On current versions (QEMU 2.8, GNOME-Shell 3.22.3 on Wayland), the screensaver will activate. Cursor control is given to the lock screen, everything works properly. After the screen is unlocked, the cursor is given back to QEMU and is still in "mouse grab" mode.
** Changed in: qemu Status: Incomplete => Fix Released -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/986318 Title: [sdl] Mouse grab breaks GNOME 3 screensaver unlock screen Status in QEMU: Fix Released Bug description: When the GNOME 3 screensaver activates with the mouse cursor over the SDL window, the screensaver will not unlock unless the gnome-shell process is killed and restarted manually. This seems to be related to the fact that the key strokes are grabbed by SDL, but the screensaver will not allow the Ctrl and Alt keys to be passed to QEMU to exit the mouse grab. Qemu-kvm 1.0.1, QEMU 1.0.1, kernel 3.2.15. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/986318/+subscriptions