This is usually the problem, almost every single option I've seen is based on dedicated hardware. This is fine for many, but not for those of us running in cloud hosts and other general-purpose locations.
You can't possibly have a de-layered system on virtualised cloud hardware!
Besides, dedicated hosting for a 1U or 2U rack machine is not expensive. If you have enough traffic that it's worth building your own TCP solution, you already have enough servers that you're spending a considerable amount of money on.
Sure you can: as a random example, AWS supports SR-IOV today: you can directly communicate with a NIC from a userland linux process if you set everything up right.
The general idea is to have hardware with direct virtualization support (which is increasingly available on commodity hardware), then have a 'control plane' of layered, virtualized syscall APIs that configure a 'data plane' of virtualization-aware hardware. Permitted I/O operations occur just as if they were on bare metal, with asymptotically zero performance overhead, because you can process an arbitrary amount of data without invoking any code at the OS/hypervisor/cloud provider layer.
For example, my rented, virtualization-aware CPU allows me to run any non-privileged code that stays within a certain block of address space; my rented, virtualization-aware NIC allows me to send and receive any ethernet frames that match certain header bits; and my rented, virtualization-aware disk allows me to read and write to a certain range of LBAs. The nth-layer OS or cloud host or whatever can come in and alter these permissions at will but it need not examine every single syscall to see if it conforms to policy.
I'm aware of that, but if we could reduce dedicated hosting to a single machine through simpler code, we can feed the information from there into a cloud system. It helps a lot if the machine can be a general purpose one, since that reduces hosting costs, maintenance overhead and risk.
Definitely -- +1 to general purpose machine and doing this on normal hardware without special NIC's. However, as soon as you dump the OS, the machine would no longer be suitable as a shared tenancy/cloud host. It might be useful for some sort of dedicated service offering (that would be a cool AWS feature and allow things like Vyatta that're tied right into the kernel and SDN), but not for general purpose cloud hosting. The hypervisor/container/OS are still needed to enforce roles, manage resources, etc.
I agree, though as bcoates indicated, cloud hosts are adapting to this demand. While bare-metal access is indeed very unlikely to happen in a shared tenancy environment, there will be at least some efforts towards lower-level access.
Snabb switch has been working on zero copy drivers for kvm, for openstack. But you are unlikely to see that on generic cloud vms soon. If you want performance you need control of hardware.
