Quickemu

Simple script to "manage" Qemu virtual machines.

Made with 💝 for

Introduction

Quickemu is a simple script to "manage" Qemu virtual machines. Each virtual machine configuration is a few lines long requiring minimal setup. The main objective of the project is to enable quick testing of desktop Linux distributions where the virtual machines configuration and disk images can be stored anywhere, such as external USB storage or your home directory. Windows and macOS guests are also supported.

Quickemu will attempt to "do the right thing" rather than expose rich configuration options. Quickemu is a wrapper for QEMU. See the video where I explain some of my motivations for creating this script.

We have a Discord for this project:

Requirements

Essential requirements:

• QEMU 6.0.0 or newer
• Coreutils
• procps
• usbutils
• Wget
• xrandr

Optional requirements:

• rot13 to "decrypt" the macOS OSK key; found in the bsdgames package in Debian/Ubuntu
• spicy to connect to VMs via the SPICE protocol; found in the spice-client-gtk package in Debian/Ubuntu

Install Quickemu

Ubuntu

Quickemu is available from a PPA for Ubuntu users. The Quickemu PPA also includes a back port of QEMU 6.0.0 for 20.04 (Focal) and 21.04 (Hirsute).

sudo apt-add-repository ppa:flexiondotorg/quickemu
sudo apt install quickemu

Usage

Linux Guest

• Download a .iso image of a Linux distribution
• Create a VM configuration file; for example ubuntu.conf
  • The default guest_os is linux, so this is optional for Linux VM configs.
  • The boot option enables Legacy BIOS (legacy) or EFI (efi) booting. legacy is the default.

guest_os="linux"
iso="${HOME}/Quickemu/ubuntu/focal-desktop-amd64.iso"
disk_img="${HOME}/Quickemu/ubuntu/focal-desktop-amd64.qcow2"

• Use quickemu to start the virtual machine:

quickemu --vm ubuntu-focal-desktop.conf

• Complete the installation as normal.
• Post-install:
  • Install the SPICE agent (spice-vdagent) to enable copy/paste and USB redirection
    • Debian/Ubuntu sudo apt install spice-vdagent
  • Install the SPICE WebDAV agent (spice-webdavd) to enable file sharing.
    • Debian/Ubuntu sudo apt install spice-webdavd

Windows 10 Guest

You can use quickemu to run Windows 10 in a virtual machine.

• Download Windows 10
• Download VirtIO drivers for Windows
• Download spice-webdavd for Windows
  • Enables the Windows guest access to shared files on the host.
• Download UsbDk for Windows
  • Enables the Windows guest access to redirected USB devices from the host.
• Create a VM configuration file; for example windows10.conf
  • The boot option enables Legacy BIOS (legacy) or EFI (efi) booting. legacy is the default.
  • The guest_os="windows" line instructs quickemu to use optimise for Windows.

guest_os="windows"
iso="${HOME}/Quickemu/windows/Win10_21H1_EnglishInternational_x64.iso"
driver_iso="${HOME}/Quickemu/windows/virtio-win-0.1.208.iso"
disk_img="${HOME}/Quickemu/windows/windows.qcow2"

• Use quickemu to start the virtual machine:

quickemu --vm windows10.conf

• During the Windows 10 install you will be asked "Where do you want to install Windows?"
  • Click Load driver and OK the the dialogue box that pops up.
  • Select VirtIO SCSI controller (E:\amd64\w10\viostor.inf) from the list and click Next.
  • The disk will now be available for partitioning and formatting.
• Complete the installation as you normally would.
• Post-install:
  • Run the VirtIO installer from the CD-ROM: drive.
  • Install spice-webdavd
  • Install UsbDk

macOS Guest

There are some considerations when running macOS via Quickemu.

