I’ve now created a new tutorial that uses OpenCore instead of Clover, and it fixes a lot of problems. I recommend using the new tutorial for all new builds

This tutorial for installing macOS Catalina has been adapted for Proxmox 6 from Kholia’s GitHub project for installing into vanilla KVM. There is more documentation there which will help out with enabling extra features and diagnosing problems!

If you run into trouble, also check out the comment section of my previous tutorial on Mojave – these two versions are very similar so the problems and solutions are likely to be the same.

Requirements

I’ll assume you already have Proxmox 6 installed. You also need a real Mac available in order to fetch the OSK key.

Your Proxmox host computer’s CPU must support SSE 4.2, so for Intel your CPU must be at least as new as Nehalem, which was the first CPU generation to bear the “Core” i5/i7 branding. Older CPUs will cause the finder to repeatedly crash after installation completes (with an Illegal Instruction exception in the graphics code).

Apparently modern AMD CPUs also support SSE 4.2 and can be used with this guide without any modification (maybe Bulldozer and certainly Ryzen), but I haven’t tested this myself.



First step: Create an installation ISO

Download and run fetch-macOS.py in a terminal to download the Catalina recovery image from the Apple software distribution server (this can be run on Linux, Proxmox, or on a Mac):

This results in a ~500MB “BaseSystem.dmg” file in the current directory. Convert that dmg into an “iso” like so if you’re building this on macOS:

hdiutil convert BaseSystem.dmg -format RdWr -o Catalina-installer.iso mv Catalina-installer.iso.img Catalina-installer.iso

Or like so if you’re building this on Linux:

# Install the dmg2img package and... dmg2img BaseSystem.dmg Catalina-installer.iso # Or use qemu-img from the qemu-utils package to do it instead: qemu-img convert BaseSystem.dmg -O raw Catalina-installer.iso

The result is actually a raw disk image, not a true ISO, but Proxmox has better tools for picking and re-using ISO images than disk images. Upload the “ISO” to your Proxmox server’s ISO store (typically /var/lib/vz/template/iso).

If you don’t have an Internet connection available to Catalina during installation you’ll need to build an offline installer instead. Building the offline installer requires you to have a Mac, here are the instructions.

Prepare a Clover image

We’ll be using Clover as a bootloader for Catalina.

Download this Clover disk image (that I built using kholia’s build script from Clover r5107 on Fedora 27), unpack it, and upload it to Proxmox’s ISO store at /var/lib/vz/template/iso. Although it has a .iso file extension, this is actually a hard disk image.

Fetch the OSK authentication key

macOS checks that it is running on real Mac hardware, and refuses to boot on third-party hardware. You can get around this by reading an authentication key out of your real Mac hardware (the OSK key). Save the first block of C code from this page as smc_read.c. In a command prompt, change into the same directory as that file and run:

xcode-select --install # If you don't already have gcc gcc -o smc_read smc_read.c -framework IOKit ./smc_read

It’ll print out the 64 character OSK for you. Make a note of it.

Every Mac uses the same OSK, so don’t be surprised that it doesn’t look like a random string!

Create the VM

From the Proxmox web UI, create a new virtual machine as shown below.

Keep a note of your VM’s ID

Select the Clover ISO you uploaded and set OS type to “Other”

Set graphics to “VMWare Compatible”, set BIOS to OVMF (UEFI), set Machine to Q35, Tick Add EFI Disk and pick storage for it

Set the size of the hard disk (I chose 64GB). Attach it to SATA0. Enable discard and SSD emulation to support TRIM.

Set the number of cores for the VM, I chose 4 (note that some core counts are troublesome, try 4 first). Set the CPU to Penryn.

I chose a fixed memory of 4096MB. Disable ballooning because there is no balloon driver available for macOS.

Choose VMWare vmxnet3 for the network model



In the Options page for the VM, ensure that “use tablet for pointer” is set to “Yes”.

