Re: [Qemu-devel] [PATCH 03/12] qdev: separate core from the code used only by qemu-system-*

[Eduardo Habkost]

On Fri, Oct 19, 2012 at 09:31:00AM +0200, Markus Armbruster wrote:
> Eduardo Habkost <address@hidden> writes:
> 
> > On Wed, Oct 17, 2012 at 01:00:55PM -0500, Anthony Liguori wrote:
> [...]
> >> I don't really understand the split here and the 'system' suffix really
> >> doesn't explain it for me.  Could you at least add a comment to each of
> >> these files explaining what belongs in them?
> >
> > "system" here means "Code used only by qemu-system-*" (in other words,
> > not used by *-user, and not part of the qdev core). Do you have other
> > name suggestions?
> >
> > The goal here is to make qdev-core.c/qdev-properties as small as
> > possible (only what's absolutely required for the CPU classes), and put
> > everything else (that's only used by qemu-system-*) into
> > qdev-system.c/qdev-properties-system.c.
> 
> Creates a permanent if minor development burden: where should my
> property code go?
> 
> Doubt it's worth the trouble:
> 
>    text          data     bss     dec     hex filename
>   15897          1448       0   17345    43c1 bld/hw/qdev-properties.o
> 
> In theory, link-time optimizations can drop unused code.  Not sure they
> do in practice.

The reason for the split is not just to reduce qdev-core size, but keep
qdev dependencies under control (so it becomes feasible to use qdev on
*-user).

Most of the code moved to qdev-properties-system.c was moved because it
depends on other code that we don't include on *-user (like
bdrv_get_device_name(), net_hub_port_find(), net_hub_id_for_client(),
qemu_find_netdev(), bdrv_get_device_name(), qemu_chr_find()).

-- 
Eduardo