Re: [Qemu-devel] [PATCH 23/26] target-xtensa: implement interrupt option

[Max Filippov]

>> - cycles fed into advance_ccount may (and on real hardware actually
>> do) depend on executed commands/pipeline/cache hits. Most of this
>> stuff may be counted at the translation time;
>
> Since CCOUNT, as seen by any one thread of execution, on real hw depends
> on cache hits, interrupts, and other asynchronous stuff, then don't bother
> trying to account for it on a per-instruction basis.  Just define a clock
> that runs at a given rate and be done.  No need to advance it manually.

It means no cycle-accurate emulation. This was one of my goals, maybe
not closest one. Is it acceptable to have two simulation modes -- fast
functional and slower cycle-accurate?

>> - check_interrupts converts IRQs on enabled interrupt sources into current 
>> irq level.
> This is needed during do_interrupt, but should not be used by the translator 
> itself.

Not only during do_interrupt, but also in cpu_has_work.

Thanks.
-- Max