In the Hardware page for the VM, add a second DVD drive at IDE0, set it to use your Catalina-installer.iso.

Don’t try to start the VM just yet. First, SSH into your Proxmox server so we can make some edits to the configuration files.

Edit /etc/pve/qemu-server/YOUR-VM-ID-HERE.conf (with nano or vim). Add this line, being sure to substitute the OSK you extracted earlier into the right place:

args: -device isa-applesmc,osk="THE-OSK-YOU-EXTRACTED-GOES-HERE" -smbios type=2 -cpu Penryn,kvm=on,vendor=GenuineIntel,+kvm_pv_unhalt,+kvm_pv_eoi,+invtsc,vmware-cpuid-freq=on,+pcid,+ssse3,+sse4.2,+popcnt,+avx,+aes,+xsave,+xsaveopt,check -device usb-kbd,bus=ehci.0,port=2

We’re telling macOS that the CPU is Penryn (it doesn’t seem to like booting otherwise), but we’re enabling all the new CPU features found in Nehalem which macOS will require, plus some optional features found in later generations (AVX/AES). A USB keyboard is added here because macOS doesn’t support QEMU’s default PS/2 keyboard.

Find the line that define the two “ISOs” (ide0 and ide2), and remove the “,media=cdrom” part from them. Add “,cache=unsafe” in its place. This will treat these as hard disks rather than DVD drives.

Save your changes, return to the Options tab, and change the boot order to put IDE2 (the Clover image) first. Your final VM configuration file should resemble this:

args: -device isa-applesmc,osk="..." -smbios type=2 -cpu Penryn,kvm=on,vendor=GenuineIntel,+kvm_pv_unhalt,+kvm_pv_eoi,+invtsc,vmware-cpuid-freq=on,+pcid,+ssse3,+sse4.2,+popcnt,+avx,+aes,+xsave,+xsaveopt,check -device usb-kbd,bus=ehci.0,port=2 balloon: 0 bios: ovmf boot: cdn bootdisk: ide2 cores: 4 cpu: Penryn efidisk0: vms:vm-144-disk-1,size=128K ide0: isos:iso/Catalina-installer.iso,cache=unsafe ide2: isos:iso/clover-r5107.iso,cache=unsafe machine: q35 memory: 4096 name: catalina net0: vmxnet3=xx:xx:xx:xx:xx:xx,bridge=vmbr0,firewall=1 numa: 0 ostype: other sata0: vms:vm-144-disk-0,cache=unsafe,size=64G smbios1: uuid=xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx sockets: 1 vga: vmware

Configure Proxmox

On Proxmox, run “echo 1 > /sys/module/kvm/parameters/ignore_msrs” to avoid a bootloop during macOS boot. To make this change persist across Proxmox reboots, run:

echo "options kvm ignore_msrs=Y" >> /etc/modprobe.d/kvm.conf && update-initramfs -k all -u

You must now install a patched version of Proxmox’s OVMF library in order to be able to boot Catalina.

Install Catalina

Now start up your VM.

Go to the Console tab, quickly hit Escape or F2 at the Proxmox logo to enter the OVMF configuration. If your keyboard doesn’t work, leave the Console tab, stop the VM, start the VM, then re-enter the console tab.

Select Device Manager

Select OVMF platform configuration

Set the preferred resolution to 1920×1080

Save changes, then Reset

Follow the steps above to set the screen resolution to 1920×1080, press F10 to save your changes, and “reset” to apply the new settings (not “continue”). This step is required to avoid scrambled graphics on boot and a hang (Clover resolution must match OVMF resolution, or else the Apple logo will be off-centre and the progress bar will be smeared across the screen, resulting in a lockup).

Note that in future you’ll find that when initially started, your VM doesn’t properly apply the the 1920×1080 screen resolution until you hit “Restart Computer” in Clover when the Clover menu appears (or “Reset” on the VM). You’ll notice this happening when the “Proxmox” logo fills a large area of the screen on boot due to the low resolution.

