Re: [Qemu-arm] [PATCH v8 23/25] target-arm: introduce ARM_CP_EXIT_PC

[Peter Maydell]

On 2 February 2017 at 12:17, Alex Bennée <address@hidden> wrote:
> Peter Maydell <address@hidden> writes:
>> Your longjump is effectively skipping the normal "end of the TB" code,
>> which is what usually does the set_condexec for you. At the end of a
>> TB the expectation is that everything's been sync'd back to the CPU
>> state structure.
>
> Hmm so as long as the tlb flush helpers don't set ARM_CP_SUPPRESS_TB_END
> things should just work normally?

If they're register writes, yes -- we end the TB on writes but not
on reads (on the assumption that only writes might modify state that
requires a TB end). If the TLB instructions are reads then we can
add a "force TB end" flag.

> Is shouldn't matter if the TB with the
> flush is chained to a new TB as the exit_request test should fire before
> any more state changing operations happen?

I think so, but again if you know that you're always going to exit
the TB then there's no point setting it up so it might chain.

thanks
-- PMM