linux-kernel - Re: [PATCH iwl-next v4 6/6] ice: enable LLDP TX for VFs through tc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20250220145908.GD1615191@kernel.org>
Date: Thu, 20 Feb 2025 14:59:08 +0000
From: Simon Horman <horms@...nel.org>
To: Larysa Zaremba <larysa.zaremba@...el.com>
Cc: Tony Nguyen <anthony.l.nguyen@...el.com>,
	intel-wired-lan@...ts.osuosl.org,
	Przemek Kitszel <przemyslaw.kitszel@...el.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Michal Swiatkowski <michal.swiatkowski@...ux.intel.com>,
	Mateusz Pacuszka <mateuszx.pacuszka@...el.com>
Subject: Re: [PATCH iwl-next v4 6/6] ice: enable LLDP TX for VFs through tc

On Fri, Feb 14, 2025 at 09:50:40AM +0100, Larysa Zaremba wrote:
> Only a single VSI can be in charge of sending LLDP frames, sometimes it is
> beneficial to assign this function to a VF, that is possible to do with tc
> capabilities in the switchdev mode. It requires first blocking the PF from
> sending the LLDP frames with a following command:
> 
> tc filter add dev <ifname> egress protocol lldp flower skip_sw action drop
> 
> Then it becomes possible to configure a forward rule from a VF port
> representor to uplink instead.
> 
> tc filter add dev <vf_ifname> ingress protocol lldp flower skip_sw
> action mirred egress redirect dev <ifname>
> 
> How LLDP exclusivity was done previously is LLDP traffic was blocked for a
> whole port by a single rule and PF was bypassing that. Now at least in the
> switchdev mode, every separate VSI has to have its own drop rule. Another
> complication is the fact that tc does not respect when the driver refuses
> to delete a rule, so returning an error results in a HW rule still present
> with no way to reference it through tc. This is addressed by allowing the
> PF rule to be deleted at any time, but making the VF forward rule "dormant"
> in such case, this means it is deleted from HW but stays in tc and driver's
> bookkeeping to be restored when drop rule is added back to the PF.
> 
> Implement tc configuration handling which enables the user to transmit LLDP
> packets from VF instead of PF.
> 
> Reviewed-by: Michal Swiatkowski <michal.swiatkowski@...ux.intel.com>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@...el.com>

Reviewed-by: Simon Horman <horms@...nel.org>