Linux Virtualization - Aug 2020 - [PATCH V4 linux-next 08/12] vdpa: Modify get_vq_state() to return error code

On 2020/8/5 ??12:20, Eli Cohen wrote:
> Modify get_vq_state() so it returns an error code. In case of hardware
> acceleration, the available index may be retrieved from the device, an
> operation that can possibly fail.
>
> Reviewed-by: Parav Pandit <parav at mellanox.com>
> Signed-off-by: Eli Cohen <eli at mellanox.com>

Acked-by: Jason Wang <jasowang at redhat.com>

> ---
>   drivers/vdpa/ifcvf/ifcvf_main.c  | 5 +++--
>   drivers/vdpa/vdpa_sim/vdpa_sim.c | 5 +++--
>   drivers/vhost/vdpa.c             | 5 ++++-
>   include/linux/vdpa.h             | 4 ++--
>   4 files changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c
b/drivers/vdpa/ifcvf/ifcvf_main.c
> index dc311e972b9e..076d7ac5e723 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -237,12 +237,13 @@ static u16 ifcvf_vdpa_get_vq_num_max(struct
vdpa_device *vdpa_dev)
>   	return IFCVF_QUEUE_MAX;
>   }
>   
> -static void ifcvf_vdpa_get_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
> -				    struct vdpa_vq_state *state)
> +static int ifcvf_vdpa_get_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
> +				   struct vdpa_vq_state *state)
>   {
>   	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
>   
>   	state->avail_index = ifcvf_get_vq_state(vf, qid);
> +	return 0;
>   }
>   
>   static int ifcvf_vdpa_set_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c
b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index f1c351d5959b..c68741363643 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -464,14 +464,15 @@ static int vdpasim_set_vq_state(struct vdpa_device
*vdpa, u16 idx,
>   	return 0;
>   }
>   
> -static void vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
> -				 struct vdpa_vq_state *state)
> +static int vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
> +				struct vdpa_vq_state *state)
>   {
>   	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
>   	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
>   	struct vringh *vrh = &vq->vring;
>   
>   	state->avail_index = vrh->last_avail_idx;
> +	return 0;
>   }
>   
>   static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index c2e1e2d55084..a0b7c91948e1 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -392,7 +392,10 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa
*v, unsigned int cmd,
>   		ops->set_vq_ready(vdpa, idx, s.num);
>   		return 0;
>   	case VHOST_GET_VRING_BASE:
> -		ops->get_vq_state(v->vdpa, idx, &vq_state);
> +		r = ops->get_vq_state(v->vdpa, idx, &vq_state);
> +		if (r)
> +			return r;
> +
>   		vq->last_avail_idx = vq_state.avail_index;
>   		break;
>   	case VHOST_GET_BACKEND_FEATURES:
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 8f412620071d..fd6e560d70f9 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -192,8 +192,8 @@ struct vdpa_config_ops {
>   	bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx);
>   	int (*set_vq_state)(struct vdpa_device *vdev, u16 idx,
>   			    const struct vdpa_vq_state *state);
> -	void (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
> -			     struct vdpa_vq_state *state);
> +	int (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
> +			    struct vdpa_vq_state *state);
>   	struct vdpa_notification_area
>   	(*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
>   	int (*get_vq_irq)(struct vdpa_device *vdv, u16 idx);