QEMU 'blockdev-add' and 'blockdev-backup' tests
===============================================

Notes
-----

We're testing *two* cases: 

  (1) 'blockdev-backup' with target as device ID (e.g. 'drive-ide2-0-0')
  (2) 'blockdev-backup' with target as node name (e.g. 'node-backup2')

Using QMP connection over UNIX socket.  'blockdev-backup'.

BDSs are called as "nodes" (as they are nodes in the BDS graph).

[jsnow] I am not aware of any use cases targeting a node that isn't the
root node directly under a BB (BlockBackend).

[mreitz]
 - We like to call BDSs (BlockDriverState) "nodes" (as they are nodes
   in the BDS graph).  And you can give each BDS a name, which then is a
   node name. So you can not just target a device, but basically any BDS
   in the graph.

   Normally you'd use that for targeting root BDSs in a tree, so you add
   a BDS tree via 'blockdev-add', then you can target it via
   'blockdev-mirror' or 'blockdev-backup' or whatever, and then you can
   do with the BDS tree whatever you like -- maybe you'd like to drop it
   again via 'x-blockdev-del', maybe you'd like to attach it to a
   device.


Setup: QEMU command-line used to invoke QMP server
--------------------------------------------------

#!/bin/bash

/usr/bin/qemu-system-x86_64 \
    -machine accel=kvm \
    -name cirrvm \
    -S \
    -machine pc-i440fx-2.1,accel=kvm,usb=off \
    -cpu SandyBridge \
    -m 977 \
    -realtime mlock=off \
    -smp 1,sockets=1,cores=1,threads=1 \
    -uuid ec9714ed-b23b-4580-99c6-b2862a5bea21 \
    -nographic \
    -no-user-config \
    -nodefaults \
    -chardev socket,id=charmonitor,path=/var/tmp/cirrvm.monitor,server,nowait \
    -mon chardev=charmonitor,id=monitor,mode=control \
    -rtc base=utc,driftfix=slew \
    -global kvm-pit.lost_tick_policy=discard \
    -no-hpet \
    -no-shutdown \
    -boot strict=on \
    -device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x3.0x7 \
    -drive file=./cirros-0.3.3.qcow2,if=none,id=drive-ide0-0-0,driver=qcow2 \
    -device ide-hd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 \
    -chardev pty,id=charserial0 \
    -device isa-serial,chardev=charserial0,id=serial0 \
    -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 \
    -msg timestamp=on \
    -qmp unix:./qmp-sock,server --monitor stdio
-----------------------------------------------------


Case-1: 'blockdev-backup' with target as device ID (e.g. 'drive-ide2-0-0')
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-----------------------------------------------------

# (1) Create the backup qcow2 file

$ qemu-img create -f qcow2 backup1.qcow2 1G
Formatting 'backup1.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
$ file backup1.qcow2 
backup1.qcow2: QEMU QCOW Image (v3), 1073741824 bytes
-----------------------------------------------------

# (2) Connect to the QMP server

$ socat UNIX:/export/qemu-backup-tests/qmp-sock READLINE,history=$HOME/.qmp_history,prompt='QMP> '
{"QMP": {"version": {"qemu": {"micro": 0, "minor": 6, "major": 2}, "package": " (qemu-2.6.0-3.fc24)"}, "capabilities": []}}
QMP>
-----------------------------------------------------

# (2.1) Execute the QMP capabilities

QMP> {"execute":"qmp_capabilities"}
{"return": {}}
-----------------------------------------------------

# (3) Add the block device:

QMP> { "execute": "blockdev-add",
     "arguments": { "options" : { "driver": "qcow2", 
                                 "id": "drive-ide2-0-0",
                                 "file": { "driver": "file",
                                           "filename": "/export/backup1.qcow2"} } } }
-----------------------------------------------------

