The flags started and dev_attached are consulted only inside update_queuing_status, where the per-queue handshake provides the real synchronization; their loads and stores are relaxed.
Signed-off-by: Stephen Hemminger <[email protected]> --- drivers/net/vhost/rte_eth_vhost.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c index 05940f2461..2e3a007966 100644 --- a/drivers/net/vhost/rte_eth_vhost.c +++ b/drivers/net/vhost/rte_eth_vhost.c @@ -86,14 +86,14 @@ struct vhost_queue { }; struct pmd_internal { - rte_atomic32_t dev_attached; + RTE_ATOMIC(uint32_t) dev_attached; char *iface_name; uint64_t flags; uint64_t disable_flags; uint64_t features; uint16_t max_queues; int vid; - rte_atomic32_t started; + RTE_ATOMIC(uint32_t) started; bool vlan_strip; bool rx_sw_csum; bool tx_sw_csum; @@ -756,8 +756,12 @@ update_queuing_status(struct rte_eth_dev *dev, bool wait_queuing) if (!dev->data->rx_queues || !dev->data->tx_queues) return; - if (rte_atomic32_read(&internal->started) == 0 || - rte_atomic32_read(&internal->dev_attached) == 0) + /* These are control-plane flags consulted only here; + * the real data-path handshake is on vq->allow_queuing below. + * Relaxed is sufficient. + */ + if (rte_atomic_load_explicit(&internal->started, rte_memory_order_relaxed) == 0 || + rte_atomic_load_explicit(&internal->dev_attached, rte_memory_order_relaxed) == 0) allow_queuing = 0; state = vring_states[dev->data->port_id]; @@ -848,7 +852,7 @@ new_device(int vid) } internal->vid = vid; - if (rte_atomic32_read(&internal->started) == 1) { + if (rte_atomic_load_explicit(&internal->started, rte_memory_order_relaxed) == 1) { queue_setup(eth_dev, internal); if (dev_conf->intr_conf.rxq) eth_vhost_configure_intr(eth_dev); @@ -863,7 +867,7 @@ new_device(int vid) vhost_dev_csum_configure(eth_dev); - rte_atomic32_set(&internal->dev_attached, 1); + rte_atomic_store_explicit(&internal->dev_attached, 1, rte_memory_order_relaxed); update_queuing_status(eth_dev, false); VHOST_LOG_LINE(INFO, "Vhost device %d created", vid); @@ -893,7 +897,7 @@ destroy_device(int vid) eth_dev = list->eth_dev; internal = eth_dev->data->dev_private; - rte_atomic32_set(&internal->dev_attached, 0); + rte_atomic_store_explicit(&internal->dev_attached, 0, rte_memory_order_relaxed); update_queuing_status(eth_dev, true); eth_vhost_unconfigure_intr(eth_dev); @@ -1148,11 +1152,11 @@ eth_dev_start(struct rte_eth_dev *eth_dev) } queue_setup(eth_dev, internal); - if (rte_atomic32_read(&internal->dev_attached) == 1 && + if (rte_atomic_load_explicit(&internal->dev_attached, rte_memory_order_relaxed) == 1 && dev_conf->intr_conf.rxq) eth_vhost_configure_intr(eth_dev); - rte_atomic32_set(&internal->started, 1); + rte_atomic_store_explicit(&internal->started, 1, rte_memory_order_relaxed); update_queuing_status(eth_dev, false); for (i = 0; i < eth_dev->data->nb_rx_queues; i++) @@ -1170,7 +1174,7 @@ eth_dev_stop(struct rte_eth_dev *dev) uint16_t i; dev->data->dev_started = 0; - rte_atomic32_set(&internal->started, 0); + rte_atomic_store_explicit(&internal->started, 0, rte_memory_order_relaxed); update_queuing_status(dev, true); for (i = 0; i < dev->data->nb_rx_queues; i++) @@ -1471,8 +1475,10 @@ vhost_dev_priv_dump(struct rte_eth_dev *dev, FILE *f) fprintf(f, "features: 0x%" PRIx64 "\n", internal->features); fprintf(f, "max_queues: %u\n", internal->max_queues); fprintf(f, "vid: %d\n", internal->vid); - fprintf(f, "started: %d\n", rte_atomic32_read(&internal->started)); - fprintf(f, "dev_attached: %d\n", rte_atomic32_read(&internal->dev_attached)); + fprintf(f, "started: %u\n", + rte_atomic_load_explicit(&internal->started, rte_memory_order_relaxed)); + fprintf(f, "dev_attached: %u\n", + rte_atomic_load_explicit(&internal->dev_attached, rte_memory_order_relaxed)); fprintf(f, "vlan_strip: %d\n", internal->vlan_strip); fprintf(f, "rx_sw_csum: %d\n", internal->rx_sw_csum); fprintf(f, "tx_sw_csum: %d\n", internal->tx_sw_csum); -- 2.53.0
