I love DPDK. Super fun. I've actually made a few projects with it. But this is for creating closed network systems, not for integrating into Linux's networking infrastructure. If somebody would like to produce a WireGuard implementation (library, I guess) for DPDK, I'd be super happy about this, and I'm sure it'd find some specialized users. But for everything else, there's the ordinary design.

It is absolutely possible to create DPDK applications that send/receive data into the Linux network stack using KNI [1]. I'm not sure if I'm qualified to say whether DPDK is “for” something, but the means to achieve this exist.

[1] - http://dpdk.org/doc/guides-16.04/prog_guide/kernel_nic_inter...

Both userspace stacks bypass several standard kernel interfaces to achieve good performance. If you want to integrate with normal kernel configuration (interface, routing, etc) and BSD sockets, then maybe you do need to be in the kernel. (Maybe it's possible to improve user<->kernel interfaces to reach good performance in userspace with standard kernel configuration, but we aren't there yet.)

However it's basically true. You need to be running specific hardware and/or drivers to make use of kernel bypass. You most definitely will never be able to use DPDK on the average laptop.

For a VPN that intends end-user device deployment it's kind of silly to require specific hardware.