Fail-safe relied on the removal (RMV) interrupt and on swapping the
Rx/Tx burst functions to "safe" variants to cope with a disappearing
sub-device. When a sub-device does not support the RMV interrupt (for
example a VFIO device whose removal is only reported by the bus as a
device event on the release request), the removal was not detected:
the burst functions kept polling the gone device and traffic was not
failed over to the other sub-device.
Register a bus device-event callback for sub-devices without RMV
interrupt support and run the existing removal handling from it. The
callback is registered and unregistered by the primary process only:
struct sub_device lives in shared memory, so in a secondary process the
registration flag would read as set and sdev->dev would point into the
primary address space; dereferencing it would crash.
With removal now reported reliably, the per-burst safe/fast function
switching is no longer needed; drop failsafe_set_burst_fn() and the
_fast burst variants and keep a single burst path guarded by an
unlikely() check.
Fixes: a46f8d584eb8 ("net/failsafe: add fail-safe PMD")
Cc: [email protected]
Signed-off-by: Sandeep Penigalapati <[email protected]>
---
drivers/net/failsafe/failsafe_ether.c | 29 ++++++++-
drivers/net/failsafe/failsafe_ops.c | 16 +++++
drivers/net/failsafe/failsafe_private.h | 13 ++--
drivers/net/failsafe/failsafe_rxtx.c | 83 +------------------------
4 files changed, 49 insertions(+), 92 deletions(-)
diff --git a/drivers/net/failsafe/failsafe_ether.c
b/drivers/net/failsafe/failsafe_ether.c
index f23580ed37..2a15eb4da5 100644
--- a/drivers/net/failsafe/failsafe_ether.c
+++ b/drivers/net/failsafe/failsafe_ether.c
@@ -386,6 +386,22 @@ failsafe_eth_dev_unregister_callbacks(struct sub_device
*sdev)
" %d", SUB_ID(sdev));
sdev->lsc_callback = 0;
}
+ /*
+ * The bus device-event callback is registered by the primary only
+ * (hotplug is handled there). sub_device is shared memory, so in a
+ * secondary the flag reads as set and sdev->dev holds the primary's
+ * pointer; dereferencing it (rte_dev_name) would crash. Skip it.
+ */
+ if (rte_eal_process_type() == RTE_PROC_PRIMARY &&
+ sdev->dev_event_callback) {
+ ret = rte_dev_event_callback_unregister(rte_dev_name(sdev->dev),
+ failsafe_dev_event_callback,
+ sdev);
+ if (ret < 0)
+ WARN("Failed to unregister device event callback for"
+ " sub_device %d", SUB_ID(sdev));
+ sdev->dev_event_callback = 0;
+ }
}
void
@@ -592,8 +608,6 @@ failsafe_eth_rmv_event_callback(uint16_t port_id
__rte_unused,
return -1;
/* Switch as soon as possible tx_dev. */
fs_switch_dev(fs_dev(sdev), sdev);
- /* Use safe bursts in any case. */
- failsafe_set_burst_fn(fs_dev(sdev), 1);
/*
* Async removal, the sub-PMD will try to unregister
* the callback at the source of the current thread context.
@@ -603,6 +617,17 @@ failsafe_eth_rmv_event_callback(uint16_t port_id
__rte_unused,
return 0;
}
+void
+failsafe_dev_event_callback(const char *device_name __rte_unused,
+ enum rte_dev_event_type type,
+ void *cb_arg)
+{
+ if (type != RTE_DEV_EVENT_REMOVE)
+ return;
+ failsafe_eth_rmv_event_callback(PORT_ID((struct sub_device *)cb_arg),
+ RTE_ETH_EVENT_INTR_RMV, cb_arg, NULL);
+}
+
int
failsafe_eth_lsc_event_callback(uint16_t port_id __rte_unused,
enum rte_eth_event_type event __rte_unused,
diff --git a/drivers/net/failsafe/failsafe_ops.c
b/drivers/net/failsafe/failsafe_ops.c
index 56c7c884a1..4916d25d8b 100644
--- a/drivers/net/failsafe/failsafe_ops.c
+++ b/drivers/net/failsafe/failsafe_ops.c
@@ -82,6 +82,22 @@ fs_dev_configure(struct rte_eth_dev *dev)
else
sdev->rmv_callback = 1;
}
+ /*
+ * Without RMV interrupts, a hot-unplug is only reported by the
+ * bus (e.g. a VFIO device release request) as a device event.
