[dpdk-stable] [PATCH v2] net/virtio: handle Tx checksums correctly for tunnel packets

[Ivan Malov]

Tx prepare method calls rte_net_intel_cksum_prepare(), which
handles tunnel packets correctly, but Tx burst path does not
take tunnel presence into account when computing the offsets.

Fixes: 58169a9c8153 ("net/virtio: support Tx checksum offload")
Cc: stable at dpdk.org

Signed-off-by: Ivan Malov <ivan.malov at oktetlabs.ru>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
---
 drivers/net/virtio/virtqueue.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 03957b2bd0..b83ff32efb 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -620,19 +620,21 @@ static inline void
 virtqueue_xmit_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *cookie)
 {
 	uint64_t csum_l4 = cookie->ol_flags & PKT_TX_L4_MASK;
+	uint16_t o_l23_len = (cookie->ol_flags & PKT_TX_TUNNEL_MASK) ?
+			     cookie->outer_l2_len + cookie->outer_l3_len : 0;
 
 	if (cookie->ol_flags & PKT_TX_TCP_SEG)
 		csum_l4 |= PKT_TX_TCP_CKSUM;
 
 	switch (csum_l4) {
 	case PKT_TX_UDP_CKSUM:
-		hdr->csum_start = cookie->l2_len + cookie->l3_len;
+		hdr->csum_start = o_l23_len + cookie->l2_len + cookie->l3_len;
 		hdr->csum_offset = offsetof(struct rte_udp_hdr, dgram_cksum);
 		hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 		break;
 
 	case PKT_TX_TCP_CKSUM:
-		hdr->csum_start = cookie->l2_len + cookie->l3_len;
+		hdr->csum_start = o_l23_len + cookie->l2_len + cookie->l3_len;
 		hdr->csum_offset = offsetof(struct rte_tcp_hdr, cksum);
 		hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 		break;
@@ -650,7 +652,8 @@ virtqueue_xmit_offload(struct virtio_net_hdr *hdr, struct rte_mbuf *cookie)
 			VIRTIO_NET_HDR_GSO_TCPV6 :
 			VIRTIO_NET_HDR_GSO_TCPV4;
 		hdr->gso_size = cookie->tso_segsz;
-		hdr->hdr_len = cookie->l2_len + cookie->l3_len + cookie->l4_len;
+		hdr->hdr_len = o_l23_len + cookie->l2_len + cookie->l3_len +
+			       cookie->l4_len;
 	} else {
 		ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 		ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
-- 
2.20.1