netdev - Re: [EXT] Re: LRO/HW_GRO is not disabled when native xdp is installed

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Message-ID: <CACKFLin=JS-5mou=0-b9nvHh=4=9AopZUDGLb+ZkkVYbAsk3WQ@mail.gmail.com>
Date:   Fri, 13 Dec 2019 13:09:31 -0800
From:   Michael Chan <michael.chan@...adcom.com>
To:     Manish Chopra <manishc@...vell.com>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [EXT] Re: LRO/HW_GRO is not disabled when native xdp is installed

On Fri, Dec 13, 2019 at 1:45 AM Manish Chopra <manishc@...vell.com> wrote:

> It used to be the case for our devices as well long back. but after the commit 18c602dee4726 ("qede: Use NETIF_F_GRO_HW")
> that part was removed from our driver and commit 56f5aa77cdad1 ("net: Disable GRO_HW when generic XDP is installed on a device")
> was added to achieve the same instead of individual driver doing it, but it wasn't caught that time why later commit only does for generic xdp,
> not for native xdp. So today when native xdp is attached to our device, HW GRO aggregation remains enabled on our device.
> Please let me know if that fix is good enough to be posted. Will test it out and post.
>

The driver knows when an xdp program is attached and can disable any
features that are not compatible, so I think it is more efficient to
keep it this way.  Generic XDP on the other hand, does not involve the
driver and so we need to disable them for the driver.