Re: [dpdk-dev] [PATCH v3 2/7] mbuf: use the reserved 16 bits for double vlan

["Zhang, Helin" <helin.zhang@intel.com>]

Hi Neil

> -----Original Message-----
> From: Zhang, Helin
> Sent: Thursday, June 11, 2015 3:04 PM
> To: dev@dpdk.org
> Cc: Cao, Min; Liu, Jijiang; Wu, Jingjing; Ananyev, Konstantin; Richardson, Bruce;
> olivier.matz@6wind.com; Zhang, Helin
> Subject: [PATCH v3 2/7] mbuf: use the reserved 16 bits for double vlan
> 
> Use the reserved 16 bits in rte_mbuf structure for the outer vlan, also add QinQ
> offloading flags for both RX and TX sides.
> 
> Signed-off-by: Helin Zhang <helin.zhang@intel.com>
> ---
>  lib/librte_mbuf/rte_mbuf.h | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> v2 changes:
> * Fixed a typo.
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index
> ab6de67..84fe181 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -101,11 +101,17 @@ extern "C" {
>  #define PKT_RX_TUNNEL_IPV6_HDR (1ULL << 12) /**< RX tunnel packet with
> IPv6 header. */
>  #define PKT_RX_FDIR_ID       (1ULL << 13) /**< FD id reported if FDIR match.
> */
>  #define PKT_RX_FDIR_FLX      (1ULL << 14) /**< Flexible bytes reported if
> FDIR match. */
> +#define PKT_RX_QINQ_PKT      (1ULL << 15)  /**< RX packet with double
> VLAN stripped. */
>  /* add new RX flags here */
> 
>  /* add new TX flags here */
> 
>  /**
> + * Second VLAN insertion (QinQ) flag.
> + */
> +#define PKT_TX_QINQ_PKT    (1ULL << 49)   /**< TX packet with double
> VLAN inserted. */
> +
> +/**
>   * TCP segmentation offload. To enable this offload feature for a
>   * packet to be transmitted on hardware supporting TSO:
>   *  - set the PKT_TX_TCP_SEG flag in mbuf->ol_flags (this flag implies @@
> -279,7 +285,7 @@ struct rte_mbuf {
>  	uint16_t data_len;        /**< Amount of data in segment buffer. */
>  	uint32_t pkt_len;         /**< Total pkt len: sum of all segments. */
>  	uint16_t vlan_tci;        /**< VLAN Tag Control Identifier (CPU order) */
> -	uint16_t reserved;
> +	uint16_t vlan_tci_outer;  /**< Outer VLAN Tag Control Identifier (CPU
> +order) */
Do you think here is a ABI break or not? Just using the reserved 16 bits, which was
intended for the second_vlan_tag. Thanks in advance!
I did not see any "Incompatible" reported by validate_abi.sh.

Regards,
Helin

>  	union {
>  		uint32_t rss;     /**< RSS hash result if RSS enabled */
>  		struct {
> @@ -777,6 +783,7 @@ static inline void rte_pktmbuf_reset(struct rte_mbuf *m)
>  	m->pkt_len = 0;
>  	m->tx_offload = 0;
>  	m->vlan_tci = 0;
> +	m->vlan_tci_outer = 0;
>  	m->nb_segs = 1;
>  	m->port = 0xff;
> 
> @@ -849,6 +856,7 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi,
> struct rte_mbuf *m)
>  	mi->data_len = m->data_len;
>  	mi->port = m->port;
>  	mi->vlan_tci = m->vlan_tci;
> +	mi->vlan_tci_outer = m->vlan_tci_outer;
>  	mi->tx_offload = m->tx_offload;
>  	mi->hash = m->hash;
> 
> --
> 1.9.3