NIC is unavailable in DPDK application

[Danil Onishchenko <danil.onishchenko.info@gmail.com>]

Hello,

I'm studying DPDK and trying to create a simple application, however it 
can't see a NIC bound to DPDK.

1. Here is a list of network devices I have on my machine

$ dpdk-devbind.py --status-dev net

Network devices using kernel driver
===================================
0000:01:00.0 'RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
8168' if=enp1s0 drv=r8169 unused=vfio-pci *Active*
0000:02:00.0 'RTL8822BE 802.11a/b/g/n/ac WiFi adapter b822' if=wlp2s0 
drv=rtw_8822be unused=rtw88_8822be,vfio-pci *Active*

2. I disable my ethernet NIC (it can't be bound to DPDK while it is 
active) and bind it to vfio-pci driver successfully

$ ip link set enp1s0 down
$ dpdk-devbind.py -b vfio-pci enp1s0

3. Now dpdk-devbind.py shows that the NIC is using DPDK-compatible driver

$ dpdk-devbind.py --status-dev net

Network devices using DPDK-compatible driver
============================================
0000:01:00.0 'RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
8168' drv=vfio-pci unused=r8169

Network devices using kernel driver
===================================
0000:02:00.0 'RTL8822BE 802.11a/b/g/n/ac WiFi adapter b822' if=wlp2s0 
drv=rtw_8822be unused=rtw88_8822be,vfio-pci *Active*

4. However when I run any example DPDK application it says that there 
are no available NIC ports. For instance I wrote a simple application

int main(int argc, char *argv[])
{
     int ret;
     int total_ports, avail_ports;

     ret = rte_eal_init(argc, argv);
     if( ret < 0 )
         rte_exit(EXIT_FAILURE, "EAL initialization failed\n");

     total_ports = rte_eth_dev_count_total();
     avail_ports = rte_eth_dev_count_avail();
     printf("ETH PORTS %d %d\n", total_ports, avail_ports);

     rte_eal_cleanup();

     return 0;
}

and both rte_eth_dev_count_total() and rte_eth_dev_count_avail() return 0.

What am I doing wrong?