On Mon, 8 Jul 2024 14:49:35 +0800, Jason Wang [off-list ref] wrote:

On Fri, Jul 5, 2024 at 3:37 PM Xuan Zhuo [off-list ref] wrote:

quoted

Implement the logic of filling rq with XSK buffers.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---

v7:
   1. some small fixes

 drivers/net/virtio_net.c | 70 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 29fa25ce1a7f..2b27f5ada64a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -354,6 +354,8 @@ struct receive_queue {

        /* xdp rxq used by xsk */
        struct xdp_rxq_info xsk_rxq_info;
+
+       struct xdp_buff **xsk_buffs;
 };

 /* This structure can contain rss message with maximum settings for indirection table and keysize

@@ -1054,6 +1056,53 @@ static void check_sq_full_and_disable(struct virtnet_info *vi,
        }
 }

+static void sg_fill_dma(struct scatterlist *sg, dma_addr_t addr, u32 len)
+{
+       sg->dma_address = addr;
+       sg->length = len;
+}
+
+static int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct receive_queue *rq,
+                                  struct xsk_buff_pool *pool, gfp_t gfp)
+{
+       struct xdp_buff **xsk_buffs;
+       dma_addr_t addr;
+       int err = 0;
+       u32 len, i;
+       int num;
+
+       xsk_buffs = rq->xsk_buffs;
+
+       num = xsk_buff_alloc_batch(pool, xsk_buffs, rq->vq->num_free);
+       if (!num)
+               return -ENOMEM;
+
+       len = xsk_pool_get_rx_frame_size(pool) + vi->hdr_len;
+
+       for (i = 0; i < num; ++i) {
+               /* use the part of XDP_PACKET_HEADROOM as the virtnet hdr space */

It's better to also say we assume hdr->len is larger than
XDP_PACKET_HEADROOM. (see function xyz).

quoted

+               addr = xsk_buff_xdp_get_dma(xsk_buffs[i]) - vi->hdr_len;
+
+               sg_init_table(rq->sg, 1);
+               sg_fill_dma(rq->sg, addr, len);
+
+               err = virtqueue_add_inbuf(rq->vq, rq->sg, 1, xsk_buffs[i], gfp);
+               if (err)
+                       goto err;
+       }
+
+       return num;
+
+err:
+       if (i)
+               err = i;

Any reason to assign an index to err here?

I tried to return the num of bufs added to the ring.

But rethink this, we should return the error of virtqueue_add_inbuf() directly.

Will fix.

Thanks.

Others look good.

Thanks