Re: [PATCH 1/5] xen: add "not_essential" flag to struct xenbus_driver

[Andrew Cooper]

On 22/10/2021 07:47, Juergen Gross wrote:
> When booting the xenbus driver will wait for PV devices to have
> connected to their backends before continuing. The timeout is different
> between essential and non-essential devices.
>
> Non-essential devices are identified by their nodenames directly in the
> xenbus driver, which requires to update this list in case a new device
> type being non-essential is added (this was missed for several types
> in the past).
>
> In order to avoid this problem, add a "not_essential" flag to struct
> xenbus_driver which can be set to "true" by the respective frontend.
>
> Set this flag for the frontends currently regarded to be not essential
> (vkbs and vfb) and use it for testing in the xenbus driver.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Wouldn't it be better to annotate essential?  That way, when new misc
drivers come along, they don't by default block boot.

~Andrew