Re: [PATCH v5] xen/common: add keyhandler to show Xen command line

[dmukhin@ford.com]

On Thu, Aug 13, 2026 at 08:00:11AM +0200, Jan Beulich wrote:
> On 13.08.2026 05:51, dmukhin@ford.com wrote:
> > From: Denis Mukhin <dmukhin@ford.com> 
> > 
> > Currently there's no way to print Xen command line on the emergency
> > console for debugging purposes when 'xl' is unavailable.
> > 
> > Add new keyhander '?' to do command line printout.
> > 
> > To allow built-in command printout, drop __initconst in
> > 'opt_builtin_cmdline' declaration.
> > 
> > Signed-off-by: Denis Mukhin <dmukhin@ford.com>
> > ---
> > Changes since v4:
> > - promote opt_builtin_cmdline to __ro_after_init and use it for
> >   built-in command line reporting
> > - account for empty saved_cmdline
> > - adjust register_keyhandler() call - use '?'
> 
> This isn't quite what I was expecting, following the feedback you got on
> v4. My expectation was that we'd see a 2-patch series, first patch moving
> non-help stuff out of the 'h' handler, second patch adding the dumping of
> the command line. Naturally the new handler then wouldn't be named
> show_cmdline(). I'd then further expect tat no new use of
> register_keyhandler() would be necessary: The handler itself would live
> in keyhandler.c, and print_version() would then be accompanied by a new
> print_cmdline().

I see, will update.

> 
> Jan
>