Re: [PATCH v5 13/13] xen/arm: mmu: enable SMMU subsystem only in MMU

[Julien Grall <julien@xxxxxxx>]

Hi,

On 14/08/2023 05:25, Henry Wang wrote:
> From: Penny Zheng <Penny.Zheng@xxxxxxx>
>
> SMMU subsystem is only supported in MMU system, so we make it dependent
> on CONFIG_HAS_MMU.
"only supported" as in it doesn't work with Xen or the HW is not 
supporting it?
Also, I am not entirely convinced that anything in passthrough would 
properly work with MPU. At least none of the IOMMU drivers are. So I 
would consider to completely disable HAS_PASSTHROUGH.
> Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
> Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
> Signed-off-by: Henry Wang <Henry.Wang@xxxxxxx>
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
> ---
> v5:
> - Add Acked-by tag from Jan.
> v4:
> - No change
> v3:
> - new patch
> ---
>   xen/drivers/passthrough/Kconfig | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/xen/drivers/passthrough/Kconfig b/xen/drivers/passthrough/Kconfig
> index 864fcf3b0c..ebb350bc37 100644
> --- a/xen/drivers/passthrough/Kconfig
> +++ b/xen/drivers/passthrough/Kconfig
> @@ -5,6 +5,7 @@ config HAS_PASSTHROUGH
>   if ARM
>   config ARM_SMMU
>         bool "ARM SMMUv1 and v2 driver"
> +       depends on MMU
>         default y
>         ---help---
>           Support for implementations of the ARM System MMU architecture
> @@ -15,7 +16,7 @@ config ARM_SMMU
>   
>   config ARM_SMMU_V3
>         bool "ARM Ltd. System MMU Version 3 (SMMUv3) Support" if EXPERT
> -       depends on ARM_64 && (!ACPI || BROKEN)
> +       depends on ARM_64 && (!ACPI || BROKEN) && MMU
>         ---help---
>          Support for implementations of the ARM System MMU architecture
>          version 3. Driver is in experimental stage and should not be used in
Cheers,

--
Julien Grall