Commit bf280c03 authored by Ilya Maximets's avatar Ilya Maximets Committed by Jeff Kirsher
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ixgbe: fix double clean of Tx descriptors with xdp

Tx code doesn't clear the descriptors' status after cleaning.
So, if the budget is larger than number of used elems in a ring, some
descriptors will be accounted twice and xsk_umem_complete_tx will move
prod_tail far beyond the prod_head breaking the completion queue ring.

Fix that by limiting the number of descriptors to clean by the number
of used descriptors in the Tx ring.

'ixgbe_clean_xdp_tx_irq()' function refactored to look more like
'ixgbe_xsk_clean_tx_ring()' since we're allowed to directly use
'next_to_clean' and 'next_to_use' indexes.

Fixes: 8221c5eb

 ("ixgbe: add AF_XDP zero-copy Tx support")
Signed-off-by: default avatarIlya Maximets <>
Tested-by: default avatarWilliam Tu <>
Tested-by: default avatarEelco Chaudron <>
Signed-off-by: default avatarJeff Kirsher <>
parent 377228ac
......@@ -633,19 +633,17 @@ static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
struct ixgbe_ring *tx_ring, int napi_budget)
u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
unsigned int total_packets = 0, total_bytes = 0;
u32 i = tx_ring->next_to_clean, xsk_frames = 0;
unsigned int budget = q_vector->tx.work_limit;
struct xdp_umem *umem = tx_ring->xsk_umem;
union ixgbe_adv_tx_desc *tx_desc;
struct ixgbe_tx_buffer *tx_bi;
bool xmit_done;
u32 xsk_frames = 0;
tx_bi = &tx_ring->tx_buffer_info[i];
tx_desc = IXGBE_TX_DESC(tx_ring, i);
i -= tx_ring->count;
tx_bi = &tx_ring->tx_buffer_info[ntc];
tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
do {
while (ntc != ntu) {
if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
......@@ -661,22 +659,18 @@ bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
if (unlikely(!i)) {
i -= tx_ring->count;
if (unlikely(ntc == tx_ring->count)) {
ntc = 0;
tx_bi = tx_ring->tx_buffer_info;
tx_desc = IXGBE_TX_DESC(tx_ring, 0);
/* issue prefetch for next Tx descriptor */
/* update budget accounting */
} while (likely(budget));
i += tx_ring->count;
tx_ring->next_to_clean = i;
tx_ring->next_to_clean = ntc;
tx_ring->stats.bytes += total_bytes;
......@@ -688,8 +682,7 @@ bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
if (xsk_frames)
xsk_umem_complete_tx(umem, xsk_frames);
xmit_done = ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
return budget > 0 && xmit_done;
return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
int ixgbe_xsk_async_xmit(struct net_device *dev, u32 qid)
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