Created attachment 462377 [details]
Patch to allow xorg-x11-drv-evdev to be used for the xen mouse

Description of problem:

   If you try to configure xorg-x11-drv-evdev so that you can make use of
   absolute pointer events for Xen PV guests (which is the correct thing to
   do) you quickly run up against a problem because the driver takes over both
   the mouse and the keyboard and while you can have absolute pointer events
   you can't have keyboard events.

Version-Release number of selected component (if applicable):
   xorg-x11-drv-evdev-1.0.0.5-5.el5

How reproducible:
   Always

Steps to Reproduce:
1.  Attempt to configure xorg-x11-drv-evdev for the absolute mouse pointer
    for a Xen PV guest.  (Note that some releases of the Xen hypervisor will
    also frustrate this because they take no notice when xenkbd.abs_pointer=1
    is passed on the guest's kernel command line).
  
Actual results:
  Discover that it is not possible to have both absolute mouse events and
  a working keyboard.

Expected results:
  Working absolute mouse pointer events *and* a working keyboard.

Additional info:
  The attached patch allows you have a mouse pointer configuration like this:

     Section "InputDevice"
           Identifier  "xenmouse"
           Driver      "evdev"
           Option      "DeviceName" "xen.*(mouse|pointer)"
           Option      "IgnoreKeyboard" "True"
           Option      "WarnOnRelative" "True"
           Option      "GrabDevice" "False"
           Option      "SendCoreEvents" "True"
     EndSection

   The DeviceName, IgnoreKeyboard, WarnOnRelative and GrabDevice options are
   all new.  DeviceName allows the driver to scan /dev/input/event* looking
   for a device that matches a pattern which allows this patch to work with
   kernels that supply different drivers and name the xen mouse driver
   differently.

   IgnoreKeyboard means that the the driver ignores keyboard events coming
   from /dev/input/evdev?  (For completeness there is an IgnoreMouse option)

   WarnOnRelative is an option to print a suitable warning message to
   the Xorg log file if the driver detects relative pointer events (this helps
   tremendously when trying to work out why it isn't working)

   Finally GrabDevice allows events to be handled by other devices, in this
   case the normal keyboard driver.

   The default values for all of these are such that xorg-x11-drv-evdev is
   fully backwards compatible.