From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us.padl.com (us.padl.com [216.154.215.154]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E93A826ED5D; Sat, 6 Jun 2026 08:02:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.154.215.154 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780732964; cv=none; b=YtWC80nF6HXHuEDBo12H55LDE7W7zIHApScIATt/wxchAHYK6YV5gEkjeS7CMls31fInuEt7EClx45tpEyF6C/aDHzTEO3kj95VSS5gDh9bDEgnLf+y3uBJDuf74GN3yQr+K2e+pmfFKz2WEeffMT5TvdD5syf6kL9yYt5S1m6Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780732964; c=relaxed/simple; bh=95/Bc8g7qS6AmG65Mi9qNIx2fcFhFDs2MrupCjJhEWw=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=jtDXWKi+ZPENTpo22rjeeouEBZKnPk9jynYnQ8vEzYsJWL1y7NPnpHBGs7Gh5yeCG2DeD0W0RmAe+viLBNdCeatT9sq9iMj3S+xyEXujt3YaIO3ma1euhXipDjjrG0ChNXfrULk7MsPm8VH59iABEVFOiv8CCcHSPCBvD1MHsjM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=padl.com; spf=pass smtp.mailfrom=padl.com; dkim=pass (2048-bit key) header.d=padl.com header.i=@padl.com header.b=F75/otmZ; arc=none smtp.client-ip=216.154.215.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=padl.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=padl.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=padl.com header.i=@padl.com header.b="F75/otmZ" Received: from smtpclient.apple (border.lukktone.com [139.130.100.52]) by us.padl.com (Postfix) with ESMTPSA id 3EA6D62226; Sat, 6 Jun 2026 04:02:37 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=padl.com; s=default; t=1780732961; bh=C6knqyYtwWysw/J/UjxZx6ooyQA0Q9w3FH7GFrPkXpU=; h=Subject:From:In-Reply-To:Date:Cc:References:To:From; b=F75/otmZ69bK9Ai62vs7YMDminLgns083w1PKEkqL6BgWthAVQoOxSO7uUnhNsAbh SK0e0Dsp427FJjWJnPDYuvLH1J9RHDzHGCJ95Nb5jqpOJQIfBaLxnRZSdP68P1xUHY O1vzG1MJd9gdMjrxk2fveu+H/PF2VJdf+zNsipZsb20J31tESJa6+vyZuU84mNju0s KjjrYO/dCuD79XFdbrzGHDSZuDTeZ/hCGMDeuR/iHjXtjjssQupuN2+nt/U0LTa61z GO2tGIOuH+d7WpK+UxOhJf45nOR7IcNIwX6fOH1vpOCFtLV9DHfYUG9dscKvBjqGZS jrqtVjul/VCEA== Content-Type: text/plain; charset=utf-8 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.700.81\)) Subject: Re: [PATCH net-next v2 3/6] net: bridge: add 802.1Qat stream reservation admission control From: Luke Howard In-Reply-To: Date: Sat, 6 Jun 2026 18:02:24 +1000 Cc: Cedric Jehasse , Nikolay Aleksandrov , Jiri Pirko , Ivan Vecera , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Ido Schimmel , Andrew Lunn , David Ahern , Shuah Khan , Vladimir Oltean , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bridge@lists.linux.dev, linux-kselftest@vger.kernel.org, Max Hunter , Kieran Tyrrell Content-Transfer-Encoding: quoted-printable Message-Id: References: <20260602-mv88e6xxx-8021qat-mqprio-v2-0-72be14522e7c@padl.com> <20260602-mv88e6xxx-8021qat-mqprio-v2-3-72be14522e7c@padl.com> <537410c3-ff4e-43fd-834e-775cd1bbe89e@blackwall.org> To: Andrew Lunn X-Mailer: Apple Mail (2.3826.700.81) > So it sounds like you first need to work on the software > implementation and expand the simplified version with the features you > need. You can then add support to accelerate this by offloading it to > the hardware. Agreed. The definition of Dynamic Reservation Entries in 802.1Q (clause 8.8.7) = might support the addition of a new MDB (or even FDB) entry state to the = kernel: - add MDB_DYNAMIC_RESERVATION (a state, not a flag); - the software bridge only _classifies_ packets against = MDB_DYNAMIC_RESERVATION entries, and only when MDB is authoritative. = Classification sets dynamic_reservation_hit on tc_skb_ext; - dynamic_reservation_hit is visible to the flow dissector so can be = used for policy enforcement. Advantages: - the new MDB state maps well to 802.1Q; - minimal changes to bridge; - actual policy (reclassify, drop, etc) is left to the user; - doesn=E2=80=99t require a new tc-flower entry for each stream DA; - entry state maps 1:1 to mv88e6xxx AVB_NRL ATU EntryState. Disadvantages: - no unicast support, although potentially can be extended (there are = some subtleties); - mv88e6xxx support would either require rich enough tc-flower support = in TCAM, intercepting TCA_FLOWER_DYNAMIC_RESERVATION_HIT and mapping to = native AVB admission control, or a per-port devlink parameter (not so = nice). This is implemented and working with the software bridge, I still = haven=E2=80=99t quite figured out the right mapping for mv88e6xxx. Luke PS. I previously incorrectly asserted that 802.1Q required dropping = frames with AVB/SRP PCPs but without valid dynamic reservation entries. = 802.1Q discussions priority mapping in clause 6.9.4 for traffic from SRP = boundary ports (those not participating in SRP). In practice I think = this should all be policy, e.g. you might want to reprioritise valid = DSCP traffic from within a SRP domain, or drop instead of reprioritise, = etc.=