37. MVPP2 Poll Mode Driver

The MVPP2 PMD (librte_net_mvpp2) provides poll mode driver support for the Marvell PPv2 (Packet Processor v2) 1/10 Gbps adapter.

Detailed information about SoCs that use PPv2 can be obtained here:

37.1. Features

Features of the MVPP2 PMD are:

Speed capabilities
Link status
Tx Queue start/stop
MTU update
Jumbo frame
Promiscuous mode
Allmulticast mode
Unicast MAC filter
Multicast MAC filter
RSS hash
VLAN filter
CRC offload
L3 checksum offload
L4 checksum offload
Packet type parsing
Basic stats
Extended stats
RX flow control
Scattered TX frames
QoS
Flow API
Traffic metering and policing
Traffic Management API

37.2. Limitations

Number of lcores is limited to 9 by MUSDK internal design. If more lcores need to be allocated, locking will have to be considered. Number of available lcores can be changed via MRVL_MUSDK_HIFS_RESERVED define in mrvl_ethdev.c source file.
Flushing vlans added for filtering is not possible due to MUSDK missing functionality. Current workaround is to reset board so that PPv2 has a chance to start in a sane state.
MUSDK architecture does not support changing configuration in run time. All necessary configurations should be done before first dev_start().
RX queue start/stop is not supported.
Current implementation does not support replacement of buffers in the HW buffer pool at run time, so it is responsibility of the application to ensure that MTU does not exceed the configured buffer size.
Configuring TX flow control currently is not supported.
In current implementation, mechanism for acknowledging transmitted packets (tx_done_cleanup) is not supported.
Running more than one DPDK-MUSDK application simultaneously is not supported.

37.3. Prerequisites

Custom Linux Kernel sources

git clone https://github.com/MarvellEmbeddedProcessors/linux-marvell.git -b linux-4.4.120-armada-18.09

Out of tree mvpp2x_sysfs kernel module sources

git clone https://github.com/MarvellEmbeddedProcessors/mvpp2x-marvell.git -b mvpp2x-armada-18.09

MUSDK (Marvell User-Space SDK) sources
```
git clone https://github.com/MarvellEmbeddedProcessors/musdk-marvell.git -b musdk-armada-18.09
```
MUSDK is a light-weight library that provides direct access to Marvell’s PPv2 (Packet Processor v2). Alternatively prebuilt MUSDK library can be requested from Marvell Extranet. Once approval has been granted, library can be found by typing musdk in the search box.

To get better understanding of the library one can consult documentation available in the doc top level directory of the MUSDK sources.
DPDK environment

Follow the DPDK Getting Started Guide for Linux to setup DPDK environment.

37.4. Building DPDK

Driver needs precompiled MUSDK library during compilation.

export CROSS_COMPILE=<toolchain>/bin/aarch64-linux-gnu-
./bootstrap
./configure --host=aarch64-linux-gnu
make install

MUSDK will be installed to usr/local under current directory. For the detailed build instructions please consult doc/musdk_get_started.txt.

The path to the MUSDK installation directory needs to set in meson, shown in the command below.

For additional instructions regarding DPDK cross compilation please refer to Cross compile DPDK for ARM64.

meson setup build --cross-file config/arm/arm64_armada_linux_gcc
ninja -C build

37.5. Usage Example

MVPP2 PMD requires extra out of tree kernel modules to function properly. musdk_cma sources are part of the MUSDK. Please consult doc/musdk_get_started.txt for the detailed build instructions. For mvpp2x_sysfs please consult Documentation/pp22_sysfs.txt for the detailed build instructions.

insmod musdk_cma.ko
insmod mvpp2x_sysfs.ko

Additionally interfaces used by DPDK application need to be put up:

ip link set eth0 up
ip link set eth2 up

In order to run testpmd example application following command can be used:

./dpdk-testpmd --vdev=eth_mvpp2,iface=eth0,iface=eth2 -c 7 -- \
  --burst=128 --txd=2048 --rxd=1024 --rxq=2 --txq=2  --nb-cores=2 \
  -i -a --rss-udp

