For some reason that eludes me, sharing of the clipboard between the KVM host and the guest (sometimes referred to as clipboard integration) is on by default with QEMU/KVM and SPICE graphics.
To disable such clipboard sharing:
- Edit the guest definition XML;
virsh edit $GUESTand locate
graphics, or through virt-manager’s View > Details > Display Spice > XML
- Add or update an element
<clipboard copypaste="no"/>under the
- Save/apply the change
- Fully shut down the VM (if running)
If starting the VM from the command line, another option is to try adding
-spice disable-copy-paste to the
qemu-system-* command line. (See here.)
Clipboard sharing between the host and the guest will be disabled the next time the VM is powered on.