# SPDX-License-Identifier: GPL-2.0
# pylint: disable=invalid-name,too-many-arguments
"""Shared helpers for devmem TCP selftests."""
import os
import re
from lib.py import (bkg, cmd, defer, ethtool, rand_port, wait_port_listen,
ksft_eq, KsftSkipEx, NetNSEnter, EthtoolFamily,
NetdevFamily)
RX_PAGE_SIZE_DEFAULT = 0
RX_PAGE_SIZE_16K = 16384
PROBE_RX_PAGE_SIZES = (RX_PAGE_SIZE_DEFAULT, RX_PAGE_SIZE_16K)
NR_HUGEPAGES_FILE = "/proc/sys/vm/nr_hugepages"
def _is_aligned(value, alignment):
"""Equivalent of the kernel IS_ALIGNED(value, alignment).
alignment must be a power of two.
"""
return (value & (alignment - 1)) == 0
def _restore_nr_hugepages(nr_hugepages):
with open(NR_HUGEPAGES_FILE, 'w', encoding='utf-8') as f:
f.write(str(nr_hugepages))
def _reserve_hugepages(want=64):
"""Raise nr_hugepages to @want and arrange for it to be restored."""
with open(NR_HUGEPAGES_FILE, 'r+', encoding='utf-8') as f:
nr_hugepages = int(f.read().strip())
if nr_hugepages >= want:
return
f.seek(0)
f.write(str(want))
defer(_restore_nr_hugepages, nr_hugepages)
def _probe_devmem(cfg, rx_page_size):
"""Return True if ncdevmem can bind cfg.ifname at @rx_page_size."""
probe_command = f"{cfg.bin_local} -f {cfg.ifname}"
if rx_page_size != RX_PAGE_SIZE_DEFAULT:
probe_command += f" -b {rx_page_size}"
return cmd(probe_command, fail=False, shell=True).ret == 0
def require_devmem(cfg, rx_page_size=RX_PAGE_SIZE_DEFAULT):
"""Probe ncdevmem on cfg.ifname and SKIP the test if devmem isn't supported."""
if rx_page_size not in PROBE_RX_PAGE_SIZES:
raise RuntimeError(
f"rx-page-size={rx_page_size} is missing from "
f"PROBE_RX_PAGE_SIZES, so it was never probed.")
if not hasattr(cfg, "devmem_supported"):
_reserve_hugepages()
# Probe every size upfront: in nk tests a leased queue may land in
# ncdevmem's queue range and cause the probe to fail.
cfg.devmem_supported = {size: _probe_devmem(cfg, size)
for size in PROBE_RX_PAGE_SIZES}
if not cfg.devmem_supported[RX_PAGE_SIZE_DEFAULT]:
raise KsftSkipEx("Test requires devmem support")
if rx_page_size != RX_PAGE_SIZE_DEFAULT:
page_size = os.sysconf("SC_PAGE_SIZE")
if not _is_aligned(rx_page_size, page_size):
raise KsftSkipEx(
f"rx-page-size={rx_page_size} is invalid for this platform "
f"(must be a multiple of PAGE_SIZE={page_size})")
if not cfg.devmem_supported[rx_page_size]:
raise KsftSkipEx(
f"Test requires devmem rx-page-size={rx_page_size} support")
def configure_nic(cfg):
"""Channels, rings, RSS, queue lease for netkit devmem."""
if not hasattr(cfg, "devmem_supported"):
raise RuntimeError(
"require_devmem() must be called before configure_nic(), which "
"may lease a queue away and make later probes fail.")
