OVS DPDK INSTALL GUIDE
================================
## Contents
1. [Overview](#overview)
2. [Building and Installation](#build)
3. [Setup OVS DPDK datapath](#ovssetup)
4. [DPDK in the VM](#builddpdk)
5. [OVS Testcases](#ovstc)
6. [Limitations ](#ovslimits)
## 1. Overview
Open vSwitch can use DPDK lib to operate entirely in userspace.
This file provides information on installation and use of Open vSwitch
using DPDK datapath. This version of Open vSwitch should be built manually
with `configure` and `make`.
The DPDK support of Open vSwitch is considered 'experimental'.
### Prerequisites
* Required: DPDK 16.04, libnuma
* Hardware: [DPDK Supported NICs] when physical ports in use
## 2. Building and Installation
### 2.1 Configure & build the Linux kernel
On Linux Distros running kernel version >= 3.0, kernel rebuild is not required
and only grub cmdline needs to be updated for enabling IOMMU [VFIO support - 3.2].
For older kernels, check if kernel is built with UIO, HUGETLBFS, PROC_PAGE_MONITOR,
HPET, HPET_MMAP support.
Detailed system requirements can be found at [DPDK requirements] and also refer to
advanced install guide [INSTALL.DPDK-ADVANCED.md]
### 2.2 Install DPDK
1. [Download DPDK] and extract the file, for example in to /usr/src
and set DPDK_DIR
```
cd /usr/src/
wget http://dpdk.org/browse/dpdk/snapshot/dpdk-16.04.zip
unzip dpdk-16.04.zip
export DPDK_DIR=/usr/src/dpdk-16.04
cd $DPDK_DIR
```
2. Configure and Install DPDK
Build and install the DPDK library.
```
export DPDK_TARGET=x86_64-native-linuxapp-gcc
export DPDK_BUILD=$DPDK_DIR/$DPDK_TARGET
make install T=$DPDK_TARGET DESTDIR=install
```
Note: For IVSHMEM, Set `export DPDK_TARGET=x86_64-ivshmem-linuxapp-gcc`
### 2.3 Install OVS
OVS can be installed using different methods. For OVS to use DPDK datapath,
it has to be configured with DPDK support and is done by './configure --with-dpdk'.
This section focus on generic recipe that suits most cases and for distribution
specific instructions, refer [INSTALL.Fedora.md], [INSTALL.RHEL.md] and
[INSTALL.Debian.md].
The OVS sources can be downloaded in different ways and skip this section
if already having the correct sources. Otherwise download the correct version using
one of the below suggested methods and follow the documentation of that specific
version.
- OVS stable releases can be downloaded in compressed format from [Download OVS]
```
cd /usr/src
wget http://openvswitch.org/releases/openvswitch-.tar.gz
tar -zxvf openvswitch-.tar.gz
export OVS_DIR=/usr/src/openvswitch-
```
- OVS current development can be clone using 'git' tool
```
cd /usr/src/
git clone https://github.com/openvswitch/ovs.git
export OVS_DIR=/usr/src/ovs
```
- Install OVS dependencies
GNU make, GCC 4.x (or) Clang 3.4, libnuma (Mandatory)
libssl, libcap-ng, Python 2.7 (Optional)
More information can be found at [Build Requirements]
- Configure, Install OVS
```
cd $OVS_DIR
./boot.sh
./configure --with-dpdk=$DPDK_BUILD
make install
```
Note: Passing DPDK_BUILD can be skipped if DPDK library is installed in
standard locations i.e `./configure --with-dpdk` should suffice.
Additional information can be found in [INSTALL.md].
## 3. Setup OVS with DPDK datapath
### 3.1 Setup Hugepages
Allocate and mount 2M Huge pages:
- For persistent allocation of huge pages, write to hugepages.conf file
in /etc/sysctl.d
`echo 'vm.nr_hugepages=2048' > /etc/sysctl.d/hugepages.conf`
- For run-time allocation of huge pages
`sysctl -w vm.nr_hugepages=N` where N = No. of 2M huge pages allocated
- To verify hugepage configuration
`grep HugePages_ /proc/meminfo`
- Mount hugepages
`mount -t hugetlbfs none /dev/hugepages`
Note: Mount hugepages if not already mounted by default.
### 3.2 Setup DPDK devices using VFIO
- Supported with kernel version >= 3.6
- VFIO needs support from BIOS and kernel.