+ */
+ if (rte_eal_process_type() == RTE_PROC_PRIMARY &&
+ !rmv_interrupt && sdev->dev != NULL &&
+ sdev->dev_event_callback == 0) {
+ ret =
rte_dev_event_callback_register(rte_dev_name(sdev->dev),
+ failsafe_dev_event_callback,
+ sdev);
+ if (ret)
+ WARN("Failed to register device event callback
for sub_device %d",
+ SUB_ID(sdev));
+ else
+ sdev->dev_event_callback = 1;
+ }
dev->data->dev_conf.intr_conf.rmv = 0;
if (lsc_interrupt && sdev->lsc_callback == 0) {
ret = rte_eth_dev_callback_register(PORT_ID(sdev),
diff --git a/drivers/net/failsafe/failsafe_private.h
b/drivers/net/failsafe/failsafe_private.h
index aae091e792..a565ee2fbc 100644
--- a/drivers/net/failsafe/failsafe_private.h
+++ b/drivers/net/failsafe/failsafe_private.h
@@ -138,6 +138,8 @@ struct sub_device {
unsigned int rmv_callback:1;
/* LSC callback registration state */
unsigned int lsc_callback:1;
+ /* Bus device event (removal) callback registration state */
+ unsigned int dev_event_callback:1;
};
/*
@@ -208,18 +210,11 @@ int failsafe_hotplug_alarm_cancel(struct rte_eth_dev
*dev);
/* RX / TX */
-void failsafe_set_burst_fn(struct rte_eth_dev *dev, int force_safe);
-
uint16_t failsafe_rx_burst(void *rxq,
struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
uint16_t failsafe_tx_burst(void *txq,
struct rte_mbuf **tx_pkts, uint16_t nb_pkts);
-uint16_t failsafe_rx_burst_fast(void *rxq,
- struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
-uint16_t failsafe_tx_burst_fast(void *txq,
- struct rte_mbuf **tx_pkts, uint16_t nb_pkts);
-
/* ARGS */
int failsafe_args_parse(struct rte_eth_dev *dev, const char *params);
@@ -246,6 +241,9 @@ int failsafe_eth_rmv_event_callback(uint16_t port_id,
int failsafe_eth_lsc_event_callback(uint16_t port_id,
enum rte_eth_event_type event,
void *cb_arg, void *out);
+void failsafe_dev_event_callback(const char *device_name,
+ enum rte_dev_event_type type,
+ void *cb_arg);
int failsafe_eth_new_event_callback(uint16_t port_id,
enum rte_eth_event_type event,
void *cb_arg, void *out);
@@ -487,7 +485,6 @@ fs_switch_dev(struct rte_eth_dev *dev,
} else {
return;
}
- failsafe_set_burst_fn(dev, 0);
rte_wmb();
}
diff --git a/drivers/net/failsafe/failsafe_rxtx.c
b/drivers/net/failsafe/failsafe_rxtx.c
index 500483bda3..8d53d9dd40 100644
--- a/drivers/net/failsafe/failsafe_rxtx.c
+++ b/drivers/net/failsafe/failsafe_rxtx.c
@@ -28,39 +28,6 @@ fs_tx_unsafe(struct sub_device *sdev)
(sdev->state != DEV_STARTED);
}
-void
-failsafe_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();
-}
-
/*
* Override source port in Rx packets.
*
@@ -89,7 +56,7 @@ failsafe_rx_burst(void *queue,
rxq = queue;
sdev = rxq->sdev;
do {
- if (fs_rx_unsafe(sdev)) {
+ if (unlikely(fs_rx_unsafe(sdev))) {
nb_rx = 0;
sdev = sdev->next;
continue;
@@ -108,34 +75,6 @@ failsafe_rx_burst(void *queue,
return nb_rx;
}
-uint16_t
-failsafe_rx_burst_fast(void *queue,
- struct rte_mbuf **rx_pkts,
- uint16_t nb_pkts)
-{
- struct sub_device *sdev;
- struct rxq *rxq;
- void *sub_rxq;
- uint16_t nb_rx;
-
- rxq = queue;
- sdev = rxq->sdev;
- do {
- 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]);
- sdev = sdev->next;
- } while (nb_rx == 0 && sdev != rxq->sdev);
- rxq->sdev = sdev;
- if (nb_rx)
- failsafe_rx_set_port(rx_pkts, nb_rx,
- rxq->priv->data->port_id);
- return nb_rx;
-}
-
uint16_t
failsafe_tx_burst(void *queue,
struct rte_mbuf **tx_pkts,
@@ -156,23 +95,3 @@ failsafe_tx_burst(void *queue,
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(&rte_eth_devices[txq->priv->data->port_id]);
- 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;
-}
--
2.34.1
