[dpdk-dev] [PATCH] net/memif: fix chained mbuf determination

[Ferruh Yigit]

On 9/22/2021 7:19 AM, Jakub Grajciar -X (jgrajcia - PANTHEON TECH SRO at Cisco)
wrote:
>>> Previously, TX functions call rte_pktmbuf_is_contiguous to determine
>>> whether an mbuf is chained. However, rte_pktmbuf_is_contiguous is
>>> designed to work on the first mbuf of a packet only. In case a packet
>>> contains three or more segment mbufs in a chain, it may cause
>>> truncated packets or rte_mbuf_sanity_check panics.
>>>
>>> This patch updates TX functions to determine chained mbufs using
>>> mbuf_head->nb_segs field, which works in all cases. Moreover, it
>>> maintains that the second cacheline is only accessed when chained mbuf
>>> is actually present.
>>>
>>> Signed-off-by: Junxiao Shi <git at mail1.yoursunny.com>
> 
> Looks ok to me. Thanks for the patch!
> 
> Reviewed-by: Jakub Grajciar <jgrajcia at cisco.com>
> 

    Fixes: 09c7e63a71f9 ("net/memif: introduce memory interface PMD")
    Fixes: 43b815d88188 ("net/memif: support zero-copy slave")
    Cc: stable at dpdk.org

Applied to dpdk-next-net/main, thanks.