Hi all, I'm planning to work on single-buffer AF_XDP zero-copy TX checksum offload for virtio-net.
Current net-next's virtnet_xsk_xmit_one() does not consume XSK TX checksum metadata and uses the shared zeroed virtio header. I found Xuan's 2021 proposal anticipating separate headers for checksum support, and the merged 2024 zero-copy TX series, but I couldn't find a checksum-specific follow-up implementation. The proposed scope is to map the existing XSK checksum metadata API to VIRTIO_NET_F_CSUM, using a DMA-safe per-packet virtio header whose lifetime extends until TX completion, with corresponding completion, reset, and unbind cleanup. I would keep the initial scope limited to single-buffer TX: no multi-buffer RX, timestamps, launch time, or GSO. I'd also add checksum and header-lifetime coverage using the existing XSK selftest framework with QEMU/TAP. Is anyone already working on this? If not, does this scope and per-packet-header approach sound reasonable for a follow-up patch? Thanks, Azadeh
