[dpdk][hotplug] DPDK网卡设备热插拔

dpdk pci网卡设备的热插拔。

样例程序如下：

... ...

static int driverctl(char* pci)
{
    int pid;                                                                       

    pid = fork();
    if (pid == ) {
        execlp("driverctl", "driverctl", "--nosave", "set-override",
                pci, "igb_uio", NULL);
        perror("driverctl set-override failed.");
        exit();
    } else if (pid > ) {
        wait(NULL);
    } else {
        perror("fork failed.");
        exit();
    }                                                                              

    return ;
}                                                                                  

static int dpdk_bind_ethernet(struct pci_mac_map_t* port)
{
    uint8_t portid;                                                                

    if (port->stat == PCI_STAT_DPDK)
        return ;                                                                  

    /* bind driver. */
    /* FIXME: Only support igb_uio. */
    log(LOG_INFO, "driverctl bind: %s.\n", port->pci);
    if (driverctl(port->pci) < ) {
        log(LOG_ERR, "driverctl()\n");
        return -;
    }
    /* attach. */
    log(LOG_INFO, "dpdk attach: %s.\n", port->pci);
    if (rte_eth_dev_attach(port->pci, &portid) < ) {
        ctrl_debug(LOG_ERR, "rte_eth_dev_attach()\n");
        return -;
    }                                                                              

    return portid;
}                             

... ...