Problem with KVM switch and erratic mouse movement on windows server 2008

Question

I recently installed a PS/2 KVM switch that is connecting two Ubuntu servers and a Windows 2008 server. It worked fine with the Ubuntu boxes, but on the Windows box whenever I try to move the mouse the pointer jumps all over the screen and acts as though the buttons and scroll wheel have been clicked/moved in a seemingly random pattern.

I tried shutting down all of the boxes and disconnecting both Ubuntu boxes from the KVM and resetting the KVM, but when I rebooted the Windows server the problem persisted. If I plug the mouse directly into the Windows server, it works normally, but if I plug it back into the KVM switch the problem returns. Does anyone know of any way of stopping this?

Solution

Using qemu command line

Add " -usb -usbdevice tablet" to your qemu commandline.

You will get a properly working mouse in your guests without any re-configuration of your guests. The host's mouse position will be used in the guest even without having to click inside the window to give it focus.

Using virt-manager

The equivalent for that is to open up the virtual machine details > Add Hardware > Input > EvTouch USB Graphics Tablet.

I always select "USB Connected Mouse" during the Slackware install for the mouse type but I don't think it matters.

Source

Comments

[Thalys]

Thats an interesting theory, but backing it up with sources would seriously improve your answer.

[murgatroid99]

This was definitely not it. I did not have anything plugged into the COM port, and the mouse would only move erratically when the actual mouse was moving.