https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1647389
https://lists.gnu.org/archive/html/qemu-devel/2016-08/msg03552.html
The bug reported in these pages affect my ubuntu 16.04 with qemu-kvm 2.5,
and it seems that it's not resolved in qemu-kvm 2.7 according to the 2nd link above.
If it happens with zstack iso which has qemu-kvm 2.6, it's better to migrate a vm without
the VIR_MIGRATE_TUNNELLED flag in Vm.migrate
https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1647389
https://lists.gnu.org/archive/html/qemu-devel/2016-08/msg03552.html
The bug reported in these pages affect my ubuntu 16.04 with qemu-kvm 2.5,
and it seems that it's not resolved in qemu-kvm 2.7 according to the 2nd link above.
If it happens with zstack iso which has qemu-kvm 2.6, it's better to migrate a vm without
the VIR_MIGRATE_TUNNELLED flag in Vm.migrate