Commit e7a3c1ad authored by Bobby Eshleman's avatar Bobby Eshleman Committed by Paolo Abeni
Browse files

selftests: drv-net: add HDS payload sweep test for devmem TCP 



Add check_rx_hds test that verifies header/data split works across
payload sizes. The test sweeps payload sizes from 1 byte to 8KB, if any
data propagates up to userspace as SCM_DEVMEM_LINEAR, then the test
fails. This shows that regardless of payload size, ncdevmem's
configuration of hds-thresh to 0 is respected.

Add -L (--fail-on-linear) flag to ncdevmem that causes the receiver to
fail if any SCM_DEVMEM_LINEAR cmsg is received.

Use socat option for fixed block sizing and tcp nodelay to disable
nagle's algo to avoid buffering.

Signed-off-by: default avatarBobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260211-fbnic-tcp-hds-fixes-v1-4-55d050e6f606@meta.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 0f30a31b

tools/testing/selftests/drivers/net/hw/devmem.py

+18 −1
Original line number Diff line number Diff line
@@ -63,12 +63,29 @@ def check_tx_chunks(cfg) -> None: 
    ksft_eq(socat.stdout.strip(), "hello\nworld")





def check_rx_hds(cfg) -> None:

    """Test HDS splitting across payload sizes."""

    require_devmem(cfg)



    for size in [1, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192]:

        port = rand_port()

        listen_cmd = f"{cfg.bin_local} -L -l -f {cfg.ifname} -s {cfg.addr} -p {port}"



        with bkg(listen_cmd, exit_wait=True) as ncdevmem:

            wait_port_listen(port)

            cmd(f"dd if=/dev/zero bs={size} count=1 2>/dev/null | " +

                f"socat -b {size} -u - TCP{cfg.addr_ipver}:{cfg.baddr}:{port},nodelay",

                host=cfg.remote, shell=True)



        ksft_eq(ncdevmem.ret, 0, f"HDS failed for payload size {size}")





def main() -> None:

    with NetDrvEpEnv(__file__) as cfg:

        cfg.bin_local = path.abspath(path.dirname(__file__) + "/ncdevmem")

        cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)



        ksft_run([check_rx, check_tx, check_tx_chunks],

        ksft_run([check_rx, check_tx, check_tx_chunks, check_rx_hds],

                 args=(cfg, ))

    ksft_exit()

tools/testing/selftests/drivers/net/hw/ncdevmem.c

+10 −1
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ static unsigned int ifindex; 
static unsigned int dmabuf_id;

static uint32_t tx_dmabuf_id;

static int waittime_ms = 500;

static bool fail_on_linear;



/* System state loaded by current_config_load() */

#define MAX_FLOWS	8
@@ -975,6 +976,11 @@ static int do_server(struct memory_buffer *mem) 
					"SCM_DEVMEM_LINEAR. dmabuf_cmsg->frag_size=%u\n",

					dmabuf_cmsg->frag_size);



				if (fail_on_linear) {

					pr_err("received SCM_DEVMEM_LINEAR but --fail-on-linear (-L) set");

					goto err_close_client;

				}



				continue;

			}
@@ -1398,8 +1404,11 @@ int main(int argc, char *argv[]) 
	int is_server = 0, opt;

	int ret, err = 1;



	while ((opt = getopt(argc, argv, "ls:c:p:v:q:t:f:z:")) != -1) {

	while ((opt = getopt(argc, argv, "Lls:c:p:v:q:t:f:z:")) != -1) {

		switch (opt) {

		case 'L':

			fail_on_linear = true;

			break;

		case 'l':

			is_server = 1;

			break;