Re: [PATCH v4 1/2] dt-bindings: microsoft: Add vmbus message-connection-id property

[Krzysztof Kozlowski <krzk@kernel.org>]

On Thu, Jun 19, 2025 at 04:06:34PM GMT, Hardik Garg wrote:
> Document the microsoft,message-connection-id property for VMBus DeviceTree
> node. This property allows specifying the connection ID used for

What is a connection ID and why it cannot be inferred from existing
system API?

> communication between host and guest.
> 
> Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
> ---
> v3: https://lore.kernel.org/all/6a92ca86-ad6b-4d49-af6e-1ed7651b8ab8@linux.microsoft.com
> v2: https://lore.kernel.org/all/096edaf7-cc90-42b6-aff4-c5f088574e1e@linux.microsoft.com
> v1: https://lore.kernel.org/all/6acee4bf-cb04-43b9-9476-e8d811d26dfd@linux.microsoft.com
> ---
>  Documentation/devicetree/bindings/bus/microsoft,vmbus.yaml | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/bus/microsoft,vmbus.yaml b/Documentation/devicetree/bindings/bus/microsoft,vmbus.yaml
> index 0bea4f5287ce..615b48bd6a8b 100644
> --- a/Documentation/devicetree/bindings/bus/microsoft,vmbus.yaml
> +++ b/Documentation/devicetree/bindings/bus/microsoft,vmbus.yaml
> @@ -17,6 +17,14 @@ properties:
>    compatible:
>      const: microsoft,vmbus

There's a reason why you have here generic property - this is generic
and/or discoverable and/or whatever software interface. Adding now more
properties, just because you made it generic, is not the way.

>  
> +  microsoft,message-connection-id:
> +    description: |

Drop |

> +      VMBus message connection ID to be used for communication between host and
> +      guest. If not specified, defaults to VMBUS_MESSAGE_CONNECTION_ID_4 (4) for
> +      protocol version VERSION_WIN10_V5 and above, or VMBUS_MESSAGE_CONNECTION_ID
> +      (1) for older versions.

Missing constraints, defaults, if this stays, but frankly speaking it
looks really not appropriate, considering lack of any explanation in the
binding or in commit msg.


Best regards,
Krzysztof