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

• QEMU (6.0.0 or newer)
• Coreutils
• grep
• jq
• procps
• python3
• macrecovery.py
• usbutils
• sed
• spicy
• Wget
• xdg-user-dirs
• xrandr
• zsync

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

Other Linux

git clone https://github.com/wimpysworld/quickemu
cd quickemu

Usage

Ubuntu Guest

quickget will automatically download an Ubuntu release and also create the virtual machine configuration.

quickget ubuntu focal
quickemu --vm ubuntu-focal.conf

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

Ubuntu devel (daily-live) images

quickget can also download/refresh devel images via zsync for Ubuntu developers and testers.

quickget ubuntu devel
quickemu --vm ubuntu-devel.conf

You can run quickget ubuntu devel to refresh your daily development image as often as you like, it will even automatically switch to a new series.

Ubuntu Flavours

All the official Ubuntu flavours are supported, just replace ubuntu with your preferred flavour.

• kubuntu
• lubuntu
• ubuntu-budgie
• ubuntu-kylin
• ubuntu-mate
• ubuntu-studio
• xubuntu

Linux Guest

• Download a .iso image of a Linux distribution
• Create a VM configuration file; for example debian-bullseye.conf

guest_os="linux"
disk_img="debian-bullseye/disk.qcow2"
iso="debian-bullseye/firmware-11.0.0-amd64-DVD-1.iso"

• Use quickemu to start the virtual machine:

quickemu --vm debian-bullseye.conf

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

macOS Guest

quickget automatically downloads a macOS recovery image and automatically creates a virtual machine configuration.

quickget macos catalina
quickemu --vm macos-catalina.conf

macOS high-sierra, mojave, catalina and big-sur are supported.

• Use cursor keys and enter key to select the macOS Base System
• From macOS Utilities
  • Click Disk Utility and Continue
    • On macOS Catalina and Big Sur
      • Select Apple Inc. VirtIO Block Media from the list and click Erase.
    • On macOS Mojave and High Sierra
      • Select QEMU HARDDISK Media (~68.72GB) from the list and click Erase.
  • Enter a Name: for the disk and click Erase.
  • Click Done.
  • Close Disk Utility
• From macOS Utilities
  • Click Reinstall macOS and Continue
• Complete the installation as you normally would.
  • On the first reboot use cursor keys and enter key to select macOS Installer
  • On the subsequent reboots use cursor keys and enter key to select the disk you named

The default macOS configuration looks like this:

guest_os="macos"
img="macos-big-sur/RecoveryImage.img"
disk_img="macos-big-sur/disk.qcow2"

• The guest_os="macos" line instructs Quickemu to optimise for macOS.
• If you want to disable VirtIO Block Media and use SATA emulation add virtio_blk="off" to your configuration.
  • quickget disables VirtIO Block Media for High Sierra and Mojave by default since it is not supported on those releases.

macOS compatibility

There are some considerations when running macOS via Quickemu.

• quickemu will automatically download the required OpenCore bootloader and OVMF firmware from OSX-KVM.
• Supported macOS releases:
  • High Sierra
  • Mojave
  • Catalina
  • Big Sur
• Optimised by default
  • Host CPU vendor is detected and guest CPU is optimised accordingly.
  • VirtIO block device is used for the system disk where supported.
  • VirtIO usb-tablet is used for the mouse.
  • vmxnet3 network device is used.
• USB host pass-through is limited to UHCI (USB 2.0).
• Display resolution can only be changed via macOS System Preferences.
• File sharing between guest and host is available via virtio-9p.
• SPICE has limited supported on macOS:
  • Copy/paste via SPICE agent is not available.
  • File sharing via SPICE webdavd is not available.
  • USB pass-through via SPICE is not available.
  • Smartcard pass-through is not available.

Windows 10 Guest

quickget automatically downloads Windows 10, the VirtIO drivers for Windows and creates a virtual machine configuration.

quickget windows 10
quickemu --vm windows-10.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 (virtio-win-gt-x64) from the CD Drive (E:).
  • Run the Guest Tools installer (virtio-win-guest-tools) from the CD Drive (E:).
  • Download and install spice-webdavd
    • Enables file sharing between the host and guest.
  • Download and install UsbDk
    • Enables USB SPICE pass-through between the host and guest.

Regional versions

By default quickget will download the "English International" release, but you can optionally specify one of the supported languages: For example:

quickget windows 10 "Chinese (Traditional)"

The default Windows 10 configuration looks like this:

guest_os="windows"
disk_img="windows-10/disk.qcow2"
iso="windows-10/Win10_21H1_English_x64.iso"
fixed_iso="windows-10/virtio-win.iso"

• The guest_os="windows" line instructs quickemu to optimise for Windows.
• The fixed_iso= line specifies the ISO image that provides VirtIO drivers.

SPICE

The following features are available while using the SPICE protocol:

• Copy/paste between the guest and host
• Host file sharing to the guest
• USB device redirection

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.conf --display spice

BIOS and EFI

Since Quickemu 2.1.0 efi is the default boot option. If you want to override this behaviour then add the following line to you VM configuration to enable legacy BIOS.

• boot="legacy" - Enable Legacy BIOS boot

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

Disk preallocation

Preallocation mode (allowed values: off, metadata (default), falloc, full). An image with preallocated metadata is initially larger but can improve performance when the image needs to grow. falloc and full preallocations are like the same options of raw format, but sets up metadata also.

Specify what disk preallocation should be used, if any, when creating the system disk image by adding a line like this to your VM configuration.

• preallocation="metadata"

CD-ROM disks

If you want to expose an ISO image from the host to guest add the following line to the VM configuration:

• fixed_iso="/path/to/image.iso"

Floppy disks

If you're like Alan Pope you'll probably want to mount a floppy disk image in the guest. To do so add the following line to the VM configuration:

• floppy="/path/to/floppy.img"

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 supports USB redirection via SPICE pass-through and host pass-through.

SPICE redirection (recommended)

Using SPICE for USB pass-through 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 guest.

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:user /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

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

• Add spice-app support via virt-viewer; requires virt-viewer 8.0 or newer
• Add support for ignore_msrs for macOS. echo "options kvm ignore_msrs=Y" >> /etc/modprobe.d/kvm.conf && update-initramfs -k all -u
• Add discrete GPU pass-through
• Include macOS compatible firmware
• Add BSD support
• Improve disk management

References

Useful reference that assisted the development of Quickemu.

• macOS
  • https://www.nicksherlock.com/2020/06/installing-macos-big-sur-on-proxmox/
  • https://passthroughpo.st/mac-os-adds-early-support-for-virtio-qemu/
  • 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://www.nicksherlock.com/2017/10/passthrough-of-advanced-cpu-features-for-macos-high-sierra-guests/
  • http://philjordan.eu/osx-virt/
  • https://github.com/Dids/clover-builder
  • OpenCore Configurator.
• 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/
  • https://turlucode.com/qemu-command-line-args/
  • https://github.com/pbatard/Fido
• 9p & virtiofs
  • https://wiki.qemu.org/Documentation/9p
  • https://wiki.qemu.org/Documentation/9psetup
  • https://www.kraxel.org/blog/2019/06/macos-qemu-guest/
  • https://superuser.com/questions/628169/how-to-share-a-directory-with-the-host-without-networking-in-qemu
  • https://virtio-fs.gitlab.io/