On Sat, 16 Jan 2021 10:59:26 +0800 Xuan Zhuo wrote:

+	idx = sq->xsk.hdr_con % sq->xsk.hdr_n;

The arguments here are 64 bit, this code will not build on 32 bit
machines:

ERROR: modpost: "__umoddi3" [drivers/net/virtio_net.ko] undefined!

There's also a sparse warning in this patch:

drivers/net/virtio_net.c:2704:16: warning: incorrect type in assignment (different address spaces)
drivers/net/virtio_net.c:2704:16:    expected struct virtnet_xsk_hdr *xskhdr
drivers/net/virtio_net.c:2704:16:    got struct virtnet_xsk_hdr [noderef] __rcu *