Re: [PATCH v2 21/35] xen/console: introduce console_init_owner()

[Denis Mukhin <dmkhn@xxxxxxxxx>]

On Thursday, December 12th, 2024 at 2:23 AM, Roger Pau Monné 
<roger.pau@xxxxxxxxxx> wrote:

>
>
> On Thu, Dec 05, 2024 at 08:41:51PM -0800, Denis Mukhin via B4 Relay wrote:
>
> > From: Denis Mukhin dmukhin@xxxxxxxx
> >
> > console_init_owner() is introduced for selecting the boot-time console 
> > owner.
> >
> > Signed-off-by: Denis Mukhin dmukhin@xxxxxxxx
> > ---
> > xen/drivers/char/console.c | 27 +++++++++++++++++----------
> > 1 file changed, 17 insertions(+), 10 deletions(-)
> >
> > diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
> > index 
> > a8ab5c2bcb98e4cadf9ad2c9ad28d297977d0557..6261bdb5a2ac1075bc89fa408c0fd6cfef380ae6
> >  100644
> > --- a/xen/drivers/char/console.c
> > +++ b/xen/drivers/char/console.c
> > @@ -554,6 +554,22 @@ static void console_find_owner(void)
> > console_set_owner(DOMID_XEN);
> > }
> >
> > +static void console_init_owner(void)
>
>
> __init attribute missing (given current call context), but see below.
>
> > +{
> > + domid_t domid;
> > +
> > + /*
> > + * If user specifies so, we fool the switch routine to redirect input
> > + * straight back to Xen.
> > + */
> > + if ( opt_conswitch[1] == 'x' )
> > + domid = DOMID_XEN;
> > + else
> > + domid = get_initial_domain_id();
> > +
> > + console_set_owner(domid);
> > +}
> > +
> > static void __serial_rx(char c)
> > {
> > switch ( console_owner )
> > @@ -1143,14 +1159,6 @@ void __init console_endboot(void)
> >
> > video_endboot();
> >
> > - /*
> > - * If user specifies so, we fool the switch routine to redirect input
> > - * straight back to Xen. I use this convoluted method so we still print
> > - * a useful 'how to switch' message.
> > - */
> > - if ( opt_conswitch[1] == 'x' )
> > - console_owner = DOMID_XEN;
> > -
> > register_keyhandler('w', dump_console_ring_key,
> > "synchronously dump console ring buffer (dmesg)", 0);
> > register_irq_keyhandler('+', &do_inc_thresh,
> > @@ -1160,8 +1168,7 @@ void __init console_endboot(void)
> > register_irq_keyhandler('G', &do_toggle_guest,
> > "toggle host/guest log level adjustment", 0);
> >
> > - /* Serial input is directed to DOM0 by default. */
> > - console_find_owner();
> > + console_init_owner();
>
>
> Oh, so this is what fixes the regression introduced in patch 19/35.
> THB I'm not sure it's worth introducing the console_init_owner()
> helper if it's just for this usage. You could do:
>
> console_set_owner(opt_conswitch[1] == 'x' ? DOMID_XEN
> : get_initial_domain_id());

Right, thank you.
Addressed in v3.

>
> Thanks, Roger.