[Qemu-devel] [Bug 1814418] Re: persistent bitmap will be inconsistent when qemu crash,

[Cheng Chen]

Thanks, all:

I only want to know:

1. Is this a bug?
2. Which qemu version will fix the bug?

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1814418

Title:
  persistent bitmap will be inconsistent when qemu  crash,

Status in QEMU:
  New

Bug description:
  Follow these steps to reappear the bug:

  1. start qemu
  2. add persistent bitmap: '{ "execute": "block-dirty-bitmap-add", 
"arguments": {"node": "drive-virtio-disk1","name": "bitmap0", "persistent":true 
}}'
  3. stop qemu (Friendly shutdown)
  4. re-start qemu
  5. kill -9 qemu (simulate Host crash, eg. lose power)
  6. re-start qemu

  Now, the '{ "execute": "query-block" }' can't find the bitmap0. I can
  understand at this point, because the bitmap0 has not been
  synchronized yet.

  But, when I try to add persistent bitmap0 again: '{ "execute": "block-
  dirty-bitmap-add", "arguments": {"node": "drive-virtio-disk1","name":
  "bitmap0", "persistent":true }}', It failed:

  {"id":"libvirt-42","error":{"class":"GenericError","desc":"Can't make
  bitmap 'bitmap0' persistent in 'drive-virtio-disk1': Bitmap with the
  same name is already stored"}}

  In other word, when qemu crash, the qcow2 image remain the incomplete
  persistent bitmap.

  ---

  host: centos 7.5
  qemu version: 2.12.0 and 3.1.0, other version I does not test yet.
  qemu command: qemu-system-x86_64 -name guest=test,debug-threads=on -S -object 
secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-190-test./master-key.aes
 -machine pc-i440fx-3.1,accel=kvm,usb=off,dump-guest-core=off,mem-merge=off -m 
1024 -mem-prealloc -mem-path /dev/hugepages1G/libvirt/qemu/190-test -realtime 
mlock=off -smp 1,sockets=1,cores=1,threads=1 -uuid 
1c8611c2-a18a-4b1c-b40b-9d82040eafa4 -smbios type=1,manufacturer=IaaS 
-no-user-config -nodefaults -chardev socket,id=charmonitor,fd=31,server,nowait 
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown 
-boot menu=on,strict=on -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 
-device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x3 -drive 
file=/opt/vol/sas/fb0c7c37-13e7-41fe-b3f8-f0fbaaeec7ce,format=qcow2,if=none,id=drive-virtio-disk0,cache=writeback
 -device 
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1,write-cache=on
 -drive 
file=/opt/vol/sas/bde66671-536d-49cd-8b46-a4f1ea7be513,format=qcow2,if=none,id=drive-virtio-disk1,cache=writeback
 -device 
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x7,drive=drive-virtio-disk1,id=virtio-disk1,write-cache=on
 -netdev tap,fd=33,id=hostnet0,vhost=on,vhostfd=34 -device 
virtio-net-pci,netdev=hostnet0,id=net0,mac=00:85:45:3e:d4:3a,bus=pci.0,addr=0x6 
-chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 
-chardev socket,id=charchannel0,fd=35,server,nowait -device 
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0
 -device usb-tablet,id=input0,bus=usb.0,port=1 -vnc 0.0.0.0:0,password -device 
cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device 
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 -msg timestamp=on

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1814418/+subscriptions