RFE: Linux Bridge vhost-user support via fast path detection
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
networking-6wind |
New
|
Undecided
|
Unassigned | ||
neutron |
Won't Fix
|
Undecided
|
Unassigned |
Bug Description
Fast path technology is a user-space stack for high performance packets offloading the Linux networking functions: IPv4/IPv6 routing, linux bridge, iptables, conntrack...
To benefit from the offloading, a VM needs to use vhost-user instead of vhost-net backend for virtio interfaces.
As a consequence, we have:
- a forked ML2 linux bridge mechanism driver: https:/
- a forked linux agent: https:/
Problem Description
===================
We need to maintain a fork version of the ML2 linux bridge mechanism driver and also one for the linux bridge agent , it is not a proper design.
From users point of view, having to install a specific mechanism driver and an agent to benefit of the fastpath offloading, it is an extra operation. We should avoid to add extra operation for easiness.
Proposed Change
===============
LinuxBridge Agent
-----------------
The linux bridge agent shall detect whether a fast path offload is enabled, and it shall report it to the mechanism driver with the use of agent_state.
For this capability, a new field will be added in agent_state.
ML2 LinuxBridge
---------------
The mechanism driver LinuxBridge in the try_bind_
- set the vif_type to LINUXBRIDGE if agent['
- set the vif_type to VHOSTUSER if agent['
Specific vif_details needs to be added for vhost-user:
- vhost_user_socket (i.e '/tmp/usv-XXXX')
- vhost_user_fp_plug should be set True to create a tap netdevice with a vhostuser socket
Note: The vhost_user_fp_plug is a modification under review in Nova. See: https:/
Fix proposed to branch: master /review. openstack. org/246536
Review: https:/