# KVM

32 Hacker News commenters recommended KVM and 9 criticized it, November 2025 to November 2026. It was recommended in 12 of 13 months. It meets the Hacker Approved badge rule.

**Verdict:** Free Linux kernel hypervisor that people trust for VMs, including moving Windows guests from VMware. Critics say its attack surface is large and it has had guest-to-host escape bugs.

## Why people recommend it

- Free, open hypervisor (2 comments): "good on KVM and others for pushing open hypervisor technology" ([source](https://news.ycombinator.com/item?id=49608452)) "great and free KVM virtualization" ([source](https://news.ycombinator.com/item?id=49039167))
- Smooth move from VMware (3 comments): "I've done it a few times, moving between VMware and KVM of Windows guests pretty much just worked" ([source](https://news.ycombinator.com/item?id=48599802)) "those that found their store-brand version of KVM to replace VMware are certainly happy" ([source](https://news.ycombinator.com/item?id=47722751)) "at a more convenient level using KVM than full-fledged VMware VMs" ([source](https://news.ycombinator.com/item?id=48503956))
- Strong security record (3 comments): "CVEs for runc are much more frequent than CVEs for KVM." ([source](https://news.ycombinator.com/item?id=49898530)) "Kernel KVM has a very good record for security" ([source](https://news.ycombinator.com/item?id=48818505)) "KVM escapes are very rare" ([source](https://news.ycombinator.com/item?id=48883089))
- Works reliably out of the box (3 comments): "via KVM and it seems to work well" ([source](https://news.ycombinator.com/item?id=46764033)) "you are right, it just works" ([source](https://news.ycombinator.com/item?id=47000675)) "kvm itself feels good too" ([source](https://news.ycombinator.com/item?id=46368815))

## What people warn about

- Large, complex attack surface (3 comments): "shadow MMU is highly complicated legacy code (i.e. outside of the main happy path)" ([source](https://news.ycombinator.com/item?id=49205154)) "the surface area of kvm and qemu is still very large and difficult to reason about" ([source](https://news.ycombinator.com/item?id=49460230)) "KVM has a much larger attack surface than Xen" ([source](https://news.ycombinator.com/item?id=49039429))
- Guest-to-host escape bugs (3 comments): "kvm can be leveraged to gain access to the host by means of exploits" ([source](https://news.ycombinator.com/item?id=49487431)) "it was KVM that turned out to have the worst bugs, not QEMU" ([source](https://news.ycombinator.com/item?id=49454666)) "2 KVM guest->host control ones" ([source](https://news.ycombinator.com/item?id=50033437))
- Not perfect, has had bugs (2 comments): "kvm is also pretty good, but not perfect" ([source](https://news.ycombinator.com/item?id=48178352)) "A kvm hypervisor is not perfect" ([source](https://news.ycombinator.com/item?id=46668717))

## Alternatives hackers recommend

- [Proxmox VE](https://hackerapproved.com/p/proxmox-ve.md): 208 recommend
- [Incus](https://hackerapproved.com/p/incus.md): 90 recommend
- [bhyve hypervisor](https://hackerapproved.com/p/bhyve.md): 17 recommend
- [Sylve](https://hackerapproved.com/p/sylve.md): 17 recommend
- [Xen hypervisor](https://hackerapproved.com/p/xen.md): 12 recommend

## Cite as

Hacker Approved, "KVM", https://hackerapproved.com/p/kvm/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).