[dpdk-dev] [PATCH] mbuf: new flag when Vlan is stripped

[Olivier Matz <olivier.matz@6wind.com>]

The behavior of PKT_RX_VLAN_PKT was not very well defined, resulting in
PMDs not advertising the same flags in similar conditions.

Following discussion in [1], introduce 2 new flags PKT_RX_VLAN_STRIPPED
and PKT_RX_QINQ_STRIPPED that are better defined:

  PKT_RX_VLAN_STRIPPED: a vlan has been stripped by the hardware and its
  tci is saved in mbuf->vlan_tci. This can only happen if vlan stripping
  is enabled in the RX configuration of the PMD.

For now, the old flag PKT_RX_VLAN_PKT is kept but marked as deprecated.
It should be removed from applications and PMDs in a future revision.

This patch also updates the drivers. For PKT_RX_VLAN_PKT:

- e1000, enic, i40e, mlx5, nfp, vmxnet3: done, PKT_RX_VLAN_PKT already
  had the same meaning than PKT_RX_VLAN_STRIPPED, minor update is
  required.
- fm10k: done, PKT_RX_VLAN_PKT already had the same meaning than
  PKT_RX_VLAN_STRIPPED, and vlan stripping is always enabled on fm10k.
- ixgbe: modification done for standard mode (vector does not support
  vlan stripping)
- the other drivers do not support vlan stripping.

For PKT_RX_QINQ_PKT, it was only supported on i40e, and the meaning was
already correct, so we can reuse the same value for PKT_RX_QINQ_STRIPPED.

[1] http://dpdk.org/ml/archives/dev/2016-April/037837.html,

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---

RFC -> v1:
- fix checkpatch and check-git-log.sh issues
- add a deprecation notice for the old vlan flags
- rebase on head


 app/test-pmd/rxonly.c                |  4 +--
 doc/guides/rel_notes/deprecation.rst |  5 ++++
 drivers/net/e1000/em_rxtx.c          |  3 ++-
 drivers/net/e1000/igb_rxtx.c         |  3 ++-
 drivers/net/enic/enic_rx.c           |  2 +-
 drivers/net/i40e/i40e_rxtx.c         |  2 +-
 drivers/net/ixgbe/ixgbe_ethdev.c     |  7 +++++
 drivers/net/ixgbe/ixgbe_rxtx.c       | 21 +++++++++++----
 drivers/net/ixgbe/ixgbe_rxtx.h       |  1 +
 drivers/net/mlx5/mlx5_rxtx.c         |  6 +++--
 drivers/net/nfp/nfp_net.c            |  2 +-
 drivers/net/vmxnet3/vmxnet3_rxtx.c   |  2 +-
 lib/librte_mbuf/rte_mbuf.c           |  2 ++
 lib/librte_mbuf/rte_mbuf.h           | 50 ++++++++++++++++++++++++++++++++----
 14 files changed, 90 insertions(+), 20 deletions(-)

diff --git a/app/test-pmd/rxonly.c b/app/test-pmd/rxonly.c
index 14555ab..c69b344 100644
--- a/app/test-pmd/rxonly.c
+++ b/app/test-pmd/rxonly.c
@@ -156,9 +156,9 @@ pkt_burst_receive(struct fwd_stream *fs)
 				printf("hash=0x%x ID=0x%x ",
 				       mb->hash.fdir.hash, mb->hash.fdir.id);
 		}
-		if (ol_flags & PKT_RX_VLAN_PKT)
+		if (ol_flags & PKT_RX_VLAN_STRIPPED)
 			printf(" - VLAN tci=0x%x", mb->vlan_tci);
-		if (ol_flags & PKT_RX_QINQ_PKT)
+		if (ol_flags & PKT_RX_QINQ_STRIPPED)
 			printf(" - QinQ VLAN tci=0x%x, VLAN tci outer=0x%x",
 					mb->vlan_tci, mb->vlan_tci_outer);
 		if (mb->packet_type) {
diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index ad05eba..2233a90 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -57,3 +57,8 @@ Deprecation Notices
   a handle, like the way kernel exposes an fd to user for locating a
   specific file, and to keep all major structures internally, so that
   we are likely to be free from ABI violations in future.
+
+* The mbuf flags PKT_RX_VLAN_PKT and PKT_RX_QINQ_PKT are deprecated and
+  are respectively replaced by PKT_RX_VLAN_STRIPPED and
+  PKT_RX_QINQ_STRIPPED, that are better described. The old flags and
+  their behavior will be kept in 16.07 and will be removed in 16.11.
diff --git a/drivers/net/e1000/em_rxtx.c b/drivers/net/e1000/em_rxtx.c
index 3d36f21..6d8750a 100644
--- a/drivers/net/e1000/em_rxtx.c
+++ b/drivers/net/e1000/em_rxtx.c
@@ -629,7 +629,8 @@ rx_desc_status_to_pkt_flags(uint32_t rx_status)
 	uint64_t pkt_flags;
 
