diff options
Diffstat (limited to 'drivers/net/virtio_net.c')
| -rw-r--r-- | drivers/net/virtio_net.c | 110 |
1 files changed, 76 insertions, 34 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 626c273..2337460 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -443,12 +443,8 @@ static bool __virtnet_xdp_xmit(struct virtnet_info *vi, sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data); err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp->data, GFP_ATOMIC); - if (unlikely(err)) { - struct page *page = virt_to_head_page(xdp->data); - - put_page(page); - return false; - } + if (unlikely(err)) + return false; /* Caller handle free/refcnt */ return true; } @@ -456,8 +452,18 @@ static bool __virtnet_xdp_xmit(struct virtnet_info *vi, static int virtnet_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp) { struct virtnet_info *vi = netdev_priv(dev); - bool sent = __virtnet_xdp_xmit(vi, xdp); + 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. + */ + xdp_prog = rcu_dereference(rq->xdp_prog); + if (!xdp_prog) + return -ENXIO; + sent = __virtnet_xdp_xmit(vi, xdp); if (!sent) return -ENOSPC; return 0; @@ -498,6 +504,7 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, page_off += *len; while (--*num_buf) { + int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); unsigned int buflen; void *buf; int off; @@ -512,7 +519,7 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, /* guard against a misconfigured or uncooperative backend that * is sending packet larger than the MTU. */ - if ((page_off + buflen) > PAGE_SIZE) { + if ((page_off + buflen + tailroom) > PAGE_SIZE) { put_page(p); goto err_buf; } @@ -546,8 +553,11 @@ 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, err; + unsigned int delta = 0; struct page *xdp_page; + bool sent; + int err; + len -= vi->hdr_len; rcu_read_lock(); @@ -558,7 +568,7 @@ static struct sk_buff *receive_small(struct net_device *dev, void *orig_data; u32 act; - if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags)) + if (unlikely(hdr->hdr.gso_type)) goto err_xdp; if (unlikely(xdp_headroom < virtnet_get_headroom(vi))) { @@ -596,16 +606,19 @@ static struct sk_buff *receive_small(struct net_device *dev, delta = orig_data - xdp.data; break; case XDP_TX: - if (unlikely(!__virtnet_xdp_xmit(vi, &xdp))) + sent = __virtnet_xdp_xmit(vi, &xdp); + if (unlikely(!sent)) { trace_xdp_exception(vi->dev, xdp_prog, act); - else - *xdp_xmit = true; + goto err_xdp; + } + *xdp_xmit = true; rcu_read_unlock(); goto xdp_xmit; case XDP_REDIRECT: err = xdp_do_redirect(dev, &xdp, xdp_prog); - if (!err) - *xdp_xmit = true; + if (err) + goto err_xdp; + *xdp_xmit = true; rcu_read_unlock(); goto xdp_xmit; default: @@ -677,6 +690,7 @@ 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; @@ -689,7 +703,12 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, void *data; u32 act; - /* This happens when rx buffer size is underestimated */ + /* This happens when rx buffer size is underestimated + * or headroom is not enough because of the buffer + * was refilled before XDP is set. This should only + * happen for the first several packets, so we don't + * care much about its performance. + */ if (unlikely(num_buf > 1 || headroom < virtnet_get_headroom(vi))) { /* linearize data for XDP */ @@ -724,9 +743,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, act = bpf_prog_run_xdp(xdp_prog, &xdp); - if (act != XDP_PASS) - ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len); - switch (act) { case XDP_PASS: /* recalculate offset to account for any header @@ -746,18 +762,28 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, } break; case XDP_TX: - if (unlikely(!__virtnet_xdp_xmit(vi, &xdp))) + sent = __virtnet_xdp_xmit(vi, &xdp); + if (unlikely(!sent)) { trace_xdp_exception(vi->dev, xdp_prog, act); - else - *xdp_xmit = true; + if (unlikely(xdp_page != page)) + put_page(xdp_page); + goto err_xdp; + } + *xdp_xmit = true; if (unlikely(xdp_page != page)) goto err_xdp; rcu_read_unlock(); goto xdp_xmit; case XDP_REDIRECT: err = xdp_do_redirect(dev, &xdp, xdp_prog); - if (!err) - *xdp_xmit = true; + if (err) { + if (unlikely(xdp_page != page)) + put_page(xdp_page); + goto err_xdp; + } + *xdp_xmit = true; + if (unlikely(xdp_page != page)) + goto err_xdp; rcu_read_unlock(); goto xdp_xmit; default: @@ -1003,13 +1029,18 @@ static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq, } static unsigned int get_mergeable_buf_len(struct receive_queue *rq, - struct ewma_pkt_len *avg_pkt_len) + struct ewma_pkt_len *avg_pkt_len, + unsigned int room) { const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); unsigned int len; - len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len), + if (room) + return PAGE_SIZE - room; + + len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len), rq->min_buf_len, PAGE_SIZE - hdr_len); + return ALIGN(len, L1_CACHE_BYTES); } @@ -1018,21 +1049,27 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, { struct page_frag *alloc_frag = &rq->alloc_frag; unsigned int headroom = virtnet_get_headroom(vi); + unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0; + unsigned int room = SKB_DATA_ALIGN(headroom + tailroom); char *buf; void *ctx; int err; unsigned int len, hole; - len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len); - if (unlikely(!skb_page_frag_refill(len + headroom, alloc_frag, gfp))) + /* Extra tailroom is needed to satisfy XDP's assumption. This + * means rx frags coalescing won't work, but consider we've + * disabled GSO for XDP, it won't be a big issue. + */ + len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len, room); + if (unlikely(!skb_page_frag_refill(len + room, alloc_frag, gfp))) return -ENOMEM; buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset; buf += headroom; /* advance address leaving hole at front of pkt */ get_page(alloc_frag->page); - alloc_frag->offset += len + headroom; + alloc_frag->offset += len + room; hole = alloc_frag->size - alloc_frag->offset; - if (hole < len + headroom) { + if (hole < len + room) { /* To avoid internal fragmentation, if there is very likely not * enough space for another buffer, add the remaining space to * the current buffer. @@ -2175,8 +2212,9 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, } /* Make sure NAPI is not using any XDP TX queues for RX. */ - for (i = 0; i < vi->max_queue_pairs; i++) - napi_disable(&vi->rq[i].napi); + if (netif_running(dev)) + for (i = 0; i < vi->max_queue_pairs; i++) + napi_disable(&vi->rq[i].napi); netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp); err = _virtnet_set_queues(vi, curr_qp + xdp_qp); @@ -2195,7 +2233,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, } if (old_prog) bpf_prog_put(old_prog); - virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); + if (netif_running(dev)) + virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); } return 0; @@ -2566,12 +2605,15 @@ static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue, { struct virtnet_info *vi = netdev_priv(queue->dev); unsigned int queue_index = get_netdev_rx_queue_index(queue); + unsigned int headroom = virtnet_get_headroom(vi); + unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0; struct ewma_pkt_len *avg; BUG_ON(queue_index >= vi->max_queue_pairs); avg = &vi->rq[queue_index].mrg_avg_pkt_len; return sprintf(buf, "%u\n", - get_mergeable_buf_len(&vi->rq[queue_index], avg)); + get_mergeable_buf_len(&vi->rq[queue_index], avg, + SKB_DATA_ALIGN(headroom + tailroom))); } static struct rx_queue_attribute mergeable_rx_buffer_size_attribute = |