37.6. Extended stats

MVPP2 PMD supports the following extended statistics:

rx_bytes: number of RX bytes

rx_packets: number of RX packets

rx_unicast_packets: number of RX unicast packets

rx_errors: number of RX MAC errors

rx_fullq_dropped: number of RX packets dropped due to full RX queue

rx_bm_dropped: number of RX packets dropped due to no available buffers in the HW pool

rx_early_dropped: number of RX packets that were early dropped

rx_fifo_dropped: number of RX packets dropped due to RX fifo overrun

rx_cls_dropped: number of RX packets dropped by classifier

tx_bytes: number of TX bytes

tx_packets: number of TX packets

tx_unicast_packets: number of TX unicast packets

tx_errors: number of TX MAC errors

37.7. QoS Configuration

QoS configuration is done through external configuration file. Path to the file must be given as cfg in driver’s vdev parameter list.

37.7.1. Configuration syntax

[policer <policer_id>]
token_unit = <token_unit>
color = <color_mode>
cir = <cir>
ebs = <ebs>
cbs = <cbs>

[port <portnum> default]
default_tc = <default_tc>
mapping_priority = <mapping_priority>

rate_limit_enable = <rate_limit_enable>
rate_limit = <rate_limit>
burst_size = <burst_size>

default_policer = <policer_id>

[port <portnum> tc <traffic_class>]
rxq = <rx_queue_list>
pcp = <pcp_list>
dscp = <dscp_list>
default_color = <default_color>

[port <portnum> tc <traffic_class>]
rxq = <rx_queue_list>
pcp = <pcp_list>
dscp = <dscp_list>

[port <portnum> txq <txqnum>]
sched_mode = <sched_mode>
wrr_weight = <wrr_weight>

rate_limit_enable = <rate_limit_enable>
rate_limit = <rate_limit>
burst_size = <burst_size>

Where:

<portnum>: DPDK Port number (0..n).
<default_tc>: Default traffic class (e.g. 0)
<mapping_priority>: QoS priority for mapping (ip, vlan, ip/vlan or vlan/ip).
<traffic_class>: Traffic Class to be configured.
<rx_queue_list>: List of DPDK RX queues (e.g. 0 1 3-4)
<pcp_list>: List of PCP values to handle in particular TC (e.g. 0 1 3-4 7).
<dscp_list>: List of DSCP values to handle in particular TC (e.g. 0-12 32-48 63).
<default_policer>: Id of the policer configuration section to be used as default.
<policer_id>: Id of the policer configuration section (0..31).
<token_unit>: Policer token unit (bytes or packets).
<color_mode>: Policer color mode (aware or blind).
<cir>: Committed information rate in unit of kilo bits per second (data rate) or packets per second.
<cbs>: Committed burst size in unit of kilo bytes or number of packets.
<ebs>: Excess burst size in unit of kilo bytes or number of packets.
<default_color>: Default color for specific tc.
<rate_limit_enable>: Enables per port or per txq rate limiting (0/1 to disable/enable).
<rate_limit>: Committed information rate, in kilo bits per second.
<burst_size>: Committed burst size, in kilo bytes.
<sched_mode>: Egress scheduler mode (wrr or sp).
<wrr_weight>: Txq weight.

Setting PCP/DSCP values for the default TC is not required. All PCP/DSCP values not assigned explicitly to particular TC will be handled by the default TC.

