Re: [PATCH v3 5/5] arm/dom0less: introduce Kconfig for dom0less feature

[Michal Orzel <michal.orzel@xxxxxxx>]

Hi Luca,

On 09/11/2023 10:06, Luca Fancellu wrote:
> 
> 
> Introduce a Kconfig for the dom0less feature, enabled by default,
> to be able to choose if the feature should be compiled or not.
> 
> Provide static inline stubs when the option is disabled for the
> functions externally visible.
> 
> Use the new Kconfig to remove dom0less DT binding from the efi-boot.h
> code when the Kconfig is not enabled, do the same for
> allocate_bank_memory inside domain_build.c that currently is used
> only by dom0less-build.c module, but it's kept there provisioning
> its usage by dom0 code.
> 
> Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
> ---
> Changes from v2:
>  - protect allocate_bank_memory with the new Kconfig
> ---
>  xen/arch/arm/Kconfig                      |  9 +++++++++
>  xen/arch/arm/Makefile                     |  2 +-
>  xen/arch/arm/domain_build.c               |  2 ++
>  xen/arch/arm/efi/efi-boot.h               |  4 ++++
>  xen/arch/arm/include/asm/dom0less-build.h | 12 ++++++++++++
>  xen/arch/arm/include/asm/domain_build.h   |  2 ++
>  6 files changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index 0045a3762d86..0399f2faf734 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -88,6 +88,15 @@ config GICV2
>           Driver for the ARM Generic Interrupt Controller v2.
>           If unsure, say Y
> 
> +config DOM0LESS_BOOT
> +       bool "Dom0less boot support" if EXPERT
> +       depends on ARM
You're in the Arm Kconfig, so there should be no need for this dependency (it 
is implicit).

Apart from that, we have 2 features: static mem and static shmem that are only 
meant for dom0less domUs.
Shouldn't we make them dependent on DOM0LESS_BOOT? Otherwise, what is the 
purpose of selecting them
with DOM0LESS_BOOT=n?

~Michal