Also CC'd Stefano, ovs-dev, Ilya, and Eelco
Jakub Kicinski <[email protected]> writes: > On Tue, 27 Jan 2026 22:51:29 +0000 Aleksei Oladko wrote: >> This series addresses several issues in the networking kselftests >> that cause false-positive failures depending on the host environment, >> kernel configuration, or library versions. >> >> The main focus of these changes is to isolate tests from the host >> environment (using namespaces) and to ensure proper fallback or >> skipping when dependencies are missing. >> >> Summary of changes: >> 1. Adds a check for cls_basic module in fib_tests. Without this >> module, the test fails when attempting to add tc rules instead >> of skipping. >> 2. Fixes ovs-dpctl.py to return a non-zero exit code when pyroute2 >> is too old. This allows pmtu.sh to correctly fall back to ovs-vsctl >> instead of assuming the configuration was successful. >> 3,4. Move reuseport and pmtu.sh tests info dedicated network namespaces. >> This prevents failures caused by port conflicts with host processes >> or interference from host firewall rules. >> 5. Ensures io_uring is enabled via sysctl before running io_uring_zerocopy >> test, preventing failures on systems where kernel.io_uring_disabled >> is set. > > Something in this series breaks the pmtu test for us in the CI: > > # 64.84 [+2.54] TEST: IPv6, bridged geneve6: PMTU exceptions - nexthop > objects [ OK ] > # 65.73 [+0.89] ovs_bridge not supported > # 65.73 [+0.00] TEST: IPv4, OVS vxlan4: PMTU exceptions > [SKIP] > # 67.20 [+1.47] ovs_bridge not supported > # 67.20 [+0.00] TEST: IPv6, OVS vxlan4: PMTU exceptions > [SKIP] > # 68.66 [+1.45] ovs_bridge not supported > # 68.66 [+0.00] TEST: IPv4, OVS vxlan6: PMTU exceptions > [SKIP] > # 70.11 [+1.45] ovs_bridge not supported > # 70.11 [+0.00] TEST: IPv6, OVS vxlan6: PMTU exceptions > [SKIP] > # 71.57 [+1.45] ovs_bridge not supported > # 71.57 [+0.00] TEST: IPv4, OVS geneve4: PMTU exceptions > [SKIP] > # 73.01 [+1.44] ovs_bridge not supported > # 73.01 [+0.00] TEST: IPv6, OVS geneve4: PMTU exceptions > [SKIP] > # 74.46 [+1.45] ovs_bridge not supported > # 74.46 [+0.00] TEST: IPv4, OVS geneve6: PMTU exceptions > [SKIP] > # 75.92 [+1.46] ovs_bridge not supported > # 75.93 [+0.00] TEST: IPv6, OVS geneve6: PMTU exceptions > [SKIP] > > https://netdev-ctrl.bots.linux.dev/logs/vmksft/net/results/492641/137-pmtu-wrapper-sh/stdout > > It was fine before: > > https://netdev-ctrl.bots.linux.dev/logs/vmksft/net-dbg/results/492461/6-pmtu-sh/stdout > > Since this is a bash test there are of course no logs to go by.. :/ FYI- we can run the script with '-v' and it will include all of the command output. That could help understand what is going on if you can duplicate the [SKIP] behavior in another environment. I'll try to get my vmtest environment back up for it. > I tried running > python tools/testing/selftests/net/openvswitch/ovs-dpctl.py add-dp br0 > in a netns and that works just fine. Yes, I tested just changing the ovs-dpctl.py side (no other changes to pmtu.sh), and then tried with older pyroute2, no pyroute2, and no ovs-vswitchd userspace to fall back on, and didn't see anything odd on my end. I am still nervous that maybe the test is/was passing even in cases where it shouldn't be. > No idea what's going on.. +1, the setup_ovs_bridge seems to be returning some kind of error. NOTE that I was concerned maybe the test would be passing whether or