Re: [PATCH v5] xen/console: print Xen version via keyhandler

[Jan Beulich <jbeulich@xxxxxxxx>]

On 17.02.2025 22:33, dmkhn@xxxxxxxxx wrote:
> Add Xen version printout to 'h' keyhandler output.
> 
> That is useful for debugging systems that have been left intact for a long
> time.
> 
> Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

Hmm, wait - there's yet another issue:

> --- a/xen/common/keyhandler.c
> +++ b/xen/common/keyhandler.c
> @@ -129,6 +129,10 @@ static void cf_check show_handlers(unsigned char key)
>      unsigned int i;
>  
>      printk("'%c' pressed -> showing installed handlers\n", key);
> +
> +    print_version();
> +    print_build_id();

Here and in console_init_preirq() you expect to be able to call the two
functions, no matter what the tool chain. Then ...

> --- a/xen/common/version.c
> +++ b/xen/common/version.c
> @@ -210,9 +210,28 @@ void __init xen_build_init(void)
>          }
>      }
>  #endif /* CONFIG_X86 */
> -    if ( !rc )
> -        printk(XENLOG_INFO "build-id: %*phN\n", build_id_len, build_id_p);
>  }
> +
> +void print_version(void)
> +{
> +    printk("Xen version %d.%d%s (%s@%s) (%s) %s %s\n",
> +           xen_major_version(), xen_minor_version(), xen_extra_version(),
> +           xen_compile_by(), xen_compile_domain(), xen_compiler(),
> +           xen_build_info(), xen_compile_date());
> +
> +    printk("Latest ChangeSet: %s\n", xen_changeset());
> +}
> +
> +void print_build_id(void)
> +{
> +    /*
> +     * NB: build_id_len may be 0 if XEN_HAS_BUILD_ID=n.
> +     * Do not print empty build-id.
> +     */
> +    if ( build_id_len )
> +        printk("build-id: %*phN\n", build_id_len, build_id_p);
> +}
> +
>  #endif /* BUILD_ID */

... their definitions cannot be inside an #ifdef. They want to move up:
- print_build_id() between xen_build_id() and the #ifdef BUILD_ID,
- print_version() yet higher up, perhaps after xen_build_info().
I guess I can do so while committing.

Jan