On Tue, Jun 18, 2024 at 3:57 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
>
> Implement the logic of filling rq with XSK buffers.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> 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.
Btw, the code assumes vi->hdr_len < xsk_pool_get_headroom(). It's
better to fail if it's not true when enabling xsk.
Thanks
