[dpdk-dev] [PATCH] vdpa/mlx5: fix event setup

[Matan Azrad]

The completion event mechanism should work only if at least one of the
virtqs has valid callfd to be notified on.

When all the virtqs works with poll mode, the event mechanism should not
be configured.

The driver didn't take it into account and crashed in the above case.

Do not configure event interrupt when all the virtqs are in poll mode.

Fixes: 8395927cdfaf ("vdpa/mlx5: prepare HW queues")

Signed-off-by: Matan Azrad <matan at mellanox.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa_event.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_event.c b/drivers/vdpa/mlx5/mlx5_vdpa_event.c
index 16276f5..dd60150 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_event.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_event.c
@@ -237,8 +237,14 @@
 int
 mlx5_vdpa_cqe_event_setup(struct mlx5_vdpa_priv *priv)
 {
-	int flags = fcntl(priv->eventc->fd, F_GETFL);
-	int ret = fcntl(priv->eventc->fd, F_SETFL, flags | O_NONBLOCK);
+	int flags;
+	int ret;
+
+	if (!priv->eventc)
+		/* All virtqs are in poll mode. */
+		return 0;
+	flags = fcntl(priv->eventc->fd, F_GETFL);
+	ret = fcntl(priv->eventc->fd, F_SETFL, flags | O_NONBLOCK);
 	if (ret) {
 		DRV_LOG(ERR, "Failed to change event channel FD.");
 		rte_errno = errno;
-- 
1.8.3.1