- BIOS changes:
Enable VT-d, can be verified from `dmesg | grep -e DMAR -e IOMMU` output
- GRUB bootline:
Add `iommu=pt intel_iommu=on`, can be verified from `cat /proc/cmdline` output
- Load modules and bind the NIC to VFIO driver
```
modprobe vfio-pci
sudo /usr/bin/chmod a+x /dev/vfio
sudo /usr/bin/chmod 0666 /dev/vfio/*
$DPDK_DIR/tools/dpdk_nic_bind.py --bind=vfio-pci eth1
$DPDK_DIR/tools/dpdk_nic_bind.py --status
```
Note: If running kernels < 3.6 UIO drivers to be used,
please check [DPDK in the VM], DPDK devices using UIO section for the steps.
### 3.3 Setup OVS
1. DB creation (One time step)
```
mkdir -p /usr/local/etc/openvswitch
mkdir -p /usr/local/var/run/openvswitch
rm /usr/local/etc/openvswitch/conf.db
ovsdb-tool create /usr/local/etc/openvswitch/conf.db \
/usr/local/share/openvswitch/vswitch.ovsschema
```
2. Start ovsdb-server
No SSL support
```
ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock \
--remote=db:Open_vSwitch,Open_vSwitch,manager_options \
--pidfile --detach
```
SSL support
```
ovsdb-server --remote=punix:/usr/local/var/run/openvswitch/db.sock \
--remote=db:Open_vSwitch,Open_vSwitch,manager_options \
--private-key=db:Open_vSwitch,SSL,private_key \
--certificate=Open_vSwitch,SSL,certificate \
--bootstrap-ca-cert=db:Open_vSwitch,SSL,ca_cert --pidfile --detach
```
3. Initialize DB (One time step)
```
ovs-vsctl --no-wait init
```
4. Start vswitchd
DPDK configuration arguments can be passed to vswitchd via Open_vSwitch
'other_config' column. The important configuration options are listed below.
Defaults will be provided for all values not explicitly set. Refer
ovs-vswitchd.conf.db(5) for additional information on configuration options.
* dpdk-init
Specifies whether OVS should initialize and support DPDK ports. This is
a boolean, and defaults to false.
* dpdk-lcore-mask
Specifies the CPU cores on which dpdk lcore threads should be spawned and
expects hex string (eg '0x123').
* dpdk-socket-mem
Comma separated list of memory to pre-allocate from hugepages on specific
sockets.
* dpdk-hugepage-dir
Directory where hugetlbfs is mounted
* vhost-sock-dir
Option to set the path to the vhost_user unix socket files.
NOTE: Changing any of these options requires restarting the ovs-vswitchd
application.
Open vSwitch can be started as normal. DPDK will be initialized as long
as the dpdk-init option has been set to 'true'.
```
export DB_SOCK=/usr/local/var/run/openvswitch/db.sock
ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-init=true
ovs-vswitchd unix:$DB_SOCK --pidfile --detach
```
If allocated more than one GB hugepage (as for IVSHMEM), set amount and
use NUMA node 0 memory. For details on using ivshmem with DPDK, refer to
[OVS Testcases].
```
ovs-vsctl --no-wait set Open_vSwitch . other_config:dpdk-socket-mem="1024,0"
ovs-vswitchd unix:$DB_SOCK --pidfile --detach
```
To better scale the work loads across cores, Multiple pmd threads can be
created and pinned to CPU cores by explicity specifying pmd-cpu-mask.
eg: To spawn 2 pmd threads and pin them to cores 1, 2
```
ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=6
```
5. Create bridge & add DPDK devices
create a bridge with datapath_type "netdev" in the configuration database
`ovs-vsctl add-br br0 -- set bridge br0 datapath_type=netdev`
Now you can add DPDK devices. OVS expects DPDK device names to start with
"dpdk" and end with a portid. vswitchd should print (in the log file) the
number of dpdk devices found.
```
ovs-vsctl add-port br0 dpdk0 -- set Interface dpdk0 type=dpdk
ovs-vsctl add-port br0 dpdk1 -- set Interface dpdk1 type=dpdk
```
After the DPDK ports get added to switch, a polling thread continuously polls
DPDK devices and consumes 100% of the core as can be checked from 'top' and 'ps' cmds.
```
top -H
ps -eLo pid,psr,comm | grep pmd
```
Note: creating bonds of DPDK interfaces is slightly different to creating
bonds of system interfaces. For DPDK, the interface type must be explicitly
set, for example:
```
ovs-vsctl add-bond br0 dpdkbond dpdk0 dpdk1 -- set Interface dpdk0 type=dpdk -- set Interface dpdk1 type=dpdk
```
6. PMD thread statistics
```
# Check current stats
ovs-appctl dpif-netdev/pmd-stats-show
# Show port/rxq assignment
ovs-appctl dpif-netdev/pmd-rxq-show
# Clear previous stats
ovs-appctl dpif-netdev/pmd-stats-clear
```
7. Stop vswitchd & Delete bridge
```
ovs-appctl -t ovs-vswitchd exit
ovs-appctl -t ovsdb-server exit
ovs-vsctl del-br br0
```
## 4. DPDK in the VM
DPDK 'testpmd' application can be run in the Guest VM for high speed
packet forwarding between vhostuser ports. DPDK and testpmd application
has to be compiled on the guest VM. Below are the steps for setting up
the testpmd application in the VM. More information on the vhostuser ports
can be found in [Vhost Walkthrough].
