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[PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test

Vishwanath Seshagiri posted 2 patches 4 days, 2 hours ago
There is a newer version of this series
[PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test
Posted by Vishwanath Seshagiri 4 days, 2 hours ago 
Add iperf3-based test to verify RX buffer handling under load.
Optionally logs page_pool tracepoints when available.

Signed-off-by: Vishwanath Seshagiri <vishs@meta.com>
---
 .../drivers/net/virtio_net/basic_features.sh  | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
index cf8cf816ed48..fa98505c4674 100755
--- a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
+++ b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
@@ -6,6 +6,7 @@
 ALL_TESTS="
 	initial_ping_test
 	f_mac_test
+	buffer_circulation_test
 "
 
 source virtio_net_common.sh
@@ -16,6 +17,8 @@ source "$lib_dir"/../../../net/forwarding/lib.sh
 h1=${NETIFS[p1]}
 h2=${NETIFS[p2]}
 
+IPERF_SERVER_PID=""
+
 h1_create()
 {
 	simple_if_init $h1 $H1_IPV4/24 $H1_IPV6/64
@@ -83,6 +86,84 @@ f_mac_test()
 	log_test "$test_name"
 }
 
+buffer_circulation_test()
+{
+	RET=0
+	local test_name="buffer circulation"
+	local tracefs="/sys/kernel/tracing"
+
+	if ! check_command iperf3; then
+		log_test_skip "$test_name" "iperf3 not installed"
+		return 0
+	fi
+
+	setup_cleanup
+	setup_prepare
+
+	ping -c 1 -I "$h1" "$H2_IPV4" >/dev/null
+	if [ $? -ne 0 ]; then
+		check_err 1 "Ping failed"
+		log_test "$test_name"
+		return
+	fi
+
+	local rx_start=$(cat /sys/class/net/"$h2"/statistics/rx_packets)
+	local tx_start=$(cat /sys/class/net/"$h1"/statistics/tx_packets)
+
+	if [ -d "$tracefs/events/page_pool" ]; then
+		echo > "$tracefs/trace"
+		echo 1 > "$tracefs/events/page_pool/enable"
+	fi
+
+	local port=$(shuf -i 49152-65535 -n 1)
+
+	iperf3 -s -1 --bind-dev "$h2" -p "$port" &>/dev/null &
+	IPERF_SERVER_PID=$!
+	sleep 1
+
+	if ! kill -0 "$IPERF_SERVER_PID" 2>/dev/null; then
+		IPERF_SERVER_PID=""
+		if [ -d "$tracefs/events/page_pool" ]; then
+			echo 0 > "$tracefs/events/page_pool/enable"
+		fi
+		check_err 1 "iperf3 server died"
+		log_test "$test_name"
+		return
+	fi
+
+	iperf3 -c "$H2_IPV4" --bind-dev "$h1" -p "$port" -t 5 >/dev/null 2>&1
+	local iperf_ret=$?
+
+	if [ -n "$IPERF_SERVER_PID" ]; then
+		kill "$IPERF_SERVER_PID" 2>/dev/null || true
+		wait "$IPERF_SERVER_PID" 2>/dev/null || true
+		IPERF_SERVER_PID=""
+	fi
+
+	if [ -d "$tracefs/events/page_pool" ]; then
+		echo 0 > "$tracefs/events/page_pool/enable"
+		local trace="$tracefs/trace"
+		local hold=$(grep -c "page_pool_state_hold" "$trace" 2>/dev/null)
+		local release=$(grep -c "page_pool_state_release" "$trace" 2>/dev/null)
+		log_info "page_pool events: hold=${hold:-0}, release=${release:-0}"
+	fi
+
+	local rx_end=$(cat /sys/class/net/"$h2"/statistics/rx_packets)
+	local tx_end=$(cat /sys/class/net/"$h1"/statistics/tx_packets)
+	local rx_delta=$((rx_end - rx_start))
+	local tx_delta=$((tx_end - tx_start))
+
+	log_info "Circulated TX:$tx_delta RX:$rx_delta"
+
+	if [ "$iperf_ret" -ne 0 ]; then
+		check_err 1 "iperf3 failed"
+	elif [ "$rx_delta" -lt 10000 ]; then
+		check_err 1 "Too few packets: $rx_delta"
+	fi
+
+	log_test "$test_name"
+}
+
 setup_prepare()
 {
 	virtio_device_rebind $h1
@@ -113,6 +194,11 @@ setup_cleanup()
 
