A smart HPC interconnect for clusters of virtual machines

In this paper, we present the design of a VM-aware, high-performance cluster interconnect architecture over 10Gbps Ethernet. Our framework provides a direct data path to the NIC for applications that run on VMs, leaving non-critical paths (such as control) to be handled by intermediate virtualization layers. As a result, we are able to multiplex and prioritize network access per VM. We evaluate our design via a prototype implementation that integrates RDMA semantics into the privileged guest of the Xen virtualization platform. Our framework allows VMs to communicate with the network using a simple user-level RDMA protocol. Preliminary results show that our prototype achieves 681MiB/sec over generic 10GbE hardware and relieves the guest from CPU overheads, while limiting the guest's CPU utilisation to 34%.