• Hangbin Liu's avatar
    xdp: Extend xdp_redirect_map with broadcast support · e624d4ed
    Hangbin Liu authored
    This patch adds two flags BPF_F_BROADCAST and BPF_F_EXCLUDE_INGRESS to
    extend xdp_redirect_map for broadcast support.
    
    With BPF_F_BROADCAST the packet will be broadcasted to all the interfaces
    in the map. with BPF_F_EXCLUDE_INGRESS the ingress interface will be
    excluded when do broadcasting.
    
    When getting the devices in dev hash map via dev_map_hash_get_next_key(),
    there is a possibility that we fall back to the first key when a device
    was removed. This will duplicate packets on some interfaces. So just walk
    the whole buckets to avoid this issue. For dev array map, we also walk the
    whole map to find valid interfaces.
    
    Function bpf_clear_redirect_map() was removed in
    commit ee75aef2 ("bpf, xdp: Restructure redirect actions").
    Add it back as we need to use ri->map again.
    
    With test topology:
      +-------------------+             +-------------------+
      | Host A (i40e 10G) |  ---------- | eno1(i40e 10G)    |
      +-------------------+             |                   |
                                        |   Host B          |
      +-------------------+             |                   |
      | Host C (i40e 10G) |  ---------- | eno2(i40e 10G)    |
      +-------------------+             |                   |
                                        |          +------+ |
                                        | veth0 -- | Peer | |
                                        | veth1 -- |      | |
                                        | veth2 -- |  NS  | |
                                        |          +------+ |
                                        +-------------------+
    
    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.
    All the veth peers in the NS have a XDP_DROP program loaded. The
    forward_map max_entries in xdp_redirect_map_multi is modify to 4.
    
    Testing the performance impact on the regular xdp_redirect path with and
    without patch (to check impact of additional check for broadcast mode):
    
    5.12 rc4         | redirect_map        i40e->i40e      |    2.0M |  9.7M
    5.12 rc4         | redirect_map        i40e->veth      |    1.7M | 11.8M
    5.12 rc4 + patch | redirect_map        i40e->i40e      |    2.0M |  9.6M
    5.12 rc4 + patch | redirect_map        i40e->veth      |    1.7M | 11.7M
    
    Testing the performance when cloning packets with the redirect_map_multi
    test, using a redirect map size of 4, filled with 1-3 devices:
    
    5.12 rc4 + patch | redirect_map multi  i40e->veth (x1) |    1.7M | 11.4M
    5.12 rc4 + patch | redirect_map multi  i40e->veth (x2) |    1.1M |  4.3M
    5.12 rc4 + patch | redirect_map multi  i40e->veth (x3) |    0.8M |  2.6M
    Signed-off-by: default avatarHangbin Liu <liuhangbin@gmail.com>
    Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
    Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
    Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
    Acked-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
    Link: https://lore.kernel.org/bpf/20210519090747.1655268-3-liuhangbin@gmail.com
    e624d4ed
cpumap.c 18.9 KB