KVM vs QEMU: key differences and how they work together

KVM (Kernel-based Virtual Machine) and QEMU are two integral components of Linux virtualisation, with KVM acting as a kernel module providing hardware-accelerated CPU virtualisation, and QEMU functioning as a user-space emulator handling device emulation and management. While they are often misconceived as alternatives, they are typically used in tandem to deliver near-native performance and comprehensive hardware support for virtual machines, forming the backbone of many modern virtualisation solutions. Technologies like Firecracker and Kata Containers build on this foundation to offer microVM isolation with varying degrees of device emulation and startup speeds, catering to different use cases such as serverless functions and AI sandboxes. Northflank leverages these technologies to provide production-ready microVM isolation without the complexity of managing the virtualisation stack, facilitating quick and efficient workload deployment.