[PATCH net-next v2 09/13] virtio_net: xsk: bind/unbind xsk for tx

Xuan Zhuo
2024-10-30T08:25:05Z

This patch implement the logic of bind/unbind xsk pool to sq and rq.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 53 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 37e86e0a1d8e..2d2658fcad07 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -295,6 +295,10 @@ struct send_queue {

/* Record whether sq is in reset state. */
bool reset;
+
+ struct xsk_buff_pool *xsk_pool;
+
+ dma_addr_t xsk_hdr_dma_addr;
};

/* Internal representation of a receive virtqueue */
@@ -497,6 +501,8 @@ struct virtio_net_common_hdr {
};
};

+static struct virtio_net_common_hdr xsk_hdr;
+
static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
struct net_device *dev,
@@ -5496,6 +5502,29 @@ static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queu
return err;
}

+static int virtnet_sq_bind_xsk_pool(struct virtnet_info *vi,
+ struct send_queue *sq,
+ struct xsk_buff_pool *pool)
+{
+ int err, qindex;
+
+ qindex = sq - vi->sq;
+
+ virtnet_tx_pause(vi, sq);
+
+ err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf);
+ if (err) {
+ netdev_err(vi->dev, "reset tx fail: tx queue index: %d err: %d\n", qindex, err);
+ pool = NULL;
+ }
+
+ sq->xsk_pool = pool;
+
+ virtnet_tx_resume(vi, sq);
+
+ return err;
+}
+
static int virtnet_xsk_pool_enable(struct net_device *dev,
struct xsk_buff_pool *pool,
u16 qid)
@@ -5504,6 +5533,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
struct receive_queue *rq;
struct device *dma_dev;
struct send_queue *sq;
+ dma_addr_t hdr_dma;
int err, size;

if (vi->hdr_len > xsk_pool_get_headroom(pool))
@@ -5541,6 +5571,11 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
if (!rq->xsk_buffs)
return -ENOMEM;

+ hdr_dma = virtqueue_dma_map_single_attrs(sq->vq, &xsk_hdr, vi->hdr_len,
+ DMA_TO_DEVICE, 0);
+ if (virtqueue_dma_mapping_error(sq->vq, hdr_dma))
+ return -ENOMEM;
+
err = xsk_pool_dma_map(pool, dma_dev, 0);
if (err)
goto err_xsk_map;
@@ -5549,11 +5584,24 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
if (err)
goto err_rq;

+ err = virtnet_sq_bind_xsk_pool(vi, sq, pool);
+ if (err)
+ goto err_sq;
+
+ /* Now, we do not support tx offload(such as tx csum), so all the tx
+ * virtnet hdr is zero. So all the tx packets can share a single hdr.
+ */
+ sq->xsk_hdr_dma_addr = hdr_dma;
+
return 0;

+err_sq:
+ virtnet_rq_bind_xsk_pool(vi, rq, NULL);
err_rq:
xsk_pool_dma_unmap(pool, 0);
err_xsk_map:
+ virtqueue_dma_unmap_single_attrs(rq->vq, hdr_dma, vi->hdr_len,
+ DMA_TO_DEVICE, 0);
return err;
}

@@ -5562,19 +5610,24 @@ static int virtnet_xsk_pool_disable(struct net_device *dev, u16 qid)
struct virtnet_info *vi = netdev_priv(dev);
struct xsk_buff_pool *pool;
struct receive_queue *rq;
+ struct send_queue *sq;
int err;

if (qid >= vi->curr_queue_pairs)
return -EINVAL;

+ sq = &vi->sq[qid];
rq = &vi->rq[qid];

pool = rq->xsk_pool;

err = virtnet_rq_bind_xsk_pool(vi, rq, NULL);
+ err |= virtnet_sq_bind_xsk_pool(vi, sq, NULL);

xsk_pool_dma_unmap(pool, 0);

+ virtqueue_dma_unmap_single_attrs(sq->vq, sq->xsk_hdr_dma_addr,
+ vi->hdr_len, DMA_TO_DEVICE, 0);
kvfree(rq->xsk_buffs);

return err;
--
2.32.0.3.g01195cf9f