 cleanup()
 {
+	if [ -n "$IPERF_SERVER_PID" ]; then
+		kill "$IPERF_SERVER_PID" 2>/dev/null || true
+		wait "$IPERF_SERVER_PID" 2>/dev/null || true
+	fi
+
 	pre_cleanup
 	setup_cleanup
 }
-- 
2.47.3
Re: [PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test
Posted by Michael S. Tsirkin 3 days, 15 hours ago 
On Wed, Feb 04, 2026 at 11:36:17AM -0800, Vishwanath Seshagiri wrote:
> Add iperf3-based test to verify RX buffer handling under load.
> Optionally logs page_pool tracepoints when available.

but it doesn't verify/validate them - it's just a generic throughput
test. so what is the value add here?


> Signed-off-by: Vishwanath Seshagiri <vishs@meta.com>
> ---
>  .../drivers/net/virtio_net/basic_features.sh  | 86 +++++++++++++++++++
>  1 file changed, 86 insertions(+)
> 
> diff --git a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
> index cf8cf816ed48..fa98505c4674 100755
> --- a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
> +++ b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
> @@ -6,6 +6,7 @@
>  ALL_TESTS="
>  	initial_ping_test
>  	f_mac_test
> +	buffer_circulation_test
>  "
>  
>  source virtio_net_common.sh
> @@ -16,6 +17,8 @@ source "$lib_dir"/../../../net/forwarding/lib.sh
>  h1=${NETIFS[p1]}
>  h2=${NETIFS[p2]}
>  
> +IPERF_SERVER_PID=""
> +
>  h1_create()
>  {
>  	simple_if_init $h1 $H1_IPV4/24 $H1_IPV6/64
> @@ -83,6 +86,84 @@ f_mac_test()
>  	log_test "$test_name"
>  }
>  
> +buffer_circulation_test()
> +{
> +	RET=0
> +	local test_name="buffer circulation"
> +	local tracefs="/sys/kernel/tracing"
> +
> +	if ! check_command iperf3; then
> +		log_test_skip "$test_name" "iperf3 not installed"
> +		return 0
> +	fi
> +
> +	setup_cleanup
> +	setup_prepare
> +
> +	ping -c 1 -I "$h1" "$H2_IPV4" >/dev/null
> +	if [ $? -ne 0 ]; then
> +		check_err 1 "Ping failed"
> +		log_test "$test_name"
> +		return
> +	fi
> +
> +	local rx_start=$(cat /sys/class/net/"$h2"/statistics/rx_packets)
> +	local tx_start=$(cat /sys/class/net/"$h1"/statistics/tx_packets)
> +
> +	if [ -d "$tracefs/events/page_pool" ]; then
> +		echo > "$tracefs/trace"
> +		echo 1 > "$tracefs/events/page_pool/enable"
> +	fi
> +
> +	local port=$(shuf -i 49152-65535 -n 1)
> +
> +	iperf3 -s -1 --bind-dev "$h2" -p "$port" &>/dev/null &
> +	IPERF_SERVER_PID=$!
> +	sleep 1
> +
> +	if ! kill -0 "$IPERF_SERVER_PID" 2>/dev/null; then
> +		IPERF_SERVER_PID=""
> +		if [ -d "$tracefs/events/page_pool" ]; then
> +			echo 0 > "$tracefs/events/page_pool/enable"
> +		fi
> +		check_err 1 "iperf3 server died"
> +		log_test "$test_name"
> +		return
> +	fi
> +
> +	iperf3 -c "$H2_IPV4" --bind-dev "$h1" -p "$port" -t 5 >/dev/null 2>&1
> +	local iperf_ret=$?
> +
> +	if [ -n "$IPERF_SERVER_PID" ]; then
> +		kill "$IPERF_SERVER_PID" 2>/dev/null || true
> +		wait "$IPERF_SERVER_PID" 2>/dev/null || true
> +		IPERF_SERVER_PID=""
> +	fi
> +
> +	if [ -d "$tracefs/events/page_pool" ]; then
> +		echo 0 > "$tracefs/events/page_pool/enable"
> +		local trace="$tracefs/trace"
> +		local hold=$(grep -c "page_pool_state_hold" "$trace" 2>/dev/null)
> +		local release=$(grep -c "page_pool_state_release" "$trace" 2>/dev/null)
> +		log_info "page_pool events: hold=${hold:-0}, release=${release:-0}"
> +	fi
> +
> +	local rx_end=$(cat /sys/class/net/"$h2"/statistics/rx_packets)
> +	local tx_end=$(cat /sys/class/net/"$h1"/statistics/tx_packets)
> +	local rx_delta=$((rx_end - rx_start))
> +	local tx_delta=$((tx_end - tx_start))
> +
> +	log_info "Circulated TX:$tx_delta RX:$rx_delta"
> +
> +	if [ "$iperf_ret" -ne 0 ]; then
> +		check_err 1 "iperf3 failed"
> +	elif [ "$rx_delta" -lt 10000 ]; then
> +		check_err 1 "Too few packets: $rx_delta"
> +	fi
> +
> +	log_test "$test_name"
> +}
> +
>  setup_prepare()
>  {
>  	virtio_device_rebind $h1
> @@ -113,6 +194,11 @@ setup_cleanup()
>  
>  cleanup()
>  {
> +	if [ -n "$IPERF_SERVER_PID" ]; then
> +		kill "$IPERF_SERVER_PID" 2>/dev/null || true
> +		wait "$IPERF_SERVER_PID" 2>/dev/null || true
> +	fi
> +
>  	pre_cleanup
>  	setup_cleanup
>  }
> -- 
> 2.47.3
Re: [PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test
Posted by Jakub Kicinski 3 days, 16 hours ago 
On Wed, 4 Feb 2026 11:36:17 -0800 Vishwanath Seshagiri wrote:
> Add iperf3-based test to verify RX buffer handling under load.
> Optionally logs page_pool tracepoints when available.

