Re: [Qemu-devel] [PATCH v4 12/21] target-arm: A64: Implement DC ZVA

[Richard Henderson]

On 03/07/2014 07:11 AM, Peter Maydell wrote:
>> > As a bonus, you'll have accurate exceptions should the access throw, so you
>> > don't need to force the save of PC before calling the helper.  Which... I 
>> > don't
>> > see you doing, so perhaps there's a bug here at the moment.
> Mmm. (In system mode we'll save PC as a side effect of having
> an accessfn defined for the DC_ZVA reginfo.)

Ah, I see it.

I'll note that the GETRA/PC thing can be made to work with any helper.  It's
just a matter of passing down the outermost helper's retaddr to
cpu_restore_state.  C.f. target-alpha's dynamic_excp/arith_excp functions.

So in theory there's no need for the accessfn to require storing the pc first.


r~