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

[Claudio Fontana]

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>