Re: [PATCH v4 1/2] Revert "vhost-user: fix lost reconnect"

[Raphael Norwitz]

On Wed, May 15, 2024 at 10:58 PM Li Feng <fengli@smartx.com> wrote:
>
> This reverts commit f02a4b8e6431598612466f76aac64ab492849abf.
>
> Since the current patch cannot completely fix the lost reconnect
> problem, there is a scenario that is not considered:
> - When the virtio-blk driver is removed from the guest os,
>   s->connected has no chance to be set to false, resulting in
>   subsequent reconnection not being executed.
>
> The next patch will completely fix this issue with a better approach.
>

Reviewed-by: Raphael Norwitz <raphael@enfabrica.net>

> Signed-off-by: Li Feng <fengli@smartx.com>
> ---
>  hw/block/vhost-user-blk.c      |  2 +-
>  hw/scsi/vhost-user-scsi.c      |  3 +--
>  hw/virtio/vhost-user-base.c    |  2 +-
>  hw/virtio/vhost-user.c         | 10 ++--------
>  include/hw/virtio/vhost-user.h |  3 +--
>  5 files changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> index 9e6bbc6950..41d1ac3a5a 100644
> --- a/hw/block/vhost-user-blk.c
> +++ b/hw/block/vhost-user-blk.c
> @@ -384,7 +384,7 @@ static void vhost_user_blk_event(void *opaque, 
> QEMUChrEvent event)
>      case CHR_EVENT_CLOSED:
>          /* defer close until later to avoid circular close */
>          vhost_user_async_close(dev, &s->chardev, &s->dev,
> -                               vhost_user_blk_disconnect, 
> vhost_user_blk_event);
> +                               vhost_user_blk_disconnect);
>          break;
>      case CHR_EVENT_BREAK:
>      case CHR_EVENT_MUX_IN:
> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> index a63b1f4948..48a59e020e 100644
> --- a/hw/scsi/vhost-user-scsi.c
> +++ b/hw/scsi/vhost-user-scsi.c
> @@ -214,8 +214,7 @@ static void vhost_user_scsi_event(void *opaque, 
> QEMUChrEvent event)
>      case CHR_EVENT_CLOSED:
>          /* defer close until later to avoid circular close */
>          vhost_user_async_close(dev, &vs->conf.chardev, &vsc->dev,
> -                               vhost_user_scsi_disconnect,
> -                               vhost_user_scsi_event);
> +                               vhost_user_scsi_disconnect);
>          break;
>      case CHR_EVENT_BREAK:
>      case CHR_EVENT_MUX_IN:
> diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c
> index a83167191e..4b54255682 100644
> --- a/hw/virtio/vhost-user-base.c
> +++ b/hw/virtio/vhost-user-base.c
> @@ -254,7 +254,7 @@ static void vub_event(void *opaque, QEMUChrEvent event)
>      case CHR_EVENT_CLOSED:
>          /* defer close until later to avoid circular close */
>          vhost_user_async_close(dev, &vub->chardev, &vub->vhost_dev,
> -                               vub_disconnect, vub_event);
> +                               vub_disconnect);
>          break;
>      case CHR_EVENT_BREAK:
>      case CHR_EVENT_MUX_IN:
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index cdf9af4a4b..c929097e87 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -2776,7 +2776,6 @@ typedef struct {
>      DeviceState *dev;
>      CharBackend *cd;
>      struct vhost_dev *vhost;
> -    IOEventHandler *event_cb;
>  } VhostAsyncCallback;
>
>  static void vhost_user_async_close_bh(void *opaque)
> @@ -2791,10 +2790,7 @@ static void vhost_user_async_close_bh(void *opaque)
>       */
>      if (vhost->vdev) {
>          data->cb(data->dev);
> -    } else if (data->event_cb) {
> -        qemu_chr_fe_set_handlers(data->cd, NULL, NULL, data->event_cb,
> -                                 NULL, data->dev, NULL, true);
> -   }
> +    }
>
>      g_free(data);
>  }
> @@ -2806,8 +2802,7 @@ static void vhost_user_async_close_bh(void *opaque)
>   */
>  void vhost_user_async_close(DeviceState *d,
>                              CharBackend *chardev, struct vhost_dev *vhost,
> -                            vu_async_close_fn cb,
> -                            IOEventHandler *event_cb)
> +                            vu_async_close_fn cb)
>  {
>      if (!runstate_check(RUN_STATE_SHUTDOWN)) {
>          /*
> @@ -2823,7 +2818,6 @@ void vhost_user_async_close(DeviceState *d,
>          data->dev = d;
>          data->cd = chardev;
>          data->vhost = vhost;
> -        data->event_cb = event_cb;
>
>          /* Disable any further notifications on the chardev */
>          qemu_chr_fe_set_handlers(chardev,
> diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
> index d7c09ffd34..324cd8663a 100644
> --- a/include/hw/virtio/vhost-user.h
> +++ b/include/hw/virtio/vhost-user.h
> @@ -108,7 +108,6 @@ typedef void (*vu_async_close_fn)(DeviceState *cb);
>
>  void vhost_user_async_close(DeviceState *d,
>                              CharBackend *chardev, struct vhost_dev *vhost,
> -                            vu_async_close_fn cb,
> -                            IOEventHandler *event_cb);
> +                            vu_async_close_fn cb);
>
>  #endif
> --
> 2.45.0
>