Ido Schimmel
2021-Aug-11 21:52 UTC
[Bridge] [PATCH net-next] net: bridge: switchdev: allow port isolation to be offloaded
On Thu, Aug 12, 2021 at 12:45:06AM +0300, Vladimir Oltean wrote:> On Thu, Aug 12, 2021 at 12:38:56AM +0300, Ido Schimmel wrote: > > On Wed, Aug 11, 2021 at 09:52:46PM +0800, DENG Qingfang wrote: > > > Add BR_ISOLATED flag to BR_PORT_FLAGS_HW_OFFLOAD, to allow switchdev > > > drivers to offload port isolation. > > > > > > Suggested-by: Vladimir Oltean <olteanv at gmail.com> > > > Signed-off-by: DENG Qingfang <dqfext at gmail.com> > > > --- > > > net/bridge/br_switchdev.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c > > > index 6bf518d78f02..898257153883 100644 > > > --- a/net/bridge/br_switchdev.c > > > +++ b/net/bridge/br_switchdev.c > > > @@ -71,7 +71,8 @@ bool nbp_switchdev_allowed_egress(const struct net_bridge_port *p, > > > > > > /* Flags that can be offloaded to hardware */ > > > #define BR_PORT_FLAGS_HW_OFFLOAD (BR_LEARNING | BR_FLOOD | \ > > > - BR_MCAST_FLOOD | BR_BCAST_FLOOD) > > > + BR_MCAST_FLOOD | BR_BCAST_FLOOD | \ > > > + BR_ISOLATED) > > > > Why add it now and not as part of a patchset that actually makes use of > > the flag in a driver that offloads port isolation? > > The way the information got transmitted is a bit unfortunate. > > Making BR_ISOLATED part of BR_PORT_FLAGS_HW_OFFLOAD is a matter of > correctness when switchdev offloads the data path. Since this feature > will not work correctly without driver intervention, it makes sense that > drivers should reject it currently, which is exactly what this patch > accomplishes - it makes the code path go through the > SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS driver handlers, which return > -EINVAL for everything they don't recognize.If the purpose is correctness, then this is not the only flag that was missed. BR_HAIRPIN_MODE is also relevant for the data path, for example. Anyway, the commit message needs to be reworded to reflect the true purpose of the patch.> > (yes, we do still have a problem for drivers that don't catch > SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS at all, switchdev will return > -EOPNOTSUPP for those which is then ignored, but those are in the > minority)
Vladimir Oltean
2021-Aug-11 21:58 UTC
[Bridge] [PATCH net-next] net: bridge: switchdev: allow port isolation to be offloaded
On Thu, Aug 12, 2021 at 12:52:48AM +0300, Ido Schimmel wrote:> On Thu, Aug 12, 2021 at 12:45:06AM +0300, Vladimir Oltean wrote: > > On Thu, Aug 12, 2021 at 12:38:56AM +0300, Ido Schimmel wrote: > > > On Wed, Aug 11, 2021 at 09:52:46PM +0800, DENG Qingfang wrote: > > > > Add BR_ISOLATED flag to BR_PORT_FLAGS_HW_OFFLOAD, to allow switchdev > > > > drivers to offload port isolation. > > > > > > > > Suggested-by: Vladimir Oltean <olteanv at gmail.com> > > > > Signed-off-by: DENG Qingfang <dqfext at gmail.com> > > > > --- > > > > net/bridge/br_switchdev.c | 3 ++- > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c > > > > index 6bf518d78f02..898257153883 100644 > > > > --- a/net/bridge/br_switchdev.c > > > > +++ b/net/bridge/br_switchdev.c > > > > @@ -71,7 +71,8 @@ bool nbp_switchdev_allowed_egress(const struct net_bridge_port *p, > > > > > > > > /* Flags that can be offloaded to hardware */ > > > > #define BR_PORT_FLAGS_HW_OFFLOAD (BR_LEARNING | BR_FLOOD | \ > > > > - BR_MCAST_FLOOD | BR_BCAST_FLOOD) > > > > + BR_MCAST_FLOOD | BR_BCAST_FLOOD | \ > > > > + BR_ISOLATED) > > > > > > Why add it now and not as part of a patchset that actually makes use of > > > the flag in a driver that offloads port isolation? > > > > The way the information got transmitted is a bit unfortunate. > > > > Making BR_ISOLATED part of BR_PORT_FLAGS_HW_OFFLOAD is a matter of > > correctness when switchdev offloads the data path. Since this feature > > will not work correctly without driver intervention, it makes sense that > > drivers should reject it currently, which is exactly what this patch > > accomplishes - it makes the code path go through the > > SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS driver handlers, which return > > -EINVAL for everything they don't recognize. > > If the purpose is correctness, then this is not the only flag that was > missed. BR_HAIRPIN_MODE is also relevant for the data path, for example.I never wanted to suggest that I'm giving a comprehensive answer, I just answered Qingfang's punctual question here: https://lore.kernel.org/netdev/CALW65jbotyW0MSOd-bd1TH_mkiBWhhRCQ29jgn+d12rXdj2pZA at mail.gmail.com/ Tobias also pointed out the same issue about BR_MULTICAST_TO_UNICAST in conjunction with tx_fwd_offload (although the same is probably true even without it): https://patchwork.kernel.org/project/netdevbpf/cover/20210426170411.1789186-1-tobias at waldekranz.com/> Anyway, the commit message needs to be reworded to reflect the true > purpose of the patch.Agree, and potentially extended with all the bridge port flags which are broken without switchdev driver intervention.