Hi Lorenzo and Marek,
Thanks for your work.
On 2023-01-14 16:54:32 +0100, Lorenzo Bianconi wrote:
[...]
>
> Turn 'hw-offload' feature flag on for:
> - netronome (nfp)
> - netdevsim.
Is there a definition of the 'hw-offload' written down somewhere? From
reading this series I take it is the ability to offload a BPF program?
It would also be interesting to read documentation for the other flags
added in this series.
[...]
> diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> index 18fc9971f1c8..5a8ddeaff74d 100644
> --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> @@ -2529,10 +2529,14 @@ static void nfp_net_netdev_init(struct nfp_net *nn)
> netdev->features &= ~NETIF_F_HW_VLAN_STAG_RX;
> nn->dp.ctrl &= ~NFP_NET_CFG_CTRL_RXQINQ;
>
> + nn->dp.netdev->xdp_features = NETDEV_XDP_ACT_BASIC |
> + NETDEV_XDP_ACT_HW_OFFLOAD;
If my assumption about the 'hw-offload' flag above is correct I think
NETDEV_XDP_ACT_HW_OFFLOAD should be conditioned on that the BPF firmware
flavor is in use.
nn->dp.netdev->xdp_features = NETDEV_XDP_ACT_BASIC;
if (nn->app->type->id == NFP_APP_BPF_NIC)
nn->dp.netdev->xdp_features |= NETDEV_XDP_ACT_HW_OFFLOAD;
> +
> /* Finalise the netdev setup */
> switch (nn->dp.ops->version) {
> case NFP_NFD_VER_NFD3:
> netdev->netdev_ops = &nfp_nfd3_netdev_ops;
> + nn->dp.netdev->xdp_features |= NETDEV_XDP_ACT_XSK_ZEROCOPY;
> break;
> case NFP_NFD_VER_NFDK:
> netdev->netdev_ops = &nfp_nfdk_netdev_ops;
This is also a wrinkle I would like to understand. Currently NFP support
zero-copy on NFD3, but not for offloaded BPF programs. But with the BPF
firmware flavor running the device can still support zero-copy for
non-offloaded programs.
Is it a problem that the driver advertises support for both
hardware-offload _and_ zero-copy at the same time, even if they can't be
used together but separately?
--
Kind Regards,
Niklas Söderlund
