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

[Slava Ovsiienko <viacheslavo@mellanox.com>]

> -----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