qemu | Cheatsheet
QEMU is a free and open-source emulator. It emulates the machine's processor through
dynamic binary translation and provides a set of different hardware and device models for the machine,
enabling it to run a variety of guest operating systems.
Examples
- vID = Vendor ID for USB
- pID = Product ID for USB
| Option |
Description |
| qemu-system-x86_64 |
Excute qemu |
| -serial stdio |
Serial ? |
| -enable-kvm |
Enable KVM |
| -cpu host |
Emulate the host processor. (Recommended) |
| -smp 4 |
Enable cpu + 4 core (-smp $(nproc) for use all) |
| -device usb-ehci,id=ehci |
Enable EHCI (2.0) |
| -device qemu-xhci,id=xhci |
ENABLE XHCI (3.0) |
| -device usb-tablet,bus=xhci.0 |
DONT GRAB THE MOUSE |
| -net nic -net user |
ENABLE LAN |
| -m 4192 |
RAM MEMORY |
| -device usb-host,vendorid=\({vID},productid=\) |
START WITH A USB DEVICE (lsub) |
| -device usb-host,vendorid=\({vID},productid=\) |
START WITH A USB DEVICE (lsub) |
| -boot d |
BOOT FROM DRIVE |
| -hda win7.img |
Harddrive |
| -cdrom some.iso |
Use localetime |
| cdrom /dev/cdrom |
Boot from real cdrom slot |
| -bios /usr/share/edk2-ovmf/OVMF_CODE.fd |
Boot with UEFI |
| -localtime |
Set a virtual CDROM drive and use the host drive for it. |
| -k keymap |
Set a keymap |
| -g 1920x1080 |
Set resolution |
Boot order
| Option |
Description |
| -boot c |
Boot the first virtual hard drive |
| -boot d |
Boot the first virtual CD-ROM drive |
| -boot n |
Boot from virtual network |
Display options
| Option |
Description |
| -display sdl |
Display video output via SDL |
| -display curses |
Displays video output via curses. |
| -display none |
Do not display video output |
| -display gtk |
Display video output in a GTK window |
| -display vnc=127.0.0.1: |
Start a VNC server on display X |
Graphics card
| Option |
Description |
| -vga cirrus |
Simple graphics card. Every guest OS has a built-in driver. |
| -vga std |
Support resolutions >= 1280x1024x16. Linux, Windows XP and newer guest have a built-in driver |
| -vga vmware |
VMware SVGA-II, more powerful graphics card. Install x11-drivers/xf86-video-vmware in Linux guests |
| -vga qxl |
More powerful graphics card for use with SPICE. (QXL video causes low resolution) |
Audio (Intel HD Audio)
| Option |
Description |
| -device ich9-intel-hda |
Add the audio controller |
| -device hda-output,audiodev=snd0 |
Add the audio codec and map it to a host audio backend id |
| -device AC97,audiodev=snd0 |
Intel 82801AA AC97 |
Network card
| Option |
Description |
| -netdev user |
The QEMU process will create TCP and UDP connections |
| -device virtio-net,netdev=vmnic -netdev user,id=vmnic |
(Recommended) Pass-through with VirtIO support. |
| -netdev user,id=vmnic,hostfwd=tcp:127.0.0.1:9001-:22 |
Let QEMU listen on port 9001. |
| -nic user,hostfwd=tcp::10022-:22 |
QEMU can forward ports from the host to the guest to enable |
| -nic user,hostfwd=tcp::10022-:22,hostfwd=tcp::5900-:5900 |
You can use SSHFS to mount the guest's file system at the host for shared read and write access. |
| -net nic -net user,smb=shared_dir_path |
QEMU's built-in SMB server |
Spice
| Option |
Description |
| -device virtio-serial-pci |
Adds a virtio-serial device |
| -spice port=5930,disable-ticketing=on |
5930 for spice channels listening and allow client to connect without authentication |
Create harddrive
qemu-img create -f qcow2 foo.img 100G
Create myimage.img mysize
qemu-img create myimage.img mysize
Creates a qcow2 image with a maximum size of 10GB
qemu-img create -f qcow2 foo.img 10G
This example increases the size of a qcow2 image
qemu-img resize foo.img 20G
Creates a RAW image with a maximum size of 10GB
qemu-img create -f raw foo.img 10G
This example increases the size of a RAW image
qemu-img resize -f qcow2 20G
Displays attributes of a RAW image
qemu-img info /var/lib/libvirt/images/disk1.img
Install virtiofs is required for sharing folders
emerge app-emulation/virtiofsd