Is virtualizing aarch64 macos via qemu on aarch64 Linux within the realm of possibility? I know it can be done for x86-64, but would be pretty cool if an aarch64 kvm hackintosh would be possible. I have an Nvidia Jetson AGX and honeycomb lx2 which in theory could be up to the task.
There are additional instructions only available on Apple chips beyond the aarch64 standard, so I don't think that this could be done in hardware (someone correct me if I'm wrong because this isn't my area)
Of course it's possible in software in principle but obviously that would be awful.
Apple has their own custom conventions and ABI (https://developer.apple.com/documentation/xcode/writing-arm6...). I believe you are right that they have their own custom instructions too. The asahi Linux project has good documentation on their wiki about the hardware.
Also important here is the bespoke ASIC functionality on their CPUs - as it's a system on chip, you'll likely need to emulate the full SoC, including all the peripherals the system expects to be there. Unlike x86_64, ARM isn't really designed to do device discovery on extensible buses in the same way. Your peripherals should all be in the same place, many being on the chip on internal interconnects.
Emulating anything would be possible with enough effort. But you'd likely need to emulate a whole host of extra bespoke silicon functionality on the SoC to get it working. For example, given every ARM Mac has a hardware neural engine, you might find unmodified Mac OS assumes it's there and usable for core functionality (or does so in future). It would probably be a lot of work to emulate all of the extra SoC stuff to the point you could boot the OS unmodified. But nothing is impossible - I think iOS has been run in third party emulators etc.
ABI, which calling conventions are one part of, only affects how different pieces of code within the operating system talk to each other. It’s not uncommon to customize it - for instance, Windows does too. [1] Having a custom ABI does not present any obstacle to emulation.
Yeah, agreed. I think of every ARM SoC as more like its entire own architecture, for OS compat purposes. A Raspberry Pi SoC will require an entirely different level of compatibility to an M1 Mac, or a Snapdragon based Chromebook.
I think we've been somewhat spoilt by x86 and how easy loads of different machines will boot the same OS image. It's really really different in ARM land.
To ease execution of x86₆₄ applications on Apple Silicon the Apple processor team implemented the x86 memory model with a series of additional experiences.
macOS VMs eschew most apple extensions anyway (no AMX there for example).
The big roadblock that we've hit is that arm64 macOS has no software rasteriser for rendering the GUI. The result is that unless you implement Metal and the paravirtualised GPU infrastructure, you're stuck in console mode.
> The big roadblock that we've hit is that arm64 macOS has no software rasteriser for rendering the GUI. The result is that unless you implement Metal and the paravirtualised GPU infrastructure, you're stuck in console mode.
And this has been just as much of an issue for virtualizing x86 macOS… although it does have a software rasterizer, it's almost unusably slow. The only way you're going to get decent performance with that is with passthrough of a GPU that macOS has drivers for (which for modern GPUs, means some Radeon 500 series, Radeon 5000/6000 series, or Intel iGPU up through Coffee Lake).
Since the early 2000s, real Macs have practically never been configured in such a way that there's no usable GPU, and so the software rasterizer never got any attention since it's an absolute-last-resort fallback. With ARM Macs, all models have some form of usable GPU available (presumably, even the forthcoming M-series cheesegrater tower will have a few GPU cores in its SoC) and they don't care to support virtualization on anything but macOS so they dropped the rasterizer entirely.
Why I’d really like to see is a lightweight vm using the virtualization.framework to run 32 bit pre-catalina apps on current macOS. (On intel machines)
Docker desktop for macOS requires a linux vm on the macOS host, so nested virtualization is required if you want to use docker desktop inside the macOS guest.
Other Tools like multipass kind and minikube on the guest will not work
Parallels run a similar thin wrapper on top of the OS-provided VM API which looks somewhat like: vm = createVM([device list]); vmWindow = createVMWindow(vm); vm.run();
Those are well known limitations of Apple virtualized OSes. The threshold for solving those issues involves using a different virtualization framework and a lot of reverse engineering.
Yes, I use macOS as development VM on a maxed out 16 inch M1 MacBook Pro. It all works as expected, except you don’t have any VM settings (e.g. how much ram / cpu you want to give the VM) and Docker doesn’t run inside the VM.
I’ve been using it on Monterey. It’s not nearly as optimized as virtualized Windows or Linux on the same hardware (most Parallels features like auto-scaling not available yet), but I think the situation should improve with Ventura.
Oddly enough, I was a ThreadRipper early adopter and for me macOS was more stable than everything else. I dual booted macOS and Slackware current on it from 2017 until early this year. That machine is retired now.
It's a bit peculiar but yeah, if you find a hardware combination that macOS "likes", it can be surprisingly solid. Back in the early 2010s I had one laptop that no version of Windows or Linux distribution particularly liked, but ran great with hackintoshed 10.6-10.9.
The only way to make it usable in other operating systems was to disable GPU power management under Windows, which turned it into an oven, or to run Nouveau drivers under Linux which had serious performance problems, graphical artifacting, etc. The Nvidia drivers bundled with macOS had no such problems, running it at full performance with proper power management and no lockups.
Yeah, I increasingly believe every OS is picky. People are just accustomed to a lot of things never working quite right, to the extent that they sometimes don't even notice.
UTM should support most of the same features (aside from ease of us for installing all macOS versions). It also now supports paravirtualisation using the hypervisor framework.
Comparing the code between the two, VirtualBuddy seems like the better option to me (albeit not by a lot though). They are both lightweight wrappers around MacOS’s built in hypervisor, so I’m really not sure what you’re going on.
Look at the code for the one he’s suggesting. It’s the same essentially. One is just more upfront about giving its visitors a clear understanding. Taken out of context I can maybe see what you mean, but like come on, it’s not an effort to keep up is it?
