[Qemu-devel] Re: [PATCH] virtio-serial: don't set MULTIPORT for 1 port dev

[Amit Shah <amit.shah@redhat.com>]

On (Fri) Feb 12 2010 [15:42:14], Michael S. Tsirkin wrote:
> Since commit 98b19252cf1bd97c54bc4613f3537c5ec0aae263, all
> serial devices declare MULTIPORT feature.
> To allow 0.12 compatibility, we should clear this when
> max_nr_ports is 1.

In addition to this, setting max_nr_ports to 1 is needed when -M 0.12 is
selected.

However, is this the only way to do it? Gerd?

> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/virtio-serial-bus.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
> index ab456ea..d0e0219 100644
> --- a/hw/virtio-serial-bus.c
> +++ b/hw/virtio-serial-bus.c
> @@ -335,8 +335,10 @@ static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
>  
>  static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
>  {
> -    features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
> -
> +    VirtIOSerial *vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
> +    if (vser->bus->max_nr_ports > 1) {
> +        features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
> +    }
>      return features;
>  }
>  
> -- 
> 1.6.6.144.g5c3af

		Amit