linux-kernel - Re: [PATCH net-next v7 15/16] net: ethtool: ts: Let the active time stamping layer be selectable

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: <20231122143618.cqyb45po7bon2xzg@skbuf>
Date:   Wed, 22 Nov 2023 16:36:18 +0200
From:   Vladimir Oltean <vladimir.oltean@....com>
To:     Jakub Kicinski <kuba@...nel.org>
Cc:     Köry Maincent <kory.maincent@...tlin.com>,
        Florian Fainelli <florian.fainelli@...adcom.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@...adcom.com>,
        Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>,
        Richard Cochran <richardcochran@...il.com>,
        Radu Pirea <radu-nicolae.pirea@....nxp.com>,
        Jay Vosburgh <j.vosburgh@...il.com>,
        Andy Gospodarek <andy@...yhouse.net>,
        Nicolas Ferre <nicolas.ferre@...rochip.com>,
        Claudiu Beznea <claudiu.beznea@...on.dev>,
        Willem de Bruijn <willemdebruijn.kernel@...il.com>,
        Jonathan Corbet <corbet@....net>,
        Horatiu Vultur <horatiu.vultur@...rochip.com>,
        UNGLinuxDriver@...rochip.com, Simon Horman <horms@...nel.org>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-doc@...r.kernel.org,
        Maxime Chevallier <maxime.chevallier@...tlin.com>
Subject: Re: [PATCH net-next v7 15/16] net: ethtool: ts: Let the active time
 stamping layer be selectable

On Wed, Nov 22, 2023 at 04:08:50PM +0200, Vladimir Oltean wrote:
> The concept of an "active phc_index" would not explicitly exist in the
> UAPI. Thus I'm not sure what's with this TSINFO_SET being floated around.
> The only thing would exist is a configurable rx_filter and tx_type per
> hwtstamp provider (aka "{phc_index, qualifier}"). User space will have
> to learn to select the hwtstamp provider it wants to configure through
> netlink, and use for its class of traffic.

@Jakub, for your long-term "MAC timestamps for PTP, DMA for everything else".
How do you see this? I guess we need some sort of priority function in
the UAPI between hwtstamp providers.

And even with that, I think the enums that we currently have for filters
are not specific enough. The most we could expose is:

                      MAC provider                      DMA provider

hwtstamp_rx_filters   HWTSTAMP_FILTER_PTP_V2_EVENT      HWTSTAMP_FILTER_ALL
tx_type               HWTSTAMP_TX_ON                    HWTSTAMP_TX_ON

but it isn't clear: for PTP, does the DMA provider give you an RX
timestamp too? What about a TX timestamp?