[vfio-users] input-linux first impressions

Gerd Hoffmann kraxel at redhat.com
Thu Apr 14 14:35:36 UTC 2016

On Do, 2016-04-14 at 14:12 +0000, Ivan Volosyuk wrote:
> First of all it is pretty cool to be able to skip the synergy and
> short-circuit multiple layers on the way of keyboard and mouse events.
> It was pretty easy to setup once I found the right options:
> EXTRA_ARGS+=" -object
> input-linux,id=mouse1,evdev=/dev/input/by-id/usb-Logitech_USB-PS_2_Optical_Mouse-event-mouse"
> EXTRA_ARGS+=" -object
> input-linux,id=mouse3,evdev=/dev/input/by-id/usb-Razer_Razer_DeathAdder-event-mouse"
> EXTRA_ARGS+=" -object
> input-linux,id=kbd1,evdev=/dev/input/by-id/usb-0b38_0010-event-kbd,grab_all=on"
> EXTRA_ARGS+=" -object
> input-linux,id=kbd2,evdev=/dev/input/by-id/usb-Chicony_USB_Keyboard-event-kbd,grab_all=on"
> The was some rough edges as well. I stress-tested it playing Stacraft
> 2 with a lot of mouse and keyboard events. Some of my keybindings
> require 2 modifiers: e.g. ctrl-shift-r. The issues I found:
> - It seems some modifiers sometimes was getting stuck, so I was
> puzzled a few times when I couldn't select single unit (probably shift
> was stuck). I have to press all modifiers to get it released.
> - At some point mouse was ungrabbed and remained this way even I could
> still toggle grab state for my keyboard.

That could be because of the two keyboard devices.

Does it happen with only one keyboard too?

Does it happen with two keyboards, but grab_all=on specified for only
one of them?

Why do you assign two keyboards in the first place?

> - I have 2 extra mouse buttons and the Windows 8.1 didn't seem to
> receive any events for them.

Yep, that is because the mouse devices emulated by qemu can't handle
more buttons.  Improving that shouldn't be too difficult, but will not
happen for the 2.6 release because we are in freeze already.


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