Hi Narcisa, [ Cc Ricardo and Sebastian ]
> Add IPv4 and IPv6 test cases that exercise GSO packets under BIG TCP > size limits. > 1..2 > ok 1 tso.big_tcp_ipv4 > ok 2 tso.big_tcp_ipv6 > Both of them run the existing tx-tcp-segmentation > and tx-tcp6-segmentation tests at the increased TSO maximum. > Additionally, reserve a hugepage and transmit its content using > MSG_ZEROCOPY to produce skb fragments larger than 65536. > Check that the number of retransmissions represents a small > percentage of the total packets sent. Record the number of drops > before and after the send to catch issues with large frag > handling during segmentation. > Signed-off-by: Narcisa Vasile <[email protected]> LGTM, but I'm not really an expert on network drivers testing. Acked-by: Petr Vorel <[email protected]> Kind regards, Petr > --- > tools/testing/selftests/drivers/net/hw/tso.py | 161 ++++++++++++++++++ > 1 file changed, 161 insertions(+) > diff --git a/tools/testing/selftests/drivers/net/hw/tso.py > b/tools/testing/selftests/drivers/net/hw/tso.py > index 67f6c9ca9a64..176ddf97fabb 100755 > --- a/tools/testing/selftests/drivers/net/hw/tso.py > +++ b/tools/testing/selftests/drivers/net/hw/tso.py > @@ -4,6 +4,7 @@ > """A simple test for TSO.""" > import fcntl > +import mmap > import socket > import struct > import termios > @@ -15,6 +16,87 @@ from lib.py import EthtoolFamily, NetdevFamily, NetDrvEpEnv > from lib.py import bkg, cmd, defer, ethtool, ip, rand_port, wait_port_listen > +MAP_HUGETLB = getattr(mmap, "MAP_HUGETLB", 0x40000) > +MSG_ZEROCOPY = getattr(socket, "MSG_ZEROCOPY", 0x4000000) > +SO_ZEROCOPY = getattr(socket, "SO_ZEROCOPY", 60) > + > +GSO_LEGACY_MAX_SIZE = 65536 > + > +# Pool of the default hugepage size, the one /proc/meminfo reports on. > +NR_HUGEPAGES = "/proc/sys/vm/nr_hugepages" > + > + > +def default_huge_page_size(): > + """Return the hugepage size in bytes""" > + try: > + with open("/proc/meminfo", encoding="utf-8") as meminfo: > + for line in meminfo: > + if line.startswith("Hugepagesize:"): > + return int(line.split()[1]) * 1024 > + except OSError: > + pass > + > + return 2 * 1024 * 1024 > + > + > +def hugepages_free(): > + """Return the number of unused hugepages of the default size.""" > + try: > + with open("/proc/meminfo", encoding="utf-8") as meminfo: > + for line in meminfo: > + if line.startswith("HugePages_Free:"): > + return int(line.split()[1]) > + except OSError: > + pass > + return 0 > + > + > +def set_nr_hugepages(count): > + with open(NR_HUGEPAGES, "w", encoding="utf-8") as sysctl: > + sysctl.write(f"{count}\n") > + > + > +def tx_dropped(ifname): > + with open(f"/sys/class/net/{ifname}/statistics/tx_dropped", > + encoding="utf-8") as counter: > + return int(counter.read()) > + > + > +def setup_hugepage(): > + """Reserve one hugepage, and put the pool back afterwards.""" > + if hugepages_free() >= 1: > + return > + > + try: > + with open(NR_HUGEPAGES, encoding="utf-8") as sysctl: > + old_count = int(sysctl.read()) > + set_nr_hugepages(old_count + 1) > + except OSError as error: > + raise KsftSkipEx(f"Unable to reserve a hugepage: {error}") from error > + > + defer(set_nr_hugepages, old_count) > + > + if hugepages_free() < 1: > + raise KsftSkipEx("Unable to reserve a hugepage") > + > + > +def mmap_large_buffer(): > + """Allocate a buffer backed by one huge page.""" > + size = default_huge_page_size() > + > + setup_hugepage() > + > + try: > + return mmap.mmap(-1, size, > + flags=mmap.MAP_PRIVATE | > + mmap.MAP_ANONYMOUS | > + MAP_HUGETLB, > + prot=mmap.PROT_READ) > + except OSError as e: > + raise KsftSkipEx(f"Unable to allocate a {size >> 20}MB hugepage " > + f"buffer: {e}") from e > + > + > def sock_wait_drain(sock, max_wait=1000): > """Wait for all pending write data on the socket to get ACKed.""" > for _ in range(max_wait): > @@ -33,6 +115,32 @@ def tcp_sock_get_retrans(sock): > return struct.unpack("I", info[100:104])[0] > +def setup_big_tcp(cfg): > + """Lift the GSO ceiling to what the device advertises for TSO.""" > + if cfg.dev["tso_max_size"] <= GSO_LEGACY_MAX_SIZE: > + raise KsftSkipEx("Device does not support BIG TCP") > + > + ip(f"link set dev {cfg.ifname} " > + f"gso_max_size {cfg.dev['tso_max_size']} " > + f"gso_ipv4_max_size {cfg.dev['tso_max_size']}") > + > + defer(ip, f"link set dev {cfg.ifname} " > + f"gso_max_size {cfg.dev['gso_max_size']} " > + f"gso_ipv4_max_size {cfg.dev['gso_ipv4_max_size']}") > + > + > +def sock_send_zerocopy(sock): > + """Send with MSG_ZEROCOPY, return the bytes queued.""" > + try: > + sock.setsockopt(socket.SOL_SOCKET, SO_ZEROCOPY, 1) > + except OSError as e: > + raise KsftSkipEx(f"SO_ZEROCOPY not supported: {e}") from e > + > + with mmap_large_buffer() as tx_buf: > + sock.sendall(tx_buf, MSG_ZEROCOPY) > + return len(tx_buf) > + > + > def run_one_stream(cfg, ipver, remote_v4, remote_v6, should_lso): > cfg.require_cmd("socat", local=False, remote=True) > @@ -96,6 +204,46 @@ def run_one_stream(cfg, ipver, remote_v4, remote_v6, > should_lso): > 500, comment="Number of LSO wire-packets with LSO > disabled") > +def run_big_tcp_stream(cfg, ipver, remote_v4, remote_v6): > + """Send with MSG_ZEROCOPY out of a huge page, so the frags exceed > 64kB.""" > + cfg.require_cmd("socat", local=False, remote=True) > + > + # No clamping, as it would keep the frags under 64kB > + port = rand_port() > + listen_opts = f"{port},reuseport" > + listen_cmd = f"socat -{ipver} -t 2 -u TCP-LISTEN:{listen_opts} > /dev/null,ignoreeof" > + > + with bkg(listen_cmd, host=cfg.remote, exit_wait=True): > + wait_port_listen(port, host=cfg.remote) > + > + if ipver == "4": > + sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) > + sock.connect((remote_v4, port)) > + else: > + sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM) > + sock.connect((remote_v6, port)) > + > + # Small send to make sure the connection is working. > + sock.send("ping".encode()) > + sock_wait_drain(sock) > + > + retrans_old = tcp_sock_get_retrans(sock) > + drops_old = tx_dropped(cfg.ifname) > + > + sent = sock_send_zerocopy(sock) > + sock_wait_drain(sock) > + > + drops = tx_dropped(cfg.ifname) - drops_old > + retrans = tcp_sock_get_retrans(sock) - retrans_old > + sock.close() > + > + ksft_eq(drops, 0, comment="Driver TX drops during BIG TCP send") > + > + # Same best effort bound as the plain stream. > + total_lso_wire = sent * 0.90 // cfg.dev["mtu"] > + ksft_lt(retrans, total_lso_wire / 16) > + > + > def build_tunnel(cfg, outer_ipver, tun_info): > local_v4 = NetDrvEpEnv.nsim_v4_pfx + "1" > local_v6 = NetDrvEpEnv.nsim_v6_pfx + "1" > @@ -147,6 +295,11 @@ def test_builder(name, cfg, outer_ipver, feature, > tun=None, inner_ipver=None): > if feature not in cfg.hw_features: > raise KsftSkipEx(f"Device does not support {feature}") > + # Run non-tunnel test cases under the BIG TCP limits too. > + big_tcp = "big_tcp" in name > + if big_tcp: > + setup_big_tcp(cfg) > + > ipver = outer_ipver > if tun: > remote_v4, remote_v6 = build_tunnel(cfg, ipver, tun) > @@ -159,6 +312,9 @@ def test_builder(name, cfg, outer_ipver, feature, > tun=None, inner_ipver=None): > ethtool(f"-K {cfg.ifname} {feature} off") > run_one_stream(cfg, ipver, remote_v4, remote_v6, should_lso=False) > + if big_tcp: > + run_big_tcp_stream(cfg, ipver, remote_v4, remote_v6) > + > ethtool(f"-K {cfg.ifname} tx-gso-partial off") > ethtool(f"-K {cfg.ifname} tx-tcp-mangleid-segmentation off") > if feature in cfg.partial_features: > @@ -171,6 +327,9 @@ def test_builder(name, cfg, outer_ipver, feature, > tun=None, inner_ipver=None): > ethtool(f"-K {cfg.ifname} {feature} on") > run_one_stream(cfg, ipver, remote_v4, remote_v6, should_lso=True) > + if big_tcp: > + run_big_tcp_stream(cfg, ipver, remote_v4, remote_v6) > + > f.__name__ = name + ((outer_ipver + "_") if tun else "") + "ipv" + > inner_ipver > return f > @@ -230,6 +389,8 @@ def main() -> None: > # name, v4/v6 ethtool_feature tun:(type, > args, inner ip versions) > ("", "4", "tx-tcp-segmentation", None), > ("", "6", "tx-tcp6-segmentation", None), > + ("big_tcp_", "4", "tx-tcp-segmentation", None), > + ("big_tcp_", "6", "tx-tcp6-segmentation", None), > ("vxlan", "4", "tx-udp_tnl-segmentation", ("vxlan", "id > 100 dstport 4789 noudpcsum", ("4", "6"))), > ("vxlan", "6", "tx-udp_tnl-segmentation", ("vxlan", "id > 100 dstport 4789 udp6zerocsumtx udp6zerocsumrx", ("4", "6"))), > ("vxlan_csum", "", "tx-udp_tnl-csum-segmentation", ("vxlan", "id > 100 dstport 4789 udpcsum", ("4", "6"))),
