Hi Xuan, Thank you for the response and encouragement. I'll proceed with the single-buffer AF_XDP zero-copy TX checksum offload work and share an RFC patch for review once the initial implementation and tests are ready.
Thanks, Azadeh > On Oct 7, 2026, at 8:35 PM, Xuan Zhuo <[email protected]> wrote: > > On Mon, 5 Oct 2026 17:28:35 -0500, Azadeh Aftahi <[email protected]> wrote: >> 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? > > It seems no one has taken this work forward yet; I would welcome it if you > were > to do so. > > Thanks. > > >> >> Thanks, >> Azadeh
