[PATCH v2 bpf-next 22/22] selftests/xsk: reset NIC settings to default after running test suite

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
	andrii@kernel.org
Cc: netdev@vger.kernel.org, magnus.karlsson@intel.com,
	bjorn@kernel.org, tirthendu.sarkar@intel.com,
	Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Subject: [PATCH v2 bpf-next 22/22] selftests/xsk: reset NIC settings to default after running test suite
Date: Mon, 29 May 2023 17:50:24 +0200	[thread overview]
Message-ID: <20230529155024.222213-23-maciej.fijalkowski@intel.com> (raw)
In-Reply-To: <20230529155024.222213-1-maciej.fijalkowski@intel.com>

Currently, when running ZC test suite, after finishing first run of test
suite and then switching to busy-poll tests within xskxceiver, such
errors are observed:

libbpf: Kernel error message: ice: MTU is too large for linear frames and XDP prog does not support frags
1..26
libbpf: Kernel error message: Native and generic XDP can't be active at the same time
Error attaching XDP program
not ok 1 [xskxceiver.c:xsk_reattach_xdp:1568]: ERROR: 17/"File exists"

this is because test suite ends with 9k MTU and native xdp program being
loaded. Busy-poll tests start non-multi-buffer tests for generic mode.
To fix this, let us introduce bash function that will reset NIC settings
to default (e.g. 1500 MTU and no xdp progs loaded) so that test suite
can continue without interrupts. It also means that after busy-poll
tests NIC will have those default settings, whereas right now it is left
with 9k MTU and xdp prog loaded in native mode.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---
 tools/testing/selftests/bpf/test_xsk.sh    | 5 +++++
 tools/testing/selftests/bpf/xsk_prereqs.sh | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_xsk.sh b/tools/testing/selftests/bpf/test_xsk.sh
index c2ad50f26b63..2aa5a3445056 100755
--- a/tools/testing/selftests/bpf/test_xsk.sh
+++ b/tools/testing/selftests/bpf/test_xsk.sh
@@ -171,7 +171,10 @@ exec_xskxceiver
 
 if [ -z $ETH ]; then
 	cleanup_exit ${VETH0} ${VETH1}
+else
+	cleanup_iface ${ETH} ${MTU}
 fi
+
 TEST_NAME="XSK_SELFTESTS_${VETH0}_BUSY_POLL"
 busy_poll=1
 
@@ -184,6 +187,8 @@ exec_xskxceiver
 
 if [ -z $ETH ]; then
 	cleanup_exit ${VETH0} ${VETH1}
+else
+	cleanup_iface ${ETH} ${MTU}
 fi
 
 failures=0
diff --git a/tools/testing/selftests/bpf/xsk_prereqs.sh b/tools/testing/selftests/bpf/xsk_prereqs.sh
index ae697a10a056..29175682c44d 100755
--- a/tools/testing/selftests/bpf/xsk_prereqs.sh
+++ b/tools/testing/selftests/bpf/xsk_prereqs.sh
@@ -53,6 +53,13 @@ test_exit()
 	exit 1
 }
 
+cleanup_iface()
+{
+	ip link set $1 mtu $2
+	ip link set $1 xdp off
+	ip link set $1 xdpgeneric off
+}
+
 clear_configs()
 {
 	[ $(ip link show $1 &>/dev/null; echo $?;) == 0 ] &&
-- 
2.35.3

