Re: [PATCH 0/4] target/ppc: Catch invalid real address accesses

["Cédric Le Goater" <clegoate@redhat.com>]

>>>> qemu-system-ppc.exe -M mac99,via=pmu -cdrom C:\mac-iso\9.2.2.iso -boot d -L pc-bios
>>>> crashes Mac OS with an address error. (with unpatched and patched builds).
>>>
>>> Same on Linux. I get an invalid opcode. QEMU 7.2 work fine though.
>>>
>>> C.
>>
>> That certainly shouldn't happen, and if it worked in 7.2 then there's definitely a regression which has crept in there somewhere. I'll try and bisect this at some point soon, but feel free to try and beat me ;)
> 
> bisect points to :
> 
> commit e506ad6a05c806bbef460a7d014a184ff8d707a6
> Author: Richard Henderson <richard.henderson@linaro.org>
> Date:   Mon Mar 6 04:30:11 2023 +0300
> 
>      accel/tcg: Pass last not end to tb_invalidate_phys_range
>      Pass the address of the last byte to be changed, rather than
>      the first address past the last byte.  This avoids overflow
>      when the last page of the address space is involved.
>      Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>      Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> 
>   include/exec/exec-all.h   |  2 +-
>   accel/tcg/tb-maint.c      | 31 ++++++++++++++++---------------
>   accel/tcg/translate-all.c |  2 +-
>   accel/tcg/user-exec.c     |  2 +-
>   softmmu/physmem.c         |  2 +-
>   5 files changed, 20 insertions(+), 19 deletions(-)
> 
> 
> I think the instruction is fnmadds. Needs more digging.

the invalid opcode is just a symptom of something bad happening.

C.