# (4) Perform 'blockdev-backup' to the target

$ socat UNIX:/export/qemu-backup-tests/qmp-sock READLINE,history=$HOME/.qmp_history,prompt='QMP> '
{"QMP": {"version": {"qemu": {"micro": 0, "minor": 6, "major": 2}, "package": " (qemu-2.6.0-3.fc24)"}, "capabilities": []}}
QMP> {"execute":"qmp_capabilities"}
{"return": {}}

QMP> 
{   "execute": "blockdev-backup", 
    "arguments": {
        "device": "drive-ide0-0-0", 
        "target": "drive-ide2-0-0", 
        "sync": "full"
    }
}
-----------------------------------------------------

# (5) Result of 'blockdev-backup' invocation

QMP> {"execute":"qmp_capabilities"}
{"return": {}}
QMP> {   "execute": "blockdev-backup", 
QMP>     "arguments": {
QMP>         "device": "drive-ide0-0-0", 
QMP>         "target": "drive-ide2-0-0", 
QMP>         "sync": "full"
QMP>     }
QMP> }
{"return": {}}
{"timestamp": {"seconds": 1466158164, "microseconds": 695444}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "drive-ide0-0-0", "len": 41126400, "offset": 41126400, "speed": 0, "type": "backup"}}
QMP> 
-----------------------------------------------------


Case-2: 'blockdev-backup' with target as node-name (e.g. 'node-backup2')
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

NOTE: We're continuing on the same QMP connection from Case-1, where 
'qmp_capabilities' was already executed.

-----------------------------------------------------

# (1) Create the backup file

$ qemu-img create -f qcow2 backup2.qcow2 1G
Formatting 'backup2.qcow2', fmt=qcow2 size=1073741824 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
$ file backup2.qcow2 
backup2.qcow2: QEMU QCOW Image (v3), 1073741824 bytes
-----------------------------------------------------

# (2) Invocation of 'blockdev-add' [ensure that 'node-name' is 

# under the root ('options'), rather than nesting _inside_ 'file'.]
QMP> { "execute": "blockdev-add",
       "arguments": { "options" : { "driver": "qcow2", 
                                    "id": "drive-ide2-0-0",
                                    "node-name": "node-backup2",
                                    "file": { "driver": "file",
                                              "filename": "/export/backup2.qcow2"} } } }
-----------------------------------------------------

# (3) Result of 'blockdev-add'

QMP> { "execute": "blockdev-add",
QMP>        "arguments": { "options" : { "driver": "qcow2", 
QMP>                                     "id": "drive-ide2-0-0",
QMP>                                     "node-name": "node-backup2",
QMP>                                     "file": { "driver": "file",
QMP>                                               "filename": "/export/backup2.qcow2"} } } }
{"return": {}}
-----------------------------------------------------

# (4) Invocation of 'blockdev-backup' with target as 'node-name'

QMP> { "execute": "blockdev-backup", 
       "arguments": {
         "device": "drive-ide0-0-0", 
         "target": "node-backup2", 
         "sync": "full" }}
-----------------------------------------------------

# (5) Result of 'blockdev-backup'

QMP> { "execute": "blockdev-backup", 
QMP>        "arguments": {
QMP>          "device": "drive-ide0-0-0", 
QMP>          "target": "node-backup2", 
QMP>          "sync": "full" }}
{"return": {}}
{"timestamp": {"seconds": 1466161195, "microseconds": 268589}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "drive-ide0-0-0", "len": 41126400, "offset": 41126400, "speed": 0, "type": "backup"}}
-----------------------------------------------------

# (6) On the QEMU (HMP) monitor

(qemu) info block
drive-ide0-0-0 (#block190): ./cirros-0.3.3.qcow2 (qcow2)
    Cache mode:       writeback

drive-ide2-0-0 (node-backup2): /export/backup2.qcow2 (qcow2)
    Removable device: not locked, tray closed
    Cache mode:       writeback
(qemu) 
-----------------------------------------------------


    * * *


To delete the block device (NB: The 'x' indicates it is experimental.):

  QMP> {'execute':'x-blockdev-del', 'arguments': { 'id': 'drive-ide2-0-0'}}
  {"return": {}}