Re: [PATCH] xen: Add macro for version number string

[Jan Beulich <jbeulich@xxxxxxxx>]

On 07.09.2022 14:04, Leo Yan wrote:
> On Arm64 Linux kernel prints log for Xen version number:
> 
>   Xen XEN_VERSION.XEN_SUBVERSION support found
> 
> The header file "xen/compile.h" is missed so that XEN_VERSION and
> XEN_SUBVERSION are not defined, __stringify() wrongly converts them as
> strings and concatenate to string "XEN_VERSION.XEN_SUBVERSION".
> 
> This patch introduces a string macro XEN_VERSION_STRING, we can directly
> use it as version number string, as a result it drops to use of
> __stringify() to make the code more readable.
> 
> The change has been tested on Ampere AVA Arm64 platform.
> 
> Fixes: 5d797ee199b3 ("xen/arm: split domain_build.c")
> Suggested-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
with perhaps a small adjustment (but it'll be the Arm maintainers to judge):

> @@ -91,7 +92,7 @@ static int __init acpi_make_hypervisor_node(const struct 
> kernel_info *kinfo,
>                                              struct membank tbl_add[])
>  {
>      const char compat[] =
> -        "xen,xen-"__stringify(XEN_VERSION)"."__stringify(XEN_SUBVERSION)"\0"
> +        "xen,xen-"XEN_VERSION_STRING"\0"

I think readability would benefit here from adding blanks around
XEN_VERSION_STRING here and ...

> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -1367,7 +1367,7 @@ static int __init make_hypervisor_node(struct domain *d,
>                                         int addrcells, int sizecells)
>  {
>      const char compat[] =
> -        "xen,xen-"__stringify(XEN_VERSION)"."__stringify(XEN_SUBVERSION)"\0"
> +        "xen,xen-"XEN_VERSION_STRING"\0"

... here (as an aside I wonder why these variables aren't static
__initconst), just like ...

> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -1341,8 +1341,8 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
> *SystemTable)
>              efi_console_set_mode();
>      }
>  
> -    PrintStr(L"Xen " __stringify(XEN_VERSION) "." __stringify(XEN_SUBVERSION)
> -             XEN_EXTRAVERSION " (c/s " XEN_CHANGESET ") EFI loader\r\n");
> +    PrintStr(L"Xen " XEN_VERSION_STRING XEN_EXTRAVERSION
> +          " (c/s " XEN_CHANGESET ") EFI loader\r\n");

... it is here in particular for XEN_CHANGESET.

The other general remark I have: Please follow patch submission guidelines
and send To: the list with maintainers on Cc:.

Jan