Re: [PATCH net-next v2 1/6] net: add netmem_tx modes that indicate dma capability
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-05-07 02:30:27
Also in:
bpf, linux-doc, linux-kselftest, linux-rdma, lkml
On Mon, 04 May 2026 17:27:48 -0700 Bobby Eshleman wrote:
quoted hunk ↗ jump to hunk
--- 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:
quoted hunk ↗ jump to hunk
@@ -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.