Regards _Sugesh
> -----Original Message----- > From: Jesse Gross [mailto:je...@kernel.org] > Sent: Saturday, August 20, 2016 2:07 AM > To: Chandran, Sugesh <sugesh.chand...@intel.com> > Cc: ovs dev <dev@openvswitch.org> > Subject: Re: [RFC PATCHv2] netdev-dpdk: Enable Rx checksum offloading > feature on DPDK physical ports. > > On Fri, Aug 19, 2016 at 3:40 AM, Sugesh Chandran > <sugesh.chand...@intel.com> wrote: > > diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index > > e5f2cdd..113e6d8 100644 > > --- a/lib/netdev-dpdk.c > > +++ b/lib/netdev-dpdk.c > > @@ -1090,6 +1127,15 @@ netdev_dpdk_set_config(struct netdev > *netdev, > > const struct smap *args) > > > > dpdk_eth_flow_ctrl_setup(dev); > > > > + /* Rx checksum offload configuration */ > > + /* By default the Rx checksum offload is ON */ > > + rx_chksm_ofld = smap_get_bool(args, "rx-checksum-offload", true); > > + temp_flag = (dev->hw_ol_features & > NETDEV_RX_CHECKSUM_OFFLOAD) > > + != 0; > > + if (temp_flag != rx_chksm_ofld) { > > + dev->hw_ol_features ^= NETDEV_RX_CHECKSUM_OFFLOAD; > > + } > > + dpdk_eth_checksum_offload_configure(dev); > > ovs_mutex_unlock(&dev->mutex); > > I think that while we are going through the trouble of checking whether the > old flag is different from the new one, we might as well only call > dpdk_eth_checksum_offload_configure() if there is a difference. [Sugesh] Sure, Will move in the ' dpdk_eth_checksum_offload_configure(dev)' inside the if statement. > > > diff --git a/lib/netdev-native-tnl.c b/lib/netdev-native-tnl.c index > > ce2582f..23e987c 100644 > > --- a/lib/netdev-native-tnl.c > > +++ b/lib/netdev-native-tnl.c > > @@ -85,9 +85,11 @@ netdev_tnl_ip_extract_tnl_md(struct dp_packet > > *packet, struct flow_tnl *tnl, > > > > ovs_be32 ip_src, ip_dst; > > > > - if (csum(ip, IP_IHL(ip->ip_ihl_ver) * 4)) { > > - VLOG_WARN_RL(&err_rl, "ip packet has invalid checksum"); > > - return NULL; > > + if(OVS_UNLIKELY(!dp_packet_ip_checksum_valid(packet))) { > > + if (csum(ip, IP_IHL(ip->ip_ihl_ver) * 4)) { > > + VLOG_WARN_RL(&err_rl, "ip packet has invalid checksum"); > > + return NULL; > > + } > > } > > > > if (ntohs(ip->ip_tot_len) > l3_size) { @@ -179,18 +181,20 @@ > > udp_extract_tnl_md(struct dp_packet *packet, struct flow_tnl *tnl, > > } > > > > if (udp->udp_csum) { > > - uint32_t csum; > > - if (netdev_tnl_is_header_ipv6(dp_packet_data(packet))) { > > - csum = packet_csum_pseudoheader6(dp_packet_l3(packet)); > > - } else { > > - csum = packet_csum_pseudoheader(dp_packet_l3(packet)); > > - } > > - > > - csum = csum_continue(csum, udp, dp_packet_size(packet) - > > - ((const unsigned char *)udp - > > - (const unsigned char > > *)dp_packet_l2(packet))); > > - if (csum_finish(csum)) { > > - return NULL; > > + if(OVS_UNLIKELY(!dp_packet_l4_checksum_valid(packet))) { > > + uint32_t csum; > > + if (netdev_tnl_is_header_ipv6(dp_packet_data(packet))) { > > + csum = packet_csum_pseudoheader6(dp_packet_l3(packet)); > > + } else { > > + csum = packet_csum_pseudoheader(dp_packet_l3(packet)); > > + } > > + > > + csum = csum_continue(csum, udp, dp_packet_size(packet) - > > + ((const unsigned char *)udp - > > + (const unsigned char > > *)dp_packet_l2(packet))); > > + if (csum_finish(csum)) { > > + return NULL; > > + } > > } > > tnl->flags |= FLOW_TNL_F_CSUM; > > } > > I think the previous version of the patch cleared the offload flags after > popping off the tunnel headers. I think that's probably a good idea here as > well. Since we're not terminating the payload it's probably relatively rare > that > we would have multiple checksums but it's theoretically possible that we > might have a tunnel-in-tunnel situation (and I suppose that it's that we might > want to use checksum offload for higher level services - connection > tracking/NAT/load balancing, etc.). > [Sugesh] Yes . it make sense , in fact the old patch was doing that. Will reset the flags after the use. > In the future, if DPDK offloads become tunnel aware some of these issues > can become quite complicated due to the presence of multiple checksums > being offloaded and how that is represented. On the Linux side there was a > fair amount of work put into this over the past several years, so it might be > worth taking a look at that for some inspiration before the DPDK interfaces > get locked down. [Sugesh] May be in the future when DPDK starts supporting checksum offload for inner packets, Its worth to define it as 'csum_level' with CHECKSUM_UNNECESSARY than defining separate flags for every packet type, which is similar to what kernel is doing for tunnel packet checksum offloading. The checksum reset & validation logic must take care of this by changing the csum_level value and CHECKSUM_* flag accordingly. However the current DPDK driver only supports IP and L4 checksum offloading using independent flags. Will provide the inputs when other checksum offloading features are implementing in DPDK in the future. I am sending out next version of patch after incorporating your comments, let me know your comments or suggestions if any. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
