From c5f3e72f04c02cc2a0671adbb16224e61dc4bd8a Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Mon, 8 May 2023 14:14:12 +0800 Subject: [PATCH] virtio_net: introduce receive_small_xdp() The purpose of this patch is to simplify the receive_small(). Separate all the logic of XDP of small into a function. Signed-off-by: Xuan Zhuo Acked-by: Jason Wang Signed-off-by: Jakub Kicinski --- drivers/net/virtio_net.c | 165 ++++++++++++++++++++++++++++------------------- 1 file changed, 100 insertions(+), 65 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 0baa6651..bc3bf19 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -931,6 +931,99 @@ err_buf: return NULL; } +static struct sk_buff *receive_small_xdp(struct net_device *dev, + struct virtnet_info *vi, + struct receive_queue *rq, + struct bpf_prog *xdp_prog, + void *buf, + unsigned int xdp_headroom, + unsigned int len, + unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats) +{ + unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom; + unsigned int headroom = vi->hdr_len + header_offset; + struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; + struct page *page = virt_to_head_page(buf); + struct page *xdp_page; + unsigned int buflen; + struct xdp_buff xdp; + struct sk_buff *skb; + unsigned int delta = 0; + unsigned int metasize = 0; + void *orig_data; + u32 act; + + if (unlikely(hdr->hdr.gso_type)) + goto err_xdp; + + buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + + if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { + int offset = buf - page_address(page) + header_offset; + unsigned int tlen = len + vi->hdr_len; + int num_buf = 1; + + xdp_headroom = virtnet_get_headroom(vi); + header_offset = VIRTNET_RX_PAD + xdp_headroom; + headroom = vi->hdr_len + header_offset; + buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + xdp_page = xdp_linearize_page(rq, &num_buf, page, + offset, header_offset, + &tlen); + if (!xdp_page) + goto err_xdp; + + buf = page_address(xdp_page); + put_page(page); + page = xdp_page; + } + + xdp_init_buff(&xdp, buflen, &rq->xdp_rxq); + xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, + xdp_headroom, len, true); + orig_data = xdp.data; + + act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); + + switch (act) { + case XDP_PASS: + /* Recalculate length in case bpf program changed it */ + delta = orig_data - xdp.data; + len = xdp.data_end - xdp.data; + metasize = xdp.data - xdp.data_meta; + break; + + case XDP_TX: + case XDP_REDIRECT: + goto xdp_xmit; + + default: + goto err_xdp; + } + + skb = build_skb(buf, buflen); + if (!skb) + goto err; + + skb_reserve(skb, headroom - delta); + skb_put(skb, len); + if (metasize) + skb_metadata_set(skb, metasize); + + return skb; + +err_xdp: + stats->xdp_drops++; +err: + stats->drops++; + put_page(page); +xdp_xmit: + return NULL; +} + static struct sk_buff *receive_small(struct net_device *dev, struct virtnet_info *vi, struct receive_queue *rq, @@ -947,9 +1040,6 @@ static struct sk_buff *receive_small(struct net_device *dev, unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); struct page *page = virt_to_head_page(buf); - unsigned int delta = 0; - struct page *xdp_page; - unsigned int metasize = 0; len -= vi->hdr_len; stats->bytes += len; @@ -969,56 +1059,10 @@ static struct sk_buff *receive_small(struct net_device *dev, rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (xdp_prog) { - struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; - struct xdp_buff xdp; - void *orig_data; - u32 act; - - if (unlikely(hdr->hdr.gso_type)) - goto err_xdp; - - if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { - int offset = buf - page_address(page) + header_offset; - unsigned int tlen = len + vi->hdr_len; - int num_buf = 1; - - xdp_headroom = virtnet_get_headroom(vi); - header_offset = VIRTNET_RX_PAD + xdp_headroom; - headroom = vi->hdr_len + header_offset; - buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - xdp_page = xdp_linearize_page(rq, &num_buf, page, - offset, header_offset, - &tlen); - if (!xdp_page) - goto err_xdp; - - buf = page_address(xdp_page); - put_page(page); - page = xdp_page; - } - - xdp_init_buff(&xdp, buflen, &rq->xdp_rxq); - xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, - xdp_headroom, len, true); - orig_data = xdp.data; - - act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); - - switch (act) { - case XDP_PASS: - /* Recalculate length in case bpf program changed it */ - delta = orig_data - xdp.data; - len = xdp.data_end - xdp.data; - metasize = xdp.data - xdp.data_meta; - break; - case XDP_TX: - case XDP_REDIRECT: - rcu_read_unlock(); - goto xdp_xmit; - default: - goto err_xdp; - } + skb = receive_small_xdp(dev, vi, rq, xdp_prog, buf, xdp_headroom, + len, xdp_xmit, stats); + rcu_read_unlock(); + return skb; } rcu_read_unlock(); @@ -1026,25 +1070,16 @@ skip_xdp: skb = build_skb(buf, buflen); if (!skb) goto err; - skb_reserve(skb, headroom - delta); + skb_reserve(skb, headroom); skb_put(skb, len); - if (!xdp_prog) { - buf += header_offset; - memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); - } /* keep zeroed vnet hdr since XDP is loaded */ - - if (metasize) - skb_metadata_set(skb, metasize); + buf += header_offset; + memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); return skb; -err_xdp: - rcu_read_unlock(); - stats->xdp_drops++; err: stats->drops++; put_page(page); -xdp_xmit: return NULL; } -- 2.7.4