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Date:   Wed, 2 Jun 2021 10:45:36 +0300
From:   Eli Cohen <elic@nvidia.com>
To:     Jason Wang <jasowang@redhat.com>
CC:     <mst@redhat.com>, <virtualization@lists.linux-foundation.org>,
        <linux-kernel@vger.kernel.org>, <kvm@vger.kernel.org>,
        <netdev@vger.kernel.org>, <eli@mellanox.com>
Subject: Re: [PATCH V2 RESEND 1/4] vdpa: support packed virtqueue for
 set/get_vq_state()
Message-ID: <20210602074536.GE12498@mtl-vdi-166.wap.labs.mlnx>
References: <20210602021536.39525-1-jasowang@redhat.com>
 <20210602021536.39525-2-jasowang@redhat.com>
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On Wed, Jun 02, 2021 at 10:15:33AM +0800, Jason Wang wrote:
> This patch extends the vdpa_vq_state to support packed virtqueue
> state which is basically the device/driver ring wrap counters and the
> avail and used index. This will be used for the virito-vdpa support
> for the packed virtqueue and the future vhost/vhost-vdpa support for
> the packed virtqueue.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
> ---
>  drivers/vdpa/ifcvf/ifcvf_main.c   |  4 ++--
>  drivers/vdpa/mlx5/net/mlx5_vnet.c |  8 ++++----
>  drivers/vdpa/vdpa_sim/vdpa_sim.c  |  4 ++--
>  drivers/vhost/vdpa.c              |  4 ++--
>  include/linux/vdpa.h              | 25 +++++++++++++++++++++++--
>  5 files changed, 33 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index ab0ab5cf0f6e..5d3891b1ca28 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -264,7 +264,7 @@ static int ifcvf_vdpa_get_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
>  {
>  	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
>  
> -	state->avail_index = ifcvf_get_vq_state(vf, qid);
> +	state->split.avail_index = ifcvf_get_vq_state(vf, qid);
>  	return 0;
>  }
>  
> @@ -273,7 +273,7 @@ static int ifcvf_vdpa_set_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
>  {
>  	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
>  
> -	return ifcvf_set_vq_state(vf, qid, state->avail_index);
> +	return ifcvf_set_vq_state(vf, qid, state->split.avail_index);
>  }
>  
>  static void ifcvf_vdpa_set_vq_cb(struct vdpa_device *vdpa_dev, u16 qid,
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 189e4385df40..e5505d760bca 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1427,8 +1427,8 @@ static int mlx5_vdpa_set_vq_state(struct vdpa_device *vdev, u16 idx,
>  		return -EINVAL;
>  	}
>  
> -	mvq->used_idx = state->avail_index;
> -	mvq->avail_idx = state->avail_index;
> +	mvq->used_idx = state->split.avail_index;
> +	mvq->avail_idx = state->split.avail_index;
>  	return 0;
>  }
>  
> @@ -1449,7 +1449,7 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device *vdev, u16 idx, struct vdpa
>  		 * Since both values should be identical, we take the value of
>  		 * used_idx which is reported correctly.
>  		 */
> -		state->avail_index = mvq->used_idx;
> +		state->split.avail_index = mvq->used_idx;
>  		return 0;
>  	}
>  
> @@ -1458,7 +1458,7 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device *vdev, u16 idx, struct vdpa
>  		mlx5_vdpa_warn(mvdev, "failed to query virtqueue\n");
>  		return err;
>  	}
> -	state->avail_index = attr.used_index;
> +	state->split.avail_index = attr.used_index;
>  	return 0;
>  }
>  
> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> index 98f793bc9376..14e024de5cbf 100644
> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
> @@ -374,7 +374,7 @@ static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx,
>  	struct vringh *vrh = &vq->vring;
>  
>  	spin_lock(&vdpasim->lock);
> -	vrh->last_avail_idx = state->avail_index;
> +	vrh->last_avail_idx = state->split.avail_index;
>  	spin_unlock(&vdpasim->lock);
>  
>  	return 0;
> @@ -387,7 +387,7 @@ static int vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
>  	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
>  	struct vringh *vrh = &vq->vring;
>  
> -	state->avail_index = vrh->last_avail_idx;
> +	state->split.avail_index = vrh->last_avail_idx;
>  	return 0;
>  }
>  
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index fb41db3da611..210ab35a7ebf 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -383,7 +383,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
>  		if (r)
>  			return r;
>  
> -		vq->last_avail_idx = vq_state.avail_index;
> +		vq->last_avail_idx = vq_state.split.avail_index;
>  		break;
>  	}
>  
> @@ -401,7 +401,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
>  		break;
>  
>  	case VHOST_SET_VRING_BASE:
> -		vq_state.avail_index = vq->last_avail_idx;
> +		vq_state.split.avail_index = vq->last_avail_idx;
>  		if (ops->set_vq_state(vdpa, idx, &vq_state))
>  			r = -EINVAL;
>  		break;
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index f311d227aa1b..3357ac98878d 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -28,13 +28,34 @@ struct vdpa_notification_area {
>  };
>  
>  /**
> - * struct vdpa_vq_state - vDPA vq_state definition
> + * struct vdpa_vq_state_split - vDPA split virtqueue state
>   * @avail_index: available index
>   */
> -struct vdpa_vq_state {
> +struct vdpa_vq_state_split {
>  	u16	avail_index;
>  };
>  
> +/**
> + * struct vdpa_vq_state_packed - vDPA packed virtqueue state
> + * @last_avail_counter: last driver ring wrap counter observed by device
> + * @last_avail_idx: device available index
> + * @last_used_counter: device ring wrap counter
> + * @last_used_idx: used index
> + */
> +struct vdpa_vq_state_packed {
> +        u16	last_avail_counter:1;
> +        u16	last_avail_idx:15;
> +        u16	last_used_counter:1;
> +        u16	last_used_idx:15;
> +};
> +
> +struct vdpa_vq_state {
> +     union {
> +          struct vdpa_vq_state_split split;
> +          struct vdpa_vq_state_packed packed;
> +     };
> +};
> +
>  struct vdpa_mgmt_dev;
>  
>  /**
> -- 
> 2.25.1
>