From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiayu Hu Subject: [PATCH v6] doc: add GRO limitations in prog_guide Date: Wed, 16 Jan 2019 10:13:42 +0800 Message-ID: <1547604822-9920-1-git-send-email-jiayu.hu@intel.com> References: <1547021995-14231-1-git-send-email-jiayu.hu@intel.com> Cc: konstantin.ananyev@intel.com, thomas@monjalon.net, Jiayu Hu , stable@dpdk.org To: dev@dpdk.org Return-path: In-Reply-To: <1547021995-14231-1-git-send-email-jiayu.hu@intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" This patch adds GRO limitations in the programmer guide. Fixes: 2c900d09055e ("doc: add GRO guide") Cc: stable@dpdk.org Signed-off-by: Jiayu Hu --- 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. -- 2.7.4