• quickemu will automatically download the required OpenCore bootloader and OVMF firmware from OSX-KVM.
• macOS 10.14.3 or newer is supported:
  • VirtIO block devices QEMU standard VGA are supported since macOS 10.14.3 (Mohave).
  • VirtIO usb-tablet devices are supported since macOS 10.11 (El Capitan).
  • vmxnet3 network devices are supported since macOS 10.11 (El Capitan).
  • Running macOS on QEMU required the guest CPU is set to Penryn.
  • This is a very old architecture, so to unlock higher CPU performance; AVX, AES-NI, SSE et al are enabled.
• UHCI USB (USB 2.0) is the fastest supported.
  • USB pass-through has not been tested.
• Copy/paste between the guest and host is not supported in macOS.
• File sharing is not supported on macOS.

You can use quickemu to run a macOS virtual machine.

• Download macOS using fetch-macOS-v2.py

wget https://github.com/kholia/OSX-KVM/blob/master/fetch-macOS-v2.py -O fetch-macOS-v2.py
python3 ./fetch-macOS-v2.py

This will display the following menu.

1. High Sierra (10.13)
2. Mojave (10.14)
3. Catalina (10.15) - RECOMMENDED
4. Latest (Big Sur - 11)
Choose a product to download (1-4):

When prompted choose the recommended release.

qemu-img convert BaseSystem/BaseSystem.dmg -O raw BaseSystem.img

• Create a VM configuration file; for example macos.conf
  • The guest_os="macos" line instructs quickemu to use optimise for macOS.
  • The img= sets the boot disk that you downloaded with fetch-macOS-v2.py.

guest_os="macos"
img="${HOME}/Quickemu/macos/BaseSystem.img"
disk_img="${HOME}/Quickemu/macos/macos.qcow2"

• Use quickemu to start the virtual machine:

quickemu --vm macos.conf

• Boot from the BaseSystem (use cursor keys if the mouse doesn't work)
  • Click Disk Utility and Continue
  • Select Apple Inc. VirtIO Block Media that is ~65GB from the list and click Erase.
  • Enter a Name: for the disk and click Erase.
  • Click Done.
  • Close Disk Utility
  • Click Reinstall macOS and Continue
• Complete the installation as you normally would.

SPICE

The following features are only available while using the SPICE protocol:

• Copy/paste between the guest and host (not available for macOS guests)
• Host file sharing to the guest (not available for macOS guests)
• USB device redirection (untested on macOS)

To use SPICE add --display spice to the Quickemu invocation, this requires that the spicy client is installed, available from the spice-client-gtk package in Debian/Ubuntu.

quickemu --vm ubuntu-focal-desktop.conf --display spice

Tuning CPU cores, RAM & disks

By default, Quickemu will calculate the number of CPUs cores and RAM to allocate to a VM based on the specifications of your host computer. You can override this default behaviour and tune the VM configuration to your liking.

Add additional lines to your virtual machine configuration:

• cpu_cores="4" - Specify the number of CPU cores allocated to the VM
• ram="4G" - Specify the amount of RAM to allocate to the VM
• disk="16G" - Specify the size of the virtual disk allocated to the VM

Network port forwarding

Add an additional line to your virtual machine configuration. For example:

• port_forwards=("8123:8123" "8888:80")

In the example above:

• Port 8123 on the host is forwarded to port 8123 on the guest.
• Port 8888 on the host is forwarded to port 80 on the guest.

USB redirection

Quickemu support USB redirection via host passthrough and SPICE passthrough.

SPICE redirection

Using SPICE for USB passthrough is easiest as it doesn't require any elevated permission, start Quickemu with --display spice and then select Input -> Select USB Device for redirection from the menu to chose which device(s) you want to attach to the VM.

Host redirection

USB host redirection is not recommended, it is provided purely for backwards compatibility to older versions of Quickemu. Using SPICE is preferred, see above.

Add an additional line to your virtual machine configuration. For example:

• usb_devices=("046d:082d" "046d:085e")

In the example above:

• The USB device with vendor_id 046d and product_id 082d will be exposed to the guest.
• The USB device with vendor_id 046d and product_id 085e will be exposed to the guest.

