Re: [PATCH RFC PREVIEW 2/6] iommu: Make IOMMU_IOPF selectable in Kconfig

[Jason Gunthorpe <jgg@ziepe.ca>]

On Mon, Aug 26, 2024 at 01:40:28PM +0200, Klaus Jensen wrote:
> From: Joel Granados <j.granados@samsung.com>
> 
> IOMMU_IOPF is no longer selectable through INTEL_IOMMU_SVM effectively
> severing their relation and allowing them to be used independently.
> 
> Signed-off-by: Joel Granados <j.granados@samsung.com>
> ---
>  drivers/iommu/Kconfig       | 2 +-
>  drivers/iommu/intel/Kconfig | 1 -
>  2 files changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index a82f10054aec..d3ee8a0ad4a6 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -164,7 +164,7 @@ config IOMMU_SVA
>  	bool
>  
>  config IOMMU_IOPF
> -	bool
> +	bool "Enable IO page fault in IOMMU"


Currently IOMMU_IOPF indicates that the driver wants to consume the
library functions around IOPF, it is not a user selectable because any
driver that links to those functions should have them working. If you
want to make the core driver use them then the select should be moved
from the SVM sub config to the core driver config.

If you want to change IOMMU_IOPF to a user configurable then it should
have a full help text and all the kconfig places touching it should be
turned into

  depends IOMMU_IOPF

Ie you can't enable any drivers SVA kconfig without also picking
IOMMU_IOPF.

This is doing neither fully.. Pick one :)

Jason