if not hasattr(cfg, 'netns'):
return
cfg.require_ipver('6')
ethnl = EthtoolFamily()
channels = ethnl.channels_get({'header': {'dev-index': cfg.ifindex}})
channels = channels['combined-count']
if channels < 2:
raise KsftSkipEx(
'Test requires NETIF with at least 2 combined channels'
)
rings = ethnl.rings_get({'header': {'dev-index': cfg.ifindex}})
orig_rx_rings = rings['rx']
orig_hds_thresh = rings.get('hds-thresh', 0)
ethnl.rings_set({'header': {'dev-index': cfg.ifindex},
'tcp-data-split': 'enabled',
'hds-thresh': 0,
'rx': min(64, orig_rx_rings)})
defer(ethnl.rings_set, {'header': {'dev-index': cfg.ifindex},
'tcp-data-split': 'unknown',
'hds-thresh': orig_hds_thresh,
'rx': orig_rx_rings})
cfg.src_queue = channels - 1
ethtool(f"-X {cfg.ifname} equal {cfg.src_queue}")
defer(ethtool, f"-X {cfg.ifname} default")
if not hasattr(cfg, 'nk_queue'):
with NetNSEnter(str(cfg.netns)):
netdevnl = NetdevFamily()
lease_result = netdevnl.queue_create({
"ifindex": cfg.nk_guest_ifindex,
"type": "rx",
"lease": {
"ifindex": cfg.ifindex,
"queue": {"id": cfg.src_queue, "type": "rx"},
"netns-id": 0,
},
})
cfg.nk_queue = lease_result['id']
def set_flow_rule(cfg, port):
"""Install a flow rule steering to src_queue and return the flow rule ID."""
output = ethtool(
f"-N {cfg.ifname} flow-type tcp6 dst-port {port}"
f" action {cfg.src_queue}"
).stdout
return int(re.search(r'ID (\d+)', output).group(1))
def ncdevmem_rx(cfg, port, verify=True, fail_on_linear=False, flow_steer=False,
rx_page_size=RX_PAGE_SIZE_DEFAULT):
"""Build the ncdevmem RX listener command."""
if hasattr(cfg, 'netns'):
flow_rule_id = set_flow_rule(cfg, port)
defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
ifname = cfg.nk_guest_ifname
addr = cfg.nk_guest_ipv6
extras = [f"-t {cfg.nk_queue}", "-q 1", "-n"]
else:
ifname = cfg.ifname
addr = cfg.addr
extras = []
if flow_steer:
extras.append(f"-c {cfg.remote_addr}")
if verify:
extras.append("-v 7")
if fail_on_linear:
extras.append("-L")
if rx_page_size != RX_PAGE_SIZE_DEFAULT:
extras.append(f"-b {rx_page_size}")
parts = [cfg.bin_local, "-l", f"-f {ifname}", f"-s {addr}",
f"-p {port}", *extras]
return " ".join(parts)
def ncdevmem_tx(cfg, port, chunk_size=0):
"""Build the ncdevmem TX send command."""
if hasattr(cfg, 'netns'):
ifname = cfg.nk_guest_ifname
addr = cfg.remote_addr_v['6']
extras = ["-t 0", "-q 1", "-n"]
else:
ifname = cfg.ifname
addr = cfg.remote_addr
extras = []
if chunk_size:
extras.append(f"-z {chunk_size}")
parts = [cfg.bin_local, f"-f {ifname}", f"-s {addr}",
f"-p {port}", *extras]
return " ".join(parts)
def socat_send(cfg, port, buf_size=0):
"""Socat command for sending to the devmem listener.
When buf_size > 0, force one TCP segment per write of exactly that size by
setting socat's buffer (-b) and disabling Nagle (TCP_NODELAY).
"""
proto = f"TCP{cfg.addr_ipver}"
if hasattr(cfg, 'netns'):
addr = f"[{cfg.nk_guest_ipv6}]"
else:
addr = cfg.baddr
suffix = f",bind={cfg.remote_baddr}:{port}"
buf = ""
if buf_size:
buf = f"-b {buf_size}"
suffix += ",nodelay"
return f"socat {buf} -u - {proto}:{addr}:{port}{suffix}"
def socat_listen(cfg, port):
"""Socat listen command for TX tests."""
return f"socat -U - TCP{cfg.addr_ipver}-LISTEN:{port}"
def setup_test(cfg, bin_local):
"""Stash the local ncdevmem path on cfg and deploy it to the remote."""