 	/* Check if VLAN present */
-	pkt_flags = ((rx_status & E1000_RXD_STAT_VP) ?  PKT_RX_VLAN_PKT : 0);
+	pkt_flags = ((rx_status & E1000_RXD_STAT_VP) ?
+		PKT_RX_VLAN_PKT | PKT_RX_VLAN_STRIPPED : 0);
 
 	return pkt_flags;
 }
diff --git a/drivers/net/e1000/igb_rxtx.c b/drivers/net/e1000/igb_rxtx.c
index 18aeead..9d80a0b 100644
--- a/drivers/net/e1000/igb_rxtx.c
+++ b/drivers/net/e1000/igb_rxtx.c
@@ -729,7 +729,8 @@ rx_desc_status_to_pkt_flags(uint32_t rx_status)
 	uint64_t pkt_flags;
 
 	/* Check if VLAN present */
-	pkt_flags = (rx_status & E1000_RXD_STAT_VP) ?  PKT_RX_VLAN_PKT : 0;
+	pkt_flags = ((rx_status & E1000_RXD_STAT_VP) ?
+		PKT_RX_VLAN_PKT | PKT_RX_VLAN_STRIPPED : 0);
 
 #if defined(RTE_LIBRTE_IEEE1588)
 	if (rx_status & E1000_RXD_STAT_TMST)
diff --git a/drivers/net/enic/enic_rx.c b/drivers/net/enic/enic_rx.c
index f92f6bc..6459e97 100644
--- a/drivers/net/enic/enic_rx.c
+++ b/drivers/net/enic/enic_rx.c
@@ -197,7 +197,7 @@ enic_cq_rx_to_pkt_flags(struct cq_desc *cqd, struct rte_mbuf *mbuf)
 
 	/* VLAN stripping */
 	if (bwflags & CQ_ENET_RQ_DESC_FLAGS_VLAN_STRIPPED) {
-		pkt_flags |= PKT_RX_VLAN_PKT;
+		pkt_flags |= PKT_RX_VLAN_PKT | PKT_RX_VLAN_STRIPPED;
 		mbuf->vlan_tci = enic_cq_rx_desc_vlan(cqrd);
 	} else {
 		mbuf->vlan_tci = 0;
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index c833aa3..aa161a9 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -99,7 +99,7 @@ i40e_rxd_to_vlan_tci(struct rte_mbuf *mb, volatile union i40e_rx_desc *rxdp)
 #ifndef RTE_LIBRTE_I40E_16BYTE_RX_DESC
 	if (rte_le_to_cpu_16(rxdp->wb.qword2.ext_status) &
 		(1 << I40E_RX_DESC_EXT_STATUS_L2TAG2P_SHIFT)) {
-		mb->ol_flags |= PKT_RX_QINQ_PKT;
+		mb->ol_flags |= PKT_RX_QINQ_STRIPPED;
 		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",
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index a2b170b..e7717e3 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -1636,6 +1636,7 @@ ixgbe_vlan_hw_strip_bitmap_set(struct rte_eth_dev *dev, uint16_t queue, bool on)
 {
 	struct ixgbe_hwstrip *hwstrip =
 		IXGBE_DEV_PRIVATE_TO_HWSTRIP_BITMAP(dev->data->dev_private);
+	struct ixgbe_rx_queue *rxq;
 
 	if (queue >= IXGBE_MAX_RX_QUEUE_NUM)
 		return;
@@ -1644,6 +1645,12 @@ ixgbe_vlan_hw_strip_bitmap_set(struct rte_eth_dev *dev, uint16_t queue, bool on)
 		IXGBE_SET_HWSTRIP(hwstrip, queue);
 	else
 		IXGBE_CLEAR_HWSTRIP(hwstrip, queue);
+
+	if (queue >= dev->data->nb_rx_queues)
+		return;
+
+	rxq = dev->data->rx_queues[queue];
+	rxq->vlan_strip = on;
 }
 
 static void
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index 9c6eaf2..3d740df 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -1221,16 +1221,23 @@ ixgbe_rxd_pkt_info_to_pkt_flags(uint16_t pkt_info)
 }
 
 static inline uint64_t
-rx_desc_status_to_pkt_flags(uint32_t rx_status)
+rx_desc_status_to_pkt_flags(uint32_t rx_status, uint8_t vlan_strip)
 {
 	uint64_t pkt_flags;
+	uint64_t vlan_flags;
+
+	/* if vlan is stripped, set the proper flag */
+	if (vlan_strip)
+		vlan_flags = PKT_RX_VLAN_PKT | PKT_RX_VLAN_STRIPPED;
+	else
+		vlan_flags = PKT_RX_VLAN_PKT;
 
