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我正在尝试运行 AF_XDP 轮询模式驱动程序。内核版本为 5.4（CONFIG_XDP_SOCKETS=y）。当我运行 DPDK 网站提供的示例时，发生了错误。

root@n211-203-164:~# dpdk-testpmd --vdev=net_af_xdp0,iface=eth3 -- -i --total-num-mbufs=10240
EAL: Detected 96 lcore(s)
EAL: Detected 2 NUMA nodes
EAL: Detected static linkage of DPDK
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Selected IOVA mode 'PA'
EAL: No available 1048576 kB hugepages reported
EAL: VFIO support initialized
EAL: Probe PCI driver: mlx5_pci (15b3:1017) device: 0000:5e:00.0 (socket 0)
mlx5_net: Default miss action is not supported.
EAL: Probe PCI driver: mlx5_pci (15b3:1017) device: 0000:5e:00.1 (socket 0)
mlx5_net: Default miss action is not supported.
EAL: Probe PCI driver: mlx5_pci (15b3:1017) device: 0000:86:00.0 (socket 1)
mlx5_net: Default miss action is not supported.
EAL: Probe PCI driver: mlx5_pci (15b3:1017) device: 0000:86:00.1 (socket 1)
mlx5_net: Default miss action is not supported.
Interactive-mode selected
testpmd: create a new mbuf pool <mb_pool_0>: n=10240, size=2176, socket=0
testpmd: preferred mempool ops selected: ring_mp_mc
testpmd: create a new mbuf pool <mb_pool_1>: n=10240, size=2176, socket=1
testpmd: preferred mempool ops selected: ring_mp_mc

Warning! port-topology=paired and odd forward ports number, the last port will pair with itself.

Configuring Port 0 (socket 0)
Port 0: B8:CE:F6:35:DB:3A
Configuring Port 1 (socket 0)
Port 1: B8:CE:F6:35:DB:3B
Configuring Port 2 (socket 1)
Port 2: B8:CE:F6:3B:31:4A
Configuring Port 3 (socket 1)
Port 3: B8:CE:F6:3B:31:4B
Configuring Port 4 (socket 0)
xsk_configure(): Failed to create xsk socket.
eth_rx_queue_setup(): Failed to configure xdp socket
Fail to configure port 4 rx queues
EAL: Error - exiting with code: 1
  Cause: Start ports failed

似乎 XSK 套接字调用 bind() 失败，因此 eth_rx_queue_setup() 失败。

如何正确配置 EAL 参数以使用 vdev=af_net_xdp0 运行 dpdk-testpmd？任何帮助是极大的赞赏。

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1 回答 1

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这是关于 rlimit 的问题。我写了一个简单的测试程序员。

#include <bpf.h>
#include <xsk.h>
#include <stdio.h>
//#include <sys/resource.h>

//static struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};

int main() {
        //setrlimit(RLIMIT_MEMLOCK, & r);

        int fd = bpf_create_map_name(BPF_MAP_TYPE_XSKMAP, "xsks_map", sizeof(int), sizeof(int), 1, 0);
        printf("fd:%d\n", fd);
        return 0;
}

执行cmd strace -e bpf ./test-prog，结果可能是这样的：

root@n211-203-164:~# strace -e bpf ./test 
bpf(BPF_MAP_CREATE, {map_type=0x11 /* BPF_MAP_TYPE_??? */, key_size=4, value_size=4, max_entries=1}, 112) = -1 EPERM (Operation not permitted)
fd:-1 1
+++ exited with 0 +++

这意味着max locked memory造成资源分配不足。执行 cmdulimit -a可以找到max locked memory64 kbytes。max locked memory解决方案有两种，一种是通过执行 cmd 全局放大，ulimit -S -l <a big value>另一种是在创建 BPF map 时调用 setrlimit() 到 libbpf.so 中。

于 2021-09-07T02:49:17.383 回答