Tested with Fedora 25 and Kali 2017. This wil enable copy/paste between guest and host and automatically resize resolution after resizing the guest VM window.

• Install the Kali VM using GNOME boxes.
• Install the latest updates:

  apt-get update
  apt-get upgrade

• Install needed packages:

  apt-get install xserver-xorg-video-qxl spice-vdagent

• Enable the service:

  systemctl enable spice-vdagent

• Shutdown, boot the VM and you're done!