[PATCH net] ice: Fix ice_xdp_xmit() when XDP TX queue number is not sufficient

[PATCH net] ice: Fix ice_xdp_xmit() when XDP TX queue number is not sufficient

[Larysa Zaremba]

The original patch added the static branch to handle the situation,
when assigning an XDP TX queue to every CPU is not possible,
so they have to be shared.

However, in the XDP transmit handler ice_xdp_xmit(), an error was
returned in such cases even before static condition was checked,
thus making queue sharing still impossible.

Fixes: 22bf877e528f ("ice: introduce XDP_TX fallback path")
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 42b42f4b21ef..a5a0c9706b5a 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -610,7 +610,7 @@ ice_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 	if (test_bit(ICE_VSI_DOWN, vsi->state))
 		return -ENETDOWN;
 
-	if (!ice_is_xdp_ena_vsi(vsi) || queue_index >= vsi->num_xdp_txq)
+	if (!ice_is_xdp_ena_vsi(vsi))
 		return -ENXIO;
 
 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
@@ -621,6 +621,9 @@ ice_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 		xdp_ring = vsi->xdp_rings[queue_index];
 		spin_lock(&xdp_ring->tx_lock);
 	} else {
+		/* Generally, should not happen */
+		if (unlikely(queue_index >= vsi->num_xdp_txq))
+			return -ENXIO;
 		xdp_ring = vsi->xdp_rings[queue_index];
 	}
 
-- 
2.35.3

Re: [PATCH net] ice: Fix ice_xdp_xmit() when XDP TX queue number is not sufficient

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 19 Sep 2022 15:43:46 +0200 you wrote:
> The original patch added the static branch to handle the situation,
> when assigning an XDP TX queue to every CPU is not possible,
> so they have to be shared.
> 
> However, in the XDP transmit handler ice_xdp_xmit(), an error was
> returned in such cases even before static condition was checked,
> thus making queue sharing still impossible.
> 
> [...]

Here is the summary with links:
  - [net] ice: Fix ice_xdp_xmit() when XDP TX queue number is not sufficient
    https://git.kernel.org/netdev/net/c/114f398d48c5

You are awesome, thank you!
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