QEMU 10.1.0

QEMU is truly excellent software, from the perspective of a person who very rarely needs to emulate another architecture. It "just works" and has wonderful integrations with basically everything I could want.. sometimes it feels like magic: even if the commandline UX is a bit weird in places.

I've always wondered though how it works with KVM: I know KVM is a virtualisation accelerator that enables passing through native code to the CPU somehow; but it feels like QEMU/KVM basically runs the internet now. Almost the entire modern cloud is built on QEMU and KVM as a hypervisor (right?) but I feel like I'm missing a lot about how it's working.

I also wonder if this steals huge amounts of resources away from emulation, or does it end up helping out. Because to say the modern internet is largely running on QEMU is likely a massive understatement.

Not everything uses qemu. Some do. More use KVM. Not everything does.

Example: https://firecracker-microvm.github.io/

I've found QEMUs microvm to be faster at boot while having nicer tooling and a cleaner upgrade path if needing more features. Aside from hype I'm actually not sure why anyone would still use firecracker.