[dpdk-dev] [PATCH v3] i40: fix the VXLAN TSO issue

[Zhe Tao <zhe.tao@intel.com>]

Problem:
When using the TSO + VXLAN feature in i40e, the outer UDP length fields in
the multiple UDP segments which are TSOed by the i40e will have a
wrong value.

Fix this problem by adding the tunnel type field in the i40e descriptor
which was missed before.

Fixes: 77b8301733c3 ("i40e: VXLAN Tx checksum offload")

Signed-off-by: Zhe Tao <zhe.tao@intel.com>
---
v2: edited the comments
v3: added external IP offload flag when TSO is enabled for tunnelling packets

 app/test-pmd/csumonly.c      | 29 +++++++++++++++++++++--------
 drivers/net/i40e/i40e_rxtx.c | 12 +++++++++---
 lib/librte_mbuf/rte_mbuf.h   | 16 +++++++++++++++-
 3 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index ac4bd8f..aaa006f 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -204,7 +204,8 @@ parse_ethernet(struct ether_hdr *eth_hdr, struct testpmd_offload_info *info)
 static void
 parse_vxlan(struct udp_hdr *udp_hdr,
 	    struct testpmd_offload_info *info,
-	    uint32_t pkt_type)
+	    uint32_t pkt_type,
+	    uint64_t *ol_flags)
 {
 	struct ether_hdr *eth_hdr;
 
@@ -215,6 +216,7 @@ parse_vxlan(struct udp_hdr *udp_hdr,
 		RTE_ETH_IS_TUNNEL_PKT(pkt_type) == 0)
 		return;
 
+	*ol_flags |= PKT_TX_TUNNEL_VXLAN;
 	info->is_tunnel = 1;
 	info->outer_ethertype = info->ethertype;
 	info->outer_l2_len = info->l2_len;
@@ -231,7 +233,9 @@ parse_vxlan(struct udp_hdr *udp_hdr,
 
 /* Parse a gre header */
 static void
-parse_gre(struct simple_gre_hdr *gre_hdr, struct testpmd_offload_info *info)
+parse_gre(struct simple_gre_hdr *gre_hdr,
+	  struct testpmd_offload_info *info,
+	  uint64_t *ol_flags)
 {
 	struct ether_hdr *eth_hdr;
 	struct ipv4_hdr *ipv4_hdr;
@@ -242,6 +246,8 @@ parse_gre(struct simple_gre_hdr *gre_hdr, struct testpmd_offload_info *info)
 	if ((gre_hdr->flags & _htons(~GRE_SUPPORTED_FIELDS)) != 0)
 		return;
 
+	*ol_flags |= PKT_TX_TUNNEL_GRE;
+
 	gre_len += sizeof(struct simple_gre_hdr);
 
 	if (gre_hdr->flags & _htons(GRE_KEY_PRESENT))
@@ -417,7 +423,7 @@ process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
  * packet */
 static uint64_t
 process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
-	uint16_t testpmd_ol_flags)
+	uint16_t testpmd_ol_flags, uint64_t orig_ol_flags)
 {
 	struct ipv4_hdr *ipv4_hdr = outer_l3_hdr;
 	struct ipv6_hdr *ipv6_hdr = outer_l3_hdr;
@@ -428,7 +434,8 @@ process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
 		ipv4_hdr->hdr_checksum = 0;
 		ol_flags |= PKT_TX_OUTER_IPV4;
 
-		if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_OUTER_IP_CKSUM)
+		if ((testpmd_ol_flags & TESTPMD_TX_OFFLOAD_OUTER_IP_CKSUM) ||
+		    (info->tso_segsz != 0))
 			ol_flags |= PKT_TX_OUTER_IP_CKSUM;
 		else
 			ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
@@ -442,6 +449,9 @@ process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
 	 * hardware supporting it today, and no API for it. */
 
 	udp_hdr = (struct udp_hdr *)((char *)outer_l3_hdr + info->outer_l3_len);
+	if ((orig_ol_flags & PKT_TX_TCP_SEG) &&
+	    ((orig_ol_flags & PKT_TX_TUNNEL_MASK) == PKT_TX_TUNNEL_VXLAN))
+		udp_hdr->dgram_cksum = 0;
 	/* do not recalculate udp cksum if it was 0 */
 	if (udp_hdr->dgram_cksum != 0) {
 		udp_hdr->dgram_cksum = 0;
@@ -705,15 +715,18 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			if (info.l4_proto == IPPROTO_UDP) {
 				struct udp_hdr *udp_hdr;
 				udp_hdr = (struct udp_hdr *)((char *)l3_hdr +
-					info.l3_len);
-				parse_vxlan(udp_hdr, &info, m->packet_type);
+					   info.l3_len);
+				parse_vxlan(udp_hdr, &info, m->packet_type,
+					    &ol_flags);
 			} else if (info.l4_proto == IPPROTO_GRE) {
 				struct simple_gre_hdr *gre_hdr;
 				gre_hdr = (struct simple_gre_hdr *)
 					((char *)l3_hdr + info.l3_len);
-				parse_gre(gre_hdr, &info);
+				parse_gre(gre_hdr, &info, &ol_flags);
 			} else if (info.l4_proto == IPPROTO_IPIP) {
 				void *encap_ip_hdr;
+
+				ol_flags |= PKT_TX_TUNNEL_IPIP;
 				encap_ip_hdr = (char *)l3_hdr + info.l3_len;
 				parse_encap_ip(encap_ip_hdr, &info);
 			}
@@ -745,7 +758,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 		 * processed in hardware. */
 		if (info.is_tunnel == 1) {
 			ol_flags |= process_outer_cksums(outer_l3_hdr, &info,
-				testpmd_ol_flags);
+				testpmd_ol_flags, ol_flags);
 		}
 
