Hangbin Liu <liuhangbin@xxxxxxxxx> writes: > This patch is for xdp multicast support. which has been discussed before[0], > The goal is to be able to implement an OVS-like data plane in XDP, i.e., > a software switch that can forward XDP frames to multiple ports. > > To achieve this, an application needs to specify a group of interfaces > to forward a packet to. It is also common to want to exclude one or more > physical interfaces from the forwarding operation - e.g., to forward a > packet to all interfaces in the multicast group except the interface it > arrived on. While this could be done simply by adding more groups, this > quickly leads to a combinatorial explosion in the number of groups an > application has to maintain. > > To avoid the combinatorial explosion, we propose to include the ability > to specify an "exclude group" as part of the forwarding operation. This > needs to be a group (instead of just a single port index), because there > may have multi interfaces you want to exclude. > > Thus, the logical forwarding operation becomes a "set difference" > operation, i.e. "forward to all ports in group A that are not also in > group B". This series implements such an operation using device maps to > represent the groups. This means that the XDP program specifies two > device maps, one containing the list of netdevs to redirect to, and the > other containing the exclude list. > > To achieve this, I re-implement a new helper bpf_redirect_map_multi() > to accept two maps, the forwarding map and exclude map. If user > don't want to use exclude map and just want simply stop redirecting back > to ingress device, they can use flag BPF_F_EXCLUDE_INGRESS. > > The 1st patch is Jesper's run devmap xdp_prog later in bulking step. > The 2st patch add a new bpf arg to allow NULL map pointer. > The 3rd patch add the new bpf_redirect_map_multi() helper. > The 4-6 patches are for usage sample and testing purpose. > > I did same perf tests with the following topo: > > --------------------- --------------------- > | Host A (i40e 10G) | ---------- | eno1(i40e 10G) | > --------------------- | | > | Host B | > --------------------- | | > | Host C (i40e 10G) | ---------- | eno2(i40e 10G) | > --------------------- vlan2 | -------- | > | veth1 -- | veth0| | > | -------- | > --------------------| > On Host A: > # pktgen/pktgen_sample03_burst_single_flow.sh -i eno1 -d $dst_ip -m $dst_mac -s 64 > > On Host B(Intel(R) Xeon(R) CPU E5-2690 v3 @ 2.60GHz, 128G Memory): > Use xdp_redirect_map and xdp_redirect_map_multi in samples/bpf for testing. > The veth0 in netns load dummy drop program. The forward_map max_entries in > xdp_redirect_map_multi is modify to 4. > > Here is the perf result with 5.10 rc6: > > The are about +/- 0.1M deviation for native testing > Version | Test | Generic | Native | Native + 2nd > 5.10 rc6 | xdp_redirect_map i40e->i40e | 2.0M | 9.1M | 8.0M > 5.10 rc6 | xdp_redirect_map i40e->veth | 1.7M | 11.0M | 9.7M > 5.10 rc6 + patch1 | xdp_redirect_map i40e->i40e | 2.0M | 9.5M | 7.5M > 5.10 rc6 + patch1 | xdp_redirect_map i40e->veth | 1.7M | 11.6M | 9.1M > 5.10 rc6 + patch1-6 | xdp_redirect_map i40e->i40e | 2.0M | 9.5M | 7.5M > 5.10 rc6 + patch1-6 | xdp_redirect_map i40e->veth | 1.7M | 11.6M | 9.1M > 5.10 rc6 + patch1-6 | xdp_redirect_map_multi i40e->i40e | 1.7M | 7.8M | 6.4M > 5.10 rc6 + patch1-6 | xdp_redirect_map_multi i40e->veth | 1.4M | 9.3M | 7.5M > 5.10 rc6 + patch1-6 | xdp_redirect_map_multi i40e->i40e+veth | 1.0M | 3.2M | 2.7M > > Last but not least, thanks a lot to Toke, Jesper, Jiri and Eelco for > suggestions and help on implementation. Nice work, and thank you for sticking with this! With the last couple of fixes discussed for patch 1, when you resubmit please add my: Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> for the series! -Toke
