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authorBjörn Töpel2020-12-11 15:57:12 +0100
committerJakub Kicinski2020-12-16 10:51:07 -0800
commit64050b5b8706d304ba647591b06e1eddc55e8bd9 (patch)
tree371bc1fdaaeb6fe6b187afc334ac954221551a38 /drivers/net
parent8d14768a7972b92c73259f0c9c45b969d85e3a60 (diff)
i40e, xsk: clear the status bits for the next_to_use descriptor
On the Rx side, the next_to_use index points to the next item in the HW ring to be refilled/allocated, and next_to_clean points to the next item to potentially be processed. When the HW Rx ring is fully refilled, i.e. no packets has been processed, the next_to_use will be next_to_clean - 1. When the ring is fully processed next_to_clean will be equal to next_to_use. The latter case is where a bug is triggered. If the next_to_use bits are not cleared, and the "fully processed" state is entered, a stale descriptor can be processed. The skb-path correctly clear the status bit for the next_to_use descriptor, but the AF_XDP zero-copy path did not do that. This change adds the status bits clearing of the next_to_use descriptor. Fixes: 3b4f0b66c2b3 ("i40e, xsk: Migrate to new MEM_TYPE_XSK_BUFF_POOL") Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_xsk.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index bfa84bfb0488..47eb9c584a12 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -220,8 +220,11 @@ bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
} while (count);
no_buffers:
- if (rx_ring->next_to_use != ntu)
+ if (rx_ring->next_to_use != ntu) {
+ /* clear the status bits for the next_to_use descriptor */
+ rx_desc->wb.qword1.status_error_len = 0;
i40e_release_rx_desc(rx_ring, ntu);
+ }
return ok;
}