[dpdk-dev] [PATCH v3 3/3] app/testpmd:change tx_checksum command and csum forwarding engine
Olivier MATZ
olivier.matz at 6wind.com
Thu Dec 11 11:52:36 CET 2014
Hi Jijiang,
Some more comments, in addition to the one I've made in the cover
letter. Reference link for patchwork readers:
http://dpdk.org/ml/archives/dev/2014-December/009886.html
On 12/10/2014 02:03 AM, Jijiang Liu wrote:
> --- a/app/test-pmd/cmdline.c
> +++ b/app/test-pmd/cmdline.c
> @@ -316,16 +316,30 @@ static void cmd_help_long_parsed(void *parsed_result,
> " Disable hardware insertion of a VLAN header in"
> " packets sent on a port.\n\n"
>
> - "tx_cksum set (ip|udp|tcp|sctp|vxlan) (hw|sw) (port_id)\n"
> + "tx_cksum set (ip|udp|tcp|sctp) (hw|sw) (port_id)\n"
> " Select hardware or software calculation of the"
> " checksum with when transmitting a packet using the"
> " csum forward engine.\n"
> - " ip|udp|tcp|sctp always concern the inner layer.\n"
> - " vxlan concerns the outer IP and UDP layer (in"
> - " case the packet is recognized as a vxlan packet by"
> - " the forward engine)\n"
> + " In the case of tunneling packet, ip|udp|tcp|sctp"
> + " always concern the inner layer.\n\n"
> +
> + "tx_cksum set tunnel (hw|sw|none) (port_id)\n"
> + " Select hardware or software calculation of the"
> + " checksum with when transmitting a tunneling packet"
> + " using the csum forward engine.\n"
> + " The none option means treat tunneling packet as ordinary"
> + " packet when using the csum forward engine\n."
> + " Tunneling packet concerns the outer IP, inner IP"
> + " and inner L4\n"
> " Please check the NIC datasheet for HW limits.\n\n"
>
> + "tx_cksum set (outer-ip) (hw|sw) (port_id)\n"
> + " Select hardware or software calculation of the"
> + " checksum with when transmitting a packet using the"
> + " csum forward engine.\n"
> + " outer-ip always concern the outer layer of"
> + " tunneling packet.\n\n"
> +
> "tx_checksum show (port_id)\n"
> " Display tx checksum offload configuration\n\n"
>
not sure we need 2 different commands for tx_cksum set (outer-ip) and
tx_cksum set (ip|udp|tcp|sctp). As the syntax is exactly the same, it
may result in less code to have only one command.
> --- a/app/test-pmd/csumonly.c
> +++ b/app/test-pmd/csumonly.c
> @@ -256,17 +256,16 @@ process_outer_cksums(void *outer_l3_hdr, uint16_t outer_ethertype,
> struct udp_hdr *udp_hdr;
> uint64_t ol_flags = 0;
>
> - if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_VXLAN_CKSUM)
> - ol_flags |= PKT_TX_UDP_TUNNEL_PKT;
> -
> if (outer_ethertype == _htons(ETHER_TYPE_IPv4)) {
> ipv4_hdr->hdr_checksum = 0;
>
> - if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_VXLAN_CKSUM)
> + if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_OUTER_IP_CKSUM)
> ol_flags |= PKT_TX_OUTER_IP_CKSUM;
> - else
> + else {
> ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
> - } else if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_VXLAN_CKSUM)
> + ol_flags |= PKT_TX_OUTER_IPV4;
> + }
> + } else if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_TUNNEL_CKSUM)
> ol_flags |= PKT_TX_OUTER_IPV6;
>
> udp_hdr = (struct udp_hdr *)((char *)outer_l3_hdr + outer_l3_len);
> @@ -300,11 +299,14 @@ process_outer_cksums(void *outer_l3_hdr, uint16_t outer_ethertype,
> * Ether / (vlan) / outer IP|IP6 / outer UDP / VxLAN / Ether / IP|IP6 /
> * UDP|TCP|SCTP
> *
> - * The testpmd command line for this forward engine sets the flags
> + * These testpmd command lines for this forward engine sets the flags
> * TESTPMD_TX_OFFLOAD_* in ports[tx_port].tx_ol_flags. They control
> - * wether a checksum must be calculated in software or in hardware. The
> - * IP, UDP, TCP and SCTP flags always concern the inner layer. The
> - * VxLAN flag concerns the outer IP (if packet is recognized as a vxlan packet).
> + * wether a checksum must be calculated in software or in hardware.