37.7.1.1. Configuration file example

[policer 0]
token_unit = bytes
color = blind
cir = 100000
ebs = 64
cbs = 64

[port 0 default]
default_tc = 0
mapping_priority = ip

rate_limit_enable = 1
rate_limit = 1000
burst_size = 2000

[port 0 tc 0]
rxq = 0 1

[port 0 txq 0]
sched_mode = wrr
wrr_weight = 10

[port 0 txq 1]
sched_mode = wrr
wrr_weight = 100

[port 0 txq 2]
sched_mode = sp

[port 0 tc 1]
rxq = 2
pcp = 5 6 7
dscp = 26-38

[port 1 default]
default_tc = 0
mapping_priority = vlan/ip

default_policer = 0

[port 1 tc 0]
rxq = 0
dscp = 10

[port 1 tc 1]
rxq = 1
dscp = 11-20

[port 1 tc 2]
rxq = 2
dscp = 30

[port 1 txq 0]
rate_limit_enable = 1
rate_limit = 10000
burst_size = 2000

37.7.1.2. Usage example

./dpdk-testpmd --vdev=eth_mvpp2,iface=eth0,iface=eth2,cfg=/home/user/mrvl.conf \
  -c 7 -- -i -a --disable-hw-vlan-strip --rxq=3 --txq=3

37.8. Flow API

PPv2 offers packet classification capabilities via classifier engine which can be configured via generic flow API offered by DPDK.

The Flow isolated mode is supported.

For an additional description please refer to DPDK Generic flow API (rte_flow).

37.8.1. Supported flow actions

Following flow action items are supported by the driver:

DROP
QUEUE

37.8.2. Supported flow items

Following flow items and their respective fields are supported by the driver:

ETH
- source MAC
- destination MAC
- ethertype
VLAN
- PCP
- VID
IPV4
- DSCP
- protocol
- source address
- destination address
IPV6
- flow label
- next header
- source address
- destination address
UDP
- source port
- destination port
TCP
- source port
- destination port

37.8.3. Classifier match engine

Classifier has an internal match engine which can be configured to operate in either exact or maskable mode.

Mode is selected upon creation of the first unique flow rule as follows:

maskable, if key size is up to 8 bytes.
exact, otherwise, i.e for keys bigger than 8 bytes.

Where the key size equals the number of bytes of all fields specified in the flow items.

Table 37.1 Examples of key size calculation
Flow pattern	Key size in bytes	Used engine
ETH (destination MAC) / VLAN (VID)	6 + 2 = 8	Maskable
VLAN (VID) / IPV4 (source address)	2 + 4 = 6	Maskable
TCP (source port, destination port)	2 + 2 = 4	Maskable
VLAN (priority) / IPV4 (source address)	1 + 4 = 5	Maskable
IPV4 (destination address) / UDP (source port, destination port)	6 + 2 + 2 = 10	Exact
VLAN (VID) / IPV6 (flow label, destination address)	2 + 3 + 16 = 21	Exact
IPV4 (DSCP, source address, destination address)	1 + 4 + 4 = 9	Exact
IPV6 (flow label, source address, destination address)	3 + 16 + 16 = 35	Exact

From the user perspective maskable mode means that masks specified via flow rules are respected. In case of exact match mode, masks which do not provide exact matching (all bits masked) are ignored.

If the flow matches more than one classifier rule the first (with the lowest index) matched takes precedence.

37.8.4. Flow rules usage example

Before proceeding run testpmd user application:

./dpdk-testpmd --vdev=eth_mvpp2,iface=eth0,iface=eth2 -c 3 -- -i --p 3 -a --disable-hw-vlan-strip

37.8.4.1. Example #1

testpmd> flow create 0 ingress pattern eth src is 10:11:12:13:14:15 / end actions drop / end

In this case key size is 6 bytes thus maskable type is selected. Testpmd will set mask to ff:ff:ff:ff:ff:ff i.e traffic explicitly matching above rule will be dropped.

37.8.4.2. Example #2

testpmd> flow create 0 ingress pattern ipv4 src spec 10.10.10.0 src mask 255.255.255.0 / tcp src spec 0x10 src mask 0x10 / end action drop / end

In this case key size is 8 bytes thus maskable type is selected. Flows which have IPv4 source addresses ranging from 10.10.10.0 to 10.10.10.255 and tcp source port set to 16 will be dropped.

