Re: [PATCH 0/4] target/arm vector improvements

[Richard Henderson]

On 11/18/19 5:26 PM, Peter Maydell wrote:
> On Thu, 17 Oct 2019 at 05:42, Richard Henderson
> <address@hidden> wrote:
>>
>> The first patch has been seen before.
>>
>>   https://patchwork.ozlabs.org/patch/1115039/
>>
>> It had a bug and I didn't fix it right away and then forgot.
>> Fixed now; I had mixed up the operand ordering for aarch32.
> 
> Since Alex had a nit on patch 1 I'm going to assume you'll
> respin this series once we're reopen for 5.0 development.

Oops, I forgot about it.  Yes, we can postpone to 5.0.

> I think we have two plausible choices for DIT:
>  (1) don't implement it, since we can't make the timing
>      guarantees it suggests
>  (2) implement it but not actually change our behaviour:
>      this is technically a lie to the guest, but it means
>      that guest OS handling of the PSTATE.DIT bit etc can
>      be tested
> 
> At the moment we by default do (1). I think we should
> probably postpone doing (2) until somebody actually
> asks us for it.

Fair enough.


r~