On macOS 11.0 our privileged virtual machine monitor was replaced by a new monitor that runs at user level and uses the Apple hypervisor framework as the virtualization engine. This required some changes to our support for nested virtualization. These changes include:
- On Fusion 12.0 nested virtualization is not supported on CPUs that do not support a feature of Intel CPUs called VMCS shadowing.
- Starting with Fusion 12.1.0 VMCS shadowing is no longer required to use nested virtualization on macOS 11.0 however performance of nested virtualization without VMCS shadowing may be degraded.
- ESX, VMware Fusion and VMware Workstation can be run as guest hypervisors although performance may be degraded when side channel mitigations are enabled.
- Windows guests with virtualization-based security, also known as “VBS”, enabled are not supported at this time due to lack of support for an Intel feature referred to as mode-based execution control (MBE). We are currently working with Apple to add support for MBE. Windows guests with VBS enabled can be used if hypervisor-protected code integrity (HVCI) is disabled.
- Some rarely used features of nested virtualization that were supported on previous versions of Fusion such as page modification logging (PML) and virtualization exceptions (#VE) are not supported when running on macOS 11.0.