Re: [Qemu-devel] [RFC 10/48] exec: export do_tb_flush

["Alex Bennée" <alex.bennee@linaro.org>]

Emilio G. Cota <cota@braap.org> writes:

> This will be used by plugin code to flush the code cache as well
> as doing other bookkeeping in a safe work environment.

This seems a little excessive given the plugin code could just call
tb_flush() directly. Wouldn't calling tb_flush after scheduling the
plugin_destroy be enough?

If there is a race condition here maybe we could build some sort of
awareness into tb_flush as to the current run state. But having two
entry points to this rather fundamental action seems likely to either be
misused or misunderstood.

>
> Signed-off-by: Emilio G. Cota <cota@braap.org>
> ---
>  include/exec/exec-all.h   | 1 +
>  accel/tcg/translate-all.c | 2 +-
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
> index 815e5b1e83..232e2f8966 100644
> --- a/include/exec/exec-all.h
> +++ b/include/exec/exec-all.h
> @@ -427,6 +427,7 @@ void tb_invalidate_phys_range(target_ulong start, target_ulong end);
>  void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs);
>  #endif
>  void tb_flush(CPUState *cpu);
> +void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count);
>  void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr);
>  TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc,
>                                     target_ulong cs_base, uint32_t flags,
> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index c8b3e0a491..db2d28f8d3 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -1230,7 +1230,7 @@ static gboolean tb_host_size_iter(gpointer key, gpointer value, gpointer data)
>  }
>
>  /* flush all the translation blocks */
> -static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
> +void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
>  {
>      mmap_lock();
>      /* If it is already been done on request of another CPU,


--
Alex Bennée