[PATCH] xen/arm: allow console=hvc0 to be omitted for guests

[Stefano Stabellini]

On Tue, 10 Feb 2015, Ian Campbell wrote:
> On Tue, 2015-02-10 at 15:51 +0800, Ard Biesheuvel wrote:
> > > FWIW on x86 this doesn't depend on console_set_on_cmdline, does it need
> > > to here?
> > >
> > 
> > I didn't check the code, but it seems inappropriate to add a preferred
> > console implicitly if the user has set 'console=' on the command line.
> 
> I had been thinking that add_preferred_console would DTRT, but it seems
> not. Seems strange that most calls to it do not check if the console is
> already set, but it does seem like the right thing in this case.
> 
> > > On x86 it does depend on !xen_initial_domain. I suppose on the principal
> > > that a VT is normally available there. I suppose that doesn't apply to
> > > ARM so much, although it could.
> > >
> > 
> > OK, I got confused by the xen_guest_init(). So do you mean if if
> > (!xen_initial_domain) should be added?
> 
> (dom0 is "Just A Guest" too ;-))
> 
> Adding it would be consistent with x86, I'm not precisely sure if that
> is important or desirable in this case. I'd be inclined to start with
> the if there.

The reasoning is that dom0 command line arguments come from its old
native grub stanza, therefore the console parameter is incorrect, right?
As opposed to regular domUs, that being freshly installed, are supposed
to have the correct console parameter?