From: David Arinzon <darinzon@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: David Arinzon <darinzon@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 614f27f18164..a27a7963df76 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -374,9 +374,9 @@ 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;
@@ -393,7 +393,7 @@ 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;
}
@@ -409,29 +409,35 @@ 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(rx_ring->netdev, xdp_prog, verdict);
xdp_stat = &rx_ring->rx_stats.xdp_invalid;
+ verdict = ENA_XDP_DROP;
}
ena_increase_stat(xdp_stat, 1, &rx_ring->syncp);
@@ -1621,12 +1627,12 @@ 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;
}
@@ -1665,7 +1671,7 @@ 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;
@@ -1693,7 +1699,7 @@ 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,
@@ -1711,13 +1717,13 @@ 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--;
@@ -1763,7 +1769,7 @@ 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 1bdce99bf688..290ae9bf47ee 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -409,6 +409,15 @@ 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;
--
2.35.1
