PSA: M4-based Macs can't run VMs with older versions of macOS

Apple recently released new MacBook Pro, iMac, and Mac mini with the M4 chip, which provides a significant performance boost, especially when it comes to AI tasks. However, users are encountering problems when trying to run virtual machines with some older versions of macOS on the new machines.

M4 Macs and Virtual Machines

As noted by researcher Csaba Fitzl (via Eclectic Light Company), it appears that recent Macs with the M4 chip cannot run virtual machines with versions of macOS prior to Ventura 13.4. The issue affects any virtualization software available for Mac.

According to the website, trying to run a virtual machine on an M4 Mac running macOS 13.3 or earlier results in a black screen where the virtual machine fails to boot. Many users have tried changing settings in the virtualizer or even booting the virtual machine in recovery mode, but the result is the same. Everything works fine on Macs with M1, M2, or M3 chips.

The bad news is that no one has a clear idea of what exactly is causing the error or incompatibility.

Unfortunately, since this error prevents the VM from booting, there is no reliable way to access its log to figure out what is wrong. The host log also shows no sign of a crash: the host appears to initialize its Virtio and other support normally, with no errors or crashes. After that, the host virtualization processes go silent, waiting for the VM to start, which never happens.

According to the researcher, the bug most likely affects an early part of the kernel boot, which would require Apple to release new IPSW files for older versions of macOS to work with M4 Macs. However, this is unlikely.

Anyone running VMs running versions of macOS earlier than 13.4 should be aware of this before upgrading to a new M4 Mac. Apple has not yet acknowledged the issue. As for other Apple Silicon-based Macs, they can run virtual machines with macOS 12 Monterey or later (the minimum recommended version for these Macs is 12.4).

In that regard, it’s worth noting that macOS Sequoia adds several improvements to virtual machines, including full support for signing in to iCloud accounts, which was previously not possible in Mac virtual machines.