Re: [PATCH v5 4/6] vhost-vdpa: add support for configure interrupt

[Jason Wang]

在 2021/4/8 下午5:38, Cindy Lu 写道:
> Add support for configure interrupt. Set the notifier's fd to
> the kernel driver when vdpa start. also set -1 while vdpa stop.
> then the kernel will release the related resource
>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>   hw/virtio/vhost-vdpa.c | 26 +++++++++++++++++++++++++-
>   1 file changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 9ba2a2bed4..7825366f64 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -467,11 +467,33 @@ static int vhost_vdpa_get_config(struct vhost_dev *dev, 
> uint8_t *config,
>       }
>       return ret;
>    }
> -


Let's keep this blank line.


> +static void vhost_vdpa_config_notify_start(struct vhost_dev *dev,
> +                                struct VirtIODevice *vdev, bool start)
> +{
> +    int fd = 0;
> +    int r = 0;
> +    if (!(dev->features & (0x1ULL << VIRTIO_NET_F_STATUS))) {
> +        return;
> +    }
> +    if (start) {
> +        fd = event_notifier_get_fd(&vdev->config_notifier);
> +        r = dev->vhost_ops->vhost_set_config_call(dev, &fd);


So you introduce a general vhost ops but it's call by devic specific 
code (vhost-vdpa).

Any reason that we don't do that in vhost_dev_start/vhost_dev_stop?

Thanks


> +        if (!r) {
> +            vdev->use_config_notifier = true;
> +            event_notifier_set(&vdev->config_notifier);
> +        }
> +    } else {
> +        fd = -1;
> +        vdev->use_config_notifier = false;
> +        r = dev->vhost_ops->vhost_set_config_call(dev, &fd);
> +    }
> +    return;
> +}
>   static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>   {
>       struct vhost_vdpa *v = dev->opaque;
>       trace_vhost_vdpa_dev_start(dev, started);
> +    VirtIODevice *vdev = dev->vdev;
>       if (started) {
>           uint8_t status = 0;
>           memory_listener_register(&v->listener, &address_space_memory);
> @@ -479,8 +501,10 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, 
> bool started)
>           vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>           vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
>   
> +        vhost_vdpa_config_notify_start(dev, vdev, true);
>           return !(status & VIRTIO_CONFIG_S_DRIVER_OK);
>       } else {
> +        vhost_vdpa_config_notify_start(dev, vdev, false);
>           vhost_vdpa_reset_device(dev);
>           vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>                                      VIRTIO_CONFIG_S_DRIVER);