On Fri, Jun 26, 2020 at 06:42:58PM +0200, Christophe de Dinechin wrote:
> In order to facilitate the move of large chunks of functionality to
> load modules, it is simpler to create a wrapper with the same name
> that simply relays the implementation. For efficiency, this is
> typically done using inline functions in the header for the
> corresponding functionality. In that case, we rename the actual
> implementation by appending _implementation to its name. This makes it
> easier to select which function you want to put a breakpoint on.
>
> Signed-off-by: Christophe de Dinechin <dinec...@redhat.com>
> ---
> include/qemu/module.h | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/include/qemu/module.h b/include/qemu/module.h
> index 011ae1ae76..1922a0293c 100644
> --- a/include/qemu/module.h
> +++ b/include/qemu/module.h
> @@ -39,6 +39,30 @@ static void __attribute__((constructor)) do_qemu_init_ ##
> function(void) \
> }
> #endif
>
> +#ifdef CONFIG_MODULES
> +/* Identify which functions are replaced by a callback stub */
> +#ifdef MODULE_STUBS
> +#define MODIFACE(Ret,Name,Args) \
> + Ret (*Name)Args; \
> + extern Ret Name##_implementation Args
> +#else /* !MODULE_STUBS */
> +#define MODIFACE(Ret,Name,Args) \
> + extern Ret (*Name)Args; \
> + extern Ret Name##_implementation Args
> +#endif /* MODULE_STUBS */
> +
> +#define MODIMPL(Ret,Name,Args) \
> + static void __attribute__((constructor)) Name##_register(void) \
> + { \
> + Name = Name##_implementation; \
> + } \
> + Ret Name##_implementation Args
> +#else /* !CONFIG_MODULES */
> +/* When not using a module, such functions are called directly */
> +#define MODIFACE(Ret,Name,Args) Ret Name Args
> +#define MODIMPL(Ret,Name,Args) Ret Name Args
> +#endif /* CONFIG_MODULES */
> +
> typedef enum {
> MODULE_INIT_MIGRATION,
> MODULE_INIT_BLOCK,
Hmm that's quite a bit of overhead for each call across modules.
Can't code patching be used somehow?
> --
> 2.26.2
