Re: [PATCH 20/37] xen: introduce CONFIG_EFI to stub API for non-EFI architecture

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 23 Sep 2021, Wei Chen wrote:
> Some architectures do not support EFI, but EFI API will be used
> in some common features. Instead of spreading #ifdef ARCH, we
> introduce this Kconfig option to give Xen the ability of stubing
> EFI API for non-EFI supported architectures.
> 
> Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
> ---
>  xen/arch/arm/Kconfig  |  1 +
>  xen/arch/arm/Makefile |  2 +-
>  xen/arch/x86/Kconfig  |  1 +
>  xen/common/Kconfig    | 11 +++++++++++
>  xen/include/xen/efi.h |  4 ++++
>  5 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index ecfa6822e4..865ad83a89 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -6,6 +6,7 @@ config ARM_64
>       def_bool y
>       depends on !ARM_32
>       select 64BIT
> +     select EFI
>       select HAS_FAST_MULTIPLY
>  
>  config ARM
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 3d3b97b5b4..ae4efbf76e 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -1,6 +1,6 @@
>  obj-$(CONFIG_ARM_32) += arm32/
>  obj-$(CONFIG_ARM_64) += arm64/
> -obj-$(CONFIG_ARM_64) += efi/
> +obj-$(CONFIG_EFI) += efi/
>  obj-$(CONFIG_ACPI) += acpi/
>  ifneq ($(CONFIG_NO_PLAT),y)
>  obj-y += platforms/
> diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
> index 28d13b9705..b9ed187f6b 100644
> --- a/xen/arch/x86/Kconfig
> +++ b/xen/arch/x86/Kconfig
> @@ -10,6 +10,7 @@ config X86
>       select ALTERNATIVE_CALL
>       select ARCH_SUPPORTS_INT128
>       select CORE_PARKING
> +     select EFI
>       select HAS_ALTERNATIVE
>       select HAS_COMPAT
>       select HAS_CPUFREQ
> diff --git a/xen/common/Kconfig b/xen/common/Kconfig
> index 9ebb1c239b..f998746a1a 100644
> --- a/xen/common/Kconfig
> +++ b/xen/common/Kconfig
> @@ -11,6 +11,16 @@ config COMPAT
>  config CORE_PARKING
>       bool
>  
> +config EFI
> +     bool

Without the title the option is not user-selectable (or de-selectable).
So the help message below can never be seen.

Either add a title, e.g.:

bool "EFI support"

Or fully make the option a silent option by removing the help text.



> +     ---help---
> +      This option provides support for runtime services provided
> +      by UEFI firmware (such as non-volatile variables, realtime
> +      clock, and platform reset). A UEFI stub is also provided to
> +      allow the kernel to be booted as an EFI application. This
> +      is only useful for kernels that may run on systems that have
> +      UEFI firmware.
> +
>  config GRANT_TABLE
>       bool "Grant table support" if EXPERT
>       default y
> @@ -196,6 +206,7 @@ config KEXEC
>  
>  config EFI_SET_VIRTUAL_ADDRESS_MAP
>      bool "EFI: call SetVirtualAddressMap()" if EXPERT
> +    depends on EFI
>      ---help---
>        Call EFI SetVirtualAddressMap() runtime service to setup memory map for
>        further runtime services. According to UEFI spec, it isn't strictly
> diff --git a/xen/include/xen/efi.h b/xen/include/xen/efi.h
> index 94a7e547f9..661a48286a 100644
> --- a/xen/include/xen/efi.h
> +++ b/xen/include/xen/efi.h
> @@ -25,6 +25,8 @@ extern struct efi efi;
>  
>  #ifndef __ASSEMBLY__
>  
> +#ifdef CONFIG_EFI
> +
>  union xenpf_efi_info;
>  union compat_pf_efi_info;
>  
> @@ -45,6 +47,8 @@ int efi_runtime_call(struct xenpf_efi_runtime_call *);
>  int efi_compat_get_info(uint32_t idx, union compat_pf_efi_info *);
>  int efi_compat_runtime_call(struct compat_pf_efi_runtime_call *);
>  
> +#endif /* CONFIG_EFI*/
> +
>  #endif /* !__ASSEMBLY__ */
>  
>  #endif /* __XEN_EFI_H__ */
> -- 
> 2.25.1
>