VirtNet Progress Report

network stack virtualization for FreeBSD

In the previous months, a prototype kernel-level virtualization framework for FreeBSD-CURRENT was developed, allowing the previously global kernel state to be instantiated and operated on in multiple independent copies. This prototype is a reasonably stable and functional; it demonstrates the abilities of a sligtly modernized virtualization methodology and framework.

The prototype was recently tested in a possible Internet router-like setup, where it was subjected to a full-view live BGP feed with forced peering flapping. The virtualized kernel endured this challenge for several days, with no observable issues.

A systematic performance evaluation of the new prototype has yet to be performed, however, a few preliminary tests --such as for loopback TCP throughput-- show that the virtualization overhead is not measurable; both the standard and the virtualized network stack yield exactly the same throughput levels.

Further progress was made in the PF firewall and NFS virtualization, as well as in improved housekeeping of virtual network stack instances. The protoype is kept in sync with the developments in FreeBSD-CURRENT, giving the ability of using the virtualized kernel as a snap-in replacement for the stock kernel, without any modifications to userspace libraries or tools. This sould attract a broader test audience.