Re: [PATCH V3 net-next 1/4] net: bridge: add fdb flag to extent locked port feature

From: Ido Schimmel <idosch@nvidia.com>
To: Hans Schultz <schultz.hans@gmail.com>
Cc: Ido Schimmel <idosch@idosch.org>,
	davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org,
	Andrew Lunn <andrew@lunn.ch>,
	Vivien Didelot <vivien.didelot@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>, Jiri Pirko <jiri@resnulli.us>,
	Ivan Vecera <ivecera@redhat.com>, Roopa Prabhu <roopa@nvidia.com>,
	Nikolay Aleksandrov <razor@blackwall.org>,
	Shuah Khan <shuah@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	linux-kernel@vger.kernel.org, bridge@lists.linux-foundation.org,
	linux-kselftest@vger.kernel.org
Subject: Re: [PATCH V3 net-next 1/4] net: bridge: add fdb flag to extent locked port feature
Date: Tue, 31 May 2022 17:23:28 +0300	[thread overview]
Message-ID: <YpYk4EIeH6sdRl+1@shredder> (raw)
In-Reply-To: <86sfoqgi5e.fsf@gmail.com>

On Tue, May 31, 2022 at 11:34:21AM +0200, Hans Schultz wrote:
> > Just to give you another data point about how this works in other
> > devices, I can say that at least in Spectrum this works a bit
> > differently. Packets that ingress via a locked port and incur an FDB
> > miss are trapped to the CPU where they should be injected into the Rx
> > path so that the bridge will create the 'locked' FDB entry and notify it
> > to user space. The packets are obviously rated limited as the CPU cannot
> > handle billions of packets per second, unlike the ASIC. The limit is not
> > per bridge port (or even per bridge), but instead global to the entire
> > device.
> 
> Btw, will the bridge not create a SWITCHDEV_FDB_ADD_TO_DEVICE event
> towards the switchcore in the scheme you mention and thus add an entry
> that opens up for the specified mac address?

It will, but the driver needs to ignore FDB entries that are notified
with locked flag. I see that you extended 'struct
switchdev_notifier_fdb_info' with the locked flag, but it's not
initialized in br_switchdev_fdb_populate(). Can you add it in the next
version?