Re: [mlx5 driver] Usage of mlx5 with unpriviledged LXC container

[David Marchand <david.marchand@redhat.com>]

On Mon, 25 Aug 2025 at 14:09, Julien <julien.marcin.tech@gmail.com> wrote:
>
> Hello,
> I have a question about using the mlx5 driver with LXC.
> I'm trying to use dpdk-testpmd in an LXC container whose root user isn't mapped to the host's root user.
> Note: The entire physical interface is given to the LXC container, not a virtual interface.
>
> The following error occured:
> mlx5_common: DevX create TIS failed errno=22 status=0 syndrome=0
> mlx5_net: Failed to create TIS 0/0 for [bonding] device mlx5_2.
> mlx5_net: TIS allocation failure
> mlx5_net: probe of PCI device 0000:27:00.0 aborted after encountering an error: Cannot allocate memory
> mlx5_common: Failed to load driver mlx5_eth
> EAL: Requested device 0000:27:00.0 cannot be used
> EAL: Bus (pci) probe failed.
>
> The "transport_domain" is created, and the mlx5_devx_cmd_create_td() function runs normally.
> The call to mlx5dv_devx_obj_create() receives an errno of 22.
>
> I don't encounter any problems when the container's root user is mapped to the host's root user.
> Has anyone experienced this before?
> Is it possible to use the driver in an unprivileged LXC container?

There is probably something missing in terms of capabilities.
I don't know how LXC behaves in this regard.

I suggest you look at "5.5.1.5. Run as Non-Root" in
https://doc.dpdk.org/guides/platform/mlx5.html.


-- 
David Marchand