +  before call GRO APIs to merge packets, user applications
> +  must set MBUF->l2_len/l3_len/l4_len/outer_l2_len/outer_l3_len/
> +  packet_type to the same values as the protocol headers of the
> +  packet.
> +
> +- GRO library doesn't support to process the packets with IPv4
> +  Options or VLAN tagged.
> +
> +- GRO library just supports to process the packet organized
> +  in a single MBUF. If the input packet consists of multiple
> +  MBUFs (i.e. chained MBUFs), GRO reassembly behaviors are
> +  unknown.
> --

Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>

> 2.7.4