wiki/gofurther/evdev.md

title	description	published	date	tags	editor	dateCreated
Share an input device with a guest using evdev		true	2023-05-13T16:00:21.759Z		markdown	2022-08-13T00:26:02.801Z

Share an input device

In this section, we focus on sharing a locally attached input device with a guest virtual machine.

Using Evdev

Since version 7.4.0, Libvirt added a low-latency local-only way to share an input device with a guest, using the Linux evdev event interface.

Configuration

• List input devices based on their identification, only listing those with an event in their name and excluding these with if:

ls /dev/input/by-id/* | grep event | grep -v if

/dev/input/by-id/usb-Corsair_CORSAIR_HARPOON_RGB_PRO_Gaming_Mouse_1902B02BAF5E04655DEB612AF5001C05-event-mouse
/dev/input/by-id/usb-Logitech_G513_RGB_MECHANICAL_GAMING_KEYBOARD_156930783132-event-kbd
/dev/input/by-id/usb-Logitech_USB_Keyboard-event-kbd
/dev/input/by-id/usb-Logitech_USB_Optical_Mouse-event-mouse

• Make sure that the correct one is selected by registering its inputs in the console:

cat /dev/input/by-id/usb-Logitech_G513_RGB_MECHANICAL_GAMING_KEYBOARD_156930783132-event-kbd

• Clicking or typing on the device you wish to share should display gibberish characters on the screen:

<EFBFBD><EFBFBD>c      $
<0A><>c<EFBFBD><63><EFBFBD>c<EFBFBD><63><EFBFBD>c<EFBFBD>$<24><>c<EFBFBD>$<24><>c׏<63><D78F>c׏<63><D78F>c                                             

• Add the following snippet to the XML domain definition of an existing virtual machine, inside the <device> section:

<input type='evdev'>
      <source dev='/dev/input/by-id/usb-Logitech_G513_RGB_MECHANICAL_GAMING_KEYBOARD_156930783132-event-kbd' grab='all' repeat='on'/>
</input>

Usage

Press Left Ctrl + Right Ctrl simultaneously to switch your devices between the guest and the host. {.is-info}

Resources

• https://libvirt.org/formatdomain.html#input-devices

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