High performance and scalable I/O virtualization via self-virtualized devices

TLDR

While industry rapidly advances system virtualization for server consolidation and maintenance, it remains unclear how virtualization can enhance the performance of high‑end systems. This paper investigates how to efficiently virtualize I/O subsystems and peripheral devices. The authors introduce self‑virtualized devices, exemplified by a self‑virtualized network interface (SV‑NIC) that offloads virtualization functions to the device, provides virtual interfaces, manages resource allocation, and delivers high‑performance, low‑overhead network access, as demonstrated on an IXP 2400‑based prototype. The SV‑NIC scales to many virtual interfaces and guests, enabling guests to interact with the device with less overhead and reduced latency, achieving 77 % higher throughput and 53 % lower latency than conventional hypervisor‑based virtualized devices.

Abstract

While industry is making rapid advances in system virtualization, for server consolidation and for improving system maintenance and management, it has not yet become clear how virtualization can contribute to the performance of high end systems. In this context, this paper addresses a key issue in system virtualization - how to efficiently virtualize I/O subsystems and peripheral devices. We have developed a novel approach to I/O virtualization, termed self-virtualized devices, which improves I/O performance by off loading select virtualization functionality onto the device. This permits guest virtual machines to more efficiently (i.e., with less overhead and reduced latency) interact with the virtualized device. The concrete instance of such a device developed and evaluated in this paper is a self-virtualized network interface (SV-NIC), targeting the high end NICs used in thehigh performance domain. The SV-NIC (1) provides virtual interfaces (VIFs) to guest virtual machines for an underlying physical device, the network interface, (2) manages the wayin which the device's physical resources are used by guest operating systems, and (3) provides high performance, low overhead network access to guest domains. Experimental results are attained in a prototyping environment using an IXP 2400-based ethernet board as a programmable network device. The SV-NIC scales to large numbers of VIFs and guests, and offers VIFs with 77% higher throughput and 53% less latency compared to the current standard virtualized device implementations on hyper visor-based platforms.