It should now boot into Clover.

Press enter to boot the “Boot macOS Install from macOS Base System” entry and the installer should appear. Choose your language.

Our virtual hard drive needs to be erased/formatted before we can install to it, so select the Disk Utility option. Follow the steps below to format the disk:

Select Disk Utility

Erase the main disk (it’ll appear as an external drive). Choose APFS. I called mine “Main”. Avoid “Encrypted” at this stage

Now we’re ready to begin installation!

Reinstall macOS

Continue…

Choose the drive you erased

It’s installing!

After the first stage of installation, the VM should reboot itself and automatically continue installation by booting from the hard drive, then reboot itself a second time and automatically boot from “filevault prebooter”. Note that an Internet connection is required during installation, as the installer needs to download Catalina.

Answer the initial install questions, and you’ll be logged on! (Note that you’ll probably want to hold off on logging into your iCloud account until you’ve configured your SMBIOS to your liking in Clover Configurator)

Answer the install questions

New features!

New automatic theme switching!

It works!

Make the Clover install permanent

We’re currently booting using Clover from the attached Clover ISO. Let’s install that to the hard drive instead. Pop open Terminal and run “diskutil list” to see what drives we have available.

Use “sudo dd if=<source> of=<dest>” to copy the “EFI” partition from the Clover CD and overwrite the EFI partition on the hard disk. The Clover CD is the small disk with the “linux filesystem” on it, and the main hard disk is the one with the large Apple_APFS “Container” partition on it.

In my case these EFI partitions ended up being called disk1s1 and disk2s1 respectively, so I ran “sudo dd if=/dev/disk1s1 of=/dev/disk2s1” (N.B. if you get these names wrong, you will overwrite the wrong disk and you’ll have to start the installation over again!).

Now shut down the VM, and remove both the Clover and the Catalina installer drives from the Hardware tab. On the Options tab, edit the boot order to place SATA0 as the first disk. Boot up. If everything went well, you should see the Clover boot menu, and you can select “Boot macOS from Main” to boot Catalina.

Sleep management

I found that I was unable to wake Catalina from sleep using my mouse or keyboard. You can either disable system sleep in Catalina’s Energy Saver settings to avoid this, or you can manually wake the VM up from sleep from Proxmox by running:

qm monitor YOUR-VM-ID-HERE

system_wakeup

quit

“Prohibited” sign on boot

On a regular Hackintosh this is typically a sign that the boot drive can’t be read, but that situation is difficult to encounter with this VM setup. Nevertheless, I receive a “prohibited” sign during boot in perhaps 1 out of 20 system boots at random (maybe a timing bug?) If this happens, just hit “reset” for the VM to retry (no need to stop and start).

If you get it persistently, something is going wrong with the boot. You can boot macOS in “verbose” mode by hitting space on the macOS option in Clover and ticking the verbose option. This’ll give you a log during booting that can narrow down when the problem occurs.

Editing your Clover/EFI settings

You can use the Clover Configurator tool (Global Edition) to edit your Clover “config.plist” configuration file, which is stored in the hard drive’s EFI partition. This tool should mount the EFI partition for you. If you want to mount it without using Clover Configurator, first check the device name of the EFI partition in the terminal:

~$ diskutil list

/dev/disk0 (external):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme 512.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Main 511.8 GB disk0s2

Then you can mount it like so:

sudo mkdir /Volumes/EFI

sudo mount -t msdos /dev/disk0s1 /Volumes/EFI

Note that if you upgrade Clover in the future, you must untick the “AudioDxe” driver during installation, because this causes Clover to hang.

Video performance

Because there is no guest video acceleration available for macOS, video performance is poor.