> + * In the case of tunneling packet, the IP, UDP, TCP and SCTP flags
> + * always concern the inner layer; the outer IP flag always concern
> + * the outer layer; the tunnel flag is used to tell the NIC that it
> + * is a tunneing packet, want hardware offload for outer layer,
> + * or inner layer, or both.
tunneing -> tunneling
"the tunnel flag is used to tell the NIC that it is a tunneing packet,
want hardware offload for outer layer, or inner layer, or both."
what does that mean?
> */
> static void
> pkt_burst_checksum_forward(struct fwd_stream *fs)
> @@ -376,7 +378,9 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
> l3_hdr = (char *)eth_hdr + l2_len;
>
> /* check if it's a supported tunnel (only vxlan for now) */
> - if (l4_proto == IPPROTO_UDP) {
> + if (((testpmd_ol_flags &
> + TESTPMD_TX_OFFLOAD_NON_TUNNEL_CKSUM) == 0)
> + && (l4_proto == IPPROTO_UDP)) {
> udp_hdr = (struct udp_hdr *)((char *)l3_hdr + l3_len);
>
> /* check udp destination port, 4789 is the default
> @@ -386,17 +390,23 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
> tunnel = 1;
>
> /* currently, this flag is set by i40e only if the
> - * packet is vxlan */
> + * packet is a tunneling packet */
> } else if (m->ol_flags & (PKT_RX_TUNNEL_IPV4_HDR |
> PKT_RX_TUNNEL_IPV6_HDR))
> tunnel = 1;
>
> if (tunnel == 1) {
> +
> + if (testpmd_ol_flags
> + & TESTPMD_TX_OFFLOAD_TUNNEL_CKSUM)
> + ol_flags |= PKT_TX_UDP_TUNNEL_PKT;
> +
> outer_ethertype = ethertype;
> outer_l2_len = l2_len;
> outer_l3_len = l3_len;
> outer_l3_hdr = l3_hdr;
>
> + /* currently, only VXLAN packet is supported */
> eth_hdr = (struct ether_hdr *)((char *)udp_hdr +
> sizeof(struct udp_hdr) +
> sizeof(struct vxlan_hdr));
> @@ -434,7 +444,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
> /* step 4: fill the mbuf meta data (flags and header lengths) */
>
> if (tunnel == 1) {
> - if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_VXLAN_CKSUM) {
> + if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_TUNNEL_CKSUM) {
> m->outer_l2_len = outer_l2_len;
> m->outer_l3_len = outer_l3_len;
> m->l2_len = l4_tun_len + l2_len;
> @@ -505,7 +515,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
> "m->l4_len=%d\n",
> m->l2_len, m->l3_len, m->l4_len);
> if ((tunnel == 1) &&
> - (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_VXLAN_CKSUM))
> + (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_TUNNEL_CKSUM))
> printf("tx: m->outer_l2_len=%d m->outer_l3_len=%d\n",
> m->outer_l2_len, m->outer_l3_len);
> if (tso_segsz != 0)
> diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
> index f8b0740..09caa6a 100644
> --- a/app/test-pmd/testpmd.h
> +++ b/app/test-pmd/testpmd.h
> @@ -125,10 +125,20 @@ struct fwd_stream {
> #define TESTPMD_TX_OFFLOAD_TCP_CKSUM 0x0004
> /** Offload SCTP checksum in csum forward engine */
> #define TESTPMD_TX_OFFLOAD_SCTP_CKSUM 0x0008
> -/** Offload VxLAN checksum in csum forward engine */
> -#define TESTPMD_TX_OFFLOAD_VXLAN_CKSUM 0x0010
> +/** Offload tunneling packet checksum in csum forward engine */
> +#define TESTPMD_TX_OFFLOAD_TUNNEL_CKSUM 0x0010
> /** Insert VLAN header in forward engine */
> #define TESTPMD_TX_OFFLOAD_INSERT_VLAN 0x0020
> +/**
> + * Offload outer-IP checksum in csum forward engine
> + * for tunneling packet
> + */
> +#define TESTPMD_TX_OFFLOAD_OUTER_IP_CKSUM 0x0040
> +/**
> + * For a tunneling packet, user requests HW offload for its outer
> + * layer checksum, and don't care is it a tunneled packet or not.
> + */
> +#define TESTPMD_TX_OFFLOAD_NON_TUNNEL_CKSUM 0x0080
>
> /**
> * The data structure associated with each port.
>
For now, I did not check the implementation of the patch. I'm not
sure I understand the specifications, so I cannot check if the code
conforms to it.
How this patch is tested? I think a report similar to
http://dpdk.org/ml/archives/dev/2014-November/007991.html would help
to verify that it works (at least on one driver), and to understand
the test-pmd API and the different use cases.
Regards,
Olivier
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