PSA: M4 Macs can’t run virtual machines with older versions of macOS

2 days ago 4

macOS Ventura Rapid Security Response Mac Apple Silicon Mac

Apple recently launched new MacBook Pro, iMac and Mac mini with the M4 chip, which brings a lot of performance improvements – especially when it comes to AI tasks. However, users are facing issues 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 seems that the latest Macs with the M4 chip are unable to run virtual machines with macOS versions prior to Ventura 13.4. The problem affects any virtualization software available for the Mac.

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

The bad news is, no one has a concrete clue as to what exactly is causing the bug or incompatibility.

Unfortunately, as this bug prevents the VM from booting, there’s no reliable way to access its log to discover what’s going wrong there. There’s no sign of the failure in the host’s log either: the host appears to initialise its Virtio and other support normally, without errors or faults. After those, virtualisation processes on the host fall silent as they wait for the VM to start, which never happens.

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

Anyone working with VMs running macOS versions earlier than 13.4 must be aware before upgrading to a new M4 Mac. Apple has yet to acknowledge the issue. As for other Apple Silicon Macs, they can run VMs with macOS 12 Monterey or later (the minimum recommended version for these Macs is 12.4).

On a related note, macOS Sequoia has added multiple enhancements for virtual machines, including full support for logging into iCloud accounts, which wasn’t possible on Mac VMs before.