Re: [net-next v2 1/1] virtual-bus: Implementation of Virtual Bus

[Jason Wang <jasowang@redhat.com>]

On 2019/11/18 下午3:48, Greg KH wrote:
> +Virtbus drivers
> +~~~~~~~~~~~~~~~
> +Virtbus drivers register with the virtual bus to be matched with virtbus
> +devices.  They expect to be registered with a probe and remove callback,
> +and also support shutdown, suspend, and resume callbacks.  They otherwise
> +follow the standard driver behavior of having discovery and enumeration
> +handled in the bus infrastructure.
> +
> +Virtbus drivers register themselves with the API entry point virtbus_drv_reg
> +and unregister with virtbus_drv_unreg.
> +
> +Device Enumeration
> +~~~~~~~~~~~~~~~~~~
> +Enumeration is handled automatically by the bus infrastructure via the
> +ida_simple methods.
> +
> +Device naming and driver binding
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +The virtbus_device.dev.name is the canonical name for the device. It is
> +built from two other parts:
> +
> +        - virtbus_device.name (also used for matching).
> +        - virtbus_device.id (generated automatically from ida_simple calls)
> +
> +This allows for multiple virtbus_devices with the same name, which will all
> +be matched to the same virtbus_driver. Driver binding is performed by the
> +driver core, invoking driver probe() after finding a match between device and driver.
> +
> +Virtual Bus API entry points
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +struct virtbus_device *virtbus_dev_alloc(const char *name, void *data)


Hi:

Several questions about the name parameter here:

- If we want to have multiple types of device to be attached, some 
convention is needed to avoid confusion during the match. But if we had 
such one (e.g prefix or suffix), it basically another bus?
- Who decides the name of this virtbus dev, is it under the control of 
userspace? If yes, a management interface is required.

Thanks


> +int virtbus_dev_register(struct virtbus_device *vdev)
> +void virtbus_dev_unregister(struct virtbus_device *vdev)
> +int virtbus_drv_register(struct virtbus_driver *vdrv, struct module *owner)
> +void virtbus_drv_unregister(struct virtbus_driver *vdrv)