There are already NICs that have this feature. XDP can run in one of three modes. The firsts mode simply runs the program in the kernel stack and is either for

There are already NICs that have this feature. XDP can run in one of three modes. The firsts mode simply runs the program in the kernel stack and is either for testing or used in the worst case where you have no driver support. The primary mode is for the driver author to write in the invocation of the eBPF program and then implement all the resulting actions into the driver. The third mode is offload, where the eBPF program is loaded into a Smart NIC, FPGA device and the packet is processed without the need for DMA. By far, the most popular form is running in the driver, which can get very close to line rate for most network cards. If you have any questions about this I'd be happy to go into more detail.