9. DPDK/OVS based lan

The futur default lan will be based on dpdk and openvswitch, it is a work that has been accelerated by the covid ievent but should go back to a slow but powerfull pace.

At the quemu level, for the guest, the driver seen for the inside guest kernel is the virtio-net driver on the frontend. The backend inside quemu is a vhost-user netdev with a memory-backend-file, this is probably the memory shared by the ovs/dpdk configuration for the whole setup to work.

As you can see on the picture, the iperf3 throughput with this socket type is more than 16 Gigabits per second. Here is the logical path for a packet:

+-------------+
|    iperf3 TX|
+-------------+
| Guest Kernel|
+-------------+
|   virtio net|
|       qemu  |
|   vhost user|
+------+------+
       |
       | User world
       v
+------+------+
|   OVS DPDK  |
+------+------+
       |
       | User world
       v
+------+------+
|   vhost user|
|       qemu  |
|  virtio net |
+-------------+
| Guest Kernel|
+-------------+
|    iperf3 RX|
+-------------+