1. A computing system comprising: a first physical computing device comprising one or more processors and memory, wherein the one or more processors are configured to execute instructions that, upon execution, configure the physical computing device to host a first plurality of virtual machine instances; a second physical computing device comprising one or more processors and memory, wherein the one or more processors are configured to execute instructions that, upon execution, configure the physical computing device to host a second plurality of virtual machine instances; an offload device, wherein the offload device is in communication with the first physical computing device and the second physical computing device via an interconnect interface, the offload device comprising one or more processors and memory, wherein the one or more processors are configured to execute instructions that, upon execution, configure the offload device to: instantiate a first virtual offload device configured to host a first plurality of virtual input/output (I/O) components associated with the first plurality of virtual machine instances on the first physical computing device, wherein the first plurality of virtual I/O components are configured to perform I/O functions on behalf of the first plurality of virtual machine instances; and instantiate a second virtual offload device configured to host a second plurality of virtual I/O components associated with the second plurality of virtual machine instances on the second physical computing device, wherein the second plurality of virtual I/O components are configured to perform I/O functions on behalf of the second plurality of virtual machine instances.