Avoid stripping vlan tag with I350 VF on a VM

My application running on a VM needs to deal with multiple VLANS on packets
received over I350 using Virtual Function. But I always see the received
packets without vlan tag.
This is my setup:
  - host: 3.13.6-031306-generic
  - QEMU emulator version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.7)
  - guest: 2.6.32-358.el6.x86_64
  - dpdk: 1.6

And this is how I set up in the VM:
-------
    memset(&port_conf, 0, sizeof(port_conf));
    if (vlanCnt > 0)
         port_conf.rxmode.hw_vlan_filter = 1;

    port_conf.rxmode.jumbo_frame = 1;
    port_conf.rxmode.max_rx_pkt_len = 9018;

    ret = rte_eth_dev_configure(port, 1, 1, &port_conf);
    if (ret < 0) {
        rte_log(RTE_LOG_CRIT, RTE_LOGTYPE_EAL, "Error on config port%u,
ret=%d\n",
                    (unsigned)port, ret);
        return -1;
    }

    for(i = 0; i < vlanCnt; i++) {
        ret = rte_eth_dev_vlan_filter(port, vlan[i], 1);
        if (ret < 0) {
            rte_log(RTE_LOG_CRIT, RTE_LOGTYPE_EAL, "Error on config port%u,
vlan%d ret=%d\n",
                    (unsigned)port, vlan[i], ret);
            return -1;
        }
    }
-----

If I also try to explicitly disable the stripping with next, but get an
error return -ENOSUP.

ret = rte_eth_dev_set_vlan_strip_on_queue(port, 0, 0);

I appreciate anyone can help. on how to set it up.

Thanks,
Shian Wong