KVM

vmhypervisoropen source

The Linux kernel's built-in , turning the kernel into a type-1 using CPU virtualization extensions.

KVM is the in-kernel Linux . Using hardware virtualization extensions (Intel VT-x / AMD-V), it lets a userspace , QEMU, Firecracker, Cloud , libkrun, run guest VMs each with their own kernel behind a hardware boundary. KVM provides the CPU/memory virtualization; the provides the device model. It is the foundation of essentially every Linux VM and tool, and the Linux equivalent of macOS's .framework.

Strengths

Hardware-enforced VM boundary, each guest gets its own kernel
In-kernel, mature, and near-native performance
The base for Firecracker, Cloud Hypervisor, QEMU, and libkrun

Limitations

Requires CPU virtualization extensions (bare metal or nested virt)
A primitive, not a tool, needs a VMM on top to be usable
Hypervisor 0-days and side channels remain the residual risk

Taught in

1. Two models: shared kernel vs. own kernel 4. microVMs, and the primitives you already know

Powers

Incus Firecracker Cloud Hypervisor QEMU libkrun Multipass Freestyle

Compare with

Hypervisor.framework Windows Hypervisor Platform QEMU Firecracker

Sources

linux-kvm.org