 	/*
 	 * Check if VLAN present only.
 	 * Do not check whether L3/L4 rx checksum done by NIC or not,
 	 * That can be found from rte_eth_rxmode.hw_ip_checksum flag
 	 */
-	pkt_flags = (rx_status & IXGBE_RXD_STAT_VP) ?  PKT_RX_VLAN_PKT : 0;
+	pkt_flags = (rx_status & IXGBE_RXD_STAT_VP) ?  vlan_flags : 0;
 
 #ifdef RTE_LIBRTE_IEEE1588
 	if (rx_status & IXGBE_RXD_STAT_TMST)
@@ -1287,6 +1294,7 @@ ixgbe_rx_scan_hw_ring(struct ixgbe_rx_queue *rxq)
 	uint32_t pkt_info[LOOK_AHEAD];
 	int i, j, nb_rx = 0;
 	uint32_t status;
+	uint8_t vlan_strip = rxq->vlan_strip;
 
 	/* get references to current descriptor and S/W ring entry */
 	rxdp = &rxq->rx_ring[rxq->rx_tail];
@@ -1328,7 +1336,8 @@ ixgbe_rx_scan_hw_ring(struct ixgbe_rx_queue *rxq)
 			mb->vlan_tci = rte_le_to_cpu_16(rxdp[j].wb.upper.vlan);
 
 			/* convert descriptor fields to rte mbuf flags */
-			pkt_flags = rx_desc_status_to_pkt_flags(s[j]);
+			pkt_flags = rx_desc_status_to_pkt_flags(s[j],
+				vlan_strip);
 			pkt_flags |= rx_desc_error_to_pkt_flags(s[j]);
 			pkt_flags |= ixgbe_rxd_pkt_info_to_pkt_flags
 					((uint16_t)pkt_info[j]);
@@ -1544,6 +1553,7 @@ ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 	uint16_t nb_rx;
 	uint16_t nb_hold;
 	uint64_t pkt_flags;
+	uint8_t vlan_strip;
 
 	nb_rx = 0;
 	nb_hold = 0;
@@ -1551,6 +1561,7 @@ ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 	rx_id = rxq->rx_tail;
 	rx_ring = rxq->rx_ring;
 	sw_ring = rxq->sw_ring;
+	vlan_strip = rxq->vlan_strip;
 	while (nb_rx < nb_pkts) {
 		/*
 		 * The order of operations here is important as the DD status
@@ -1660,7 +1671,7 @@ ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		/* Only valid if PKT_RX_VLAN_PKT set in pkt_flags */
 		rxm->vlan_tci = rte_le_to_cpu_16(rxd.wb.upper.vlan);
 
