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

Commit Message

Denis Mukhin Feb. 17, 2025, 9:33 p.m. UTC

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 <[e-mail]>
Reviewed-by: Jan Beulich <[e-mail]>
---
Changes since v4:
- switched to checking build_id_len instead of build_id_p in print_build_id()
---
 xen/common/keyhandler.c    |  4 ++++
 xen/common/version.c       | 23 +++++++++++++++++++++--
 xen/drivers/char/console.c |  8 +++-----
 xen/include/xen/lib.h      |  3 +++
 4 files changed, 31 insertions(+), 7 deletions(-)

Comments

Jan Beulich Feb. 19, 2025, 1:41 p.m. UTC | #1

On 17.02.2025 22:33, [e-mail] 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 <[e-mail]>
> Reviewed-by: Jan Beulich <[e-mail]>

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

Patch

diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index 6ea54838d4..0bb842ec00 100644
--- 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();
+
     for ( i = 0; i < ARRAY_SIZE(key_table); i++ )
         if ( key_table[i].fn )
             printk(" key '%c' (ascii '%02x') => %s\n",
diff --git a/xen/common/version.c b/xen/common/version.c
index bc3714b45f..b20754dfad 100644
--- 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 */
 /*
  * Local variables:
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 07b14b7b3f..2e23910dfa 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -1020,14 +1020,12 @@  void __init console_init_preirq(void)
     nrspin_lock(&console_lock);
     __putstr(xen_banner());
     nrspin_unlock(&console_lock);
-    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());
+
+    print_version();
 
     /* Locate and print the buildid, if applicable. */
     xen_build_init();
+    print_build_id();
 
     if ( opt_sync_console )
     {
diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 81b722ea3e..686899a63e 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -47,6 +47,9 @@  int parse_signed_integer(const char *name, const char *s, const char *e,
  */
 int cmdline_strcmp(const char *frag, const char *name);
 
+void print_version(void);
+void print_build_id(void);
+
 #ifdef CONFIG_DEBUG_TRACE
 extern void debugtrace_dump(void);
 extern void debugtrace_printk(const char *fmt, ...)