Setting/correcting keymap in Virt-Manager

The keymap is part of the VNC configuration.
Can be set manually or through virt-manager.

Details → Display VNC ¹⁾ → Remove
Add hardware → Graphics → Keymap = Same as host

Edit XML config for guest

e.g. /etc/libvirt/qemu/GuestOS.xml and add/change keymap field in graphics element, i.e.:

Before:

<graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1' keymap='en-us'/>

After:

<graphics type='vnc' port='-1' autoport='yes' listen='127.0.0.1' keymap='es'/>

Reload libvirt service configuration, e.g. on debian:

# /etc/init.d/libvirt-bin force-reload