Re: qemu-system-x86_64: warning: Unknown X11 keycode mapping '<null>'.

[Daniel P . Berrangé]

On Mon, Mar 02, 2020 at 07:19:04PM +0100, Thorsten Glaser wrote:
> On Mon, 2 Mar 2020, Daniel P. Berrangé wrote:
> 
> > There's two translations happening
> > 
> >  * The scancode emitted by the kernel and/or hardware device,
> >    and then translated/mangled by X11 and reported as the
> >    hardware keycode
> > 
> >  * The keysym which is the mapping from the hardware keycode
> >    done by XKB and/or Xmodmap
> 
> Yes, sure.
> 
> > We're dealing with the first point in QEMU, taking the hardware
> > keycode and trying to undo the X11 mangling that was performed.
> 
> That’s where VNC often fails, generally, anyway… (asd often get
> translated back as adf).
> 
> > > But if I can do anything to help debugging this, sure.
> > 
> > Can you launch 'xev' inside your VNC session and press the 'Page Up'
> > button and let me know what it reports the keycode and keysym.
> 
> Sure.
> 
> > Specifically I'm interested in this line of text:
> > 
> >     state 0x0, keycode 112 (keysym 0xff55, Prior), same_screen YES,
> > 
> > On evdev it reports 112 as hardware code which is 0x70 hex, while with
> > 'kbd' it reports 99 which is 0x63 hex. These are the only two scenarios
> > QEMU knows how to cope with.
> 
> Then we’re somewhat out of luck:
> 
> KeyPress event, serial 35, synthetic NO, window 0x1000001,
>     root 0x25, subw 0x0, time 2624181177, (244,533), root:(250,560),
>     state 0x0, keycode 71 (keysym 0xff55, Prior), same_screen YES,
>     XLookupString gives 0 bytes:
>     XmbLookupString gives 0 bytes:
>     XFilterEvent returns: False

This is all rather unfortunate, as I can't determine the well known
scancode set that this matches so far. So I'll definitely have to
investigate the source to understand what's going on.

Regards,
Daniel
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