Re: [PATCH] target/ppc: Fix lxvx/stxvx facility check

[Claudio Fontana]

ping, adding Richard.

We will need to include this downstream because of the breakage its lack causes.
It is already reviewed by me, but some TCG maintainer indicating it will be 
included in some queue would help,

Thanks,

Claudio

On 9/18/24 17:11, Claudio Fontana wrote:
> Adding Ilya FYI.
> 
> Ciao,
> 
> Claudio
> 
> On 9/11/24 18:19, Claudio Fontana wrote:
>> On 9/11/24 16:16, Fabiano Rosas wrote:
>>> The XT check for the lxvx/stxvx instructions is currently
>>> inverted. This was introduced during the move to decodetree.
>>>
>>> From the ISA:
>>>   Chapter 7. Vector-Scalar Extension Facility
>>>   Load VSX Vector Indexed X-form
>>>
>>>   lxvx XT,RA,RB
>>>   if TX=0 & MSR.VSX=0 then VSX_Unavailable()
>>>   if TX=1 & MSR.VEC=0 then Vector_Unavailable()
>>>   ...
>>>   Let XT be the value 32×TX + T.
>>>
>>> The code currently does the opposite:
>>>
>>>     if (paired || a->rt >= 32) {
>>>         REQUIRE_VSX(ctx);
>>>     } else {
>>>         REQUIRE_VECTOR(ctx);
>>>     }
>>>
>>> This was already fixed for lxv/stxv at commit "2cc0e449d1 (target/ppc:
>>> Fix lxv/stxv MSR facility check)", but the indexed forms were missed.
>>>
>>> Cc: qemu-stable@nongnu.org
>>> Fixes: 70426b5bb7 ("target/ppc: moved stxvx and lxvx from legacy to 
>>> decodtree")
>>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>>> ---
>>>  target/ppc/translate/vsx-impl.c.inc | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/target/ppc/translate/vsx-impl.c.inc 
>>> b/target/ppc/translate/vsx-impl.c.inc
>>> index 40a87ddc4a..a869f30e86 100644
>>> --- a/target/ppc/translate/vsx-impl.c.inc
>>> +++ b/target/ppc/translate/vsx-impl.c.inc
>>> @@ -2244,7 +2244,7 @@ static bool do_lstxv_PLS_D(DisasContext *ctx, 
>>> arg_PLS_D *a,
>>>  
>>>  static bool do_lstxv_X(DisasContext *ctx, arg_X *a, bool store, bool 
>>> paired)
>>>  {
>>> -    if (paired || a->rt >= 32) {
>>> +    if (paired || a->rt < 32) {
>>>          REQUIRE_VSX(ctx);
>>>      } else {
>>>          REQUIRE_VECTOR(ctx);
>>
>> Reviewed-by: Claudio Fontana <cfontana@suse.de>
>>
> 
>