A zero-copy fast channel for inter-guest and guest-host communication using VirtIO-serial

Virtualization technology, in the computer architecture domain, is characterized by the property of sharing system resources among the virtual machines (VMs) hosted on a physical server. Isolation is also a characteristic property of virtualization, which prevents the guest operating system running on these virtual machines to be aware of each other´s presence on the same host. The isolation property of virtualization is essential for the security of co-resident VMs. However, this becomes a bottleneck, when some of the co-resident VMs need to communicate with each other for accomplishing a common task. A trivial method to communicate would be using a TCP/IP channel. This does accomplish the goal of communication, albeit with unsatisfactory performance, efficiency and security. In view of this, we need a mechanism which maintains the isolation characteristic of virtualization and yet provides a fast, efficient and secure channel for communication. In this paper, we discuss virtIO-serial, a fast channel for communication on KVM, an open source hypervisor based on the Linux kernel.