lima-vm/lima · error

nested virtualization is not supported on %T

Error message

nested virtualization is not supported on %T

What it means

After confirming OS and hardware support, the driver type-asserts the VZ platform configuration to *vz.GenericPlatformConfiguration, the only configuration type that supports SetNestedVirtualizationEnabled. If the platformConfig built earlier is a different VZ configuration type (e.g. a macOS-specific platform config), the assertion fails and this error reports the actual Go type.

Source

Thrown at pkg/driver/vz/vm_darwin.go:364

	// nested virt
	if *inst.Config.NestedVirtualization {
		macOSProductVersion, err := osutil.ProductVersion()
		if err != nil {
			return fmt.Errorf("failed to get macOS product version: %w", err)
		}

		if macOSProductVersion.LessThan(*semver.New("15.0.0")) {
			return errors.New("nested virtualization requires macOS 15 or newer")
		}

		if !vz.IsNestedVirtualizationSupported() {
			return errors.New("nested virtualization is not supported on this device")
		}

		genericPlatformConfig, ok := platformConfig.(*vz.GenericPlatformConfiguration)
		if !ok {
			return fmt.Errorf("nested virtualization is not supported on %T", platformConfig)
		}

		if err := genericPlatformConfig.SetNestedVirtualizationEnabled(true); err != nil {
			return fmt.Errorf("cannot enable nested virtualization: %w", err)
		}
	}

	vmConfig.SetPlatformVirtualMachineConfiguration(platformConfig)
	return nil
}

func attachSerialPort(inst *limatype.Instance, config *vz.VirtualMachineConfiguration) error {
	path := filepath.Join(inst.Dir, filenames.SerialVirtioLog)
	serialPortAttachment, err := vz.NewFileSerialPortAttachment(path, false)
	if err != nil {
		return err
	}
	consoleConfig, err := vz.NewVirtioConsoleDeviceSerialPortConfiguration(serialPortAttachment)

View on GitHub (pinned to dd909d0973)

Solutions

1. Enable nested virtualization only for standard Linux guests (generic platform configuration).
2. Don't combine nestedVirtualization: true with the macOS-installer VM flow.
3. Check the %T in the message to see which platform config was built and adjust the instance config accordingly.
4. If you need nested VMs inside macOS guests, that's not supported — use a Linux guest.

// ensure the workload targets a Linux guest, not the macOS installer flow
# only standard Linux instances use the generic platform config

// Go: narrow the platform config type before enabling
generic, ok := platformConfig.(*vz.GenericPlatformConfiguration)
if !ok {
    return fmt.Errorf("nested virtualization is not supported on %T", platformConfig)
}
_ = generic

// Go: match on the concrete type before SetNestedVirtualizationEnabled
switch pc := platformConfig.(type) {
case *vz.GenericPlatformConfiguration:
    _ = pc.SetNestedVirtualizationEnabled(true)
default:
    // skip nested virt for non-generic configs
}

When it happens

Trigger: Enabling nestedVirtualization: true while the VM was configured with a non-generic platform configuration — notably when creating a VM via createVMForMacInstaller that uses a macOS platform configuration instead of the generic Linux one.

Common situations: Attempting nested virtualization on a macOS guest installer VM; future/alternative VZ platform configs where nested virt is not implemented in Lima.

Related errors

• failed to get macOS product version: %w
• nested virtualization requires macOS 15 or newer
• nested virtualization is not supported on this device
• cannot enable nested virtualization: %w
• nested virtualization requires macOS 15 or newer

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/5de55cfe89832ad4. Report an issue: GitHub.