A user-space virtual device driver framework for Kubernetes

Virtualization and Kubernetes have been widely used now in cloud platform. SRIOV-enabled devices can simulate multiple virtual devices from the hardware layer, each of which can be bound to a Pod from Kubernetes. So multiple Pods can share hardware resources, and resource utilization can be increased greatly. However, the existing drivers of virtual devices are mainly implemented in the Linux kernel space. If the driver fails, it will affect all applications on the host. In this paper, a user-space virtual device driver framework for Kubernetes is proposed. In the framework, only the driver and virtualization of physical device are implemented in kernel space. The IO address of virtual device is mapped into user space through VFIO and the driver of the virtual device is implemented in the Pause container. Other application containers in the same Pod can communicate with drivers in the Pause container through the API interface. Based on the framework, the user only needs to write drivers of virtual devices in the user space, which reduces the difficulty of developing the drivers and improves the reliability of the system. At the same time, because drivers of virtual device run in Pause containers, they can be distributed with applications together, which increases driver’s capability of isolation and distribution.