On Mon, 04 May 2026 17:27:48 -0700 Bobby Eshleman wrote:
> --- a/drivers/net/netkit.c
> +++ b/drivers/net/netkit.c
> @@ -466,6 +466,7 @@ static void netkit_setup(struct net_device *dev)
> dev->priv_flags |= IFF_NO_QUEUE;
> dev->priv_flags |= IFF_DISABLE_NETPOLL;
> dev->lltx = true;
> + dev->netmem_tx = NETMEM_TX_NO_DMA;
>
> dev->netdev_ops = &netkit_netdev_ops;
> dev->ethtool_ops = &netkit_ethtool_ops;
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 0e1e581efc5a..11d68e75eb4f 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1788,6 +1788,12 @@ enum netdev_stat_type {
> NETDEV_PCPU_STAT_DSTATS, /* struct pcpu_dstats */
> };
>
> +enum netmem_tx_mode {
> + NETMEM_TX_NONE, /* no netmem TX support */
> + NETMEM_TX_DMA, /* DMA-capable netmem TX (real HW) */
> + NETMEM_TX_NO_DMA, /* no DMA, e.g. passthrough for virtual devs */
Now there's a little too much here, let's move the NO_DMA changes to
another patch. Just convert the netmem_tx to an enum and change the
existing drivers in patch 1.
Next patch has:
> @@ -1164,16 +1197,30 @@ int netdev_nl_bind_tx_doit(struct sk_buff *skb,
> struct genl_info *info)
> goto err_unlock_netdev;
> }
>
> - if (!netdev->netmem_tx) {
> + if (netdev->netmem_tx == NETMEM_TX_NONE) {
> err = -EOPNOTSUPP;
> NL_SET_ERR_MSG(info->extack,
> "Driver does not support netmem TX");
> goto err_unlock_netdev;
> }
which also should have been in patch 1.
