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

[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@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

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

[Slava Ovsiienko]

> -----Original Message-----
> From: Matan Azrad <matan@mellanox.com>
> Sent: Tuesday, February 25, 2020 10:44
> To: dev@dpdk.org
> Cc: Slava Ovsiienko <viacheslavo@mellanox.com>; Thomas Monjalon
> <thomas@monjalon.net>; Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH] vdpa/mlx5: fix event setup
> 
> 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@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@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

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

[Thomas Monjalon]

25/02/2020 09:43, 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@mellanox.com>

Applied, thanks
Note: there is no regression risk because it is fixing a new driver.