Re: [PATCH] vfio: mlx5, pds: add IOMMU_SUPPORT dependency

[Joao Martins <joao.m.martins@oracle.com>]

On 23/10/2023 14:12, Jason Gunthorpe wrote:
> On Mon, Oct 23, 2023 at 01:37:28PM +0100, Joao Martins wrote:
> 
>> iommufd Kconfig is only included in the IOMMU_SUPPORT kconfig if clause; so
>> moving it out from the iommufd kconfig out into iommu kconfig should fix it.
>> Didn't realize that one can select IOMMU_API yet have IOMMU_SUPPORT unset/unmet.
>> I'll make the move in v6
> 
> I think this is some cruft that accumulated over the years, it doesn't
> make alot of sense that there are two kconfigs now..

To be specific what I meant to move is the IOMMUFD_DRIVER kconfig part, not the
whole iommufd Kconfig [in the patch introducing the problem] e.g.

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 2b12b583ef4b..5cc869db1b79 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -7,6 +7,10 @@ config IOMMU_IOVA
 config IOMMU_API
        bool

+config IOMMUFD_DRIVER
+       bool
+       default n
+
 menuconfig IOMMU_SUPPORT
        bool "IOMMU Hardware Support"
        depends on MMU
diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig
index 1fa543204e89..99d4b075df49 100644
--- a/drivers/iommu/iommufd/Kconfig
+++ b/drivers/iommu/iommufd/Kconfig
@@ -11,10 +11,6 @@ config IOMMUFD

          If you don't know what to do here, say N.

-config IOMMUFD_DRIVER
-       bool
-       default n
-
 if IOMMUFD
 config IOMMUFD_VFIO_CONTAINER
        bool "IOMMUFD provides the VFIO container /dev/vfio/vfio"

(...) or in alternative, do similar to this patch except that it's:

	select IOMMUFD_DRIVER if IOMMU_SUPPORT

In the mlx5/pds vfio drivers.

Perhaps the merging of IOMMU_API with IOMMU_SUPPORT should be best done separately?

	Joao