TBH I wouldn't bother with this.

We run full battery of driver tests in netdev CI, there's not much
value in a dedicated virtio test that just runs iperf...
-- 
pw-bot: cr
Re: [PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test
Posted by Vishwanath Seshagiri 3 days, 15 hours ago 

On 2/4/26 9:25 PM, Jakub Kicinski wrote:
> On Wed, 4 Feb 2026 11:36:17 -0800 Vishwanath Seshagiri wrote:
>> Add iperf3-based test to verify RX buffer handling under load.
>> Optionally logs page_pool tracepoints when available.
> 
> TBH I wouldn't bother with this.
> 
> We run full battery of driver tests in netdev CI, there's not much
> value in a dedicated virtio test that just runs iperf...

Okay. I will remove it in v5.
Re: [PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test
Posted by Jason Wang 3 days, 17 hours ago 
On Thu, Feb 5, 2026 at 3:36 AM Vishwanath Seshagiri <vishs@meta.com> wrote:
>
> Add iperf3-based test to verify RX buffer handling under load.
> Optionally logs page_pool tracepoints when available.
>
> Signed-off-by: Vishwanath Seshagiri <vishs@meta.com>
> ---
>  .../drivers/net/virtio_net/basic_features.sh  | 86 +++++++++++++++++++
>  1 file changed, 86 insertions(+)
>
> diff --git a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
> index cf8cf816ed48..fa98505c4674 100755
> --- a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
> +++ b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
> @@ -6,6 +6,7 @@
>  ALL_TESTS="
>         initial_ping_test
>         f_mac_test
> +       buffer_circulation_test
>  "
>
>  source virtio_net_common.sh
> @@ -16,6 +17,8 @@ source "$lib_dir"/../../../net/forwarding/lib.sh
>  h1=${NETIFS[p1]}
>  h2=${NETIFS[p2]}
>
> +IPERF_SERVER_PID=""
> +
>  h1_create()
>  {
>         simple_if_init $h1 $H1_IPV4/24 $H1_IPV6/64
> @@ -83,6 +86,84 @@ f_mac_test()
>         log_test "$test_name"
>  }
>
> +buffer_circulation_test()
> +{
> +       RET=0
> +       local test_name="buffer circulation"
> +       local tracefs="/sys/kernel/tracing"
> +
> +       if ! check_command iperf3; then
> +               log_test_skip "$test_name" "iperf3 not installed"
> +               return 0
> +       fi
> +
> +       setup_cleanup
> +       setup_prepare
> +
> +       ping -c 1 -I "$h1" "$H2_IPV4" >/dev/null
> +       if [ $? -ne 0 ]; then
> +               check_err 1 "Ping failed"
> +               log_test "$test_name"
> +               return
> +       fi
> +
> +       local rx_start=$(cat /sys/class/net/"$h2"/statistics/rx_packets)
> +       local tx_start=$(cat /sys/class/net/"$h1"/statistics/tx_packets)
> +
> +       if [ -d "$tracefs/events/page_pool" ]; then
> +               echo > "$tracefs/trace"
> +               echo 1 > "$tracefs/events/page_pool/enable"
> +       fi
> +
> +       local port=$(shuf -i 49152-65535 -n 1)
> +
> +       iperf3 -s -1 --bind-dev "$h2" -p "$port" &>/dev/null &
> +       IPERF_SERVER_PID=$!
> +       sleep 1

