[Qemu-devel] Re: [PATCH 27/49] ac97: add active to the state

[Juan Quintela]

malc <address@hidden> wrote:
> On Wed, 30 Sep 2009, Juan Quintela wrote:

> active doesn't belong in the above structure, it's not used for anything
> other than save/loadvm.

It is used for reset, for instance.  We can discuss if it belongs there
or not, but will let that for another day.

> If this "design" doesn't allow this, either find
> another way to accomplish the same or fix the "design".

VMStateDescription is a list of offsets from a known address.  Address
is the one from the state.  That is the design.

Now, back to ac97.  Rest of ac97 don't need the active field, because it
is stored anywhere else (basically where AUD_set_active* store it).

Clearly it is part of ac97 state, becase it is needed for load/save/reset to
work properly.  It just happens that it is stored anywhere else for the
design of the audio system.

At load/save time we don't want to call malloc(), and now we have
descriptions of the state, not functions that save/load the state.
Only sane way of storing this kind of variables is storing them
into the state.

Sorry, there is no way that we are going to have a declarative
description of the state and retain the old functions to do save/load.
You can only get only declarative description or functions, not both.

There are more temporary variables in other devices, and this was the
way it was done there.  Normally I would have called it active_vmstate
to make that explicit, but here, it was also used for reset, that is the
way I named it with the _vmstate suffix.

Later, Juan.