===== Disable kWallet =====
Under Plasma, when closing a KVM VM (and most likely at other occasions too) kWallet might ask to provide your credentials - even though you never initialized kWallet. In the dialog that opens, just remove the check mark from "Enable the KDE wallet subsystem". 

As desktop user run\\
''kcmshell5 kwalletconfig5''

{{linux:disablekwallet.png}}\\