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net/ixgbe: add vector Rx parameter check

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Under the circumstance that `rx_tail` wrap back to zero
and the advance speed of `rx_tail` is greater than `rxrearm_start`,
`rx_tail` will catch up with `rxrearm_start` and surpass it.
This may cause some mbufs be reused by application.

So we need to make some restrictions to ensure that
 `rx_tail` will not exceed `rxrearm_start`.

e.g.

RDH: 972 RDT: 991 rxrearm_nb: 991 rxrearm_start: 992 rx_tail: 959
RDH: 1004 RDT: 1023 rxrearm_nb: 991 rxrearm_start: 0 rx_tail: 991
RDH: 12 RDT: 31 rxrearm_nb: 991 rxrearm_start: 32 rx_tail: 1023
RDH: 31 RDT: 63 rxrearm_nb: 960 rxrearm_start: 64 rx_tail: 0
RDH: 95 RDT: 95 rxrearm_nb: 1016 rxrearm_start: 96 rx_tail: 88
RDH: 95 RDT: 127 rxrearm_nb: 991 rxrearm_start: 128 rx_tail: 95
...
RDH: 908 RDT: 927 rxrearm_nb: 991 rxrearm_start: 928 rx_tail: 895
RDH: 940 RDT: 959 rxrearm_nb: 991 rxrearm_start: 960 rx_tail: 927
RDH: 980 RDT: 991 rxrearm_nb: 991 rxrearm_start: 992 rx_tail: 959
RDH: 991 RDT: 991 rxrearm_nb: 1026 rxrearm_start: 992 rx_tail: 994

when `rx_tail` catches up with `rxrearm_start`,
2(994 - 992) mbufs be reused by application !

Bugzilla ID: 882
Fixes: 5a3cca3424 ("net/ixgbe: fix vector Rx")
Cc: stable@dpdk.org

Signed-off-by: Bin Zheng <zhengbin.89740@bytedance.com>
Acked-by: Leyi Rong <leyi.rong@intel.com>
Reviewed-by: Haiyue Wang <haiyue.wang@intel.com>
Reviewed-by: Liang Ma <liangma@liangbit.com>
This commit is contained in:
Bin Zheng 2021-12-10 16:22:09 +08:00 committed by Qi Zhang
parent ff8b8bcd2e
commit c59f93d9a1
1 changed files with 11 additions and 0 deletions
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11
drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c
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@ -364,6 +364,17 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
uint8_t vlan_flags;
uint16_t udp_p_flag = 0; /* Rx Descriptor UDP header present */
/*
* Under the circumstance that `rx_tail` wrap back to zero
* and the advance speed of `rx_tail` is greater than `rxrearm_start`,
* `rx_tail` will catch up with `rxrearm_start` and surpass it.
* This may cause some mbufs be reused by application.
*
* So we need to make some restrictions to ensure that
* `rx_tail` will not exceed `rxrearm_start`.
*/
nb_pkts = RTE_MIN(nb_pkts, RTE_IXGBE_RXQ_REARM_THRESH);
/* nb_pkts has to be floor-aligned to RTE_IXGBE_DESCS_PER_LOOP */
nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_IXGBE_DESCS_PER_LOOP);