[
 {
  "op": "add",
  "path": "/definitions/BlockDeviceMapping/requiredXor",
  "value": [
   "VirtualName",
   "Ebs",
   "NoDevice"
  ]
 },
 {
  "op": "add",
  "path": "/definitions/BlockDeviceMapping/properties/VirtualName/pattern",
  "value": "^ephemeral([0-9]|[1][0-9]|[2][0-3])$"
 }
]
