iperf result when vhost is enabled:
root@anfernee-XPS-8700:/home/anfernee/VM/images# iperf3 -c 192.168.122.41
Connecting to host 192.168.122.41, port 5201
[ 5] local 192.168.122.1 port 50716 connected to 192.168.122.41 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 4.72 GBytes 40.6 Gbits/sec 0 1.95 MBytes
[ 5] 1.00-2.00 sec 4.97 GBytes 42.7 Gbits/sec 0 2.64 MBytes
[ 5] 2.00-3.00 sec 4.86 GBytes 41.7 Gbits/sec 0 2.77 MBytes
[ 5] 3.00-4.00 sec 4.54 GBytes 39.0 Gbits/sec 0 4.00 MBytes
[ 5] 4.00-5.00 sec 4.78 GBytes 41.0 Gbits/sec 0 4.00 MBytes
[ 5] 5.00-6.00 sec 4.85 GBytes 41.6 Gbits/sec 0 4.00 MBytes
[ 5] 6.00-7.00 sec 4.92 GBytes 42.3 Gbits/sec 0 4.00 MBytes
[ 5] 7.00-8.00 sec 4.91 GBytes 42.2 Gbits/sec 0 4.00 MBytes
[ 5] 8.00-9.00 sec 4.61 GBytes 39.6 Gbits/sec 0 4.00 MBytes
[ 5] 9.00-10.00 sec 4.76 GBytes 40.9 Gbits/sec 0 4.00 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 47.9 GBytes 41.2 Gbits/sec 0 sender
[ 5] 0.00-10.00 sec 47.9 GBytes 41.2 Gbits/sec receiver
iperf Done.
Disable vhost by add
<model type='virtio'/>
<driver name="qemu"/>
<alias name='net0'/>
iperf result:
root@anfernee-XPS-8700:/home/anfernee/VM/images# iperf3 -c 192.168.122.41
Connecting to host 192.168.122.41, port 5201
[ 5] local 192.168.122.1 port 53958 connected to 192.168.122.41 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 3.44 GBytes 29.5 Gbits/sec 0 3.79 MBytes
[ 5] 1.00-2.00 sec 3.45 GBytes 29.6 Gbits/sec 0 3.98 MBytes
[ 5] 2.00-3.00 sec 3.42 GBytes 29.4 Gbits/sec 0 3.98 MBytes
[ 5] 3.00-4.00 sec 3.52 GBytes 30.2 Gbits/sec 0 3.98 MBytes
[ 5] 4.00-5.00 sec 3.49 GBytes 29.9 Gbits/sec 0 3.98 MBytes
[ 5] 5.00-6.00 sec 3.51 GBytes 30.2 Gbits/sec 0 3.98 MBytes
[ 5] 6.00-7.00 sec 3.30 GBytes 28.3 Gbits/sec 0 3.98 MBytes
[ 5] 7.00-8.00 sec 3.35 GBytes 28.8 Gbits/sec 0 3.98 MBytes
[ 5] 8.00-9.00 sec 3.60 GBytes 30.9 Gbits/sec 0 3.98 MBytes
[ 5] 9.00-10.00 sec 3.14 GBytes 26.9 Gbits/sec 0 3.98 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 34.2 GBytes 29.4 Gbits/sec 0 sender
[ 5] 0.00-10.00 sec 34.2 GBytes 29.4 Gbits/sec receiver
https://www.redhat.com/en/blog/hands-vhost-net-do-or-do-not-there-no-try