37.8.4.3. Example #3

testpmd> flow create 0 ingress pattern vlan vid spec 0x10 vid mask 0x10 / ipv4 src spec 10.10.1.1 src mask 255.255.0.0 dst spec 11.11.11.1 dst mask 255.255.255.0 / end actions drop / end

In this case key size is 10 bytes thus exact type is selected. Even though each item has partial mask set, masks will be ignored. As a result only flows with VID set to 16 and IPv4 source and destination addresses set to 10.10.1.1 and 11.11.11.1 respectively will be dropped.

37.8.5. Limitations

Following limitations need to be taken into account while creating flow rules:

For IPv4 exact match type the key size must be up to 12 bytes.
For IPv6 exact match type the key size must be up to 36 bytes.
Following fields cannot be partially masked (all masks are treated as if they were exact):
- ETH: ethertype
- VLAN: PCP, VID
- IPv4: protocol
- IPv6: next header
- TCP/UDP: source port, destination port
Only one classifier table can be created thus all rules in the table have to match table format. Table format is set during creation of the first unique flow rule.
Up to 5 fields can be specified per flow rule.
Up to 20 flow rules can be added.

For additional information about classifier please consult doc/musdk_cls_user_guide.txt.

37.9. Traffic metering and policing

MVPP2 PMD supports DPDK traffic metering and policing that allows the following:

Meter ingress traffic.
Do policing.
Gather statistics.

For an additional description please refer to DPDK Traffic Metering and Policing API.

The policer objects defined by this feature can work with the default policer defined via config file as described in QoS Support.

37.9.1. Limitations

The following capabilities are not supported:

MTR object meter DSCP table update
MTR object policer action update
MTR object enabled statistics

37.9.2. Usage example

Run testpmd user app:

./dpdk-testpmd --vdev=eth_mvpp2,iface=eth0,iface=eth2 -c 6 -- -i -p 3 -a --txd 1024 --rxd 1024

Create meter profile:

testpmd> add port meter profile 0 0 srtcm_rfc2697 2000 256 256

Create meter:

testpmd> create port meter 0 0 0 yes d d d 0 1 0

Create flow rule witch meter attached:

testpmd> flow create 0 ingress pattern ipv4 src is 10.10.10.1 / end actions meter mtr_id 0 / end

For a detailed usage description please refer to “Traffic Metering and Policing” section in DPDK Testpmd Runtime Functions.

37.10. Traffic Management API

MVPP2 PMD supports generic DPDK Traffic Management API which allows to configure the following features:

Hierarchical scheduling
Traffic shaping
Congestion management
Packet marking

Internally TM is represented by a hierarchy (tree) of nodes. Node which has a parent is called a leaf whereas node without parent is called a non-leaf (root). MVPP2 PMD supports two level hierarchy where level 0 represents ports and level 1 represents tx queues of a given port.

Nodes hold following types of settings:

for egress scheduler configuration: weight
for egress rate limiter: private shaper
bitmask indicating which statistics counters will be read

Hierarchy is always constructed from the top, i.e first a root node is added then some number of leaf nodes. Number of leaf nodes cannot exceed number of configured tx queues.

After hierarchy is complete it can be committed.

For an additional description please refer to DPDK Traffic Management API.

37.10.1. Limitations

The following capabilities are not supported:

Traffic manager WRED profile and WRED context
Traffic manager shared shaper update
Traffic manager packet marking
Maximum number of levels in hierarchy is 2
Currently dynamic change of a hierarchy is not supported

37.10.2. Usage example

For a detailed usage description please refer to “Traffic Management” section in DPDK Testpmd Runtime Functions.

Run testpmd as follows:

./dpdk-testpmd --vdev=net_mrvl,iface=eth0,iface=eth2,cfg=./qos_config -c 7 -- \
-i -p 3 --disable-hw-vlan-strip --rxq 3 --txq 3 --txd 1024 --rxd 1024

Stop all ports:
```
testpmd> port stop all
```

Add shaper profile:

testpmd> add port tm node shaper profile 0 0 900000 70000 0