* Instantiate the Guest
```
Qemu version >= 2.2.0
export VM_NAME=Centos-vm
export GUEST_MEM=3072M
export QCOW2_IMAGE=/root/CentOS7_x86_64.qcow2
export VHOST_SOCK_DIR=/usr/local/var/run/openvswitch
qemu-system-x86_64 -name $VM_NAME -cpu host -enable-kvm -m $GUEST_MEM -object memory-backend-file,id=mem,size=$GUEST_MEM,mem-path=/dev/hugepages,share=on -numa node,memdev=mem -mem-prealloc -smp sockets=1,cores=2 -drive file=$QCOW2_IMAGE -chardev socket,id=char0,path=$VHOST_SOCK_DIR/dpdkvhostuser0 -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce -device virtio-net-pci,mac=00:00:00:00:00:01,netdev=mynet1,mrg_rxbuf=off -chardev socket,id=char1,path=$VHOST_SOCK_DIR/dpdkvhostuser1 -netdev type=vhost-user,id=mynet2,chardev=char1,vhostforce -device virtio-net-pci,mac=00:00:00:00:00:02,netdev=mynet2,mrg_rxbuf=off --nographic -snapshot
```
* Download the DPDK Srcs to VM and build DPDK
```
cd /root/dpdk/
wget http://dpdk.org/browse/dpdk/snapshot/dpdk-16.04.zip
unzip dpdk-16.04.zip
export DPDK_DIR=/root/dpdk/dpdk-16.04
export DPDK_TARGET=x86_64-native-linuxapp-gcc
export DPDK_BUILD=$DPDK_DIR/$DPDK_TARGET
cd $DPDK_DIR
make install T=$DPDK_TARGET DESTDIR=install
```
* Build the test-pmd application
```
cd app/test-pmd
export RTE_SDK=$DPDK_DIR
export RTE_TARGET=$DPDK_TARGET
make
```
* Setup Huge pages and DPDK devices using UIO
```
sysctl vm.nr_hugepages=1024
mkdir -p /dev/hugepages
mount -t hugetlbfs hugetlbfs /dev/hugepages (only if not already mounted)
modprobe uio
insmod $DPDK_BUILD/kmod/igb_uio.ko
$DPDK_DIR/tools/dpdk_nic_bind.py --status
$DPDK_DIR/tools/dpdk_nic_bind.py -b igb_uio 00:03.0 00:04.0
```
vhost ports pci ids can be retrieved using `lspci | grep Ethernet` cmd.
## 5. OVS Testcases
Below are few testcases and the list of steps to be followed.
### 5.1 PHY-PHY
The steps (1-5) in 3.3 section will create & initialize DB, start vswitchd and also
add DPDK devices to bridge 'br0'.
1. Add Test flows to forward packets betwen DPDK port 0 and port 1
```
# Clear current flows
ovs-ofctl del-flows br0
# Add flows between port 1 (dpdk0) to port 2 (dpdk1)
ovs-ofctl add-flow br0 in_port=1,action=output:2
ovs-ofctl add-flow br0 in_port=2,action=output:1
```
### 5.2 PHY-VM-PHY [VHOST LOOPBACK]
The steps (1-5) in 3.3 section will create & initialize DB, start vswitchd and also
add DPDK devices to bridge 'br0'.
1. Add dpdkvhostuser ports to bridge 'br0'. More information on the dpdkvhostuser ports
can be found in [Vhost Walkthrough].
