Re: [PATCH net-next] selftests/net: allow GRO coalesce test on veth

On Wed, Aug 25, 2021 at 6:25 AM Paolo Abeni [off-list ref] wrote:

This change extends the existing GRO coalesce test to
allow running on top of a veth pair, so that no H/W dep
is required to run them.

By default gro.sh will use the veth backend, and will try
to use exiting H/W in loopback mode if a specific device
name is provided with the '-i' command line option.

No functional change is intended for the loopback-based
tests, just move all the relevant initialization/cleanup
code into the related script.

Introduces a new initialization helper script for the
veth backend, and plugs the correct helper script according
to the provided command line.

Additionally, enable veth-based tests by default.

Very nice. Thanks for extending the test to be run as part of
continuous testing over veth, Paolo.

+setup_veth_ns() {
+       local -r link_dev="$1"
+       local -r ns_name="$2"
+       local -r ns_dev="$3"
+       local -r ns_mac="$4"
+       local -r addr="$5"
+
+       [[ -e /var/run/netns/"${ns_name}" ]] || ip netns add "${ns_name}"
+       echo 100000 > "/sys/class/net/${ns_dev}/gro_flush_timeout"
+       ip link set dev "${ns_dev}" netns "${ns_name}" mtu 65535
+       ip -netns "${ns_name}" link set dev "${ns_dev}" up
+       if [[ -n "${addr}" ]]; then
+               ip -netns "${ns_name}" addr add dev "${ns_dev}" "${addr}"
+       fi

unused? setup_veth_ns is always called with four arguments.

+
+       ip netns exec "${ns_name}" ethtool -K "${ns_dev}" gro on tso off
+}
+
+setup_ns() {
+       # Set up server_ns namespace and client_ns namespace
+       ip link add name server type veth peer name client
+
+       setup_veth_ns "${dev}" server_ns server "${SERVER_MAC}"
+       setup_veth_ns "${dev}" client_ns client "${CLIENT_MAC}"
+}