在 2022/12/28 下午2:30, Jason Wang 写道:
在 2022/12/27 16:26, Heng Qi 写道:
在 2022/12/27 下午3:12, Jason Wang 写道:
在 2022/12/20 22:14, Heng Qi 写道:
This serves as the basis for XDP_TX and XDP_REDIRECT
to send a multi-buffer xdp_frame.
Signed-off-by: Heng Qi <hengqi@xxxxxxxxxxxxxxxxx>
Reviewed-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
drivers/net/virtio_net.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 40bc58fa57f5..9f31bfa7f9a6 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -563,22 +563,39 @@ static int __virtnet_xdp_xmit_one(struct
virtnet_info *vi,
struct xdp_frame *xdpf)
{
struct virtio_net_hdr_mrg_rxbuf *hdr;
- int err;
+ struct skb_shared_info *shinfo;
+ u8 nr_frags = 0;
+ int err, i;
if (unlikely(xdpf->headroom < vi->hdr_len))
return -EOVERFLOW;
- /* Make room for virtqueue hdr (also change xdpf->headroom?) */
+ if (unlikely(xdp_frame_has_frags(xdpf))) {
+ shinfo = xdp_get_shared_info_from_frame(xdpf);
+ nr_frags = shinfo->nr_frags;
+ }
+
+ /* Need to adjust this to calculate the correct postion
+ * for shinfo of the xdpf.
+ */
+ xdpf->headroom -= vi->hdr_len;
Any reason we need to do this here? (Or if it is, is it only needed
for multibuffer XDP?)
Going back to its wrapping function virtnet_xdp_xmit(), we need to
free up the pending old buffers.
If the "is_xdp_frame(ptr)" condition is met, then we need to
calculate the position of skb_shared_info
in xdp_get_frame_len() and xdp_return_frame(), which will involve to
xdpf->data and xdpf->headroom.
Therefore, we need to update the value of headroom synchronously here.
Let's tweak the comment above to something like this.
Ok, thanks for your energy.
With that fixed,
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
Also, it's not necessary for single-buffer xdp, but we need to keep
it because it's harmless and as it should be.
Thanks.
Other looks good.
Thanks
xdpf->data -= vi->hdr_len;
/* Zero header and leave csum up to XDP layers */
hdr = xdpf->data;
memset(hdr, 0, vi->hdr_len);
xdpf->len += vi->hdr_len;
- sg_init_one(sq->sg, xdpf->data, xdpf->len);
+ sg_init_table(sq->sg, nr_frags + 1);
+ sg_set_buf(sq->sg, xdpf->data, xdpf->len);
+ for (i = 0; i < nr_frags; i++) {
+ skb_frag_t *frag = &shinfo->frags[i];
+
+ sg_set_page(&sq->sg[i + 1], skb_frag_page(frag),
+ skb_frag_size(frag), skb_frag_off(frag));
+ }
- err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
- GFP_ATOMIC);
+ err = virtqueue_add_outbuf(sq->vq, sq->sg, nr_frags + 1,
+ xdp_to_ptr(xdpf), GFP_ATOMIC);
if (unlikely(err))
return -ENOSPC; /* Caller handle free/refcnt */
