[dundarious]

If I'm understanding ublk and your question correctly, then yes, there are a lot of kernel-bypass networking options out there, such as openonload, dpdk, mellanox (though they seem to have been absorbed into nvidia). You'll likely need a special/particular network card, an external kernel module, and at least an LD_PRELOAD to use them though.

[bullen]

Is there no way to avoid kernel copying all network data?

I understand the frustration of having the network driver crash but could it not be run in a way that it doesn't bring down the OS?

It seems to me Java would have a no-brainer advantage of a user-space networking option since you're already in a VM!?

When I saturate my HTTP server the kernel takes 30% of the CPU just copying data for no good reason?!

[wmf]

It's happening. https://lwn.net/Articles/879724/

[dundarious]

Yes, and also just to note, zero-copy and kernel-bypass are independent. Traditional Berkeley socket syscalls are copy+kernel, io_uring has/will have zerocopy+kernel, openonload provides both APIs for copy+kernelbypass and zerocopy+kernelbypass.