If the USB devices are not writable, quickemu will display the appropriate commands to modify the USB device(s) access permissions, like this:

 - USB:      Host pass-through requested:
              - Sennheiser Communications EPOS GTW 270 on bus 001 device 005 needs permission changes:
                sudo chown -v root:martin /dev/bus/usb/001/005
                ERROR! USB permission changes are required 👆

All the options

Here are the usage instructions:

Usage
  quickemu --vm ubuntu.conf

You can also pass optional parameters
  --delete                : Delete the disk image.
  --display               : Select display backend. 'sdl' (default), 'gtk' or 'spice'
  --shortcut              : Create a desktop shortcut
  --snapshot apply <tag>  : Apply/restore a snapshot.
  --snapshot create <tag> : Create a snapshot.
  --snapshot delete <tag> : Delete a snapshot.
  --snapshot info         : Show disk/snapshot info.
  --status-quo            : Do not commit any changes to disk/snapshot.
  --fullscreen            : Starts VM in full screen mode (Ctl+Alt+f to exit)"
  --screen <screen>       : Use specified screen to determine the window size.

Desktop shortcuts

Desktop shortcuts can be created for a VM, the shortcuts are saved in ~/.local/share/applications. Here is an example of how to create a shortcut.

quickemu --vm ubuntu-focal-desktop.conf --shortcut

Screen and window size

Note about screen and window size

qemu will always default to the primary monitor to display the VM's window.

Without the --screen option, quickemu will look for the size of the smallest monitor, and use a size that fits on said monitor.

The --screen option forces quickemu to use the size of the given monitor to compute the size of the window. It wont't use that monitor to display the VM's window if it's not the primary monitor. This is useful if the primary monitor if not the smallest one, and if the VM's window doesn't need to be moved around.

The --screen option is also useful with the --fullscreen option, again because qemu will always use the primary monitor. In order for the fullscreen mode to work properly, the resolution of the VM's window must match the resolution of the screen.

To know which screen to use, type:

xrandr --listmonitors | grep -v Monitors

The command will output something like this:

 0: +*HDMI-0 2560/597x1440/336+1920+0  HDMI-0
 1: +DVI-D-0 1920/527x1080/296+0+0  DVI-D-0

The first number is what needs to be passed to the --screen option.

For example:

quickemu --vm vm.conf --screen 0

The above uses the 2560x1440 screen to compute the size of the window, which Quickemu sizes to 2048x1152. Without the --screen option, Quickemu would have used the 1920x1080 monitor which results in a window size of 1664x936.

TODO

• Default to EFI booting.
• Only use video drivers with legacy VGA when legacy boot is enabled.
• Include macOS compatible firmware.
• Make default virtual disk capacity suitable for the target guest OS.
• Optimise macOS guests.
• Optimise Windows guests.
• Add BSD support.
• spice-app support via virt-viewer.
• Improve disk management.
• Add Faux OEM.

References

• macOS
  • https://www.nicksherlock.com/2020/06/installing-macos-big-sur-on-proxmox/
  • https://github.com/kholia/OSX-KVM
  • https://github.com/thenickdude/KVM-Opencore
  • https://github.com/acidanthera/OpenCorePkg/tree/master/Utilities/macrecovery
  • https://www.kraxel.org/blog/2017/09/running-macos-as-guest-in-kvm/
  • https://github.com/Dids/clover-builder
• Windows
  • https://www.heiko-sieger.info/running-windows-10-on-linux-using-kvm-with-vga-passthrough/
  • https://leduccc.medium.com/improving-the-performance-of-a-windows-10-guest-on-qemu-a5b3f54d9cf5
  • https://frontpagelinux.com/tutorials/how-to-use-linux-kvm-to-optimize-your-windows-10-virtual-machine/