On 1/24/25 08:27, Peter Maydell wrote:
> The pseudocode ResetSVEState() does:
> FPSR = ZeroExtend(0x0800009f<31:0>, 64);
> but QEMU's arm_reset_sve_state() called vfp_set_fpcr() by accident.
>
> Before the advent of FEAT_AFP, this was only setting a collection of
> RES0 bits, which vfp_set_fpsr() would then ignore, so the only effect
> was that we didn't actually set the FPSR the way we are supposed to
> do. Once FEAT_AFP is implemented, setting the bottom bits of FPSR
> will change the floating point behaviour.
>
> Call vfp_set_fpsr(), as we ought to.
>
> (Note for stable backports: commit 7f2a01e7368f9 moved this function
> from sme_helper.c to helper.c, but it had the same bug before the
> move too.)
>
> Cc: qemu-stable@nongnu.org
> Fixes: f84734b87461 ("target/arm: Implement SMSTART, SMSTOP")
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> target/arm/helper.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 63997678513..40bdfc851a5 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -6413,7 +6413,7 @@ static void arm_reset_sve_state(CPUARMState *env)
> memset(env->vfp.zregs, 0, sizeof(env->vfp.zregs));
> /* Recall that FFR is stored as pregs[16]. */
> memset(env->vfp.pregs, 0, sizeof(env->vfp.pregs));
> - vfp_set_fpcr(env, 0x0800009f);
> + vfp_set_fpsr(env, 0x0800009f);
> }
>
> void aarch64_set_svcr(CPUARMState *env, uint64_t new, uint64_t mask)
Oops.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~