Nit:

It's better to use a more robust detecting instead of a sleep 1.

Thanks
Re: [PATCH net-next v4 2/2] selftests: virtio_net: add buffer circulation test
Posted by Vishwanath Seshagiri 3 days, 16 hours ago 

On 2/4/26 8:12 PM, Jason Wang wrote:
> > 
> On Thu, Feb 5, 2026 at 3:36 AM Vishwanath Seshagiri <vishs@meta.com> wrote:
>>
>> Add iperf3-based test to verify RX buffer handling under load.
>> Optionally logs page_pool tracepoints when available.
>>
>> Signed-off-by: Vishwanath Seshagiri <vishs@meta.com>
>> ---
>>   .../drivers/net/virtio_net/basic_features.sh  | 86 +++++++++++++++++++
>>   1 file changed, 86 insertions(+)
>>
>> diff --git a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
>> index cf8cf816ed48..fa98505c4674 100755
>> --- a/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
>> +++ b/tools/testing/selftests/drivers/net/virtio_net/basic_features.sh
>> @@ -6,6 +6,7 @@
>>   ALL_TESTS="
>>          initial_ping_test
>>          f_mac_test
>> +       buffer_circulation_test
>>   "
>>
>>   source virtio_net_common.sh
>> @@ -16,6 +17,8 @@ source "$lib_dir"/../../../net/forwarding/lib.sh
>>   h1=${NETIFS[p1]}
>>   h2=${NETIFS[p2]}
>>
>> +IPERF_SERVER_PID=""
>> +
>>   h1_create()
>>   {
>>          simple_if_init $h1 $H1_IPV4/24 $H1_IPV6/64
>> @@ -83,6 +86,84 @@ f_mac_test()
>>          log_test "$test_name"
>>   }
>>
>> +buffer_circulation_test()
>> +{
>> +       RET=0
>> +       local test_name="buffer circulation"
>> +       local tracefs="/sys/kernel/tracing"
>> +
>> +       if ! check_command iperf3; then
>> +               log_test_skip "$test_name" "iperf3 not installed"
>> +               return 0
>> +       fi
>> +
>> +       setup_cleanup
>> +       setup_prepare
>> +
>> +       ping -c 1 -I "$h1" "$H2_IPV4" >/dev/null
>> +       if [ $? -ne 0 ]; then
>> +               check_err 1 "Ping failed"
>> +               log_test "$test_name"
>> +               return
>> +       fi
>> +
>> +       local rx_start=$(cat /sys/class/net/"$h2"/statistics/rx_packets)
>> +       local tx_start=$(cat /sys/class/net/"$h1"/statistics/tx_packets)
>> +
>> +       if [ -d "$tracefs/events/page_pool" ]; then
>> +               echo > "$tracefs/trace"
>> +               echo 1 > "$tracefs/events/page_pool/enable"
>> +       fi
>> +
>> +       local port=$(shuf -i 49152-65535 -n 1)
>> +
>> +       iperf3 -s -1 --bind-dev "$h2" -p "$port" &>/dev/null &
>> +       IPERF_SERVER_PID=$!
>> +       sleep 1
> 
> Nit:
> 
> It's better to use a more robust detecting instead of a sleep 1.

Can I make it similar to wait_local_port_listen() function in
tools/testing/selftests/net/lib.sh? It proceeds as soon as it is
available, but checks the port every 100ms.

> 
> Thanks
>

Patchew 2.1-devel-b67e4c2

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