Kernel based vRouter support live migration, while DPDK based vRouter doesn't support live migration

[Groundsea]

Hi expert,
Kernel based vRouter support live migration, while DPDK based vRouter doesn't support live migration.
I'm using Redhat OSP10+Contrail 4.1.1
while use DPDK vRouter, the VM's live migration operation always get failure result.

The failure log is displayed on destionation host's message:
Jan 11 03:53:05 overcloud-contraildpdk-1 libvirtd: 2019-01-11 03:53:05.691+0000: 59541: warning : qemuDomainObjBeginJobInternal:4709 : Cannot start job (query, none) for domain instance-00000004; current job is (none, migration in) owned by (0 , 0 remoteDispatchDomainMigratePrepare3Params) for (0s, 89s)
Jan 11 03:53:05 overcloud-contraildpdk-1 libvirtd: 2019-01-11 03:53:05.691+0000: 59541: error : qemuDomainObjBeginJobInternal:4721 : Timed out during operation: cannot acquire state change lock (held by remoteDispatchDomainMigratePrepare3Params)

below is qemu debug information
Thread 8 (Thread 0x7f0d50ab2700 (LWP 84881)):
#0 0x00007f0d79177bfd in recvmsg () from /lib64/libpthread.so.0
#1 0x000055c1399cf18c in qio_channel_socket_readv ()
#2 0x000055c1399c05e2 in tcp_chr_recv ()
#3 0x000055c1399c1da1 in tcp_chr_sync_read ()
#4 0x000055c1399bc761 in qemu_chr_fe_read_all ()
#5 0x000055c13976a15b in vhost_user_read.isra.6 ()
#6 0x000055c13976a776 in vhost_user_set_log_base ()
#7 0x000055c139766eed in vhost_log_global_start ()
#8 0x000055c13971726e in memory_global_dirty_log_start ()
#9 0x000055c13971de76 in ram_save_setup ()
#10 0x000055c1398e4f95 in qemu_savevm_state_setup ()
#11 0x000055c1398e0d8f in migration_thread ()
#12 0x00007f0d79170dd5 in start_thread () from /lib64/libpthread.so.0
#13 0x00007f0d78e9ab3d in clone () from /lib64/libc.so.6

Redhat guy said "qemu call recvmsg in qio_channel_socket_readv and keep waiting for vrouter's response, but vrouter doesn't give any response"

So please help to identify this issue, thank you very much!