Re: [PATCH v5 03/45] target/arm: Trap non-streaming usage when Streaming SVE is active

[Peter Maydell]

On Wed, 6 Jul 2022 at 09:38, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> This new behaviour is in the ARM pseudocode function
> AArch64.CheckFPAdvSIMDEnabled, which applies to AArch32
> via AArch32.CheckAdvSIMDOrFPEnabled when the EL to which
> the trap would be delivered is in AArch64 mode.
>
> Given that ARMv9 drops support for AArch32 outside EL0, the trap EL
> detection ought to be trivially true, but the pseudocode still contains
> a number of conditions, and QEMU has not yet committed to dropping A32
> support for EL[12] when v9 features are present.
>
> Since the computation of SME_TRAP_NONSTREAMING is necessarily different
> for the two modes, we might as well preserve bits within TBFLAG_ANY and
> allocate separate bits within TBFLAG_A32 and TBFLAG_A64 instead.
>
> Note that DDI0616A.a has typos for bits [22:21] of LD1RO in the table
> of instructions illegal in streaming mode.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM