Re: [kvm-unit-tests PATCH 12/32] powerpc: Fix emulator illegal instruction test for powernv

["Nicholas Piggin" <npiggin@gmail.com>]

On Fri Mar 1, 2024 at 9:50 PM AEST, Thomas Huth wrote:
> On 26/02/2024 11.11, Nicholas Piggin wrote:
> > Illegal instructions cause 0xe40 (HEAI) interrupts rather
> > than program interrupts.
> > 
> > Acked-by: Thomas Huth <thuth@redhat.com>
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >   lib/powerpc/asm/processor.h |  1 +
> >   lib/powerpc/setup.c         | 13 +++++++++++++
> >   powerpc/emulator.c          | 21 ++++++++++++++++++++-
> >   3 files changed, 34 insertions(+), 1 deletion(-)
> > 
> > diff --git a/lib/powerpc/asm/processor.h b/lib/powerpc/asm/processor.h
> > index 9d8061962..cf1b9d8ff 100644
> > --- a/lib/powerpc/asm/processor.h
> > +++ b/lib/powerpc/asm/processor.h
> > @@ -11,6 +11,7 @@ void do_handle_exception(struct pt_regs *regs);
> >   #endif /* __ASSEMBLY__ */
> >   
> >   extern bool cpu_has_hv;
> > +extern bool cpu_has_heai;
> >   
> >   static inline uint64_t mfspr(int nr)
> >   {
> > diff --git a/lib/powerpc/setup.c b/lib/powerpc/setup.c
> > index 89e5157f2..3c81aee9e 100644
> > --- a/lib/powerpc/setup.c
> > +++ b/lib/powerpc/setup.c
> > @@ -87,6 +87,7 @@ static void cpu_set(int fdtnode, u64 regval, void *info)
> >   }
> >   
> >   bool cpu_has_hv;
> > +bool cpu_has_heai;
> >   
> >   static void cpu_init(void)
> >   {
> > @@ -108,6 +109,18 @@ static void cpu_init(void)
> >   		hcall(H_SET_MODE, 0, 4, 0, 0);
> >   #endif
> >   	}
> > +
> > +	switch (mfspr(SPR_PVR) & PVR_VERSION_MASK) {
> > +	case PVR_VER_POWER10:
> > +	case PVR_VER_POWER9:
> > +	case PVR_VER_POWER8E:
> > +	case PVR_VER_POWER8NVL:
> > +	case PVR_VER_POWER8:
> > +		cpu_has_heai = true;
> > +		break;
> > +	default:
> > +		break;
> > +	}
> >   }
> >   
> >   static void mem_init(phys_addr_t freemem_start)
> > diff --git a/powerpc/emulator.c b/powerpc/emulator.c
> > index 39dd59645..c9b17f742 100644
> > --- a/powerpc/emulator.c
> > +++ b/powerpc/emulator.c
> > @@ -31,6 +31,20 @@ static void program_check_handler(struct pt_regs *regs, void *opaque)
> >   	regs->nip += 4;
> >   }
> >   
> > +static void heai_handler(struct pt_regs *regs, void *opaque)
> > +{
> > +	int *data = opaque;
> > +
> > +	if (verbose) {
> > +		printf("Detected invalid instruction %#018lx: %08x\n",
> > +		       regs->nip, *(uint32_t*)regs->nip);
> > +	}
> > +
> > +	*data = 8; /* Illegal instruction */
> > +
> > +	regs->nip += 4;
> > +}
> > +
> >   static void alignment_handler(struct pt_regs *regs, void *opaque)
> >   {
> >   	int *data = opaque;
> > @@ -362,7 +376,12 @@ int main(int argc, char **argv)
> >   {
> >   	int i;
> >   
> > -	handle_exception(0x700, program_check_handler, (void *)&is_invalid);
> > +	if (cpu_has_heai) {
> > +		handle_exception(0xe40, heai_handler, (void *)&is_invalid);
> > +		handle_exception(0x700, program_check_handler, (void *)&is_invalid);
> > +	} else {
> > +		handle_exception(0x700, program_check_handler, (void *)&is_invalid);
>
> The 0x700 line looks identical to the other part of the if-statement ... I'd 
> suggest to leave it outside of the if-statement, drop the else-part and just 
> set 0xe40 if cpu_has_heai.

Can do.

Thanks,
Nick