Comment 8 for bug 1836078

Revision history for this message
Peter Maydell (pmaydell) wrote : Re: [PATCH v2 for 4.1] target/arm: report ARMv8-A FP support for AArch32 -cpu max

On Thu, 11 Jul 2019 at 11:37, Alex Bennée <email address hidden> wrote:
>
> When we converted to using feature bits in 602f6e42cfbf we missed out
> the fact (dp && arm_dc_feature(s, ARM_FEATURE_V8)) was supported for
> -cpu max configurations. This caused a regression in the GCC test
> suite. Fix this by setting the appropriate bits in mvfr1.FPHP to
> report ARMv8-A with FP support (but not ARMv8.2-FP16).
>
> Fixes: https://bugs.launchpad.net/qemu/+bug/1836078
> Signed-off-by: Alex Bennée <email address hidden>
> Reviewed-by: Richard Henderson <email address hidden>
> ---
> target/arm/cpu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index e75a64a25a..ad164a773b 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -2452,6 +2452,10 @@ static void arm_max_initfn(Object *obj)
> t = FIELD_DP32(t, ID_ISAR6, SPECRES, 1);
> cpu->isar.id_isar6 = t;
>
> + t = cpu->isar.mvfr1;
> + t = FIELD_DP32(t, MVFR1, FPHP, 2); /* v8.0 FP support */
> + cpu->isar.mvfr1 = t;
> +
> t = cpu->isar.mvfr2;
> t = FIELD_DP32(t, MVFR2, SIMDMISC, 3); /* SIMD MaxNum */
> t = FIELD_DP32(t, MVFR2, FPMISC, 4); /* FP MaxNum */
> --
> 2.20.1

Applied to target-arm.next, thanks.

-- PMM