Re: Smarter Kconfig help

Russell King - ARM Linux admin
2019-03-06T12:50:34Z

Hi Mark,

On Wed, Mar 06, 2019 at 09:35:21AM +0000, Mark Rutland wrote:
> On Tue, Mar 05, 2019 at 05:31:12PM +0000, Russell King - ARM Linux admin wrote:
> > Guys,
>
> Hi Russell,
>
> > We need to be smarter when writing Kconfig help. I'm just going
> > through updating my build trees with the results of 5.0 development,
> > and a number of the help texts are next to useless. For example,
> >
> > PVPANIC - is this something that should be enabled for a host or
> > guest kernel? Answer: you have to read the driver code to find out.
>
> When I looked at the help text:
>
> This driver provides support for the pvpanic device. pvpanic is
> a paravirtualized device provided by QEMU; it lets a virtual machine
> (guest) communicate panic events to the host.
>
> ... it seemed clear to me that this was for a guest, given the text says
> QEMU provides the device. I guess you read that as meaning QEMU asks the
> host kernel to provide the device to the guest?

Yes - that's exactly where the confusion was. It could be something
like a tap network device to allow a guest access to a facility on the
host, or it could be something that the guest kernel uses to communicate
with its host environment.

> Do you have a suggestion for how to word that unambiguously?

It used to be normal to include a sugestion in the help text that
guided when an option should be enabled. So, adding something like:

"Say Y here if you are building a kernel for a virtual machine."

would make it clear. This used to be standard throughout the kernel,
but it seems in recent years, this has been omitted.