Re: [PATCH 08/13] powerpc/64s: irq replay remove spurious irq reason

[Nicholas Piggin <npiggin@gmail.com>]

On Sun, 06 Aug 2017 09:00:32 +1000
Benjamin Herrenschmidt <benh@au1.ibm.com> wrote:

> On Sun, 2017-08-06 at 03:02 +1000, Nicholas Piggin wrote:
> > HVI interrupts have always used 0x500, so remove the dead branch.  
> 
> Maybe we should fix that and "catch" in incorrect entry via 0x500
> which would mean the XIVE is trying to deliver guest irqs to the OS...

I should be more clear, when I say 0x500, it is only in reference to
the constant used by the soft-irq replay. After patch 6 the replay is
sent to the 0xea0 common handler.

> That can happen if some LPCR bits aren't set properly and/or KVM
> doesn't pull the guest in time. I had bugs like that in my early
> dev so I've been running with a b . at 0x500 for a while :-)

So that's a separate issue of hardware actually doing a 0x500. I
had this

http://patchwork.ozlabs.org/patch/750033/


> 
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >  arch/powerpc/kernel/exceptions-64s.S | 2 --
> >  1 file changed, 2 deletions(-)
> > 
> > diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> > index 29253cecf713..566cf126c13b 100644
> > --- a/arch/powerpc/kernel/exceptions-64s.S
> > +++ b/arch/powerpc/kernel/exceptions-64s.S
> > @@ -1680,8 +1680,6 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_300)
> >  BEGIN_FTR_SECTION
> >  	cmpwi	r3,0xa00
> >  	beq	h_doorbell_common_msgclr
> > -	cmpwi	r3,0xea0
> > -	beq	h_virt_irq_common
> >  	cmpwi	r3,0xe60
> >  	beq	hmi_exception_common
> >  FTR_SECTION_ELSE  
>