Re: [PATCH net-next v6 3/3] selftests: drv-net: Test queue xsk attribute

[Paolo Abeni]

On 2/10/25 8:38 PM, Joe Damato wrote:
> +def check_xdp(cfg, nl, xdp_queue_id=0) -> None:
> +    test_dir = os.path.dirname(os.path.realpath(__file__))
> +    xdp = subprocess.Popen([f"{test_dir}/xdp_helper", f"{cfg.ifindex}", f"{xdp_queue_id}"],
> +                           stdin=subprocess.PIPE, stdout=subprocess.PIPE, bufsize=1,
> +                           text=True)
> +    defer(xdp.kill)
> +
> +    stdout, stderr = xdp.communicate(timeout=10)
> +    rx = tx = False
> +
> +    queues = nl.queue_get({'ifindex': cfg.ifindex}, dump=True)
> +    if not queues:
> +        raise KsftSkipEx("Netlink reports no queues")
> +
> +    for q in queues:
> +        if q['id'] == 0:
> +            if q['type'] == 'rx':
> +                rx = True
> +            if q['type'] == 'tx':
> +                tx = True
> +
> +            ksft_eq(q['xsk'], {})
> +        else:
> +            if 'xsk' in q:
> +                _fail("Check failed: xsk attribute set.")
> +
> +    ksft_eq(rx, True)
> +    ksft_eq(tx, True)

This causes self-test failures:

https://netdev-3.bots.linux.dev/vmksft-net-drv/results/987742/4-queues-py/stdout

but I really haven't done any real investigation here.

/P

>  
>  def get_queues(cfg, nl) -> None:
>      snl = NetdevFamily(recv_size=4096)
> @@ -81,7 +112,7 @@ def check_down(cfg, nl) -> None:
>  
>  def main() -> None:
>      with NetDrvEnv(__file__, queue_count=100) as cfg:
> -        ksft_run([get_queues, addremove_queues, check_down], args=(cfg, NetdevFamily()))
> +        ksft_run([get_queues, addremove_queues, check_down, check_xdp], args=(cfg, NetdevFamily()))
>      ksft_exit()
>  
>  
> diff --git a/tools/testing/selftests/drivers/net/xdp_helper.c b/tools/testing/selftests/drivers/net/xdp_helper.c
> new file mode 100644
> index 000000000000..b04d4e0ea30a
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/xdp_helper.c
> @@ -0,0 +1,89 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/mman.h>
> +#include <sys/socket.h>
> +#include <linux/if_xdp.h>
> +#include <linux/if_link.h>
> +#include <net/if.h>
> +#include <inttypes.h>
> +
> +#define UMEM_SZ (1U << 16)
> +#define NUM_DESC (UMEM_SZ / 2048)
> +
> +/* this is a simple helper program that creates an XDP socket and does the
> + * minimum necessary to get bind() to succeed.
> + *
> + * this test program is not intended to actually process packets, but could be
> + * extended in the future if that is actually needed.
> + *
> + * it is used by queues.py to ensure the xsk netlinux attribute is set
> + * correctly.
> + */
> +int main(int argc, char **argv)
> +{
> +	struct xdp_umem_reg umem_reg = { 0 };
> +	struct sockaddr_xdp sxdp = { 0 };
> +	int num_desc = NUM_DESC;
> +	void *umem_area;
> +	int ifindex;
> +	int sock_fd;
> +	int queue;
> +	char byte;
> +
> +	if (argc != 3) {
> +		fprintf(stderr, "Usage: %s ifindex queue_id", argv[0]);
> +		return 1;
> +	}
> +
> +	sock_fd = socket(AF_XDP, SOCK_RAW, 0);
> +	if (sock_fd < 0) {
> +		perror("socket creation failed");
> +		return 1;
> +	}
> +
> +	ifindex = atoi(argv[1]);
> +	queue = atoi(argv[2]);
> +
> +	umem_area = mmap(NULL, UMEM_SZ, PROT_READ | PROT_WRITE, MAP_PRIVATE |
> +			MAP_ANONYMOUS, -1, 0);
> +	if (umem_area == MAP_FAILED)
> +		return -1;
> +
> +	umem_reg.addr = (uintptr_t)umem_area;
> +	umem_reg.len = UMEM_SZ;
> +	umem_reg.chunk_size = 2048;
> +	umem_reg.headroom = 0;
> +
> +	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_REG, &umem_reg,
> +		   sizeof(umem_reg));
> +	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_FILL_RING, &num_desc,
> +		   sizeof(num_desc));
> +	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_COMPLETION_RING, &num_desc,
> +		   sizeof(num_desc));
> +	setsockopt(sock_fd, SOL_XDP, XDP_RX_RING, &num_desc, sizeof(num_desc));
> +
> +	sxdp.sxdp_family = AF_XDP;
> +	sxdp.sxdp_ifindex = ifindex;
> +	sxdp.sxdp_queue_id = queue;
> +	sxdp.sxdp_flags = 0;
> +
> +	if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) != 0) {
> +		perror("bind failed");
> +		close(sock_fd);
> +		return 1;
> +	}
> +
> +	/* give the parent program some data when the socket is ready*/
> +	fprintf(stdout, "%d\n", sock_fd);
> +
> +	/* parent program will write a byte to stdin when its ready for this
> +	 * helper to exit
> +	 */
> +	read(STDIN_FILENO, &byte, 1);
> +
> +	close(sock_fd);
> +	return 0;
> +}