On Fri, 28 Jun 2024 10:19:37 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
> 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.
Do you mean replace it inside the comment?
I want to describe use the headroom of xsk, the size of the headroom is
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.
It is ok.
Thanks.
>
> Thanks
>
