Re: [PATCH 4/4] vfio: Allow type-1 IOMMU instantiation with a virtio-iommu

[Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Wed, 14 Feb 2018 14:53:40 +0000
Jean-Philippe Brucker <jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org> wrote:

> When enabling both VFIO and VIRTIO_IOMMU modules, automatically select
> VFIO_IOMMU_TYPE1 as well.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org>
> ---
>  drivers/vfio/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> index c84333eb5eb5..65a1e691110c 100644
> --- a/drivers/vfio/Kconfig
> +++ b/drivers/vfio/Kconfig
> @@ -21,7 +21,7 @@ config VFIO_VIRQFD
>  menuconfig VFIO
>  	tristate "VFIO Non-Privileged userspace driver framework"
>  	depends on IOMMU_API
> -	select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM_SMMU || ARM_SMMU_V3)
> +	select VFIO_IOMMU_TYPE1 if (X86 || S390 || ARM_SMMU || ARM_SMMU_V3 || VIRTIO_IOMMU)
>  	select ANON_INODES
>  	help
>  	  VFIO provides a framework for secure userspace device drivers.

Why are we basing this on specific IOMMU drivers in the first place?
Only ARM is doing that.  Shouldn't IOMMU_API only be enabled for ARM
targets that support it and therefore we can forget about the specific
IOMMU drivers?  Thanks,

Alex