Could you review this patch today ? If possible, I hope this patch set can be included RC2.
> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Jijiang Liu > Sent: Thursday, November 27, 2014 4:19 PM > To: dev at dpdk.org > Subject: [dpdk-dev] [PATCH 0/3] i40e VXLAN TX checksum rework > > We have got some feedback about backward compatibility of VXLAN TX checksum > offload API with 1G/10G NIC after the i40e VXLAN TX checksum codes were > applied, so we have to rework the APIs on i40e, including the changes of mbuf, > i40e PMD and csum engine. > > The main changes in mbuf are as follows, In place of removing > PKT_TX_VXLAN_CKSUM, we introducing 2 new flags: PKT_TX_OUT_IP_CKSUM, > PKT_TX_UDP_TUNNEL_PKT, and a new field: l4_tun_len. > Replace the inner_l2_len and the inner_l3_len field with the outer_l2_len and > outer_l3_len field. > > The existing flags are listed below, > PKT_TX_IP_CKSUM: HW IPv4 checksum for non-tunnelling packet/ HW inner > IPv4 checksum for tunnelling packet > PKT_TX_TCP_CKSUM: HW TCP checksum for non-tunnelling packet/ HW inner > TCP checksum for tunnelling packet > PKT_TX_SCTP_CKSUM: HW SCTP checksum for non-tunnelling packet/ HW inner > SCTP checksum for tunnelling packet > PKT_TX_UDP_CKSUM: HW SCTP checksum for non-tunnelling packet/ HW inner > SCTP checksum for tunnelling packet > PKT_TX_IPV4: IPv4 with no HW checksum offload for non-tunnelling > packet/inner IPv4 with no HW checksum offload for tunnelling packet > PKT_TX_IPV6: IPv6 non-tunnelling packet/ inner IPv6 with no HW checksum > offload for tunnelling packet > > let's use a few examples to demonstrate how to use these flags: > Let say we have a tunnel packet: > eth_hdr_out/ipv4_hdr_out/udp_hdr_out/vxlan_hdr/ehtr_hdr_in/ipv4_hdr_in/tcp > _hdr_in.There could be several scenarios: > > A) User requests HW offload for ipv4_hdr_out checksum. > He doesn't care is it a tunnelled packet or not. > So he sets: > > mb->l2_len = eth_hdr_out; > mb->l3_len = ipv4_hdr_out; > mb->ol_flags |= PKT_TX_IPV4_CSUM; > > B) User is aware that it is a tunnelled packet and requests HW offload for > ipv4_hdr_in and tcp_hdr_in *only*. > He doesn't care about outer IP checksum offload. > In that case, for FVL he has 2 choices: > 1. Treat that packet as a 'proper' tunnelled packet, and fill all the > fields: > mb->l2_len = eth_hdr_in; > mb->l3_len = ipv4_hdr_in; > mb->outer_l2_len = eth_hdr_out; > mb->outer_l3_len = ipv4_hdr_out; > mb->l4tun_len = vxlan_hdr; > mb->ol_flags |= PKT_TX_UDP_TUNNEL_PKT | PKT_TX_IP_CKSUM | > PKT_TX_TCP_CKSUM; > > 2. As user doesn't care about outer IP hdr checksum, he can treat > everything > before ipv4_hdr_in as L2 header. > So he knows, that it is a tunnelled packet, but makes HW to treat it as > ordinary > (non-tunnelled) packet: > mb->l2_len = eth_hdr_out + ipv4_hdr_out + udp_hdr_out + vxlan_hdr + > ehtr_hdr_in; > mb->l3_len = ipv4_hdr_in; > mb->ol_flags |= PKT_TX_IP_CKSUM | PKT_TX_TCP_CKSUM; > > i40e PMD will support both B.1 and B.2. > ixgbe/igb/em PMD supports only B.2. > if HW supports both - it will be up to user app which method to choose. > tespmd will support both methods, and it should be configurable by user which > approach to use (cmdline parameter). > So the user can try/test both methods and select an appropriate for him. > > Now, B.2 is exactly what Oliver suggested. > I think it has few important advantages over B.1: > First of all - compatibility. It works across all HW we currently support > (i40e/ixgbe/igb/em). > Second - it is probably faster even on FVL, as for it we have to fill only > TXD, while > with approach #2 we have to fill both TCD and TXD. > > C) User knows that is a tunnelled packet, and wants HW offload for all 3 > checksums: outer IP hdr checksum, inner IP checksum, inner TCP checksum. > Then he has to setup all TX checksum fields: > mb->l2_len = eth_hdr_in; > mb->l3_len = ipv4_hdr_in; > mb->outer_l2_len = eth_hdr_out; > mb->outer_l3_len = ipv4_hdr_out; > mb->l4tun_len = vxlan_hdr; > mb->ol_flags |= PKT_TX_OUT_IP_CKSUM | PKT_TX_UDP_TUNNEL | > PKT_TX_IP_CKSUM | PKT_TX_TCP_CKSUM; > > Jijiang Liu (3): > mbuf change > i40e PMD change in i40e_rxtx.c > rework csum forward engine > > app/test-pmd/csumonly.c | 55 +++++++++++++++++++++----------------- > lib/librte_mbuf/rte_mbuf.c | 2 +- > lib/librte_mbuf/rte_mbuf.h | 23 ++++++++++------ > lib/librte_pmd_i40e/i40e_rxtx.c | 40 ++++++++++++--------------- > 4 files changed, 63 insertions(+), 57 deletions(-) > > -- > 1.7.7.6