Hi Jijiang, On 11/10/2014 07:03 AM, Liu, Jijiang wrote: >> Another thing is surprising me. >> >> - if PKT_TX_VXLAN_CKSUM is not set (legacy use case), then the >> driver use l2_len and l3_len to offload inner IP/UDP/TCP checksums. > If the flag is not set, and imply that it is not VXLAN packet, > and do TX checksum offload as regular packet. > >> - if PKT_TX_VXLAN_CKSUM is set, then the driver has to use >> inner_l{23}_len instead of l{23}_len for the same operation. > Your understanding is not fully correct. > The l{23}_len is still used for TX checksum offload, please refer to > i40e_txd_enable_checksum() implementation.
This fields are part of public mbuf API. You cannot say to refer to i40e PMD code to understand how to use it. >> Adding PKT_TX_VXLAN_CKSUM changes the semantic of l2_len and l3_len. >> To fix this, I suggest to remove the new fields inner_l{23}_len then add >> outer_l{23}_len instead. Therefore, the semantic of l2_len and l3_len would >> not >> change, and a driver would always use the same field for a specific offload. > Oh... Does it mean you agree? >> For my TSO development, I will follow the current semantic. > For TSO, you still can use l{2,3} _len . > When I develop tunneling TSO, I will use inner_l3_len/inner_l4_len. I've just submitted a first version, please feel free to comment it. Regards, Olivier