> Fiona reports broken connectivity for virtio net setup using UDP tunnel
> inside the guest and NIC with not UDP tunnel TSO support in the host.
>
> Currently the virtio_net driver exposes csum offload for UDP-tunneled,
> TCP non GSO packets. Such packet reach the host as CSUM_PARTIAL ones
> with the 'encapsulation' flag cleared, as the virtio specification do
> not support this specific kind of offload.
>
> HW NICs with UDP tunnel TSO support - and those drivers directly
> accessing skb->csum_start/csum_offset - are still capable of computing
> the needed csum correctly, but otherwise the packets reach the wire with
> bad csum on both the inner and outer transport header.
>
> Address the issue explicitly disabling csum offload for UDP tunneled,
> non GSO packets via the ndo_features_check op.
>
> Fixes: 56a06bd40fab ("virtio_net: enable gso over UDP tunnel support.")
> Reported-by: Fiona Ebner <[email protected]>
> Closes: https://bugzilla.proxmox.com/show_bug.cgi?id=7627
> Tested-by: Fiona Ebner <[email protected]>
> Tested-by: Gabriel Goller <[email protected]>
> Acked-by: Michael S. Tsirkin <[email protected]>
> Signed-off-by: Paolo Abeni <[email protected]>
Tested it on our testbench, consider:
Reviewed-by: Gabriel Goller <[email protected]>
Tested-by: Gabriel Goller <[email protected]>
--
Gabriel Goller <[email protected]>
