=== -blockdev/-device=<node-name> ===
 
-Testing: -blockdev driver=null-co,node-name=null -device ide-hd,drive=null
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device ide-hd,drive=null
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device ide-hd,drive=null,id=qdev_id
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device ide-hd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device scsi-hd,drive=null
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device scsi-hd,drive=null
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device scsi-hd,drive=null,id=qdev_id
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device scsi-hd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device virtio-blk-pci,drive=null
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device virtio-blk-pci,drive=null
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device virtio-blk-pci,drive=null,id=qdev_id
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device virtio-blk-pci,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device floppy,drive=null
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device floppy,drive=null
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device floppy,drive=null,id=qdev_id
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device floppy,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device ide-cd,drive=null
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device ide-cd,drive=null
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device ide-cd,drive=null,id=qdev_id
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device ide-cd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device scsi-cd,drive=null
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device scsi-cd,drive=null
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -blockdev driver=null-co,node-name=null -device scsi-cd,drive=null,id=qdev_id
+Testing: -blockdev driver=null-co,read-zeroes=on,node-name=null -device scsi-cd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-null: null-co:// (null-co)
+null: json:{"read-zeroes": true, "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
 === -drive if=none/-device=<node-name> ===
 
-Testing: -drive if=none,driver=null-co,node-name=null -device ide-hd,drive=null,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device ide-hd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
-null: null-co:// (null-co)
+null: json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device scsi-hd,drive=null,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device scsi-hd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
-null: null-co:// (null-co)
+null: json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device virtio-blk-pci,drive=null,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device virtio-blk-pci,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
-null: null-co:// (null-co)
+null: json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device floppy,drive=null,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device floppy,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
-null: null-co:// (null-co)
+null: json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device ide-cd,drive=null,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device ide-cd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
-null: null-co:// (null-co)
+null: json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device scsi-cd,drive=null,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device scsi-cd,drive=null,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
-null: null-co:// (null-co)
+null: json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 
 === -drive if=none/-device=<bb-name> (with medium) ===
 
-Testing: -drive if=none,driver=null-co,node-name=null -device ide-hd,drive=none0
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device ide-hd,drive=none0
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device ide-hd,drive=none0,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device ide-hd,drive=none0,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device scsi-hd,drive=none0
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device scsi-hd,drive=none0
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device scsi-hd,drive=none0,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device scsi-hd,drive=none0,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device virtio-blk-pci,drive=none0
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device virtio-blk-pci,drive=none0
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device virtio-blk-pci,drive=none0,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device virtio-blk-pci,drive=none0,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device floppy,drive=none0
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device floppy,drive=none0
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device floppy,drive=none0,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device floppy,drive=none0,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device ide-cd,drive=none0
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device ide-cd,drive=none0
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device ide-cd,drive=none0,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device ide-cd,drive=none0,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device scsi-cd,drive=none0
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device scsi-cd,drive=none0
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=none,driver=null-co,node-name=null -device scsi-cd,drive=none0,id=qdev_id
+Testing: -drive if=none,driver=null-co,read-zeroes=on,node-name=null -device scsi-cd,drive=none0,id=qdev_id
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-none0 (null): null-co:// (null-co)
+none0 (null): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      qdev_id
     Removable device: not locked, tray closed
     Cache mode:       writeback
     Removable device: not locked, tray closed
 (qemu) quit
 
-Testing: -drive if=floppy,driver=null-co
+Testing: -drive if=floppy,driver=null-co,read-zeroes=on
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-floppy0 (NODE_NAME): null-co:// (null-co)
+floppy0 (NODE_NAME): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=ide,driver=null-co
+Testing: -drive if=ide,driver=null-co,read-zeroes=on
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-ide0-hd0 (NODE_NAME): null-co:// (null-co)
+ide0-hd0 (NODE_NAME): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
     Removable device: not locked, tray closed
 (qemu) quit
 
-Testing: -drive if=ide,driver=null-co,media=cdrom
+Testing: -drive if=ide,driver=null-co,read-zeroes=on,media=cdrom
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-ide0-cd0 (NODE_NAME): null-co:// (null-co, read-only)
+ide0-cd0 (NODE_NAME): json:{"read-zeroes": "on", "driver": "null-co"} (null-co, read-only)
     Attached to:      PATH
     Removable device: not locked, tray closed
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=virtio,driver=null-co
+Testing: -drive if=virtio,driver=null-co,read-zeroes=on
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-virtio0 (NODE_NAME): null-co:// (null-co)
+virtio0 (NODE_NAME): json:{"read-zeroes": "on", "driver": "null-co"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit
 
-Testing: -drive if=pflash,driver=null-co,size=1M
+Testing: -drive if=pflash,driver=null-co,read-zeroes=on,size=1M
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) info block
-pflash0 (NODE_NAME): json:{"driver": "null-co", "size": "1M"} (null-co)
+pflash0 (NODE_NAME): json:{"read-zeroes": "on", "driver": "null-co", "size": "1M"} (null-co)
     Attached to:      PATH
     Cache mode:       writeback
 (qemu) quit