Re: [PATCH] vfio: Fix build break when SPAPR_TCE_IOMMU=n

[Michael Ellerman <mpe@ellerman.id.au>]

Michael Ellerman <mpe@ellerman.id.au> writes:

> Currently the kconfig logic for VFIO_IOMMU_SPAPR_TCE and VFIO_SPAPR_EEH
> is broken when SPAPR_TCE_IOMMU=n. Leading to:
>
>     warning: (VFIO) selects VFIO_IOMMU_SPAPR_TCE which has unmet direct dependencies (VFIO && SPAPR_TCE_IOMMU)
>     warning: (VFIO) selects VFIO_IOMMU_SPAPR_TCE which has unmet direct dependencies (VFIO && SPAPR_TCE_IOMMU)
>     drivers/vfio/vfio_iommu_spapr_tce.c:113:8: error: implicit declaration of function 'mm_iommu_find'
>
> This stems from the fact that VFIO selects VFIO_IOMMU_SPAPR_TCE, and
> although it has an if clause, the condition is not correct.
>
> We could fix it by doing select VFIO_IOMMU_SPAPR_TCE if SPAPR_TCE_IOMMU,
> but the cleaner fix is to drop the selects and tie VFIO_IOMMU_SPAPR_TCE
> to the value of VFIO, and express the dependencies in only once place.
>
> Do the same for VFIO_SPAPR_EEH.
>
> The end result is that the values of VFIO_IOMMU_SPAPR_TCE and
> VFIO_SPAPR_EEH follow the value of VFIO, except when SPAPR_TCE_IOMMU=n
> and/or EEH=n. Which is exactly what we want to happen.

Ping?

There was a bit of discussion on this patch but I think we decided it
was correct in the end.

cheers