[PATCH net-next v2 17/21] virtio_net: xsk: rx: skip dma unmap when rq is bind with AF_XDP

Xuan Zhuo
Tue, 07 Nov 2023 03:12:23 -0000

When rq is bound with AF_XDP, the buffer dma is managed
by the AF_XDP APIs. So the buffer got from the virtio core should
skip the dma unmap operation.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio/main.c       | 8 +++++---
 drivers/net/virtio/virtio_net.h | 3 +++
 drivers/net/virtio/xsk.c        | 1 +
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index 15943a22e17d..a318b2533b94 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -430,7 +430,7 @@ static void *virtnet_rq_get_buf(struct virtnet_rq *rq, u32
*len, void **ctx)
 	void *buf;

 	buf = virtqueue_get_buf_ctx(rq->vq, len, ctx);
-	if (buf && rq->do_dma)
+	if (buf && rq->do_dma_unmap)
 		virtnet_rq_unmap(rq, buf, *len);

 	return buf;
@@ -561,8 +561,10 @@ static void virtnet_set_premapped(struct virtnet_info *vi)

 		/* disable for big mode */
 		if (vi->mergeable_rx_bufs || !vi->big_packets) {
-			if (!virtqueue_set_dma_premapped(vi->rq[i].vq))
+			if (!virtqueue_set_dma_premapped(vi->rq[i].vq)) {
 				vi->rq[i].do_dma = true;
+				vi->rq[i].do_dma_unmap = true;
+			}
 		}
 	}
 }
@@ -3944,7 +3946,7 @@ void virtnet_rq_free_unused_buf(struct virtqueue *vq, void
*buf)

 	rq = &vi->rq[i];

-	if (rq->do_dma)
+	if (rq->do_dma_unmap)
 		virtnet_rq_unmap(rq, buf, 0);

 	virtnet_rq_free_buf(vi, rq, buf);
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index 1242785e311e..2005d0cd22e2 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -135,6 +135,9 @@ struct virtnet_rq {
 	/* Do dma by self */
 	bool do_dma;

+	/* Do dma unmap after getting buf from virtio core. */
+	bool do_dma_unmap;
+
 	struct {
 		struct xsk_buff_pool *pool;

diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
index e737c3353212..b09c473c29fb 100644
--- a/drivers/net/virtio/xsk.c
+++ b/drivers/net/virtio/xsk.c
@@ -210,6 +210,7 @@ static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi,
struct virtnet_rq *
 		xdp_rxq_info_unreg(&rq->xsk.xdp_rxq);

 	rq->xsk.pool = pool;
+	rq->do_dma_unmap = !pool;

 	virtnet_rx_resume(vi, rq);

--
2.32.0.3.g01195cf9f