Re: [dpdk-dev] [PATCH v4 2/4] ethdev: add Tx offload outer UDP checksum definition

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 10/8/18 7:09 PM, Jerin Jacob wrote:
> Introduced DEV_TX_OFFLOAD_OUTER_UDP_CKSUM offload flags and
> PKT_TX_OUTER_UDP_CKSUM mbuf ol_flags to enable Tx outer UDP
> checksum offload.
>
> To use hardware Tx outer UDP checksum offload, the user needs to,
>
> - enable following in mbuf:
> a) fill outer_l2_len and outer_l3_len in mbuf
> b) set the PKT_TX_OUTER_UDP_CKSUM flag
> c) set the flag PKT_TX_OUTER_IPV4 or PKT_TX_OUTER_IPV6
>
> - configure DEV_TX_OFFLOAD_OUTER_UDP_CKSUM offload flags in slow path
>
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

One question below

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

> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index a453ec008..61e6fca4d 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -200,6 +200,9 @@ extern "C" {
>   
>   /* add new TX flags here */
>   
> +/**< Outer UDP cksum of TX pkt. computed by NIC. */

Description for the block which includes PKT_TX_UDP_CKSUM has "the user 
need to"...
IMHO, it would be very useful to have similar description here as well.

> +#define PKT_TX_OUTER_UDP_CKSUM     (1ULL << 41)
> +
>   /**
>    * UDP Fragmentation Offload flag. This flag is used for enabling UDP
>    * fragmentation in SW or in HW. When use UFO, mbuf->tso_segsz is used
> @@ -367,7 +370,8 @@ extern "C" {
>   		PKT_TX_TUNNEL_MASK |	 \
>   		PKT_TX_MACSEC |		 \
>   		PKT_TX_SEC_OFFLOAD |	\
> -		PKT_TX_UDP_SEG)
> +		PKT_TX_UDP_SEG |	\
> +		PKT_TX_OUTER_UDP_CKSUM)
>   
>   /**
>    * Mbuf having an external buffer attached. shinfo in mbuf must be filled.