Re: [PATCH 05/40] vdpa: populate desc_group from net_vhost_vdpa_init

[Jason Wang]

On Fri, Dec 8, 2023 at 2:50 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>
> Add the desc_group field to struct vhost_vdpa, and get it
> populated when the corresponding vq is initialized at
> net_vhost_vdpa_init. If the vq does not have descriptor
> group capability, or it doesn't have a dedicated ASID
> group to host descriptors other than the data buffers,
> desc_group will be set to a negative value -1.
>
> Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
> ---
>  include/hw/virtio/vhost-vdpa.h |  1 +
>  net/vhost-vdpa.c               | 15 +++++++++++++--
>  2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> index 6533ad2..63493ff 100644
> --- a/include/hw/virtio/vhost-vdpa.h
> +++ b/include/hw/virtio/vhost-vdpa.h
> @@ -87,6 +87,7 @@ typedef struct vhost_vdpa {
>      Error *migration_blocker;
>      VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
>      IOMMUNotifier n;
> +    int64_t desc_group;
>  } VhostVDPA;
>
>  int vhost_vdpa_get_iova_range(int fd, struct vhost_vdpa_iova_range 
> *iova_range);
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index cb5705d..1a738b2 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -1855,11 +1855,22 @@ static NetClientState 
> *net_vhost_vdpa_init(NetClientState *peer,
>
>      ret = vhost_vdpa_add(nc, (void *)&s->vhost_vdpa, queue_pair_index, nvqs);
>      if (ret) {
> -        qemu_del_net_client(nc);
> -        return NULL;
> +        goto err;

This part of introducing the "err" label looks more like a cleanup.

Others look good.

Thanks

>      }
>
> +    if (is_datapath) {
> +        ret = vhost_vdpa_probe_desc_group(vdpa_device_fd, features,
> +                                          0, &desc_group, errp);
> +        if (unlikely(ret < 0)) {
> +            goto err;
> +        }
> +    }
> +    s->vhost_vdpa.desc_group = desc_group;
>      return nc;
> +
> +err:
> +    qemu_del_net_client(nc);
> +    return NULL;
>  }
>
>  static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
> --
> 1.8.3.1
>