On Tue, Sep 25, 2007 at 11:06:58PM +0100, Daniel P. Berrange wrote:
>
> By an unfortunate co-incidence I've just hit a similar problem myself. It
> turns out QEMU mouse handling is more complex than I realized. QEMU can
> export several different input devices to a guest OS, PS/2 mouse, VMWare
> mouse, USB mouse, USB EvTouch tablet, USB Wacom tablet. Only one of these
> devices will be fed mouse events from the host OS though at any time. The
> default is that the most recently 'activated' mouse will get the events.
> This starts off being the PS/2 mouse. Certain actions in the guest OS may
> cause one or more of the other input devices to activate itself, and thus
> claiming control of all input events from the host.
>
> You can see what mice are configured at any time from the QEMU monitor by
> typing 'info mice'. The active one has an * next to it. What I suspect
> is happening in your case is that you've configured the USB tablet, but
> during initial boot only the PS/2 mouse is activated & GPM is actually
> responding to events from the PS/2 mouse no the tablet. Then during boot
> something in HAL (or perhaps X itself) causes the USB tablet to become
> active & thus the PS/2 mouse stops getting events. But then it sounds
> like neither GPM or X are configured to use the USB tablet either, so
> you end up with no movement at all.
>
> So I guess it is probably a matter of suitably configuring Xorg to use
> the USB tablet, though I can't remember exact syntax for Fedora Core 6,
> in Fedora 7 I have successfully used:
>
> Section "InputDevice"
> Name "Mouse0"
> Driver "evdev"
> Option "Name" "QEMU 0.8.2 QEMU USB Tablet"
> Option "Mode" "Absolute"
> EndSection
>
> NB, make sure 'Mouse0' is referenced as the CorePointer in the ServerLayout
> section of the config. Also the 'Name' value varies acording to what QEMU
> version you have[1] - check /proc/bus/input/devices for exact name seen
> by the guest OS
>
Thanks for your eye-opening response! As you suspected, my guest's
haldaemon activated the USB Tablet mouse and robbed GPM of its mouse
source. And evdev's (?) by-name device selection is so nice comparing to
guessing which /dev/input/event? is used.
However, I still have a usability problem. Do you experience smooth
mouse movement with evdev? I have untolerable cursor movement, unless I
move the mouse very very very slowly. Otherwise, the cursor tends to
keep its horizontal position.
Thanks,
Dan.
