Re: [Qemu-devel] Bug in SDL key event processing

[Tomas Carnecky]

Anthony Liguori wrote:
> What's lost in your ranting is a concise description of the problem 
> you've encountered.  What behavior are you seeing and what behavior do 
> you expect to see?  What kind of physical keyboard do you have and what 
> is your keyboard configured as in your host and in your guest?  Are you 
> using a '-k' option?

When I press the 'Up' key, the xserver generates an event with keycode 
111 (tested with xev). SDL repacks the XEvent to a SDL_KeyboardEvent 
with keycode=SDLK_UP and scancode=111. If I don't supply a keymap name 
(-k), QEMU uses the SDL scancode as the index into the 
x_keycode_to_pc_keycode table, but that table incorrectly translates it 
to 'Print'. If I use '-k en-us', the QEMU sets up a correct 
SDL-keysym-to-scancode table and then all keys work.
You cannot use the SDL scancode under X11, because there's no guarantee 
that it has any meaningful value. X11 clients have to translate they 
keycode to a keysym using XKeycodeToKeysym() to get the real value, 
which you can then for example compare with 'XK_Up'.

> I'd be willing to wager that whatever problem you are encountering is a 
> configuration error on your part (unless you're using a infrequently 
> tested translation table).

I ran vanilla kvm-userspace.git. Sure, it's not the same as qemu, but I 
doubt the kvm developers wrote that part of the code. I haven't modified 
any existing code or keymap files, just added a few printf()s to see 
what's going on.


tom