There's a bug filed against debian qemu package, there: http://bugs.debian.org/758881
which says about problems sending keypress events over VNC to a qemu guest, -- some keypresses gets lost, at least. The bisection between qemu 2.0 and 2.1 leads to this commit: commit 2858ab09e6f708e381fc1a1cc87e747a690c4884 Author: Gonglei <arei.gong...@huawei.com> Date: Thu Apr 24 20:06:19 2014 +0800 ps2: set ps/2 output buffer size as the same as kernel According to the PS/2 Mouse/Keyboard Protocol, the keyboard outupt buffer size is 16 bytes. And the PS2_QUEUE_SIZE 256 was introduced in Qemu from the very beginning. When I started a redhat5.6 32bit guest, meanwhile tapped the keyboard as quickly as possible, the screen would show me "i8042.c: No controller found". As a result, I couldn't use the keyboard in the VNC client. Previous discussion about the issue in maillist: http://thread.gmane.org/gmane.comp.emulators.qemu/43294/focus=47180 This patch has been tested on redhat5.6 32-bit/suse11sp3 64-bit guests. More easy meathod to reproduce: 1.boot a guest with libvirt. 2.connect to VNC client. 3.as you see the BIOS, bootloader, Linux booting, run the follow simply shell script: for((i=0;i<10000000;i++)) do virsh send-key redhat5.6 KEY_A; done Actual results: dmesg show "i8042.c: No controller found." And the keyboard is out of work. Signed-off-by: Gonglei <arei.gong...@huawei.com> Reviewed-by: Juan Quintela <quint...@redhat.com> Signed-off-by: Gerd Hoffmann <kra...@redhat.com> So it looks like something else is not right here. Before this patch, it wasn't possible to use keyboard with VNC client with redhat 5 guest. Now, it isn't possible to use keyboard with VNC in another scenario which worked before (so it is a regression compared with 2.0 version). What do we do with this? :) Thanks, /mjt