Hello,
when a VM has the host CDROM marqued as connected and there is no CD in the drive, restarting libvirtd make the VM crash and restart.
Output from journalctl:
déc. 15 13:47:36 kiwano libvirtd[1986]: 2018-12-15 12:47:36.770+0000: 2391: error : virStorageFileBackendFileReadHeader:1474 : Failed to open file '/dev/sr0': Aucun médium trouvé
déc. 15 13:47:36 kiwano virtlogd[3241]: 2018-12-15 12:47:36.828+0000: 3241: error : virNetSocketReadWire:1801 : End of file while reading data: Erreur d'entrée/sortie
Output from VM log
2018-12-15 12:47:36.723+0000: shutting down, reason=crashed
Daniel