请教 DPDK 测试程序问题？

搭建 DPDK 测试环境时，在 /tools/setup.sh 中运行 testpmd 总提示 Port 0 Link Down ，如下

Configuring Port 0 (socket 0)
PMD: ixgbe_dev_tx_queue_setup(): sw_ring=0x7f12d5dedb40 hw_ring=0x7f12d5defb80 dma_addr=0x7cd1efb80
PMD: ixgbe_set_tx_function(): Using simple tx code path
PMD: ixgbe_set_tx_function(): Vector tx enabled.
PMD: ixgbe_dev_rx_queue_setup(): sw_ring=0x7f12d5ddd240 sw_sc_ring=0x7f12d5ddcd00 hw_ring=0x7f12d5ddd780 dma_addr=0x7cd1dd780
PMD: ixgbe_set_rx_function(): Vector rx enabled, please make sure RX burst size no less than 32.
Port 0: A0:36:9F:44:B8:3A
Checking link statuses...
Port 0 Link Down
Done`

绑定的网卡是：

Network devices using DPDK-compatible driver
============================================
0000:01:00.1 'Ethernet Controller 10-Gigabit X540-AT2' drv=igb_uio unused=ixgbe

麻烦各位老师看看是什么问题？新手，已经折腾两三天了，累啊。