From 97717e8dbda1dede65c4df12891332502df632f3 Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sat, 14 Jan 2023 16:22:26 +0800 Subject: [PATCH] virtio-net: transmit the multi-buffer xdp This serves as the basis for XDP_TX and XDP_REDIRECT to send a multi-buffer xdp_frame. Signed-off-by: Heng Qi Reviewed-by: Xuan Zhuo Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 262d215b1518..6d3cf8887dd7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -570,22 +570,43 @@ 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; + } + + /* In wrapping function virtnet_xdp_xmit(), we need to free + * up the pending old buffers, where 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. + */ + xdpf->headroom -= vi->hdr_len; 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]; - err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf), - GFP_ATOMIC); + 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, nr_frags + 1, + xdp_to_ptr(xdpf), GFP_ATOMIC); if (unlikely(err)) return -ENOSPC; /* Caller handle free/refcnt */