From a318c70ad152b24f92870dfe5d93b7675498c68f Mon Sep 17 00:00:00 2001 From: Shay Agroskin Date: Tue, 8 Dec 2020 20:02:06 +0200 Subject: [PATCH] net: ena: introduce XDP redirect implementation This patch adds a partial support for the XDP_REDIRECT directive which instructs the driver to pass the packet to an interface specified by the program. The directive is passed to the driver by calling bpf_redirect() or bpf_redirect_map() functions from the eBPF program. To lay the ground for integration with the existing XDP TX implementation the patch removes the redundant page ref count increase in ena_xdp_xmit_frame() and then decrease in ena_clean_rx_irq(). Instead it only DMA unmaps descriptors for which XDP TX or REDIRECT directive was received. The XDP Redirect support is still missing .ndo_xdp_xmit function implementation, which allows to redirect packet to an ENA interface, which would be added in a later patch. Signed-off-by: Shay Agroskin Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/amazon/ena/ena_ethtool.c | 1 + drivers/net/ethernet/amazon/ena/ena_netdev.c | 83 ++++++++++++++++----------- drivers/net/ethernet/amazon/ena/ena_netdev.h | 1 + 3 files changed, 53 insertions(+), 32 deletions(-) diff --git a/drivers/net/ethernet/amazon/ena/ena_ethtool.c b/drivers/net/ethernet/amazon/ena/ena_ethtool.c index 2ad44ae..d6cc7aa 100644 --- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c +++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c @@ -95,6 +95,7 @@ static const struct ena_stats ena_stats_rx_strings[] = { ENA_STAT_RX_ENTRY(xdp_pass), ENA_STAT_RX_ENTRY(xdp_tx), ENA_STAT_RX_ENTRY(xdp_invalid), + ENA_STAT_RX_ENTRY(xdp_redirect), }; static const struct ena_stats ena_stats_ena_com_strings[] = { diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 48cbbd4..d47814b 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -289,21 +289,17 @@ static int ena_xdp_xmit_frame(struct net_device *dev, struct ena_com_tx_ctx ena_tx_ctx = {}; struct ena_tx_buffer *tx_info; struct ena_ring *xdp_ring; - struct page *rx_buff_page; u16 next_to_use, req_id; int rc; void *push_hdr; u32 push_len; - rx_buff_page = virt_to_page(xdpf->data); - xdp_ring = &adapter->tx_ring[qid]; next_to_use = xdp_ring->next_to_use; req_id = xdp_ring->free_ids[next_to_use]; tx_info = &xdp_ring->tx_buffer_info[req_id]; tx_info->num_of_bufs = 0; - page_ref_inc(rx_buff_page); - tx_info->xdp_rx_page = rx_buff_page; + tx_info->xdp_rx_page = virt_to_page(xdpf->data); rc = ena_xdp_tx_map_frame(xdp_ring, tx_info, xdpf, &push_hdr, &push_len); if (unlikely(rc)) @@ -335,7 +331,7 @@ error_unmap_dma: ena_unmap_tx_buff(xdp_ring, tx_info); tx_info->xdpf = NULL; error_drop_packet: - __free_page(tx_info->xdp_rx_page); + xdp_return_frame(xdpf); return NETDEV_TX_OK; } @@ -354,25 +350,36 @@ static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp) verdict = bpf_prog_run_xdp(xdp_prog, xdp); - if (verdict == XDP_TX) { + switch (verdict) { + case XDP_TX: xdpf = xdp_convert_buff_to_frame(xdp); if (unlikely(!xdpf)) { trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict); xdp_stat = &rx_ring->rx_stats.xdp_aborted; - } else { - ena_xdp_xmit_frame(rx_ring->netdev, xdpf, - rx_ring->qid + rx_ring->adapter->num_io_queues); + break; + } - xdp_stat = &rx_ring->rx_stats.xdp_tx; + ena_xdp_xmit_frame(rx_ring->netdev, xdpf, + rx_ring->qid + rx_ring->adapter->num_io_queues); + xdp_stat = &rx_ring->rx_stats.xdp_tx; + break; + case XDP_REDIRECT: + if (likely(!xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog))) { + xdp_stat = &rx_ring->rx_stats.xdp_redirect; + break; } - } else