Jason Wang
2023-Apr-25 07:58 UTC
[PATCH net-next v3 10/15] virtio_net: introduce receive_small_xdp()
On Sun, Apr 23, 2023 at 6:58?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > 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 <xuanzhuo at linux.alibaba.com> > --- > 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 de5a579e8603..9b5fd2e0d27f 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -931,6 +931,99 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, > 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; > +}It looks like some of the comments of the above version is not addressed? " So we end up with some code duplication between receive_small() and receive_small_xdp() on building skbs. Is this intended? " Thanks> + > 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 @@ static struct sk_buff *receive_small(struct net_device *dev, > 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; > } > > -- > 2.32.0.3.g01195cf9f >
Xuan Zhuo
2023-Apr-25 08:00 UTC
[PATCH net-next v3 10/15] virtio_net: introduce receive_small_xdp()
On Tue, 25 Apr 2023 15:58:03 +0800, Jason Wang <jasowang at redhat.com> wrote:> On Sun, Apr 23, 2023 at 6:58?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > 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 <xuanzhuo at linux.alibaba.com> > > --- > > 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 de5a579e8603..9b5fd2e0d27f 100644 > > --- a/drivers/net/virtio_net.c > > +++ b/drivers/net/virtio_net.c > > @@ -931,6 +931,99 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, > > 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; > > +} > > It looks like some of the comments of the above version is not addressed? > > " > So we end up with some code duplication between receive_small() and > receive_small_xdp() on building skbs. Is this intended? > "I answer you in the #13 commit of the above version. This patch-set has optimize this with the last two commits. This commit is not unchanged. Thanks.> > Thanks > > > + > > 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 @@ static struct sk_buff *receive_small(struct net_device *dev, > > 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; > > } > > > > -- > > 2.32.0.3.g01195cf9f > > >