virtualbox-kvm VS OSX-KVM

This is true. If someone says "I just want something that works, and Virtualbox works" it doesn't really raise any eyebrows. It's really the tone of "I am unable to make QEMU/KVM work, since I am not a rocket scientist" that implies, maybe they would use QEMU, if only it wasn't horrifically difficult to get working. I think if your experience with QEMU is this bad, you may have just gotten a bit unlucky and gotten off into the weeds on a detour you probably did not need.

That said, are there reasons why someone who just wants things to work and doesn't want to tinker ever would choose QEMU over Virtualbox? Definitely. Here's a good one: the Virtualbox kernel modules were notoriously problematic. Back in the day, loading the vboxdrv module would add TAINT_CRAP in your running kernel[1], because the kernel developers were tired of dealing with bug reports that are the fault of the vboxdrv. Presumably it's better nowadays, but out-of-tree modules are generally a source of headache. Another good one is features: Virtualbox has a lot of great features for desktop end users, but QEMU can do a whole lot more; it supports absolutely tons of architectures and system options. You get access to a wide range of paravirtualization devices through Virtio drivers, including VirtioFS, a dramatically superior solution for mounting directories into VMs versus Virtualbox's Shared Folders feature, in my opinion. It's also possible to do a lot more advanced things, like setting up a discrete GPU passthrough and Looking Glass, or passing a portion of your Intel iGPU using GVT-g.[2]

Of course, some day Virtualbox may support a KVM backend, just as virtualization tools are starting to support unified hypervisor backends on Windows and macOS. There's even an existing patch, though I do not know what the status is and whether or not it could ever be merged upstream.[3] So maybe in the future, choosing between Virtualbox or KVM will become unnecessary.

For now though, it's definitely not clear what you should recommend to someone IMO. (For this particular use case, I don't even recommend a VM at all; I think for Windows 95, 86Box is a better solution.)

[1]: https://lkml.org/lkml/2011/10/6/317

[2]: https://wiki.archlinux.org/title/Intel_GVT-g

[3]: https://github.com/cyberus-technology/virtualbox-kvm, https://news.ycombinator.com/item?id=39300317

It was here: https://github.com/cyberus-technology/virtualbox-kvm/blob/de...

Check out our latest blog post, "VirtualBox KVM Technical Deep-Dive," where we unveil the inner workings of our newly released VirtualBox KVM variant on GitHub. Explore the replacement of the original VirtualBox kernel module with a KVM hypervisor backend for Linux.

Dive into the technical details and discover how we optimized performance, especially for Windows guests: https://cyberus-technology.de/articles/vbox-kvm-deep-dive?ut...

We also pushed our latest state to github where we enabled more paravirtualization enlightenments for Hyper-V. These enlightenments improve VM performance for Windows 10 and Windows 11 guests.

https://github.com/cyberus-technology/virtualbox-kvm/

Starting with VirtualBox 7, USB3 no longer requires the commercial extension pack. See https://github.com/cyberus-technology/virtualbox-kvm/blob/de...

Yes, I recently had to compile some stuff on Windows (I'm on an AMD Linux host) and VirtualBox just wouldn't start Microsoft's Windows dev VM (the one they provide for free for Virtualbox). I ended up learning how to use qemu and it works great...and as a bonus I was able to run a hackintosh (via https://github.com/kholia/OSX-KVM) and it works near flawlessly, which was something I was never able to accomplish with Virtualbox (granted I haven't tried in a few years).

I'm pretty happy with Qemu now, even if it's jsut a CLI interface. I was tempted to try the virt-* stuff, but honestly it seems like one more thing to learn so I'm going to hold off until I need something like copy/paste between VMs and can't figure it out in qemu direct.

Working on a patch to include it as a flake input instead of vendoring it in the repo, so this should no longer be true. I use the QCOW2s for OpenCore from osx-kvm that I have not figured out how to reproduce yet https://github.com/kholia/OSX-KVM/blob/master/OpenCore/OpenCore.qcow2

For almost a year, I have been coding a little project in Python intended to piggyback on the framework of kholia's OSX-KVM project, known as ultimate-macOS-KVM, or ULTMOS.

I just researched a bit, mac os x guest vm with pcie passthrough seems possible on linux.

Dropping the links below:

https://github.com/kholia/OSX-KVM

https://github.com/yoonsikp/macOS-KVM-PCI-Passthrough

VirGL is definitely an interesting project, but all one has to do to get GPU passthrough working (from a Linux QEMU host to any guest OS) is: 1.) research a cheap, secondary GPU that is natively supported by the guest OS, 2.) plug such a secondary GPU into a PCIe slot on the host and hook it up to the primary monitor with a secondary cable (D-Sub vs. DVI, etc.), 3.) setup Linux to ignore the secondary GPU at boot and configure a QEMU VM for the GPU passthrough. The whole process takes perhaps one or two hours and as works flawlessly, with no stability issues. (Switching across the two GPU cables can be accomplished in software by using Display Data Channel /DDC/ utilities and switching keyboard/mouse can be accomplished by using evdev /event device/ passthrough.) More information: https://github.com/kholia/OSX-KVM/blob/master/notes.md#gpu-p...

I get "verification failed" error when using https://github.com/kholia/OSX-KVM

I also see there is KVM-OSX which looks to be actively maintained, but I haven't heard anything about it.

You can use qemu/libvirt/kvm on any Linux host to run macOS pretty easily these days[1]. I run Ventura on unraid with nvidea gpu passthrough and it’s been fairly painless.

You can also run macOS in docker, but it’s ultimately running through qemu/kvm as well[2]

1. https://github.com/kholia/OSX-KVM

2. https://github.com/sickcodes/Docker-OSX

I think this could be of some use to you https://github.com/kholia/OSX-KVM

i cloned that repository