In Google Chrome in the guest you will need to toggle off the setting to “use hardware acceleration when available” to improve issues with elements not being drawn or flickering (especially video). Safari may be a better choice.

macOS’s built in “Screen Sharing” feature offers dramatically better framerates and latency than Proxmox’s browser-based VNC console, so if you have a real Mac to act as a viewing console, you can enable that in the VM’s “Sharing” settings and connect to the VM using the Screen Sharing app from your Mac instead:

Apparently Screen Sharing is also compatible with VNC clients like RealVNC, so you should be able to connect to it from Linux or Windows consoles using RealVNC.

The real magic bullet for video performance is to pass through a compatible video card using PCIe passthrough (though note that Catalina does not support most NVidia cards). This offers near-native performance. You can read more about how I’m using PCIe passthrough on my own installation here.

USB passthrough

Since I want to use this as my primary computer, I want to use a USB keyboard and mouse plugged directly into Proxmox, rather than sending my input through the web VNC console.

Proxmox has good documentation for USB passthrough. Basically, run “qm monitor YOUR-VM-ID-HERE”, then “info usbhost” to get a list of the USB devices connected to Proxmox:

qm> info usbhost

Bus 3, Addr 12, Port 6, Speed 480 Mb/s

Class 00: USB device 8564:1000, Mass Storage Device

Bus 3, Addr 11, Port 5.4, Speed 12 Mb/s

Class 00: USB device 04d9:0141, USB Keyboard

Bus 3, Addr 10, Port 5.1.2, Speed 12 Mb/s

Class 00: USB device 046d:c52b, USB Receiver

Bus 3, Addr 9, Port 14.4, Speed 12 Mb/s

Class 00: USB device 046d:c227, G15 GamePanel LCD

Bus 3, Addr 8, Port 14.1, Speed 1.5 Mb/s

Class 00: USB device 046d:c226, G15 Gaming Keyboard

In this case I can add my keyboard and mouse to USB passthrough by quitting qm, then running:

qm set YOUR-VM-ID-HERE -usb1 host=04d9:0141

qm set YOUR-VM-ID-HERE -usb2 host=046d:c52b

This saves the devices to the VM configuration for you. It’s possible to hot-add USB devices, but I just rebooted my VM to have the new settings apply.

You can also pass through USB devices by passing through an entire USB controller using Proxmox’s PCIe passthrough feature.

FileVault 2

Scrambled login prompt with FileVault

FileVault disk encryption is a little janky at the moment. It takes a long time (a couple of minutes) for the password prompt to appear on boot, and then the graphics are scrambled so you have to enter your password blind.

If you really want to use it, be certain to keep a copy of your recovery key and keep your backups up to date!

Upgrading from Mojave

First make a backup or snapshot of your system! Catalina has a new disk layout that separates user data from the system partition, so there’s a higher than normal chance of the installer destroying everything.

Update Clover to r5107 by running the Clover installer. Choose the Customise option. Choose:

Install for UEFI booting only

UEFI drivers section: Recommended Drivers: Tick all, except untick AudioDxe (it causes Clover to hang) Filesystem drivers: Tick ApfsDriverLoader Memory fix drivers: Tick OsxAptioFix3Drv FileVault 2 drivers: Tick all Additional drivers: Tick PartitionDxe



Update any kexts you have installed (Lilu, WhateverGreen, etc). Now reboot to check that Mojave still boots properly using this updated Clover install.

If you’re using any PCIe passthrough devices (particularly video cards) you’ll probably want to disable those and set “vga: vmware” instead, so you can install using Proxmox’s web console. This avoids installer problems triggered by flaky video card passthrough.

Now you can upgrade to Catalina by adding the Catalina-intaller.iso as a DVD drive, editing the VM config to replace “media=cdrom” with “cache=unsafe” and booting from that. You can probably also just install Catalina from the Mac App Store, but I haven’t tested that approach myself.

After upgrading, you may find that on boot you are dropped into the UEFI shell instead of booting Clover. If so, you can manually find and run Clover (e.g. by running “fs0:” “cd EFI\CLOVER “CLOVERX64.efi”), then use Clover’s “Boot Menu Options” menu to remove the Clover UEFI entries and re-add them.