Re: [PATCH 1/2] target/arm: add support for FEAT_DIT, Data Independent Timing

[Rebecca Cran]

On 12/11/20 7:08 AM, Richard Henderson wrote:
> Alternately, or additionally, TCG is outside of the security domain (only
> hardware accelerators like KVM are inside), and so we may implement this as a 
> NOP.

Thanks for the feedback, I'll send a v2 patch next week.


Is the comment in target/arm/op_helper.c:397 still relevant?


uint32_t HELPER(cpsr_read)(CPUARMState *env)
{
    /*
     * We store the ARMv8 PSTATE.SS bit in env->uncached_cpsr.
     * This is convenient for populating SPSR_ELx, but must be
     * hidden from aarch32 mode, where it is not visible.
     *
     * TODO: ARMv8.4-DIT -- need to move SS somewhere else.
     */
    return cpsr_read(env) & ~(CPSR_EXEC | PSTATE_SS);
}


--

Rebecca Cran