guestfsd software package provides Daemon to access to guest virtual machine through virtio serial, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install guestfsd
guestfsd is installed in your system.
Make ensure the guestfsd package were installed using the commands given below,
$ sudo dpkg-query -l | grep guestfsd *
You will get with guestfsd package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Libraries |
| Package | guestfsd |
| Version | 1:1.32.7-1+b2 |
| Description | Daemon to access to guest virtual machine through virtio serial |
| Sub Section | Libs |