How can I restore default window size in KVM/QEMU

Question

In KVM/QEMU machine window size by default matches guest OS resolution. But if I resize windows (accidently) how to restore default size?

Answer 1

Ctrl-Alt-u 

Source: http://linux.die.net/man/1/qemu-kvm

In the future, you can also try to use man (in a terminal). This gives you the user manual. You can seek a word by pressing "/" (without the quotes) and then cycle through the references using "n":

man qemu
/restore <enter>
n
n

To quit, type "q".

Answer 2

Assimunig you're talking about virt-manager or virt-viewer:

Click "View", select "Resize to VM"