linux-kernel - Re: [PATCH iwl-next v3 6/7] igc: add preemptible queue support in taprio

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

Message-ID: <20250520081805.GR365796@horms.kernel.org>
Date: Tue, 20 May 2025 09:18:05 +0100
From: Simon Horman <horms@...nel.org>
To: "Abdul Rahim, Faizal" <faizal.abdul.rahim@...el.com>
Cc: Tony Nguyen <anthony.l.nguyen@...el.com>,
	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>,
	Vladimir Oltean <vladimir.oltean@....com>,
	intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Faizal Rahim <faizal.abdul.rahim@...ux.intel.com>,
	Aleksandr Loktionov <aleksandr.loktionov@...el.com>,
	Chwee-Lin Choong <chwee.lin.choong@...el.com>
Subject: Re: [PATCH iwl-next v3 6/7] igc: add preemptible queue support in
 taprio

On Mon, May 19, 2025 at 03:19:10AM -0400, Abdul Rahim, Faizal wrote:
> From: Faizal Rahim <faizal.abdul.rahim@...ux.intel.com>
> 
> Changes:
> 1. Introduce tx_enabled flag to control preemptible queue. tx_enabled
>    is set via mmsv module based on multiple factors, including link
>    up/down status, to determine if FPE is active or inactive.
> 2. Add priority field to TXDCTL for express queue to improve data
>    fetch performance.
> 3. Block preemptible queue setup in taprio unless reverse-tsn-txq-prio
>    private flag is set. Encourages adoption of standard queue priority
>    scheme for new features.
> 4. Hardware-padded frames from preemptible queues result in incorrect
>    mCRC values, as padding bytes are excluded from the computation. Pad
>    frames to at least 60 bytes using skb_padto() before transmission to
>    ensure the hardware includes padding in the mCRC calculation.
> 
> Tested preemption with taprio by:
> 1. Enable FPE:
>    ethtool --set-mm enp1s0 pmac-enabled on tx-enabled on verify-enabled on
> 2. Enable private flag to reverse TX queue priority:
>    ethtool --set-priv-flags enp1s0 reverse-txq-prio on
> 3. Enable preemptible queue in taprio:
>    taprio num_tc 4 map 0 1 2 3 0 0 0 0 0 0 0 0 0 0 0 0 \
>    queues 1@0 1@1 1@2 1@3 \
>    fp P P P E
> 
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@...el.com>
> Co-developed-by: Chwee-Lin Choong <chwee.lin.choong@...el.com>
> Signed-off-by: Chwee-Lin Choong <chwee.lin.choong@...el.com>
> Signed-off-by: Faizal Rahim <faizal.abdul.rahim@...ux.intel.com>

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