cfg.bin_local = bin_local
cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
def run_rx(cfg):
"""Run the devmem RX test."""
require_devmem(cfg)
configure_nic(cfg)
port = rand_port()
socat = socat_send(cfg, port)
data_pipe = (f"yes $(echo -e \x01\x02\x03\x04\x05\x06) | head -c 1K"
f" | {socat}")
netns = getattr(cfg, "netns", None)
listen_cmd = ncdevmem_rx(cfg, port, flow_steer=not hasattr(cfg, 'netns'))
with bkg(listen_cmd, exit_wait=True, ns=netns) as ncdevmem:
wait_port_listen(port, proto="tcp", ns=netns)
cmd(data_pipe, host=cfg.remote, shell=True)
ksft_eq(ncdevmem.ret, 0)
def run_tx(cfg):
"""Run the devmem TX test."""
require_devmem(cfg)
configure_nic(cfg)
netns = getattr(cfg, "netns", None)
port = rand_port()
tx_cmd = ncdevmem_tx(cfg, port)
listen_cmd = socat_listen(cfg, port)
with bkg(listen_cmd, host=cfg.remote, exit_wait=True) as socat:
wait_port_listen(port, host=cfg.remote)
cmd(f"bash -c 'echo -e \"hello\\nworld\" | {tx_cmd}'", ns=netns, shell=True)
ksft_eq(socat.stdout.strip(), "hello\nworld")
def run_tx_chunks(cfg):
"""Run the devmem TX chunking test."""
require_devmem(cfg)
configure_nic(cfg)
netns = getattr(cfg, "netns", None)
port = rand_port()
tx_cmd = ncdevmem_tx(cfg, port, chunk_size=3)
listen_cmd = socat_listen(cfg, port)
with bkg(listen_cmd, host=cfg.remote, exit_wait=True) as socat:
wait_port_listen(port, host=cfg.remote)
cmd(f"bash -c 'echo -e \"hello\\nworld\" | {tx_cmd}'", ns=netns, shell=True)
ksft_eq(socat.stdout.strip(), "hello\nworld")
def run_rx_large_niov(cfg):
"""Run the devmem RX test with a large niov (rx-page-size > PAGE_SIZE).
Sweep payload sizes that straddle the niov boundary: below, equal to,
and above rx_page_size, to exercise sub-niov, exact-niov, and multi-niov
RX paths.
"""
require_devmem(cfg, rx_page_size=RX_PAGE_SIZE_16K)
_reserve_hugepages()
configure_nic(cfg)
netns = getattr(cfg, "netns", None)
for size in [1024, 4096, 8192, 16384, 32768, 65536]:
port = rand_port()
socat = socat_send(cfg, port)
listen_cmd = ncdevmem_rx(cfg, port,
flow_steer=not netns,
rx_page_size=RX_PAGE_SIZE_16K)
data_pipe = (f"yes $(echo -e \x01\x02\x03\x04\x05\x06) | "
f"head -c {size} | {socat}")
with bkg(listen_cmd, exit_wait=True, ns=netns) as ncdevmem:
wait_port_listen(port, proto="tcp", ns=netns)
cmd(data_pipe, host=cfg.remote, shell=True)
ksft_eq(ncdevmem.ret, 0,
f"large-niov failed for payload size {size}")
def run_rx_hds(cfg):
"""Run the HDS test by running devmem RX across a segment size sweep."""
require_devmem(cfg)
configure_nic(cfg)
netns = getattr(cfg, "netns", None)
for size in [1, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192]:
port = rand_port()
listen_cmd = ncdevmem_rx(cfg, port, verify=False,
fail_on_linear=True)
socat = socat_send(cfg, port, buf_size=size)
with bkg(listen_cmd, exit_wait=True, ns=netns) as ncdevmem:
wait_port_listen(port, proto="tcp", ns=netns)
cmd(f"dd if=/dev/zero bs={size} count=1 2>/dev/null | "
f"{socat}", host=cfg.remote, shell=True)
ksft_eq(ncdevmem.ret, 0, f"HDS failed for payload size {size}")
