Officially, Apple's EULA prohibits macOS virtualization on non-Apple hardware (Section 2.B of macOS license). However, from a technical perspective, running Mac OS X Server (now macOS Server) in XEN domU is possible with specific configurations, though with notable limitations.

For a Debian XEN host, you'll need:

# Install required packages
sudo apt-get install xen-system-amd64 bridge-utils

# Verify XEN installation
xl info | grep xen_version

# Configure GRUB for XEN
GRUB_CMDLINE_XEN="dom0_mem=4096M dom0_max_vcpus=2"

Since XEN lacks native macOS support, we must use HVM (Hardware Virtual Machine) mode with specific tweaks:

# Sample XEN config file (macosx.cfg)
builder = "hvm"
name = "macosx"
memory = 4096
vcpus = 2
disk = ['phy:/dev/vg0/macosx,hda,w']
vif = ['bridge=xenbr0']
acpi = 1
apic = 1
pae = 1
viridian = 1
usb=1
usbdevice='tablet'

macOS Server edition has better virtualization compatibility due to:

• Reduced graphics dependencies
• Headless operation capability
• Better BSD subsystem integration

Expect approximately 60-75% of native performance with these optimizations:

# Add to your XEN config for better performance
device_model_override = "/usr/lib/xen-4.11/bin/qemu-system-x86_64"
device_model_version = "qemu-xen"
extra = "usbcore.nousb=true"

For more reliable results, consider nested virtualization:

1. Run KVM inside XEN
2. Use QEMU with custom patches
3. Consider macOS-specific virtualization solutions like Veertu

This technical guide is for educational purposes only. Running macOS on non-Apple hardware violates Apple's EULA. For production use, consider:

• Apple's official virtualization solution (Apple Silicon only)
• Dockerized macOS services where legally permitted
• Cloud-based macOS instances from authorized providers

First and foremost, Apple's EULA prohibits macOS installation on non-Apple hardware except for specific cases with macOS Server. While technically possible through virtualization, this raises important legal considerations for production environments.

XEN traditionally supports HVM (Hardware Virtual Machine) guests better than PV (Para-Virtualization) for macOS. The main challenges include:

• Lack of official Apple-supplied virtio drivers
• Limited ACPI support in macOS for virtual environments
• Graphics acceleration limitations

Here's a sample XEN configuration file (macosx.cfg) for a macOS guest:

builder = "hvm"
name = "macosx"
memory = 4096
vcpus = 2
disk = ['phy:/dev/vg0/macosx,hda,w']
vif = ['bridge=xenbr0']
acpi = 1
apic = 1
device_model_version = "qemu-xen-traditional"
vnc = 1
vnclisten = "0.0.0.0"
vncdisplay = 1
stdvga = 0
usb = 1
usbdevice = "tablet"

For macOS Server installation on XEN:

1. Create a raw disk image: dd if=/dev/zero of=macosx.img bs=1M count=40960
2. Configure XEN with the above settings
3. Boot from installation media using CD-ROM passthrough
4. Use Disk Utility to format the virtual disk as HFS+

After successful installation, consider these optimizations:

# Enable nested page tables for better memory performance
xl set-parameter macosx hap 1

# CPU pinning for better performance
xl vcpu-pin macosx 0 2
xl vcpu-pin macosx 1 3

If you encounter boot failures, try these kernel boot arguments in your XEN config:

extra = "debug=0x144 -v"