Re: [PATCH v5 0/1] macvlan: allow source mode devices along with passthru

[Thomas Martitz]

Hello,

Apologize for forgetting a changelog entry. I'm adding it inline and hopefully don't
forget include it in the next posting (if any).

BTW: I'll be attending at LPC in Prague. Would be great to have a chat with your guys there.

Am 17.09.26 um 12:02 schrieb Thomas Martitz:
> Hello,
> 
> we're trying to solve a use case on our devices where two SoC are
> connected on the same board, using the only available high-speed interface.
> 
> One SoC runs the main Linux system including the full routing stack
> (FRITZ!OS) and the other SoC implements most of the GPON ONT side.
> 
> The high-speed interface is of course also used for the user traffic.
> Therefore we must tell the inter-SoC traffic apart from the user traffic.
> 
> We achieve this by matching the well-known MAC address of the ONT SoC.
> The user traffic passes through the ONT SoC without modifying MAC headers.
> Now we would like to use macvlan (with source mode devices) on the main
> SoC side for this but our routing stack requires the rx_handler to be
> available. Therefore macvlan is currently not an option.
> 
> With this patch macvlan becomes an option because the current limitation
> of either "one passthru device" or "any other configuration" is relaxed
> for the combination of passthru and any number of source mode devices.
> 
> This allows us to configure a source mode device for the other SoC and
> register an rx_handler for further processing on the passthru device.
> 
> Thanks in advance!
> 
---
Changes in v5
- Properly respect "macvlan_addr_busy()" again for non-passthru  interfaces (and avoid calling anymore for passthru interfaces)
- Guard NETDEV_CHANGEADDR from messing with the lower device
  address during passthru interface removal
- restore unicast address (dev_add_uc/_del_uc) handling> Changes in v4
> - Prevent macvlan_restore_mac() from changing the MAC address
>   of remaining source mode interfaces.
> - Set MACVLAN_F_PASSTHRU on the macvlan_port only after adding
>   the passthru interface truly succeeds.
> - Changing existing interfaces to passthru mode shouldn't become
>   allowed.
> 
> Changes in v3
> - fix passthru port removal caused by passing the wrong 
>   device to macvlan_port_release_mac(). This was also
>   detected by syzbot.
> - macvlan_port_release_mac() is now named macvlan_restore_mac()
>   and gets passed a "struct macvlan_port" directly.
> - Link to v2: https://lore.kernel.org/netdev/20260709100512.1383421-1-t.martitz@xxxxxxxxx/
> 
> Changes in v2:
> - changed several port-wide checks (macvlan_passthru()) to 
>   per-interface checks (vlan->mode == vlan->mode == MACVLAN_MODE_PASSTHRU)
> - correctly handle removing the passthru interface when there are still
>   source interfaces
> - Link to initial posting: https://lore.kernel.org/netdev/20260612092345.2352255-1-t.martitz@xxxxxxxxx/
> ---
> 
> Thomas Martitz (1):
>   macvlan: allow source mode devices along with passthru
> 
>  drivers/net/macvlan.c | 107 ++++++++++++++++++++++++++++--------------
>  1 file changed, 73 insertions(+), 34 deletions(-)
> 

Best regards

-- 
Thomas Martitz <t.martitz@xxxxxxxxx>
FRITZ! Technology GmbH, Berlin (Germany)