Scalable I/O Virtualization via Self-Virtualizing Devices

The virtualization of I/O devices is an integral part of system virtualization. This includes both virtualizing the physical devices and managing them across multiple guest virtual machines (VMs) or domains running on top of a virtual machine monitor (VMM) or hypervisor (HV). This paper presents the notion of self-virtualizing devices, where for higher end, `smart' I/O devices, selected virtualization functionality is o#oaded onto the devices themselves. In particular, a self-virtualizing device is aware of being used in a virtualized environment and implements the virtual device abstraction on the device itself. It also presents an interface to the HV to manage these virtual devices. Using this virtual device abstraction, a guest domain can interact with the physical device with minimal HV involvement. The outcomes are reduced I/O virtualization costs caused by the HV (and additional software components required to virtualize the device) and improved scalability for device interactions with guest domains