not the ovs-dpctl was returning '0' (from change 2/5), but I see the following when I fake out the version check: ========== 8< =========== [core@centos9 net]$ sudo ./pmtu.sh -v pmtu_ipv4_ovs_vxlan4_exception ########################################################################## COMMAND: python3 ./openvswitch/ovs-dpctl.py add-dp ovs_br0 Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: ip link set ovs_br0 up Cannot find device "ovs_br0" COMMAND: ip netns exec ns_c-VCOwRt ip link add veth_C-A type veth peer name veth_A-C COMMAND: ip netns exec ns_c-VCOwRt ip link set veth_A-C netns 1 COMMAND: ip link set veth_A-C up COMMAND: ip netns exec ns_c-VCOwRt ip link set veth_C-A up COMMAND: ip netns exec ns_c-VCOwRt ip addr add 192.168.2.10/24 dev veth_C-A COMMAND: ip netns exec ns_c-VCOwRt ip addr add fd00:2::c/64 dev veth_C-A COMMAND: python3 ./openvswitch/ovs-dpctl.py add-if ovs_br0 veth_A-C Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: ip netns exec ns_a-kmNqnY ip link set veth_A-R1 netns 1 COMMAND: ip addr add 10.0.1.1/24 dev veth_A-R1 COMMAND: ip addr add fc00:1::1/64 dev veth_A-R1 COMMAND: ip link set veth_A-R1 up COMMAND: ip route add 10.0.3.1 via 10.0.1.2 COMMAND: ip route add fc00:3::1 via fc00:1::2 COMMAND: python3 ./openvswitch/ovs-dpctl.py add-if ovs_br0 vxlan_a -t vxlan Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: python3 ./openvswitch/ovs-dpctl.py add-flow ovs_br0 recirc_id(0),in_port(),eth(),eth_type(0x0800),ipv4() set(tunnel(tun_id=1,dst=10.0.3.1,ttl=64,tp_dst=4789,flags(df|csum))), Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: python3 ./openvswitch/ovs-dpctl.py add-flow ovs_br0 recirc_id(0),in_port(),eth(),eth_type(0x86dd),ipv6() set(tunnel(tun_id=1,dst=10.0.3.1,ttl=64,tp_dst=4789,flags(df|csum))), Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: python3 ./openvswitch/ovs-dpctl.py add-flow ovs_br0 recirc_id(0),tunnel(tun_id=1,src=10.0.3.1,dst=10.0.1.1),in_port(),eth(),eth_type(0x0800),ipv4() Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: python3 ./openvswitch/ovs-dpctl.py add-flow ovs_br0 recirc_id(0),tunnel(tun_id=1,src=10.0.3.1,dst=10.0.1.1),in_port(),eth(),eth_type(0x86dd),ipv6() Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: python3 ./openvswitch/ovs-dpctl.py add-flow ovs_br0 recirc_id(0),tunnel(tun_id=1,src=10.0.3.1,dst=10.0.1.1),in_port(),eth(),eth_type(0x0806),arp() Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: python3 ./openvswitch/ovs-dpctl.py add-flow ovs_br0 recirc_id(0),in_port(),eth(),eth_type(0x0806),arp(sip=192.168.2.10,tip=192.168.2.2) set(tunnel(tun_id=1,dst=10.0.3.1,ttl=64,tp_dst=4789,flags(df|csum))), Need to upgrade the python pyroute2 package to >= 0.6. COMMAND: ip netns exec ns_b-gO9WCK ip link add vxlan_b type vxlan id 1 local 10.0.3.1 remote 10.0.1.1 ttl 64 dstport 4789 COMMAND: ip netns exec ns_b-gO9WCK ip addr add 192.168.2.2/24 dev vxlan_b COMMAND: ip netns exec ns_b-gO9WCK ip addr add fd00:2::b/64 dev vxlan_b COMMAND: ip link set vxlan_a up Cannot find device "vxlan_a" COMMAND: ip netns exec ns_b-gO9WCK ip link set vxlan_b up Cannot find device "ovs_br0" COMMAND: ip netns exec ns_c-VCOwRt ping -q -M want -i 0.1 -c 20 -s 4500 192.168.2.2 PING 192.168.2.2 (192.168.2.2) 4500(4528) bytes of data. --- 192.168.2.2 ping statistics --- 20 packets transmitted, 0 received, +20 errors, 100% packet loss, time 12790ms pipe 4 TEST: IPv4, OVS vxlan4: PMTU exceptions [FAIL]
