OK so maybe:
virsh qemu-monitor-command --hmp instance-0000001a 'drive_add 1 file=rbd:cinder-ceph/volume-d70c7674-e330-46dc-9e4a-9cbd0c5831e4:id=nova-compute:auth_supported=cephx\;none:mon_host=10.5.26.60\:6789\;10.5.26.61\:6789\;10.5.26.62\:6789,password-secret=virtio-disk0-secret1,format=raw,if=none,id=drive-virtio-disk1,serial=d70c7674-e330-46dc-9e4a-9cbd0c5831e4,cache=none'
OK so maybe:
virsh qemu-monitor- command --hmp instance-0000001a 'drive_add 1 file=rbd: cinder- ceph/volume- d70c7674- e330-46dc- 9e4a-9cbd0c5831 e4:id=nova- compute: auth_supported= cephx\; none:mon_ host=10. 5.26.60\ :6789\; 10.5.26. 61\:6789\ ;10.5.26. 62\:6789, password- secret= virtio- disk0-secret1, format= raw,if= none,id= drive-virtio- disk1,serial= d70c7674- e330-46dc- 9e4a-9cbd0c5831 e4,cache= none'