iperf3: A TCP, UDP, SCTP, and VSOCK network bandwidth measurement tool

This repository is a fork of iperf3 with VSOCK support.

The VSOCK address family facilitates communication between virtual machines and the host they are running on.

To test VSOCK sockets (only Linux), you must use the new option --vsock on both server and client. Other iperf3 options (e.g. -t, -l, -P, -R, --bidir) are well supported by VSOCK tests.

Changes from upstream iperf 3.x

New options:

--vsock                   use VSOCK address family rather than INET (Linux)

Build

Prerequisites:

• Linux kernel >= 4.8

Clone repository

git clone https://github.com/stefano-garzarella/iperf-vsock
cd iperf-vsock

Building

mkdir build
cd build
../configure
make
cd src

(Note: If configure fails, try running ./bootstrap.sh first)

Example with Fedora (host and guest):

Host: start the VM

GUEST_CID=3
sudo modprobe vhost_vsock
sudo qemu-system-x86_64 -m 1G -smp 2 -cpu host -M accel=kvm	\
     -drive if=virtio,file=/path/to/fedora.img,format=qcow2     \
     -device vhost-vsock-pci,guest-cid=${GUEST_CID}

Guest: start iperf server

# SELinux can block you, so you can write a policy or temporally disable it
sudo setenforce 0
iperf3 --vsock -s

Host: start iperf client

iperf3 --vsock -c ${GUEST_CID}

Output

Connecting to host 3, port 5201
[  5] local 2 port 4008596529 connected to 3 port 5201
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  1.30 GBytes  11.2 Gbits/sec
[  5]   1.00-2.00   sec  1.67 GBytes  14.3 Gbits/sec
[  5]   2.00-3.00   sec  1.57 GBytes  13.5 Gbits/sec
[  5]   3.00-4.00   sec  1.49 GBytes  12.8 Gbits/sec
[  5]   4.00-5.00   sec   971 MBytes  8.15 Gbits/sec
[  5]   5.00-6.00   sec  1.01 GBytes  8.71 Gbits/sec
[  5]   6.00-7.00   sec  1.44 GBytes  12.3 Gbits/sec
[  5]   7.00-8.00   sec  1.62 GBytes  13.9 Gbits/sec
[  5]   8.00-9.00   sec  1.61 GBytes  13.8 Gbits/sec
[  5]   9.00-10.00  sec  1.63 GBytes  14.0 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.00  sec  14.3 GBytes  12.3 Gbits/sec                  sender
[  5]   0.00-10.00  sec  14.3 GBytes  12.3 Gbits/sec                  receiver

iperf Done.

Sibling VMs

iperf between sibling VMs is also possible. In this case, you must use the CID of the sibling VM prefixed with s (e.g. s4) in the iperf client command. Example:

iperf3 --vsock -c s4

Firecracker's hybrid VSOCK over AF_UNIX

Firecracker, Cloud Hypervisor, and QEMU's vhost-user-vsock implement the virtio-vsock device model in userspace, and they allow the host to reach the guest using AF_UNIX sockets. More info here

iperf-vsock supports VSOCK over AF_UNIX. In order to use it, you can replace the guest CID with the UDS (Unix Domain Socket) base path.

In the following examples, the UDS base path to reach the guest is /tmp/vm.vsock

Host runs iperf client

guest

iperf3 --vsock -s

host

iperf3 --vsock -c /tmp/vm.vsock

Host runs iperf server

host

iperf3 --vsock -s -B /tmp/vm.vsock

guest

iperf3 --vsock -c 2