Comment 2 for bug 190880

I'm seeing a very similar problem. The mouse pointer within a VM will become stuck. If I move the mouse far enough so that actual OS pointer leaves the VM window, I get the OS pointer but it is effectively useless. It can not click on anything, nor does application focus follow the mouse as it normally does (and is configured to).

I'm not entirely certain of the cause, but have noticed that it consistently happens if the mouse is in a VM console (display through virt-manager's interface) and another application takes focus or the screen saver activates.