Re: [Bonding] Should we support qemu/virtio for 802.3ad mode?

[Nikolay Aleksandrov <razor@blackwall.org>]

On 01/07/2024 13:11, Hangbin Liu wrote:
> Hi Jay,
> 
> Some one propose again[1] if we should support 802.3ad mode for virtio driver.
> What do you think? Should we treat the SPEED_UNKNOWN as 1 or something else
> in __get_link_speed()?
> 
> [1] https://lore.kernel.org/all/CAJO99TmB3957Wq3Cse7azgBxKeZ2BV6QihoyAsjUjyvzc-V8dQ@mail.gmail.com/
> 
> Thanks
> Hangbin

Hi Hangbin,
Because of 802.3ad we added:
 commit 16032be56c1f
 Author: Nikolay Aleksandrov <razor@blackwall.org>
 Date:   Wed Feb 3 04:04:37 2016 +0100

    virtio_net: add ethtool support for set and get of settings
    
    This patch allows the user to set and retrieve speed and duplex of the
    virtio_net device via ethtool. Having this functionality is very helpful
    for simulating different environments and also enables the virtio_net
    device to participate in operations where proper speed and duplex are
    required (e.g. currently bonding lacp mode requires full duplex). Custom
    speed and duplex are not allowed, the user-supplied settings are validated
    before applying.
    
    Example:
    $ ethtool eth1
    Settings for eth1:
    ...
            Speed: Unknown!
            Duplex: Unknown! (255)
    $ ethtool -s eth1 speed 1000 duplex full
    $ ethtool eth1
    Settings for eth1:
    ...
            Speed: 1000Mb/s
            Duplex: Full
    
    Based on a patch by Roopa Prabhu.
    
    Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

You can set any link parameters and use virtio_net with bond/lacp today.

Cheers,
 Nik