RE: [PATCH v2] net/intel: fix assumption about tag placement order

["Loftus, Ciara" <ciara.loftus@intel.com>]

> 
> The specific placement of outer/inner VLAN tags in NIC descriptors
> is configurable. Therefore, remove the assumption that if the L2Tag2
> field is filled in, that the L2Tag1 must also be. Instead, check the
> existing mbuf VLAN flags, and move tags and set flags as appropriate.
> This fixes an issue where, with QinQ packets with different Tag ethtypes
> (0x88a8 vs 0x8100), we get an mbuf reporting two valid tags, but only
> having had one tag stripped.
> 
> Fixes: cc9d0456b870 ("i40e: support double vlan stripping and insertion")
> Fixes: 1e728b01120c ("net/iavf: rework Tx path")
> Fixes: e0dcf94a0d7f ("net/ice: support VLAN ops")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>  drivers/net/intel/i40e/i40e_rxtx.c | 10 +++++++---
>  drivers/net/intel/iavf/iavf_rxtx.c | 12 +++++++-----
>  drivers/net/intel/ice/ice_rxtx.c   | 10 +++++++---
>  3 files changed, 21 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/intel/i40e/i40e_rxtx.c
> b/drivers/net/intel/i40e/i40e_rxtx.c
> index aba3c11ee5..a1fc320d05 100644
> --- a/drivers/net/intel/i40e/i40e_rxtx.c
> +++ b/drivers/net/intel/i40e/i40e_rxtx.c
> @@ -128,9 +128,13 @@ i40e_rxd_to_vlan_tci(struct rte_mbuf *mb, volatile
> union ci_rx_desc *rxdp)
>  #ifndef RTE_NET_INTEL_USE_16BYTE_DESC
>  	if (rte_le_to_cpu_16(rxdp->wb.qword2.ext_status) &
>  		(1 << I40E_RX_DESC_EXT_STATUS_L2TAG2P_SHIFT)) {
> -		mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED |
> RTE_MBUF_F_RX_QINQ |
> -			RTE_MBUF_F_RX_VLAN_STRIPPED |
> RTE_MBUF_F_RX_VLAN;
> -		mb->vlan_tci_outer = mb->vlan_tci;
> +		if ((mb->ol_flags & RTE_MBUF_F_RX_VLAN_STRIPPED) == 0) {
> +			mb->ol_flags |= RTE_MBUF_F_RX_VLAN |
> RTE_MBUF_F_RX_VLAN_STRIPPED;
> +		} else {
> +			/* if two tags, move Tag1 to outer tag field */
> +			mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED |
> RTE_MBUF_F_RX_QINQ;
> +			mb->vlan_tci_outer = mb->vlan_tci;
> +		}
>  		mb->vlan_tci = rte_le_to_cpu_16(rxdp-
> >wb.qword2.l2tag2_2);
>  		PMD_RX_LOG(DEBUG, "Descriptor l2tag2_1: %u, l2tag2_2:
> %u",
>  			   rte_le_to_cpu_16(rxdp->wb.qword2.l2tag2_1),
> diff --git a/drivers/net/intel/iavf/iavf_rxtx.c
> b/drivers/net/intel/iavf/iavf_rxtx.c
> index 7033a74610..887dcd1b2f 100644
> --- a/drivers/net/intel/iavf/iavf_rxtx.c
> +++ b/drivers/net/intel/iavf/iavf_rxtx.c
> @@ -1169,11 +1169,13 @@ iavf_flex_rxd_to_vlan_tci(struct rte_mbuf *mb,
> 
>  	if (rte_le_to_cpu_16(rxdp->wb.status_error1) &
>  	    (1 << IAVF_RX_FLEX_DESC_STATUS1_L2TAG2P_S)) {
> -		mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED |
> -				RTE_MBUF_F_RX_QINQ |
> -				RTE_MBUF_F_RX_VLAN_STRIPPED |
> -				RTE_MBUF_F_RX_VLAN;
> -		mb->vlan_tci_outer = mb->vlan_tci;
> +		if ((mb->ol_flags & RTE_MBUF_F_RX_VLAN_STRIPPED) == 0) {
> +			mb->ol_flags |= RTE_MBUF_F_RX_VLAN |
> RTE_MBUF_F_RX_VLAN_STRIPPED;
> +		} else {
> +			/* if two tags, move Tag1 to outer tag field */
> +			mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED |
> RTE_MBUF_F_RX_QINQ;
> +			mb->vlan_tci_outer = mb->vlan_tci;
> +		}
>  		mb->vlan_tci = rte_le_to_cpu_16(rxdp->wb.l2tag2_2nd);
>  		PMD_RX_LOG(DEBUG, "Descriptor l2tag2_1: %u, l2tag2_2:
> %u",
>  			   rte_le_to_cpu_16(rxdp->wb.l2tag2_1st),
> diff --git a/drivers/net/intel/ice/ice_rxtx.c b/drivers/net/intel/ice/ice_rxtx.c
> index da508592aa..f965aab6ee 100644
> --- a/drivers/net/intel/ice/ice_rxtx.c
> +++ b/drivers/net/intel/ice/ice_rxtx.c
> @@ -1835,9 +1835,13 @@ ice_rxd_to_vlan_tci(struct rte_mbuf *mb, volatile
> union ci_rx_flex_desc *rxdp)
>  #ifndef RTE_NET_INTEL_USE_16BYTE_DESC
>  	if (rte_le_to_cpu_16(rxdp->wb.status_error1) &
>  	    (1 << ICE_RX_FLEX_DESC_STATUS1_L2TAG2P_S)) {
> -		mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED |
> RTE_MBUF_F_RX_QINQ |
> -				RTE_MBUF_F_RX_VLAN_STRIPPED |
> RTE_MBUF_F_RX_VLAN;
> -		mb->vlan_tci_outer = mb->vlan_tci;
> +		if ((mb->ol_flags & RTE_MBUF_F_RX_VLAN_STRIPPED) == 0) {
> +			mb->ol_flags |= RTE_MBUF_F_RX_VLAN |
> RTE_MBUF_F_RX_VLAN_STRIPPED;
> +		} else {
> +			/* if two tags, move Tag1 to outer tag field */
> +			mb->ol_flags |= RTE_MBUF_F_RX_QINQ_STRIPPED |
> RTE_MBUF_F_RX_QINQ;
> +			mb->vlan_tci_outer = mb->vlan_tci;
> +		}
>  		mb->vlan_tci = rte_le_to_cpu_16(rxdp->wb.l2tag2_2nd);
>  		PMD_RX_LOG(DEBUG, "Descriptor l2tag2_1: %u, l2tag2_2:
> %u",
>  			   rte_le_to_cpu_16(rxdp->wb.l2tag2_1st),
> --
> 2.48.1

Acked-by: Ciara Loftus <ciara.loftus@intel.com>