[RFC net-next v3 2/7] io_uring/zcrx: add support for custom DMA devices

From: Dragos Tatulea
Date: Fri Aug 15 2025 - 07:08:05 EST


Use the new API for getting a DMA device for a specific netdev queue.

This patch will allow io_uring zero-copy rx to work with devices
where the DMA device is not stored in the parent device. mlx5 SFs
are an example of such a device.

Signed-off-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
---
io_uring/zcrx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index e5ff49f3425e..319eddfd30e0 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -12,6 +12,7 @@
#include <net/page_pool/helpers.h>
#include <net/page_pool/memory_provider.h>
#include <net/netlink.h>
+#include <net/netdev_queues.h>
#include <net/netdev_rx_queue.h>
#include <net/tcp.h>
#include <net/rps.h>
@@ -599,7 +600,7 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx,
goto err;
}

- ifq->dev = ifq->netdev->dev.parent;
+ ifq->dev = netdev_queue_get_dma_dev(ifq->netdev, ifq->if_rxq);
if (!ifq->dev) {
ret = -EOPNOTSUPP;
goto err;
--
2.50.1