Re: [Qemu-devel] when does a target frontend need to use gen_io_start()/gen_io_end() ?

[Paolo Bonzini]

On 12/05/2015 17:32, Peter Maydell wrote:
> In order for -icount to work, it's important for the target
> translate.c code to correctly bracket any generated code which
> can "do I/O" with gen_io_start()/gen_io_end() calls. But
> does anybody know exactly what the criteria are here for this?
> It would be nice if we could document this in a comment in
> gen_icount.h -- I'm happy to write one up if somebody will just
> tell me what the right answer is :-)

It's any instruction that can cause an icount read, typically through
QEMU_CLOCK_VIRTUAL or cpu_get_ticks().

Paolo