Re: [Qemu-devel] [PATCH v2 02/20] target-i386: move back cpu_exec_init() to init

[Eduardo Habkost]

On Fri, Oct 14, 2016 at 04:33:07PM +0200, Igor Mammedov wrote:
> On Fri, 14 Oct 2016 10:48:58 -0300
> Eduardo Habkost <address@hidden> wrote:
> 
> > On Fri, Oct 14, 2016 at 03:34:17PM +0200, Laurent Vivier wrote:
> > > On 14/10/2016 15:33, Eduardo Habkost wrote:  
> > > > On Thu, Oct 13, 2016 at 06:24:44PM +0200, Laurent Vivier wrote:  
> > > >> We have now the cpu_exec_realize() in realize,
> > > >> so the init part must be in init.
> > > >>
> > > >> I've removed the cannot_destroy_with_object_finalize_yet field as
> > > >> unsafe references have been moved to cpu_exec_realize().
> > > >> (tested with QOM command provided by commit 4c315c27 with
> > > >> "athlon-x86_64-cpu")
> > > >>
> > > >> CC: Eduardo Habkost <address@hidden>
> > > >> Signed-off-by: Laurent Vivier <address@hidden>  
> > > > 
> > > > Resending the question I asked in my reply to v1:
> > > > 
> > > > Instead of creating requiring each subclass to manually call
> > > > cpu_exec_init()) on instance_init, why don't we move parts of
> > > > cpu_exec_init()/cpu_exec_realize() code to cpu_common_initfn()?
> > > > (TYPE_CPU's instance_init)
> > > > 
> > > > (And if there's any code that needs to be run after the
> > > > subclasses instance_init functions, we can just add a
> > > > instance_post_init function to TYPE_CPU).
> > > >   
> > > 
> > > It's done in PATCH 20/20.
> > > 
> > > Is that what you want?  
> > 
> > Yes (except that I would have inlined the the cpu_exec_init()
> > code inside cpu_common_init()).
> > 
> > I think I expected this to be done in a single step, that
> > wouldn't require touching code for all architectures three times.
> > Something like:
> > 
> > 1) Move cpu->as, cpu->num_ases, cpu->thread_id, cpu->memory
> >    initialization, and "memory" property registration from
> >    cpu_exec_init() to cpu_common_init() (no architecture code
> >    touched).
> > 2) (optional) Rename cpu_exec_init() to cpu_exec_realize() (only
> >    trivial changes in architecture code)
> I'd do all of it in 1 step
>   - split cpu_exec_init on init/realize parts
>     (comment in cpu_exec_init says that qom/cpu.c can't be used for
>      "memory" property)
>   - call cpu_exec_init() from cpu_common_init()
>   - s/cpu_exec_init/cpu_exec_realize/ in target-*

Personally, I don't mind if it is done in 1 or 2 steps. I would
just like to avoid changing architecture code 3 times.

In addition to make review easier, it would make the decision to
merge it easier for the maintainer who's going to do it (no need
to wait for Acked-bys/Reviewed-bys from multiple architecture
maintainers).

-- 
Eduardo