Re: [dpdk-dev] [PATCH 10/17] vhost: vring address setup for packed queues

[Tiwei Bie <tiwei.bie@intel.com>]

On Fri, Mar 16, 2018 at 04:21:13PM +0100, Jens Freimann wrote:
> From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> 
> Add code to set up packed queues when enabled.
> 
> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> Signed-off-by: Jens Freimann <jfreiman@redhat.com>
> ---
>  lib/librte_vhost/vhost.c      |  1 +
>  lib/librte_vhost/vhost.h      |  1 +
>  lib/librte_vhost/vhost_user.c | 17 ++++++++++++++++-
>  3 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index a407067..a300812 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -567,6 +567,7 @@ struct virtio_net *
>  		return -1;
>  	}
>  
> +

There is no need to add this blank line.

>  	dev->virtqueue[queue_id]->used->flags = VRING_USED_F_NO_NOTIFY;
>  	return 0;
>  }
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 06e973e..d35c4b1 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -70,6 +70,7 @@ struct batch_copy_elem {
>   */
>  struct vhost_virtqueue {
>  	struct vring_desc	*desc;
> +	struct vring_desc_packed   *desc_packed;
>  	struct vring_avail	*avail;
>  	struct vring_used	*used;

It's better to use union here.

> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 90ed211..bd1e393 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -415,6 +415,19 @@
>  	struct vhost_virtqueue *vq = dev->virtqueue[vq_index];
>  	struct vhost_vring_addr *addr = &vq->ring_addrs;
>  
> +	if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
> +		vq->desc_packed = (struct vring_desc_packed *) ring_addr_to_vva
> +			(dev, vq, addr->desc_user_addr, sizeof(vq->desc_packed));
> +		vq->desc = NULL;
> +		vq->avail = NULL;
> +		vq->used = NULL;
> +		vq->log_guest_addr = 0;
> +
> +		assert(vq->last_used_idx == 0);

As a library, we shouldn't crash the process.

Thanks