Paravirtualizing TCP

Abstract

Virtualization has proven consolidation and isolation benefits, but invariably incurs an overhead. This overhead especially penalizes latency sensitive tasks such as tcp processing, because such processing only occurs when a guest is scheduled. We evaluate a system where tcp is paravirtualized. All guest tcp processing below the socket interface takes place in the hypervisor, which enables rapid response to protocol state changes. We have built Leulo, a prototype hypervisor, and a modified Linux guest kernel that outperforms the Kernel Virtual Machine (KVM) and approaches native performance for certain workloads in an http bench-mark.