[RFC,0/5] Add bridge VLAN support

Message

Leigh Brown May 3, 2024, 2:41 p.m. UTC

For many years I have been configuring VLANs on my Linux Dom0 by
creating VLAN interfaces for each VLAN I wanted to connect a domain
to and then a corresponding bridge. So I would tend to have things
like:

enp0s0	  -> br0     -> vif1, vif2
enp0s0.10 -> br0vl10 -> vif3, vif4
enp0s0.20 -> br0vl20 -> vif5
dummy0    -> br1     -> vif6

I recently discovered that iproute2 supports creating bridge VLANs that
allows you to assign a VLAN to each of the interfaces associated to a 
bridge. This allows a greatly simplified configuration where a single 
bridge can support all the domains, and the iproute2 bridge command can 
assign each VIF to the required VLAN.  This looks like this:

# bridge vlan
port              vlan-id  
enp0s0            1 PVID Egress Untagged
                  10
                  20
br0               1 PVID Egress Untagged
vif1.0            1 PVID Egress Untagged
vif2.0            10 PVID Egress Untagged
vif3.0            10 PVID Egress Untagged
vif4.0            20 PVID Egress Untagged
vif5.0            20 PVID Egress Untagged
vif6.0            30 PVID Egress Untagged

This patch set enables this capability as follows:

1. Adds `vid' as a new member of the libxl_device_nic structure;
2. Adds support to read and write vid from the xenstore;
3. Adds `vid' as a new keyword for the vif configuration option;
4. Adds support for assign the bridge VLAN in the Linux hotplug scripts.

I don't believe NetBSD or FreeBSD support this capability, but if they
do please point me in the direction of some documentation and/or examples.

NB: I'm not very familiar with Xen code base so may have missed
something important, although I have tested it and it is working well
for me.

Cheers,

Leigh.


[e-mail] (5):
  tools/libs/light: Add vid field to libxl_device_nic
  tools/xl: add vid keyword vif option
  tools/hotplug/Linux: Add bridge VLAN support
  docs/man: document VIF vid keyword
  tools/examples: Examples Linux bridge VLAN config

 docs/man/xl-network-configuration.5.pod.in    |  6 +++
 tools/examples/linux-bridge-vlan/README       | 52 +++++++++++++++++++
 tools/examples/linux-bridge-vlan/br0.netdev   |  7 +++
 tools/examples/linux-bridge-vlan/br0.network  |  8 +++
 .../examples/linux-bridge-vlan/enp0s0.network | 16 ++++++
 tools/hotplug/Linux/xen-network-common.sh     |  9 ++++
 tools/libs/light/libxl_nic.c                  | 20 +++++++
 tools/libs/light/libxl_types.idl              |  1 +
 tools/xl/xl_parse.c                           |  2 +
 9 files changed, 121 insertions(+)
 create mode 100644 tools/examples/linux-bridge-vlan/README
 create mode 100644 tools/examples/linux-bridge-vlan/br0.netdev
 create mode 100644 tools/examples/linux-bridge-vlan/br0.network
 create mode 100644 tools/examples/linux-bridge-vlan/enp0s0.network