On 30/05/2024 14:10, David Marchand wrote: > In a typical setup like: > guest A <-virtio-> OVS A <-vxlan-> OVS B <-virtio-> guest B > > TSO packets from guest A are segmented against the OVS A physical port > mtu adjusted by the vxlan tunnel header size, regardless of guest A > interface mtu. > > As an example, let's say guest A and guest B mtu are set to 1500 bytes. > OVS A and OVS B physical ports mtu are set to 1600 bytes. > Guest A will request TCP segmentation for 1448 bytes segments. > On the other hand, OVS A will request 1498 bytes segments to the HW. > This results in OVS B dropping packets because decapsulated packets > are larger than the vhost-user port (serving guest B) mtu. > > 2024-04-17T14:13:01.239Z|00002|netdev_dpdk(pmd-c03/id:7)|WARN|vhost0: > Too big size 1564 max_packet_len 1518 > > vhost-user ports expose a guest mtu by filling mbuf->tso_segsz. > Use it as a hint. > > This may result in segments (on the wire) slightly shorter than the > optimal size. > > Reported-at: https://github.com/openvswitch/ovs-issues/issues/321 > Signed-off-by: David Marchand <[email protected]>
It seems like it should be tagged as a fix and backported. wdyt? For the changes, Acked-by: Kevin Traynor <[email protected]> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
