Re: [PATCH v2] net/iavf: preserve MAC address with i40e PF Linux driver

[Bruce Richardson <bruce.richardson@intel.com>]

On Tue, Oct 01, 2024 at 02:14:36PM +0100, Bruce Richardson wrote:
> On Tue, Oct 01, 2024 at 11:12:54AM +0200, David Marchand wrote:
> > Following two upstream Linux kernel changes (see links), the mac address
> > of a iavf port, serviced by a i40e PF driver, is lost when the DPDK iavf
> > driver probes the port again (which may be triggered at any point of a
> > DPDK application life, like when a reset event is triggered by the PF).
> > 
> > A first change results in the mac address of the VF port being reset to 0
> > during the VIRTCHNL_OP_GET_VF_RESOURCES query.
> > The i40e PF driver change is pretty obscure but the iavf Linux driver does
> > set VIRTCHNL_VF_OFFLOAD_USO.
> > Announcing such a capability in the DPDK driver does not seem to be an
> > issue, so do the same in DPDK to keep the legacy behavior of a fixed mac.
> > 
> > Then a second change in the kernel results in the VF mac address being
> > cleared when the VF driver remove its default mac address.
> > Removing (unicast or multicast) mac addresses is not done by the kernel VF
> > driver in general.
> > The reason why the DPDK driver behaves like this is undocumented
> > (and lost because the authors are not active anymore).
> > Aligning DPDK behavior to the upstream kernel driver is safer in any
> > case.
> > 
> > Cc: stable@dpdk.org
> > 
> > Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fed0d9f13266
> > Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ceb29474bbbc
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
> > ---
> 
> Seems reasonable to me.
> 
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>

Applied to dpdk-next-net-intel.

Thanks,
/Bruce