 		/* step 4: fill the mbuf meta data (flags and header lengths) */
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 049a813..4c987f2 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -801,6 +801,12 @@ i40e_txd_enable_checksum(uint64_t ol_flags,
 			union i40e_tx_offload tx_offload,
 			uint32_t *cd_tunneling)
 {
+	/* Tx pkts tunnel type*/
+	if ((ol_flags & PKT_TX_TUNNEL_MASK) == PKT_TX_TUNNEL_VXLAN)
+		*cd_tunneling |= I40E_TXD_CTX_UDP_TUNNELING;
+	else if ((ol_flags & PKT_TX_TUNNEL_MASK) == PKT_TX_TUNNEL_GRE)
+		*cd_tunneling |= I40E_TXD_CTX_GRE_TUNNELING;
+
 	/* UDP tunneling packet TX checksum offload */
 	if (ol_flags & PKT_TX_OUTER_IP_CKSUM) {
 
@@ -1510,7 +1516,8 @@ i40e_calc_context_desc(uint64_t flags)
 
 /* set i40e TSO context descriptor */
 static inline uint64_t
-i40e_set_tso_ctx(struct rte_mbuf *mbuf, union i40e_tx_offload tx_offload)
+i40e_set_tso_ctx(struct rte_mbuf *mbuf,
+		 union i40e_tx_offload tx_offload)
 {
 	uint64_t ctx_desc = 0;
 	uint32_t cd_cmd, hdr_len, cd_tso_len;
@@ -1521,7 +1528,7 @@ i40e_set_tso_ctx(struct rte_mbuf *mbuf, union i40e_tx_offload tx_offload)
 	}
 
 	/**
-	 * in case of tunneling packet, the outer_l2_len and
+	 * in case of non tunneling packet, the outer_l2_len and
 	 * outer_l3_len must be 0.
 	 */
 	hdr_len = tx_offload.outer_l2_len +
@@ -1537,7 +1544,6 @@ i40e_set_tso_ctx(struct rte_mbuf *mbuf, union i40e_tx_offload tx_offload)
 		 I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
 		((uint64_t)mbuf->tso_segsz <<
 		 I40E_TXD_CTX_QW1_MSS_SHIFT);
-
 	return ctx_desc;
 }
 
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 15e3a10..90812ea 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -133,6 +133,17 @@ extern "C" {
 /* add new TX flags here */
 
 /**
+ * Bits 45:48 used for the tunnel type.
+ * When doing Tx offload like TSO or checksum, the HW needs to configure the
+ * tunnel type into the HW descriptors.
+ */
+#define PKT_TX_TUNNEL_VXLAN   (1ULL << 45)
+#define PKT_TX_TUNNEL_GRE   (2ULL << 45)
+#define PKT_TX_TUNNEL_IPIP    (3ULL << 45)
+/* add new TX TUNNEL type here */
+#define PKT_TX_TUNNEL_MASK    (0xFULL << 45)
+
+/**
  * Second VLAN insertion (QinQ) flag.
  */
 #define PKT_TX_QINQ_PKT    (1ULL << 49)   /**< TX packet with double VLAN inserted. */
@@ -867,7 +878,10 @@ struct rte_mbuf {
 	union {
 		uint64_t tx_offload;       /**< combined for easy fetch */
 		struct {
-			uint64_t l2_len:7; /**< L2 (MAC) Header Length. */
+			uint64_t l2_len:7;
+			/**< L2 (MAC) Header Length if it isn't a tunneling pkt.
+			 * for tunnel it is outer L4 len+tunnel len+inner L2 len
+			 */
 			uint64_t l3_len:9; /**< L3 (IP) Header Length. */
 			uint64_t l4_len:8; /**< L4 (TCP/UDP) Header Length. */
 			uint64_t tso_segsz:16; /**< TCP TSO segment size */
-- 
2.1.4