Re: [Qemu-devel] [PATCH v2 04/27] target/arm: Add PAuth helpers

[Richard Henderson]

On 1/5/19 2:25 AM, Peter Maydell wrote:
> On Fri, 14 Dec 2018 at 05:24, Richard Henderson
> <address@hidden> wrote:
>>
>> The cryptographic internals are stubbed out for now,
>> but the enable and trap bits are checked.
>>
>> Signed-off-by: Richard Henderson <address@hidden>
>> ----
> 
>> +static void QEMU_NORETURN pauth_trap(CPUARMState *env, int target_el,
>> +                                     uintptr_t ra)
>> +{
>> +    CPUState *cs = ENV_GET_CPU(env);
>> +
>> +    cs->exception_index = EXCP_UDEF;
>> +    env->exception.syndrome = syn_pactrap();
>> +    env->exception.target_el = target_el;
>> +    cpu_loop_exit_restore(cs, ra);
> 
> This should use raise_exception(), or some variant on it that
> lets you pass in the ra, because otherwise you lose the
> "redirect EL1 exceptions to EL2" HCR.TGE behaviour.
> Or can we only ever call this for a target_el of 2 or 3?

This particular usage can only ever target EL 2 or 3,
in response to {SCR,HCR}.API being clear.  AFAICS that
trap is properly directed already.

But, yes, raise_exception_ra would be useful.


r~