Difference between revisions of "VPP Sandbox/turbotap"

From fd.io
Jump to: navigation, search
(Created page with "Hello Turbotap!!!")
 
Line 1: Line 1:
 
Hello Turbotap!!!
 
Hello Turbotap!!!
 +
== Abstract ==
 +
The objective of this project is to continue to build out better integration with host operating system and for providing a basis to enable completely or partially unmodified applications to take advantage of a fast datapath.
 +
 +
== Introduction ==
 +
Tap interfaces are virtual network devices in Linux Kernel. Legacy tap interfaces provide mechanism to write down user space application to send/receive packets to/from tap interfaces. VPP implements tap interfaces driver ''tapcli'' and provides tap interfaces at host side to communicate with host kernel stack or with applications running on host or for containerized applications. VPP uses tap interfaces to connect with legacy applications that use host APIs or system calls. Tapcli driver implements one system call per packet which results in huge performance issue due to context switching.
 +
 +
It is an experimental work, to use tap interfaces using socket API system calls '''sendmmsg''' or '''recvmmsg''' that allows to send/receive multiple packets using one single system call. It is a replacement for tapcli driver in VPP, which uses one system call per packet. Hence save the time for '''context switching''' between userspace and kernel space.
 +
 +
The linux kernel doesn't support socket API for tap interfaces. Therefore, a separate turbotap 'LINUX KERNEL MODULE' has been implemented to support send and receive socket system calls.
 +
 +
== Build and Install ==
 +
The turbotap driver is implemented as a plugin to send/receive packets from kernel tap interfaces. To use it, you must BUILD and INSTALL turbotap kernel module at first. Then you must build plugin and put it in VPPs runtime plugin directory. The plugin depends on vpp. This wiki assumes familiarity with the build environment for both projects.
 +
 +
Build vpp and turbotap both at once by creating symbolic links in the top level vpp directory to the turbotap directory as well as symbolic links to the respective .mk files in 'build-data/packages'.
 +
 +
```
 +
$ cd /git/vpp
 +
$ ln -sf /git/vppsb/turbotap
 +
$ ln -sf ../../turbotap/turbotap.mk build-data/packages/
 +
```
 +
 +
Now build everything and create a link to the plugin in vpp's plugin path.
 +
 +
```
 +
$ cd build-root
 +
$ ./bootstrap.sh
 +
$ make V=0 PLATFORM=vpp TAG=vpp_debug turbotap-install
 +
$ ln -sf /git/vpp/build-root/install-vpp_debug-native/router/lib64/turbotap.so.0.0.0 \
 +
        /usr/lib/vpp_plugins/
 +
 +
Once VPP is running and the plugin is loaded, turbotap interfaces can be created or deleted.
 +
 +
```
 +
$ vppctl turbotap connect turbotap0
 +
$ vppctl turbotap delete turbotap0
 +
```
 +
 +
The host operating system should see a turbotap named 'turbotap0'.
 +
 +
==  ==
 +
Currently the turbotap driver plugin uses socket API system calls. Most of the
 +
code is borrowed from tapcli driver in VPP. One can extend it to multi-queue driver.
 +
 +
### Objective

Revision as of 11:46, 10 August 2016

Hello Turbotap!!!

Abstract

The objective of this project is to continue to build out better integration with host operating system and for providing a basis to enable completely or partially unmodified applications to take advantage of a fast datapath.

Introduction

Tap interfaces are virtual network devices in Linux Kernel. Legacy tap interfaces provide mechanism to write down user space application to send/receive packets to/from tap interfaces. VPP implements tap interfaces driver tapcli and provides tap interfaces at host side to communicate with host kernel stack or with applications running on host or for containerized applications. VPP uses tap interfaces to connect with legacy applications that use host APIs or system calls. Tapcli driver implements one system call per packet which results in huge performance issue due to context switching.

It is an experimental work, to use tap interfaces using socket API system calls sendmmsg or recvmmsg that allows to send/receive multiple packets using one single system call. It is a replacement for tapcli driver in VPP, which uses one system call per packet. Hence save the time for context switching between userspace and kernel space.

The linux kernel doesn't support socket API for tap interfaces. Therefore, a separate turbotap 'LINUX KERNEL MODULE' has been implemented to support send and receive socket system calls.

Build and Install

The turbotap driver is implemented as a plugin to send/receive packets from kernel tap interfaces. To use it, you must BUILD and INSTALL turbotap kernel module at first. Then you must build plugin and put it in VPPs runtime plugin directory. The plugin depends on vpp. This wiki assumes familiarity with the build environment for both projects.

Build vpp and turbotap both at once by creating symbolic links in the top level vpp directory to the turbotap directory as well as symbolic links to the respective .mk files in 'build-data/packages'.

``` $ cd /git/vpp $ ln -sf /git/vppsb/turbotap $ ln -sf ../../turbotap/turbotap.mk build-data/packages/ ```

Now build everything and create a link to the plugin in vpp's plugin path.

``` $ cd build-root $ ./bootstrap.sh $ make V=0 PLATFORM=vpp TAG=vpp_debug turbotap-install $ ln -sf /git/vpp/build-root/install-vpp_debug-native/router/lib64/turbotap.so.0.0.0 \ 

        /usr/lib/vpp_plugins/

Once VPP is running and the plugin is loaded, turbotap interfaces can be created or deleted.

``` $ vppctl turbotap connect turbotap0 $ vppctl turbotap delete turbotap0 ```

The host operating system should see a turbotap named 'turbotap0'.

Currently the turbotap driver plugin uses socket API system calls. Most of the code is borrowed from tapcli driver in VPP. One can extend it to multi-queue driver.

      1. Objective
Retrieved from "https://wiki.fd.io/index.php?title=VPP_Sandbox/turbotap&oldid=2450"