Re: [PATCH 3/6] target/ppc: Fix instruction loading endianness in alignment interrupt

[Nicholas Piggin]

On Fri Mar 24, 2023 at 11:30 PM AEST, Fabiano Rosas wrote:
> Hi Nick,
>
> > powerpc ifetch endianness depends on MSR[LE] so it has to byteswap
> > after cpu_ldl_code(). This corrects DSISR bits in alignment
> > interrupts when running in little endian mode.
> >
>
> Just a thought, we have these tests that perhaps could have caught
> this:  https://github.com/legoater/pnv-test
>
> Despite the name they do have (some) support to pseries as well. Not
> sure how the P8 support is these days though.

Hey Fabiano,

Thanks for the review. Good thinking, and actually I did catch some
of these (the SPR size one) when running kvm-unit-tests with TCG. I
ported it to powernv too. I wonder if we should merge pnv-test into
kvm-unit-tests.

> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >  target/ppc/excp_helper.c | 27 ++++++++++++++++++++++++++-
> >  1 file changed, 26 insertions(+), 1 deletion(-)
> >
> > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
> > index 287659c74d..5f0e363363 100644
> > --- a/target/ppc/excp_helper.c
> > +++ b/target/ppc/excp_helper.c
> > @@ -133,6 +133,31 @@ static void dump_hcall(CPUPPCState *env)
> >                    env->nip);
> >  }
> >  
> > +/* Return true iff byteswap is needed in a scalar memop */
> > +static inline bool need_byteswap(CPUArchState *env)
> > +{
> > +#if TARGET_BIG_ENDIAN
>
> TARGET_BIG_ENDIAN is always set for softmmu mode. See
> configs/targets/ppc64-softmmu.mak

I see, I just took it from translate.c and actually stupidly forgot
to actually call it here :) I'll fix it up.

Thanks,
Nick