if (unlikely(verdict == XDP_ABORTED)) { + fallthrough; + case XDP_ABORTED: trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict); xdp_stat = &rx_ring->rx_stats.xdp_aborted; - } else if (unlikely(verdict == XDP_DROP)) { + break; + case XDP_DROP: xdp_stat = &rx_ring->rx_stats.xdp_drop; - } else if (unlikely(verdict == XDP_PASS)) { + break; + case XDP_PASS: xdp_stat = &rx_ring->rx_stats.xdp_pass; - } else { + break; + default: bpf_warn_invalid_xdp_action(verdict); xdp_stat = &rx_ring->rx_stats.xdp_invalid; } @@ -958,11 +965,20 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring, return 0; } +static void ena_unmap_rx_buff(struct ena_ring *rx_ring, + struct ena_rx_buffer *rx_info) +{ + struct ena_com_buf *ena_buf = &rx_info->ena_buf; + + dma_unmap_page(rx_ring->dev, ena_buf->paddr - rx_ring->rx_headroom, + ENA_PAGE_SIZE, + DMA_BIDIRECTIONAL); +} + static void ena_free_rx_page(struct ena_ring *rx_ring, struct ena_rx_buffer *rx_info) { struct page *page = rx_info->page; - struct ena_com_buf *ena_buf = &rx_info->ena_buf; if (unlikely(!page)) { netif_warn(rx_ring->adapter, rx_err, rx_ring->netdev, @@ -970,9 +986,7 @@ static void ena_free_rx_page(struct ena_ring *rx_ring, return; } - dma_unmap_page(rx_ring->dev, ena_buf->paddr - rx_ring->rx_headroom, - ENA_PAGE_SIZE, - DMA_BIDIRECTIONAL); + ena_unmap_rx_buff(rx_ring, rx_info); __free_page(page); rx_info->page = NULL; @@ -1396,9 +1410,7 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, return NULL; do { - dma_unmap_page(rx_ring->dev, - dma_unmap_addr(&rx_info->ena_buf, paddr), - ENA_PAGE_SIZE, DMA_BIDIRECTIONAL); + ena_unmap_rx_buff(rx_ring, rx_info); skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page, rx_info->page_offset, len, ENA_PAGE_SIZE); @@ -1556,6 +1568,7 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, struct sk_buff *skb; int refill_required; struct xdp_buff xdp; + int xdp_flags = 0; int total_len = 0; int xdp_verdict; int rc = 0; @@ -1603,22 +1616,25 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, &next_to_clean); if (unlikely(!skb)) { - /* The page might not actually be freed here since the - * page reference count is incremented in - * ena_xdp_xmit_frame(), and it will be decreased only - * when send completion was received from the device - */ - if (xdp_verdict == XDP_TX) - ena_free_rx_page(rx_ring, - &rx_ring->rx_buffer_info[rx_ring->ena_bufs[0].req_id]); for (i = 0; i < ena_rx_ctx.descs; i++) { - rx_ring->free_ids[next_to_clean] = - rx_ring->ena_bufs[i].req_id; + int req_id = rx_ring->ena_bufs[i].req_id; + + rx_ring->free_ids[next_to_clean] = req_id; next_to_clean = ENA_RX_RING_IDX_NEXT(next_to_clean, rx_ring->ring_size); + + /* Packets was passed for transmission, unmap it + * from RX side. + */ + if (xdp_verdict == XDP_TX || xdp_verdict == XDP_REDIRECT) { + ena_unmap_rx_buff(rx_ring, + &rx_ring->rx_buffer_info[req_id]); + rx_ring->rx_buffer_info[req_id].page = NULL; + } } if (xdp_verdict != XDP_PASS) { + xdp_flags |= xdp_verdict; res_budget--; continue; } @@ -1664,6 +1680,9 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, ena_refill_rx_bufs(rx_ring, refill_required); } + if (xdp_flags & XDP_REDIRECT) + xdp_do_flush_map(); + return work_done; error: diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h index c39f417..0fef876 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.h +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h @@ -239,6 +239,7 @@ struct ena_stats_rx { u64 xdp_pass; u64 xdp_tx; u64 xdp_invalid; + u64 xdp_redirect; }; struct ena_ring { -- 2.7.4