On Fri, Feb 07, 2025 at 09:04:28PM +0100, Eric Woudstra wrote: > Or should mlxsw_sp_switchdev_blocking_event() use > switchdev_handle_port_obj_add_foreign() to add the vxlan > foreign port? > > Then all foreign ports are added in a uniform manner and > SWITCHDEV_F_NO_FOREIGN is respected. > > I do not have the hardware to test any changes in that code. Personally, in your place I wouldn't have the courage to refactor that much in a driver as complex as spectrum, but if you CC the right people from Nvidia who can test, I guess you could give that a try. Actually, how I came to spectrum was that I was thinking about an alternative mechanism of detecting "foreign or not", other than emitting two switchdev notifiers. You emit just the usual, single one, but whoever handles it for a foreign bridge port will set a new bool port_obj_info->handled_by_foreign, very similar to the existing bool port_obj_info->handled. I was looking around to see who else open-codes the switchdev object handling rather than use the switchdev_handle_*() helpers, and that's how I came across spectrum. It would seem, at first glance, easier to set just this in spectrum: diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c index 6397ff0dc951..6926aaae7278 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c @@ -3953,6 +3953,7 @@ mlxsw_sp_switchdev_vxlan_vlans_add(struct net_device *vxlan_dev, return 0; port_obj_info->handled = true; + port_obj_info->handled_by_foreign = true; bridge_device = mlxsw_sp_bridge_device_find(mlxsw_sp->bridge, br_dev); if (!bridge_device) and this in the object replication helper: diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c index c48f66643e99..be82e79b5feb 100644 --- a/net/switchdev/switchdev.c +++ b/net/switchdev/switchdev.c @@ -763,6 +763,8 @@ static int __switchdev_handle_port_obj_add(struct net_device *dev, if (!foreign_dev_check_cb(switchdev, dev)) return err; + port_obj_info->handled_by_foreign = true; + return __switchdev_handle_port_obj_add(br, port_obj_info, check_cb, foreign_dev_check_cb, add_cb); } Just some care needs to be taken to only consider "handled_by_foreign" just when "handled" is true. I haven't yet decided which variant I like better, just thought I'd mention this as something which requires a single switchdev notification. Anyway, in the future I'll have to do some more tweaks with these flags in the context of LAG. These flags (BR_VLFLAG_ADDED_BY_SWITCHDEV, now also BR_VLFLAG_TAGGING_BY_SWITCHDEV after this patch) can dynamically change, and the existing code isn't great because it doesn't handle that. For example: ip link add br0 type bridge ip link set swp0 master br0 ip link set bond0 master br0 # bond0 is a foreign interface to swp0 at this time bridge vlan add dev bond0 vid 100 # this won't get BR_VLFLAG_TAGGING_BY_SWITCHDEV ip link set swp1 master bond0 # bond0 is no longer a foreign interface to swp0, assuming the same phys_switch_id # vid 100 should get BR_VLFLAG_TAGGING_BY_SWITCHDEV during br_switchdev_vlan_replay() Considering that br_switchdev_vlan_replay() will need to re-evaluate the BR_VLFLAG_TAGGING_BY_SWITCHDEV flag, I guess I do prefer the simpler variant after all - it is one call less that will have to be made during replay as well.
