Hi Zhang，
I have tested COLO with qemu-3.1.0 follow
https://wiki.qemu.org/Features/COLO
I got this problems on PVM:
{"timestamp": {"seconds": 1550230616, "microseconds": 644348}, "event":
"STOP"}
{"timestamp": {"seconds": 1550230616, "microseconds": 719003}, "event":
"RESUME"}
{"timestamp": {"seconds": 1550230616, "microseconds": 743554}, "event":
"STOP"}
qemu-system-x86_64: Can't receive COLO message: Input/output error
qemu-system-x86_64: Can't receive COLO message: Input/output error
{"timestamp": {"seconds": 1550230618, "microseconds": 257209}, "event":
"COLO_EXIT", "data": {"mode": "primary", "reason": "error"}}
And on SVM:
{"timestamp": {"seconds": 1550230616, "microseconds": 731544}, "event":
"STOP"}
[email protected]:colo_vm_state_change Change 'run' => 'stop'
[email protected]:colo_send_message Send 'checkpoint-reply' message
[email protected]:colo_receive_message Receive 'vmstate-send' message
[email protected]:colo_flush_ram_cache_begin dirty_pages
18446744073708498780
[email protected]:colo_flush_ram_cache_end
[email protected]:colo_receive_message Receive 'vmstate-size' message
[email protected]:colo_send_message Send 'vmstate-received' message
{"timestamp": {"seconds": 1550230616, "microseconds": 837436}, "event":
"RESUME"}
qemu-system-x86_64: block.c:5062: bdrv_detach_aio_context: Assertion
`!bs->walking_aio_notifiers' failed.
Aborted (core dumped)
./qemu-system-x86_64 -enable-kvm -m 4096 -smp 4 -qmp stdio -vnc :7 -name
primary \
-cpu qemu64,+kvmclock \
-device piix3-usb-uhci \
-device usb-tablet \
-netdev tap,id=tap0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
\
-device virtio-net-pci,id=net-pci0,netdev=tap0 \
-drive
if=virtio,id=primary-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,children.0.file.filename=/home/wenzt/image/CentOS-7-x86_64-Minimal.img,children.0.driver=raw
\
-S \
-chardev socket,id=mirror0,host=10.121.219.2,port=9003,server,nowait \
-chardev socket,id=compare1,host=10.121.219.2,port=9004,server,nowait \
-chardev socket,id=compare0,host=10.121.219.2,port=9001,server,nowait \
-chardev socket,id=compare0-0,host=10.121.219.2,port=9001 \
-chardev socket,id=compare_out,host=10.121.219.2,port=9005,server,nowait \
-chardev socket,id=compare_out0,host=10.121.219.2,port=9005 \
-object iothread,id=iothread1 \
-object filter-mirror,id=m0,netdev=tap0,queue=tx,outdev=mirror0 \
-object filter-redirector,netdev=tap0,id=redire0,queue=rx,indev=compare_out \
-object filter-redirector,netdev=tap0,id=redire1,queue=rx,outdev=compare0 \
-object
colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0,iothread=iothread1
./qemu-system-x86_64 -enable-kvm -m 4096 -smp 4 -qmp stdio -vnc :7 -name
secondary \
-cpu qemu64,+kvmclock \
-device piix3-usb-uhci \
-device usb-tablet \
-netdev tap,id=tap0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
\
-device virtio-net-pci,id=net-pci0,netdev=tap0 \
-drive
if=none,id=secondary-disk0,file.filename=/home/wenzt/image/CentOS-7-x86_64-Minimal.img,driver=raw,node-name=node0
\
-drive if=virtio,id=active-disk0,driver=replication,mode=secondary,\
file.driver=qcow2,top-id=active-disk0,\
file.file.filename=/home/wenzt/image/active_disk.img,\
file.backing.driver=qcow2,\
file.backing.file.filename=/home/wenzt/image/hidden_disk.img,\
file.backing.backing=secondary-disk0 \
-incoming tcp:0:8888 \
-chardev socket,id=red0,host=10.121.219.2,port=9003 \
-chardev socket,id=red1,host=10.121.219.2,port=9004 \
-object filter-redirector,id=f1,netdev=tap0,queue=tx,indev=red0 \
-object filter-redirector,id=f2,netdev=tap0,queue=rx,outdev=red1 \
-object filter-rewriter,id=f3,netdev=tap0,queue=all
SVM QMP:
{'execute':'qmp_capabilities'}
{'execute': 'nbd-server-start', 'arguments': {'addr': {'type': 'inet', 'data':
{'host': '10.121.219.102', 'port': '8889'} } } }
{'execute': 'nbd-server-add', 'arguments': {'device': 'secondary-disk0',
'writable': true } }
{'execute': 'trace-event-set-state', 'arguments': {'name': 'colo*', 'enable':
true} }
PVM QMP:
{'execute':'qmp_capabilities'}
{'execute': 'human-monitor-command', 'arguments': {'command-line': 'drive_add
-n buddy
driver=replication,mode=primary,file.driver=nbd,file.host=10.121.219.102,file.port=8889,file.export=secondary-disk0,node-name=nbd_client0'}}
{"execute": "migrate-set-parameters" , "arguments":{ "x-checkpoint-delay": 2000
} }
{'execute':'x-blockdev-change', 'arguments':{'parent': 'primary-disk0', 'node':
'nbd_client0' } }
{'execute': 'migrate-set-capabilities', 'arguments': {'capabilities': [
{'capability': 'x-colo', 'state': true } ] } }
{'execute': 'migrate', 'arguments': {'uri': 'tcp:10.121.219.102:8888' } }
{"execute": "x-colo-lost-heartbeat"}