-		pkt_flags = rx_desc_status_to_pkt_flags(staterr);
+		pkt_flags = rx_desc_status_to_pkt_flags(staterr, vlan_strip);
 		pkt_flags = pkt_flags | rx_desc_error_to_pkt_flags(staterr);
 		pkt_flags = pkt_flags |
 			ixgbe_rxd_pkt_info_to_pkt_flags((uint16_t)pkt_info);
@@ -1753,7 +1764,7 @@ ixgbe_fill_cluster_head_buf(
 	 */
 	head->vlan_tci = rte_le_to_cpu_16(desc->wb.upper.vlan);
 	pkt_info = rte_le_to_cpu_32(desc->wb.lower.lo_dword.data);
-	pkt_flags = rx_desc_status_to_pkt_flags(staterr);
+	pkt_flags = rx_desc_status_to_pkt_flags(staterr, rxq->vlan_strip);
 	pkt_flags |= rx_desc_error_to_pkt_flags(staterr);
 	pkt_flags |= ixgbe_rxd_pkt_info_to_pkt_flags((uint16_t)pkt_info);
 	head->ol_flags = pkt_flags;
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.h b/drivers/net/ixgbe/ixgbe_rxtx.h
index 3691a19..9ca0e8b 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.h
+++ b/drivers/net/ixgbe/ixgbe_rxtx.h
@@ -146,6 +146,7 @@ struct ixgbe_rx_queue {
 	uint8_t             crc_len;  /**< 0 if CRC stripped, 4 otherwise. */
 	uint8_t             drop_en;  /**< If not 0, set SRRCTL.Drop_En. */
 	uint8_t             rx_deferred_start; /**< not in global dev start. */
+	uint8_t             vlan_strip; /**< 1 if vlan stripping enabled. */
 	/** need to alloc dummy mbuf, for wraparound when scanning hw ring */
 	struct rte_mbuf fake_mbuf;
 	/** hold packets to return to application */
diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 13c8d71..ac96fc9 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -1051,7 +1051,8 @@ mlx5_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			pkt_buf->ol_flags = rxq_cq_to_ol_flags(rxq, flags);
 #ifdef HAVE_EXP_DEVICE_ATTR_VLAN_OFFLOADS
 			if (flags & IBV_EXP_CQ_RX_CVLAN_STRIPPED_V1) {
-				pkt_buf->ol_flags |= PKT_RX_VLAN_PKT;
+				pkt_buf->ol_flags |= PKT_RX_VLAN_PKT |
+					PKT_RX_VLAN_STRIPPED;
 				pkt_buf->vlan_tci = vlan_tci;
 			}
 #endif /* HAVE_EXP_DEVICE_ATTR_VLAN_OFFLOADS */
@@ -1207,7 +1208,8 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 			seg->ol_flags = rxq_cq_to_ol_flags(rxq, flags);
 #ifdef HAVE_EXP_DEVICE_ATTR_VLAN_OFFLOADS
 			if (flags & IBV_EXP_CQ_RX_CVLAN_STRIPPED_V1) {
-				seg->ol_flags |= PKT_RX_VLAN_PKT;
+				seg->ol_flags |= PKT_RX_VLAN_PKT |
+					PKT_RX_VLAN_STRIPPED;
 				seg->vlan_tci = vlan_tci;
 			}
 #endif /* HAVE_EXP_DEVICE_ATTR_VLAN_OFFLOADS */
diff --git a/drivers/net/nfp/nfp_net.c b/drivers/net/nfp/nfp_net.c
index ea5a2a3..5c9f350 100644
--- a/drivers/net/nfp/nfp_net.c
+++ b/drivers/net/nfp/nfp_net.c
@@ -1800,7 +1800,7 @@ nfp_net_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 		if ((rxds->rxd.flags & PCIE_DESC_RX_VLAN) &&
 		    (hw->ctrl & NFP_NET_CFG_CTRL_RXVLAN)) {
 			mb->vlan_tci = rte_cpu_to_le_32(rxds->rxd.vlan);
-			mb->ol_flags |= PKT_RX_VLAN_PKT;
+			mb->ol_flags |= PKT_RX_VLAN_PKT | PKT_RX_VLAN_STRIPPED;
 		}
 
 		/* Adding the mbuff to the mbuff array passed by the app */
diff --git a/drivers/net/vmxnet3/vmxnet3_rxtx.c b/drivers/net/vmxnet3/vmxnet3_rxtx.c
index 9fe8752..ccafc0c 100644
--- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
+++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
@@ -579,7 +579,7 @@ vmxnet3_rx_offload(const Vmxnet3_RxCompDesc *rcd, struct rte_mbuf *rxm)
 {
 	/* Check for hardware stripped VLAN tag */
 	if (rcd->ts) {
-		rxm->ol_flags |= PKT_RX_VLAN_PKT;
+		rxm->ol_flags |= (PKT_RX_VLAN_PKT | PKT_RX_VLAN_STRIPPED);
 		rxm->vlan_tci = rte_le_to_cpu_16((uint16_t)rcd->tci);
 	}
 
diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
index eec1456..2ece742 100644
--- a/lib/librte_mbuf/rte_mbuf.c
+++ b/lib/librte_mbuf/rte_mbuf.c
@@ -258,8 +258,10 @@ const char *rte_get_rx_ol_flag_name(uint64_t mask)
 	/* case PKT_RX_HBUF_OVERFLOW: return "PKT_RX_HBUF_OVERFLOW"; */
 	/* case PKT_RX_RECIP_ERR: return "PKT_RX_RECIP_ERR"; */
 	/* case PKT_RX_MAC_ERR: return "PKT_RX_MAC_ERR"; */
+	case PKT_RX_VLAN_STRIPPED: return "PKT_RX_VLAN_STRIPPED";
 	case PKT_RX_IEEE1588_PTP: return "PKT_RX_IEEE1588_PTP";
 	case PKT_RX_IEEE1588_TMST: return "PKT_RX_IEEE1588_TMST";
+	case PKT_RX_QINQ_STRIPPED: return "PKT_RX_QINQ_STRIPPED";
 	default: return NULL;
 	}
 }
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 48911a6..5b8a11a 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -79,7 +79,16 @@ extern "C" {
  * Keep these flags synchronized with rte_get_rx_ol_flag_name() and
  * rte_get_tx_ol_flag_name().
  */
-#define PKT_RX_VLAN_PKT      (1ULL << 0)  /**< RX packet is a 802.1q VLAN packet. */
+
+/**
+ * Deprecated.
+ * RX packet is a 802.1q VLAN packet. This flag was set by PMDs when
+ * the packet is recognized as a VLAN, but the behavior between PMDs
+ * was not the same. This flag is kept for some time to avoid breaking
+ * applications and should be replaced by PKT_RX_VLAN_STRIPPED.
+ */
+#define PKT_RX_VLAN_PKT      (1ULL << 0)
+
 #define PKT_RX_RSS_HASH      (1ULL << 1)  /**< RX packet with RSS hash result. */
 #define PKT_RX_FDIR          (1ULL << 2)  /**< RX packet with FDIR match indicate. */
 #define PKT_RX_L4_CKSUM_BAD  (1ULL << 3)  /**< L4 cksum of RX pkt. is not OK. */
@@ -89,11 +98,37 @@ extern "C" {
 #define PKT_RX_HBUF_OVERFLOW (0ULL << 0)  /**< Header buffer overflow. */
 #define PKT_RX_RECIP_ERR     (0ULL << 0)  /**< Hardware processing error. */
 #define PKT_RX_MAC_ERR       (0ULL << 0)  /**< MAC error. */
+
+/**
+ * A vlan has been stripped by the hardware and its tci is saved in
+ * mbuf->vlan_tci. This can only happen if vlan stripping is enabled
+ * in the RX configuration of the PMD.
+ */
+#define PKT_RX_VLAN_STRIPPED (1ULL << 6)
+
+/* hole, some bits can be reused here  */
+
 #define PKT_RX_IEEE1588_PTP  (1ULL << 9)  /**< RX IEEE1588 L2 Ethernet PT Packet. */
 #define PKT_RX_IEEE1588_TMST (1ULL << 10) /**< RX IEEE1588 L2/L4 timestamped packet.*/
 #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. */
+
+/**
+ * The 2 vlans have been stripped by the hardware and their tci are
+ * saved in mbuf->vlan_tci (inner) and mbuf->vlan_tci_outer (outer).
+ * This can only happen if vlan stripping is enabled in the RX
+ * configuration of the PMD. If this flag is set, PKT_RX_VLAN_STRIPPED
+ * must also be set.
+ */
+#define PKT_RX_QINQ_STRIPPED (1ULL << 15)
+
+/**
+ * Deprecated.
+ * RX packet with double VLAN stripped.
+ * This flag is replaced by PKT_RX_QINQ_STRIPPED.
+ */
+#define PKT_RX_QINQ_PKT      PKT_RX_QINQ_STRIPPED
+
 /* add new RX flags here */
 
 /* add new TX flags here */
@@ -761,7 +796,10 @@ struct rte_mbuf {
 
 	/*
 	 * The packet type, which is the combination of outer/inner L2, L3, L4
-	 * and tunnel types.
+	 * and tunnel types. The packet_type is about data really present in the
+	 * mbuf. Example: if vlan stripping is enabled, a received vlan packet
+	 * would have RTE_PTYPE_L2_ETHER and not RTE_PTYPE_L2_VLAN because the
+	 * vlan is stripped from the data.
 	 */
 	union {
 		uint32_t packet_type; /**< L2/L3/L4 and tunnel information. */
@@ -778,7 +816,8 @@ struct rte_mbuf {
 
 	uint32_t pkt_len;         /**< Total pkt len: sum of all segments. */
 	uint16_t data_len;        /**< Amount of data in segment buffer. */
-	uint16_t vlan_tci;        /**< VLAN Tag Control Identifier (CPU order) */
+	/** VLAN TCI (CPU order), valid if PKT_RX_VLAN_STRIPPED is set. */
+	uint16_t vlan_tci;
 
 	union {
 		uint32_t rss;     /**< RSS hash result if RSS enabled */
@@ -804,7 +843,8 @@ struct rte_mbuf {
 
 	uint32_t seqn; /**< Sequence number. See also rte_reorder_insert() */
 
-	uint16_t vlan_tci_outer;  /**< Outer VLAN Tag Control Identifier (CPU order) */
+	/** Outer VLAN TCI (CPU order), valid if PKT_RX_QINQ_STRIPPED is set. */
+	uint16_t vlan_tci_outer;
 
 	/* second cache line - fields only used in slow path or on TX */
 	MARKER cacheline1 __rte_cache_min_aligned;
-- 
2.8.0.rc3