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diff --git a/docs/usecases/contiv/VPP_CONFIG.md b/docs/usecases/contiv/VPP_CONFIG.md new file mode 100644 index 00000000000..0d0559372cb --- /dev/null +++ b/docs/usecases/contiv/VPP_CONFIG.md @@ -0,0 +1,153 @@ +## Creating VPP Startup Configuration +This document describes how to create the VPP startup configuration +file located at `/etc/vpp/contiv-vswitch.conf`. + +### Hardware Interface Configuration +#### Single-NIC Configuration +You need to configure hardware interfaces for use by VPP. First, find out the PCI address of the host's network interface. On +Debian-based distributions, you can use `lshw`: + +``` +sudo lshw -class network -businfo +Bus info Device Class Description +======================================================== +pci@0000:03:00.0 ens160 network VMXNET3 Ethernet Controller +``` + +In our case, it would be the `ens3` interface with the PCI address +`0000:00:03.0` + +Now, add or modify the VPP startup config file (`/etc/vpp/contiv-vswitch.conf`) +to contain the proper PCI address: +``` +unix { + nodaemon + cli-listen /run/vpp/cli.sock + cli-no-pager + coredump-size unlimited + full-coredump + poll-sleep-usec 100 +} +nat { + endpoint-dependent +} +dpdk { + dev 0000:00:03.0 +} +api-trace { + on + nitems 500 +} +``` +#### Multi-NIC Configuration +Similar to the single-NIC configuration, use command *lshw* to find the PCI +addresses of all the NICs in the system, for example: + +``` +$ sudo lshw -class network -businfo +Bus info Device Class Description +==================================================== +pci@0000:00:03.0 ens3 network Virtio network device +pci@0000:00:04.0 ens4 network Virtio network device +``` + +In the example above, `ens3` would be the primary interface and `ens4` would +be the interface that would be used by VPP. The PCI address of the `ens4` +interface would be `0000:00:04.0`. + +Make sure the selected interface is *shut down*, otherwise VPP +will not grab it: +``` +sudo ip link set ens4 down +``` + +Now, add or modify the VPP startup config file in `/etc/vpp/contiv-vswitch.conf` +to contain the proper PCI address: +``` +unix { + nodaemon + cli-listen /run/vpp/cli.sock + cli-no-pager + coredump-size unlimited + full-coredump + poll-sleep-usec 100 +} +nat { + endpoint-dependent +} +dpdk { + dev 0000:00:04.0 +} +api-trace { + on + nitems 500 +} +``` +If assigning multiple NICs to VPP you will need to include each NIC's PCI address +in the dpdk stanza in `/etc/vpp/contiv-vswitch.conf`. + +##### Assigning all NICs to VPP +On a multi-NIC node, it is also possible to assign all NICs from the kernel for +use by VPP. First, you need to install the STN daemon, as described [here][1], +since you will want the NICs to revert to the kernel if VPP crashes. + +You also need to configure the NICs in the VPP startup config file +in `/etc/vpp/contiv-vswitch.conf`. For example, to use both the primary and +secondary NIC, in a two-NIC node, your VPP startup config file would look +something like this: + +``` +unix { + nodaemon + cli-listen /run/vpp/cli.sock + cli-no-pager + coredump-size unlimited + full-coredump + poll-sleep-usec 100 +} +nat { + endpoint-dependent +} +dpdk { + dev 0000:00:03.0 + dev 0000:00:04.0 +} +api-trace { + on + nitems 500 +} +``` + +#### Installing `lshw` on CentOS/RedHat/Fedora +Note: On CentOS/RedHat/Fedora distributions, `lshw` may not be available +by default, install it by +``` +sudo yum -y install lshw +``` + +### Power-saving Mode +In regular operation, VPP takes 100% of one CPU core at all times (poll loop). +If high performance and low latency is not required you can "slow-down" +the poll-loop and drastically reduce CPU utilization by adding the following +stanza to the `unix` section of the VPP startup config file: +``` +unix { + ... + poll-sleep-usec 100 + ... +} +``` +The power-saving mode is especially useful in VM-based development environments +running on laptops or less powerful servers. + +### VPP API Trace +To troubleshoot VPP configuration issues in production environments, it is +strongly recommended to configure VPP API trace. This is done by adding the +following stanza to the VPP startup config file: +``` +api-trace { + on + nitems 500 +} +``` +You can set the size of the trace buffer with the <nitems> attribute. |