On Fri, Jun 28, 2024 at 1:44 PM Xuan Zhuo [off-list ref] wrote:

On Fri, 28 Jun 2024 10:19:37 +0800, Jason Wang [off-list ref] wrote:

quoted

On Tue, Jun 18, 2024 at 3:57 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>
---
 drivers/net/virtio_net.c | 68 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 66 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2bbc715f22c6..2ac5668a94ce 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -355,6 +355,8 @@ struct receive_queue {

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

@@ -1032,6 +1034,53 @@ 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;
+       u32 len, i;
+       int err = 0;
+       int num;
+
+       xsk_buffs = rq->xsk.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 */
+               addr = xsk_buff_xdp_get_dma(xsk_buffs[i]) - vi->hdr_len;

We had VIRTIO_XDP_HEADROOM, can we reuse it? Or if it's redundant
let's send a patch to switch to XDP_PACKET_HEADROOM.

Do you mean replace it inside the comment?

I meant a patch to s/VIRTIO_XDP_HEADROOM/XDP_PACKET_HEADROOM/g.

I want to describe use the headroom of xsk, the size of the headroom is
XDP_PACKET_HEADROOM.

quoted

Btw, the code assumes vi->hdr_len < xsk_pool_get_headroom(). It's
better to fail if it's not true when enabling xsk.

It is ok.

I mean do we need a check to fail xsk binding if vi->hdr_len >
xsk_pool_get_headroom() or it has been guaranteed by the code already.

Thanks

Thanks.

quoted

Thanks