From cac320c850efb25480cd0f71383b84ec61c0e138 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 17 Apr 2018 16:45:52 +0200 Subject: virtio_net: convert to use generic xdp_frame and xdp_return_frame API The virtio_net driver assumes XDP frames are always released based on page refcnt (via put_page). Thus, is only queues the XDP data pointer address and uses virt_to_head_page() to retrieve struct page. Use the XDP return API to get away from such assumptions. Instead queue an xdp_frame, which allow us to use the xdp_return_frame API, when releasing the frame. V8: Avoid endianness issues (found by kbuild test robot) V9: Change __virtnet_xdp_xmit from bool to int return value (found by Dan Carpenter) Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 54 ++++++++++++++++++++++++++---------------------- 1 file changed, 29 insertions(+), 25 deletions(-) (limited to 'drivers/net/virtio_net.c') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7b187ec7411e..f50e1ad81ad4 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -415,38 +415,48 @@ static void virtnet_xdp_flush(struct net_device *dev) virtqueue_kick(sq->vq); } -static bool __virtnet_xdp_xmit(struct virtnet_info *vi, - struct xdp_buff *xdp) +static int __virtnet_xdp_xmit(struct virtnet_info *vi, + struct xdp_buff *xdp) { struct virtio_net_hdr_mrg_rxbuf *hdr; - unsigned int len; + struct xdp_frame *xdpf, *xdpf_sent; struct send_queue *sq; + unsigned int len; unsigned int qp; - void *xdp_sent; int err; qp = vi->curr_queue_pairs - vi->xdp_queue_pairs + smp_processor_id(); sq = &vi->sq[qp]; /* Free up any pending old buffers before queueing new ones. */ - while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) { - struct page *sent_page = virt_to_head_page(xdp_sent); + while ((xdpf_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) + xdp_return_frame(xdpf_sent->data, &xdpf_sent->mem); - put_page(sent_page); - } + xdpf = convert_to_xdp_frame(xdp); + if (unlikely(!xdpf)) + return -EOVERFLOW; + + /* virtqueue want to use data area in-front of packet */ + if (unlikely(xdpf->metasize > 0)) + return -EOPNOTSUPP; - xdp->data -= vi->hdr_len; + if (unlikely(xdpf->headroom < vi->hdr_len)) + return -EOVERFLOW; + + /* Make room for virtqueue hdr (also change xdpf->headroom?) */ + xdpf->data -= vi->hdr_len; /* Zero header and leave csum up to XDP layers */ - hdr = xdp->data; + hdr = xdpf->data; memset(hdr, 0, vi->hdr_len); + xdpf->len += vi->hdr_len; - sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data); + sg_init_one(sq->sg, xdpf->data, xdpf->len); - err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp->data, GFP_ATOMIC); + err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdpf, GFP_ATOMIC); if (unlikely(err)) - return false; /* Caller handle free/refcnt */ + return -ENOSPC; /* Caller handle free/refcnt */ - return true; + return 0; } static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp) @@ -454,7 +464,6 @@ static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp) struct virtnet_info *vi = netdev_priv(dev); struct receive_queue *rq = vi->rq; struct bpf_prog *xdp_prog; - bool sent; /* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this * indicate XDP resources have been successfully allocated. @@ -463,10 +472,7 @@ static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp) if (!xdp_prog) return -ENXIO; - sent = __virtnet_xdp_xmit(vi, xdp); - if (!sent) - return -ENOSPC; - return 0; + return __virtnet_xdp_xmit(vi, xdp); } static unsigned int virtnet_get_headroom(struct virtnet_info *vi) @@ -555,7 +561,6 @@ static struct sk_buff *receive_small(struct net_device *dev, struct page *page = virt_to_head_page(buf); unsigned int delta = 0; struct page *xdp_page; - bool sent; int err; len -= vi->hdr_len; @@ -606,8 +611,8 @@ static struct sk_buff *receive_small(struct net_device *dev, delta = orig_data - xdp.data; break; case XDP_TX: - sent = __virtnet_xdp_xmit(vi, &xdp); - if (unlikely(!sent)) { + err = __virtnet_xdp_xmit(vi, &xdp); + if (unlikely(err)) { trace_xdp_exception(vi->dev, xdp_prog, act); goto err_xdp; } @@ -690,7 +695,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, struct bpf_prog *xdp_prog; unsigned int truesize; unsigned int headroom = mergeable_ctx_to_headroom(ctx); - bool sent; int err; head_skb = NULL; @@ -762,8 +766,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, } break; case XDP_TX: - sent = __virtnet_xdp_xmit(vi, &xdp); - if (unlikely(!sent)) { + err = __virtnet_xdp_xmit(vi, &xdp); + if (unlikely(err)) { trace_xdp_exception(vi->dev, xdp_prog, act); if (unlikely(xdp_page != page)) put_page(xdp_page); -- cgit v1.2.3-59-g8ed1b