Re: [RFC PATCH v4 09/20] vdpa: Save call_fd in vhost-vdpa

[Jason Wang]

在 2021/10/1 下午3:05, Eugenio Pérez 写道:
> We need to know it to switch to Shadow VirtQueue.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>   include/hw/virtio/vhost-vdpa.h | 2 ++
>   hw/virtio/vhost-vdpa.c         | 5 +++++
>   2 files changed, 7 insertions(+)
>
> diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
> index 48aae59d8e..fddac248b3 100644
> --- a/include/hw/virtio/vhost-vdpa.h
> +++ b/include/hw/virtio/vhost-vdpa.h
> @@ -30,6 +30,8 @@ typedef struct vhost_vdpa {
>       GPtrArray *shadow_vqs;
>       struct vhost_dev *dev;
>       QLIST_ENTRY(vhost_vdpa) entry;
> +    /* File descriptor the device uses to call VM/SVQ */
> +    int call_fd[VIRTIO_QUEUE_MAX];


Any reason we don't do this for kick_fd or why 
virtio_queue_get_guest_notifier() can't work here? Need a comment or 
commit log.

I think we need to have a consistent way to handle both kick and call fd.

Thanks


>       VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
>   } VhostVDPA;
>   
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 36c954a779..57a857444a 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -652,7 +652,12 @@ static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
>   static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
>                                          struct vhost_vring_file *file)
>   {
> +    struct vhost_vdpa *v = dev->opaque;
> +    int vdpa_idx = vhost_vdpa_get_vq_index(dev, file->index);
> +
>       trace_vhost_vdpa_set_vring_call(dev, file->index, file->fd);
> +
> +    v->call_fd[vdpa_idx] = file->fd;
>       return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
>   }
>