I wonder if the trick might be to repurpose technology from server hardware: partition the physical NIC into virtual PCI-e devices with distinct addresses, and map to user-space processes instead of virtual machines.
So in essence, each browser tab or even each listening UDP socket could have a distinct IPv6 address dedicated to it, with packets delivered into a ring buffer in user-mode. This is so similar to what goes on with hypervisors now that existing hardware designs might even be able to handle it already.
So in essence, each browser tab or even each listening UDP socket could have a distinct IPv6 address dedicated to it, with packets delivered into a ring buffer in user-mode. This is so similar to what goes on with hypervisors now that existing hardware designs might even be able to handle it already.
Just an idle thought...