```
ovs-vsctl add-port br0 dpdkvhostuser0 -- set Interface dpdkvhostuser0 type=dpdkvhostuser
ovs-vsctl add-port br0 dpdkvhostuser1 -- set Interface dpdkvhostuser1 type=dpdkvhostuser
```
2. Add Test flows to forward packets betwen DPDK devices and VM ports
```
# Clear current flows
ovs-ofctl del-flows br0
# Add flows
ovs-ofctl add-flow br0 in_port=1,action=output:3
ovs-ofctl add-flow br0 in_port=3,action=output:1
ovs-ofctl add-flow br0 in_port=4,action=output:2
ovs-ofctl add-flow br0 in_port=2,action=output:4
# Dump flows
ovs-ofctl dump-flows br0
```
3. Instantiate Guest VM using Qemu cmdline
Guest Configuration
```
| configuration | values | comments
|----------------------|--------|-----------------
| qemu version | 2.2.0 |
| qemu thread affinity | core 5 | taskset 0x20
| memory | 4GB | -
| cores | 2 | -
| Qcow2 image | CentOS7| -
| mrg_rxbuf | off | -
```
Instantiate Guest
```
export VM_NAME=vhost-vm
export GUEST_MEM=3072M
export QCOW2_IMAGE=/root/CentOS7_x86_64.qcow2
export VHOST_SOCK_DIR=/usr/local/var/run/openvswitch
taskset 0x20 qemu-system-x86_64 -name $VM_NAME -cpu host -enable-kvm -m $GUEST_MEM -object memory-backend-file,id=mem,size=$GUEST_MEM,mem-path=/dev/hugepages,share=on -numa node,memdev=mem -mem-prealloc -smp sockets=1,cores=2 -drive file=$QCOW2_IMAGE -chardev socket,id=char0,path=$VHOST_SOCK_DIR/dpdkvhostuser0 -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce -device virtio-net-pci,mac=00:00:00:00:00:01,netdev=mynet1,mrg_rxbuf=off -chardev socket,id=char1,path=$VHOST_SOCK_DIR/dpdkvhostuser1 -netdev type=vhost-user,id=mynet2,chardev=char1,vhostforce -device virtio-net-pci,mac=00:00:00:00:00:02,netdev=mynet2,mrg_rxbuf=off --nographic -snapshot
```
4. Guest VM using libvirt
The below is a simple xml configuration of 'demovm' guest that can be instantiated
using 'virsh'. The guest uses a pair of vhostuser port and boots with 4GB RAM and 2 cores.
More information can be found in [Vhost Walkthrough].
```
demovm4a9b3f53-fa2a-47f3-a757-dd87720d9d1d4194304419430424096hvmdestroyrestartdestroy/usr/bin/qemu-kvm
```
5. DPDK Packet forwarding in Guest VM
To accomplish this, DPDK and testpmd application have to be first compiled
on the VM and the steps are listed in [DPDK in the VM].
* Run test-pmd application
```
cd $DPDK_DIR/app/test-pmd;
./testpmd -c 0x3 -n 4 --socket-mem 1024 -- --burst=64 -i --txqflags=0xf00 --disable-hw-vlan
set fwd mac_retry
start
```
* Bind vNIC back to kernel once the test is completed.
```
$DPDK_DIR/tools/dpdk_nic_bind.py --bind=virtio-pci 0000:00:03.0
$DPDK_DIR/tools/dpdk_nic_bind.py --bind=virtio-pci 0000:00:04.0
```
Note: Appropriate PCI IDs to be passed in above example. The PCI IDs can be
retrieved using '$DPDK_DIR/tools/dpdk_nic_bind.py --status' cmd.
### 5.3 PHY-VM-PHY [IVSHMEM]
The steps for setup of IVSHMEM are covered in section 5.2(PVP - IVSHMEM)
of [OVS Testcases] in ADVANCED install guide.
## 6. Limitations
- Supports MTU size 1500, MTU setting for DPDK netdevs will be in future OVS release.
- Currently DPDK ports does not use HW offload functionality.
- Network Interface Firmware requirements:
Each release of DPDK is validated against a specific firmware version for
a supported Network Interface. New firmware versions introduce bug fixes,
performance improvements and new functionality that DPDK leverages. The
validated firmware versions are available as part of the release notes for
DPDK. It is recommended that users update Network Interface firmware to
match what has been validated for the DPDK release.
For DPDK 16.04, the list of validated firmware versions can be found at:
http://dpdk.org/doc/guides/rel_notes/release_16_04.html
Bug Reporting:
--------------
Please report problems to bugs@openvswitch.org.
[DPDK requirements]: http://dpdk.org/doc/guides/linux_gsg/sys_reqs.html
[Download DPDK]: http://dpdk.org/browse/dpdk/refs/
[Download OVS]: http://openvswitch.org/releases/
[DPDK Supported NICs]: http://dpdk.org/doc/nics
[Build Requirements]: https://github.com/openvswitch/ovs/blob/master/INSTALL.md#build-requirements
[INSTALL.DPDK-ADVANCED.md]: INSTALL.DPDK-ADVANCED.md
[OVS Testcases]: INSTALL.DPDK-ADVANCED.md#ovstc
[Vhost Walkthrough]: INSTALL.DPDK-ADVANCED.md#vhost
[DPDK in the VM]: INSTALL.DPDK.md#builddpdk
[INSTALL.md]:INSTALL.md
[INSTALL.Fedora.md]:INSTALL.Fedora.md
[INSTALL.RHEL.md]:INSTALL.RHEL.md
[INSTALL.Debian.md]:INSTALL.Debian.md