If you use virt-manager with kvm (and likely other virtualization technologies, too, but I only tried it under proper circumstances with kvm), you may experience some keyboard layout-related problems. For instance, I got «>» sign instead of forward slash. This problem may appear when you use some non-standard (or even any non-«en-us») layout on your host system.

The solution is simple:

• remove Graphics device represented by VNC server
• add a new one, but set keymap to «en-us» instead of leaving it “same as host”.
• restart you guest

(As of virt-manager 0.8.2, you cannot change VNC server settings, only remove it and add a new one)

http://en.miheev.info/2010/01/18/virt-manager-keymap.html