[dpdk-dev] [PATCH 19/20] net/ena: lock dynamic usages of the admin queue

[Michal Krawczyk <mk@semihalf.com>]

There are some cases, where the admin queue commands after the
configuration phase finished - for example, the application could ask
for the driver statitics from multiple cores at once.

As by the design, the admin queue is not multithread safe, the spinlock
was added to protect all usages of the admin queue after the
configuration is done.

Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
---
 drivers/net/ena/ena_ethdev.c | 9 +++++++++
 drivers/net/ena/ena_ethdev.h | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index 8077519735..97e383315b 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -570,7 +570,9 @@ static int ena_rss_reta_update(struct rte_eth_dev *dev,
 		}
 	}
 
+	rte_spinlock_lock(&adapter->admin_lock);
 	rc = ena_com_indirect_table_set(ena_dev);
+	rte_spinlock_unlock(&adapter->admin_lock);
 	if (unlikely(rc && rc != ENA_COM_UNSUPPORTED)) {
 		PMD_DRV_LOG(ERR, "Cannot flush the indirect table\n");
 		return rc;
@@ -599,7 +601,9 @@ static int ena_rss_reta_query(struct rte_eth_dev *dev,
 	    (reta_size > RTE_RETA_GROUP_SIZE && ((reta_conf + 1) == NULL)))
 		return -EINVAL;
 
+	rte_spinlock_lock(&adapter->admin_lock);
 	rc = ena_com_indirect_table_get(ena_dev, indirect_table);
+	rte_spinlock_unlock(&adapter->admin_lock);
 	if (unlikely(rc && rc != ENA_COM_UNSUPPORTED)) {
 		PMD_DRV_LOG(ERR, "cannot get indirect table\n");
 		return -ENOTSUP;
@@ -954,7 +958,10 @@ static int ena_stats_get(struct rte_eth_dev *dev,
 		return -ENOTSUP;
 
 	memset(&ena_stats, 0, sizeof(ena_stats));
+
+	rte_spinlock_lock(&adapter->admin_lock);
 	rc = ena_com_get_dev_basic_stats(ena_dev, &ena_stats);
+	rte_spinlock_unlock(&adapter->admin_lock);
 	if (unlikely(rc)) {
 		PMD_DRV_LOG(ERR, "Could not retrieve statistics from ENA\n");
 		return rc;
@@ -1876,6 +1883,8 @@ static int eth_ena_dev_init(struct rte_eth_dev *eth_dev)
 		goto err_delete_debug_area;
 	}
 
+	rte_spinlock_init(&adapter->admin_lock);
+
 	rte_intr_callback_register(intr_handle,
 				   ena_interrupt_handler_rte,
 				   adapter);
diff --git a/drivers/net/ena/ena_ethdev.h b/drivers/net/ena/ena_ethdev.h
index 6e24a4e582..ddc80dade0 100644
--- a/drivers/net/ena/ena_ethdev.h
+++ b/drivers/net/ena/ena_ethdev.h
@@ -200,6 +200,13 @@ struct ena_adapter {
 	u16 max_mtu;
 	struct ena_offloads offloads;
 
+	/* The admin queue isn't protected by the lock and is used to
+	 * retrieve statistics from the device. As there is no guarantee that
+	 * application won't try to get statistics from multiple threads, it is
+	 * safer to lock the queue to avoid admin queue failure.
+	 */
+	rte_spinlock_t admin_lock;
+
 	int id_number;
 	char name[ENA_NAME_MAX_LEN];
 	u8 mac_addr[RTE_ETHER_ADDR_LEN];
-- 
2.25.1