[Libguestfs] Parameter 'encrypt.key-secret' is required for cipher for virt-ls

Hello all, background: One of my VM stopped working - on startup, I get the message "No bootable device" in the virtual machine. I would like to inspect the corresponding image with libguestfs-tools. However, I don't know how to pass the encryption key to the tool. For example: virt-ls -a /opt/vm_witherror/machine1.qcow2 / libguestfs: trace: set_verbose true libguestfs: trace: set_verbose = 0 libguestfs: create: flags = 0, handle = 0x5645c40d6b00, program = virt-ls libguestfs: trace: add_drive "/opt/vm_witherror/machine1.qcow2" "readonly:true" libguestfs: creating COW overlay to protect original drive content libguestfs: trace: get_tmpdir libguestfs: trace: get_tmpdir = "/tmp" libguestfs: trace: disk_create "/tmp/libguestfsxECmri/overlay1.qcow2" "qcow2" -1 "backingfile:/opt/vm_witherror/machine1.qcow2" libguestfs: command: run: qemu-img libguestfs: command: run: \ create libguestfs: command: run: \ -f qcow2 libguestfs: command: run: \ -o backing_file=/opt/vm_witherror/machine1.qcow2 libguestfs: command: run: \ /tmp/libguestfsxECmri/overlay1.qcow2 qemu-img: /tmp/libguestfsxECmri/overlay1.qcow2: Parameter 'encrypt.key-secret' is required for cipher Could not open backing image. libguestfs: error: qemu-img: /tmp/libguestfsxECmri/overlay1.qcow2: qemu-img exited with error status 1, see debug messages above libguestfs: trace: disk_create = -1 (error) libguestfs: trace: add_drive = -1 (error) libguestfs: trace: close libguestfs: closing guestfs handle 0x5645c40d6b00 (state 0) libguestfs: command: run: rm libguestfs: command: run: \ -rf /tmp/libguestfsxECmri Could you please provide an example on how to get such an encrypted disk mounted? Thanks in advance Kind regards Dominik