numam-dpdk/drivers/net/failsafe/failsafe_rxtx.c
Matan Azrad 295f7ed2dd net/failsafe: fix Rx clean race
When removing a device, the fail-safe checks that it is not within its
datapath before cleaning it.

When checking whether an Rx burst should be performed on a device, the
remove flag is not checked. Thus the port could still enter its datapath
and miss a removal round. Furthermore, there is a race between the
thread removing the device and the polling thread.

Check the remove flag before entering a sub-device Rx burst when in safe
mode. This check mitigates the aforementioned race condition.

Fixes: 72a57bfd9a ("net/failsafe: add fast burst functions")
Cc: stable@dpdk.org

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Gaetan Rivet <gaetan.rivet@6wind.com>
2017-10-27 01:05:55 +02:00

205 lines
5.5 KiB
C

/*-
* BSD LICENSE
*
* Copyright 2017 6WIND S.A.
* Copyright 2017 Mellanox.
*
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* modification, are permitted provided that the following conditions
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* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#include <rte_atomic.h>
#include <rte_debug.h>
#include <rte_mbuf.h>
#include <rte_ethdev.h>
#include "failsafe_private.h"
static inline int
fs_rx_unsafe(struct sub_device *sdev)
{
return (ETH(sdev) == NULL) ||
(ETH(sdev)->rx_pkt_burst == NULL) ||
(sdev->state != DEV_STARTED) ||
(sdev->remove != 0);
}
static inline int
fs_tx_unsafe(struct sub_device *sdev)
{
return (sdev == NULL) ||
(ETH(sdev) == NULL) ||
(ETH(sdev)->tx_pkt_burst == NULL) ||
(sdev->state != DEV_STARTED);
}
void
set_burst_fn(struct rte_eth_dev *dev, int force_safe)
{
struct sub_device *sdev;
uint8_t i;
int need_safe;
int safe_set;
need_safe = force_safe;
FOREACH_SUBDEV(sdev, i, dev)
need_safe |= fs_rx_unsafe(sdev);
safe_set = (dev->rx_pkt_burst == &failsafe_rx_burst);
if (need_safe && !safe_set) {
DEBUG("Using safe RX bursts%s",
(force_safe ? " (forced)" : ""));
dev->rx_pkt_burst = &failsafe_rx_burst;
} else if (!need_safe && safe_set) {
DEBUG("Using fast RX bursts");
dev->rx_pkt_burst = &failsafe_rx_burst_fast;
}
need_safe = force_safe || fs_tx_unsafe(TX_SUBDEV(dev));
safe_set = (dev->tx_pkt_burst == &failsafe_tx_burst);
if (need_safe && !safe_set) {
DEBUG("Using safe TX bursts%s",
(force_safe ? " (forced)" : ""));
dev->tx_pkt_burst = &failsafe_tx_burst;
} else if (!need_safe && safe_set) {
DEBUG("Using fast TX bursts");
dev->tx_pkt_burst = &failsafe_tx_burst_fast;
}
rte_wmb();
}
uint16_t
failsafe_rx_burst(void *queue,
struct rte_mbuf **rx_pkts,
uint16_t nb_pkts)
{
struct fs_priv *priv;
struct sub_device *sdev;
struct rxq *rxq;
void *sub_rxq;
uint16_t nb_rx;
uint8_t nb_polled, nb_subs;
uint8_t i;
rxq = queue;
priv = rxq->priv;
nb_subs = priv->subs_tail - priv->subs_head;
nb_polled = 0;
for (i = rxq->last_polled; nb_polled < nb_subs; nb_polled++) {
i++;
if (i == priv->subs_tail)
i = priv->subs_head;
sdev = &priv->subs[i];
if (unlikely(fs_rx_unsafe(sdev)))
continue;
sub_rxq = ETH(sdev)->data->rx_queues[rxq->qid];
FS_ATOMIC_P(rxq->refcnt[sdev->sid]);
nb_rx = ETH(sdev)->
rx_pkt_burst(sub_rxq, rx_pkts, nb_pkts);
FS_ATOMIC_V(rxq->refcnt[sdev->sid]);
if (nb_rx) {
rxq->last_polled = i;
return nb_rx;
}
}
return 0;
}
uint16_t
failsafe_rx_burst_fast(void *queue,
struct rte_mbuf **rx_pkts,
uint16_t nb_pkts)
{
struct fs_priv *priv;
struct sub_device *sdev;
struct rxq *rxq;
void *sub_rxq;
uint16_t nb_rx;
uint8_t nb_polled, nb_subs;
uint8_t i;
rxq = queue;
priv = rxq->priv;
nb_subs = priv->subs_tail - priv->subs_head;
nb_polled = 0;
for (i = rxq->last_polled; nb_polled < nb_subs; nb_polled++) {
i++;
if (i == priv->subs_tail)
i = priv->subs_head;
sdev = &priv->subs[i];
RTE_ASSERT(!fs_rx_unsafe(sdev));
sub_rxq = ETH(sdev)->data->rx_queues[rxq->qid];
FS_ATOMIC_P(rxq->refcnt[sdev->sid]);
nb_rx = ETH(sdev)->
rx_pkt_burst(sub_rxq, rx_pkts, nb_pkts);
FS_ATOMIC_V(rxq->refcnt[sdev->sid]);
if (nb_rx) {
rxq->last_polled = i;
return nb_rx;
}
}
return 0;
}
uint16_t
failsafe_tx_burst(void *queue,
struct rte_mbuf **tx_pkts,
uint16_t nb_pkts)
{
struct sub_device *sdev;
struct txq *txq;
void *sub_txq;
uint16_t nb_tx;
txq = queue;
sdev = TX_SUBDEV(txq->priv->dev);
if (unlikely(fs_tx_unsafe(sdev)))
return 0;
sub_txq = ETH(sdev)->data->tx_queues[txq->qid];
FS_ATOMIC_P(txq->refcnt[sdev->sid]);
nb_tx = ETH(sdev)->tx_pkt_burst(sub_txq, tx_pkts, nb_pkts);
FS_ATOMIC_V(txq->refcnt[sdev->sid]);
return nb_tx;
}
uint16_t
failsafe_tx_burst_fast(void *queue,
struct rte_mbuf **tx_pkts,
uint16_t nb_pkts)
{
struct sub_device *sdev;
struct txq *txq;
void *sub_txq;
uint16_t nb_tx;
txq = queue;
sdev = TX_SUBDEV(txq->priv->dev);
RTE_ASSERT(!fs_tx_unsafe(sdev));
sub_txq = ETH(sdev)->data->tx_queues[txq->qid];
FS_ATOMIC_P(txq->refcnt[sdev->sid]);
nb_tx = ETH(sdev)->tx_pkt_burst(sub_txq, tx_pkts, nb_pkts);
FS_ATOMIC_V(txq->refcnt[sdev->sid]);
return nb_tx;
}