Re: [PATCH 12/12] vfio/pci: Introduce vfio_pci_core.ko

On Wed, Jul 28, 2021 at 07:43:06AM +0200, Christoph Hellwig wrote:

quoted

Which might reasonably be from an old kernel. 'make oldconfig' prompts:

VFIO Non-Privileged userspace driver framework (VFIO) [Y/n/m/?] y
  VFIO No-IOMMU support (VFIO_NOIOMMU) [Y/n/?] y
  VFIO support for PCI devices (VFIO_PCI_CORE) [N/m/y/?] (NEW) 

Which is completely fine, IMHO.

Why do we need to have VFIO_PCI_CORE as a user visible option?
I'd just select it.

I'm not great with kconfig, but AFAIK:

- It controls building a module so it needs to be a tristate

- tristates need to be exposed in the menu structure

- As it builds a module it also has depends on other things

- Select should not be used to target tristates

- Select should not be used to target options in the menu tree

- Select should not be used to target options that have depends

Which leaves us with this arrangement unless we delete the
vfio_pci_core.ko module - which seems like a bad direction just for
kconfig backwards compatibility.

Jason