From: David Arinzon darinzon@amazon.com
[ Upstream commit 59811faa2c54dbcf44d575b5a8f6e7077da88dc2 ]
Redirecting packets with XDP Redirect is done in two phases: 1. A packet is passed by the driver to the kernel using xdp_do_redirect(). 2. After finishing polling for new packets the driver lets the kernel know that it can now process the redirected packet using xdp_do_flush_map(). The packets' redirection is handled in the napi context of the queue that called xdp_do_redirect()
To avoid calling xdp_do_flush_map() each time the driver first checks whether any packets were redirected, using xdp_flags |= xdp_verdict; and if (xdp_flags & XDP_REDIRECT) xdp_do_flush_map()
essentially treating XDP instructions as a bitmask, which isn't the case: enum xdp_action { XDP_ABORTED = 0, XDP_DROP, XDP_PASS, XDP_TX, XDP_REDIRECT, };
Given the current possible values of xdp_action, the current design doesn't have a bug (since XDP_REDIRECT = 100b), but it is still flawed.
This patch makes the driver use a bitmask instead, to avoid future issues.
Fixes: a318c70ad152 ("net: ena: introduce XDP redirect implementation") Signed-off-by: Shay Agroskin shayagr@amazon.com Signed-off-by: David Arinzon darinzon@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/amazon/ena/ena_netdev.c | 26 ++++++++++++-------- drivers/net/ethernet/amazon/ena/ena_netdev.h | 9 +++++++ 2 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 31afbd17e690..294f21a839cf 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -378,9 +378,9 @@ static int ena_xdp_xmit(struct net_device *dev, int n,
static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp) { + u32 verdict = ENA_XDP_PASS; struct bpf_prog *xdp_prog; struct ena_ring *xdp_ring; - u32 verdict = XDP_PASS; struct xdp_frame *xdpf; u64 *xdp_stat;
@@ -397,7 +397,7 @@ static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp) if (unlikely(!xdpf)) { trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict); xdp_stat = &rx_ring->rx_stats.xdp_aborted; - verdict = XDP_ABORTED; + verdict = ENA_XDP_DROP; break; }
@@ -413,29 +413,35 @@ static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
spin_unlock(&xdp_ring->xdp_tx_lock); xdp_stat = &rx_ring->rx_stats.xdp_tx; + verdict = ENA_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; + verdict = ENA_XDP_REDIRECT; break; } trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict); xdp_stat = &rx_ring->rx_stats.xdp_aborted; - verdict = XDP_ABORTED; + verdict = ENA_XDP_DROP; break; case XDP_ABORTED: trace_xdp_exception(rx_ring->netdev, xdp_prog, verdict); xdp_stat = &rx_ring->rx_stats.xdp_aborted; + verdict = ENA_XDP_DROP; break; case XDP_DROP: xdp_stat = &rx_ring->rx_stats.xdp_drop; + verdict = ENA_XDP_DROP; break; case XDP_PASS: xdp_stat = &rx_ring->rx_stats.xdp_pass; + verdict = ENA_XDP_PASS; break; default: bpf_warn_invalid_xdp_action(verdict); xdp_stat = &rx_ring->rx_stats.xdp_invalid; + verdict = ENA_XDP_DROP; }
ena_increase_stat(xdp_stat, 1, &rx_ring->syncp); @@ -1631,12 +1637,12 @@ static int ena_xdp_handle_buff(struct ena_ring *rx_ring, struct xdp_buff *xdp) * we expect, then we simply drop it */ if (unlikely(rx_ring->ena_bufs[0].len > ENA_XDP_MAX_MTU)) - return XDP_DROP; + return ENA_XDP_DROP;
ret = ena_xdp_execute(rx_ring, xdp);
/* The xdp program might expand the headers */ - if (ret == XDP_PASS) { + if (ret == ENA_XDP_PASS) { rx_info->page_offset = xdp->data - xdp->data_hard_start; rx_ring->ena_bufs[0].len = xdp->data_end - xdp->data; } @@ -1675,7 +1681,7 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, xdp_init_buff(&xdp, ENA_PAGE_SIZE, &rx_ring->xdp_rxq);
do { - xdp_verdict = XDP_PASS; + xdp_verdict = ENA_XDP_PASS; skb = NULL; ena_rx_ctx.ena_bufs = rx_ring->ena_bufs; ena_rx_ctx.max_bufs = rx_ring->sgl_size; @@ -1703,7 +1709,7 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, xdp_verdict = ena_xdp_handle_buff(rx_ring, &xdp);
/* allocate skb and fill it */ - if (xdp_verdict == XDP_PASS) + if (xdp_verdict == ENA_XDP_PASS) skb = ena_rx_skb(rx_ring, rx_ring->ena_bufs, ena_rx_ctx.descs, @@ -1721,13 +1727,13 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi, /* Packets was passed for transmission, unmap it * from RX side. */ - if (xdp_verdict == XDP_TX || xdp_verdict == XDP_REDIRECT) { + if (xdp_verdict & ENA_XDP_FORWARDED) { 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) { + if (xdp_verdict != ENA_XDP_PASS) { xdp_flags |= xdp_verdict; total_len += ena_rx_ctx.ena_bufs[0].len; res_budget--; @@ -1773,7 +1779,7 @@ 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) + if (xdp_flags & ENA_XDP_REDIRECT) xdp_do_flush_map();
return work_done; diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h index 0c39fc2fa345..ada2f8faa33a 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.h +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h @@ -412,6 +412,15 @@ enum ena_xdp_errors_t { ENA_XDP_NO_ENOUGH_QUEUES, };
+enum ENA_XDP_ACTIONS { + ENA_XDP_PASS = 0, + ENA_XDP_TX = BIT(0), + ENA_XDP_REDIRECT = BIT(1), + ENA_XDP_DROP = BIT(2) +}; + +#define ENA_XDP_FORWARDED (ENA_XDP_TX | ENA_XDP_REDIRECT) + static inline bool ena_xdp_present(struct ena_adapter *adapter) { return !!adapter->xdp_bpf_prog;