Re: [Qemu-devel] [PATCH 4/4] Disable "info irq" and "info pic" for target-ppc

[Thomas Huth]

On Mon, 29 Jun 2015 09:52:56 +0200
Laurent Vivier <address@hidden> wrote:

> 
> 
> On 29/06/2015 07:36, David Gibson wrote:
> > The "info irq" and "info pic" HMP commands are available on some, but not
> > all targets, and what they do isn't terribly consistent.  For SPARC and
> > LM32 they do something platform specific, but for x86, powerpc, and MIPS
> > they print some information from the i8259 (and only the i8259) interrupt
> > controller.
> > 
> > It's debatable whether these commands are any use at all, and we should
> > probably make better, qdev aware ways of getting information from a
> > machines PICs.  However, those don't exist yet, so on x86 it's at least
> > potentially useful to have these HMP commands.  I can't speak for MIPS.
> > 
> > For ppc, though, the i8259, if it exists at all, is usually just a
> > secondary controller for legacy ISA.  The only case where i8259 is the
> > main system PIC on ppc is for the ancient and little-used PReP platform.
> > 
> > So, even without QOM-ish replacement, the info pic and info irq HMP
> > commands have no value on ppc.
> > 
> > This patch, therefore, disables these commands for ppc targets.  This will
> > allow ppc builds which don't include PReP to not include ISA bus support
> > either.
> > 
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> >  monitor.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/monitor.c b/monitor.c
> > index aeea2b5..8c56bfa 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -2573,7 +2573,7 @@ static mon_cmd_t info_cmds[] = {
> >          .help       = "show the command line history",
> >          .mhandler.cmd = hmp_info_history,
> >      },
> > -#if defined(TARGET_I386) || defined(TARGET_PPC) || defined(TARGET_MIPS) || 
> > \
> > +#if defined(TARGET_I386) || defined(TARGET_MIPS) || \
> >      defined(TARGET_LM32) || (defined(TARGET_SPARC) && 
> > !defined(TARGET_SPARC64))
> >      {
> >          .name       = "irq",
> > 
> 
> Perhaps we can a use a "#if defined(CONFIG_I8259) ||
> defined(CONFIG_LM32) || (defined(TARGE_SPARC) &&
> !defined(TARGET_SPARC64))" instead, so we keep the command for PReP ?

AFAIK this currently won't work since CONFIG_I8259 is only defined for
the Makefiles, but not for the C pre-processor :-(

So unless somebody fixes that first, I think David's approach is the
only practicable solution right now.

 Thomas