Re: [RFC 09/13] i386/fw_cfg: move hpet_cfg definition to hpet.c

[Zhao Liu <zhao1.liu@intel.com>]

Hi Philippe,

On Thu, Dec 05, 2024 at 01:04:58PM +0100, Philippe Mathieu-Daudé wrote:
> Date: Thu, 5 Dec 2024 13:04:58 +0100
> From: Philippe Mathieu-Daudé <philmd@linaro.org>
> Subject: Re: [RFC 09/13] i386/fw_cfg: move hpet_cfg definition to hpet.c
> 
> On 5/12/24 07:07, Zhao Liu wrote:
> > HPET device needs to access and update hpet_cfg variable, but now it is
> > defined in hw/i386/fw_cfg.c and Rust code can't access it.
> > 
> > Move hpet_cfg definition to hpet.c (and rename it to hpet_fw_cfg). This
> > allows Rust HPET device implements its own global hpet_fw_cfg variable,
> > and will further reduce the use of unsafe C code access and calls in the
> > Rust HPET implementation.
> > 
> > Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
> > ---
> >   hw/i386/fw_cfg.c        |  4 +---
> >   hw/timer/hpet.c         | 16 +++++++++-------
> >   include/hw/timer/hpet.h |  2 +-
> >   3 files changed, 11 insertions(+), 11 deletions(-)
> 
> 
> > diff --git a/include/hw/timer/hpet.h b/include/hw/timer/hpet.h
> > index d17a8d43199e..dbf709251a8f 100644
> > --- a/include/hw/timer/hpet.h
> > +++ b/include/hw/timer/hpet.h
> > @@ -74,7 +74,7 @@ struct hpet_fw_config
> >       struct hpet_fw_entry hpet[8];
> >   } QEMU_PACKED;
> > -extern struct hpet_fw_config hpet_cfg;
> > +extern struct hpet_fw_config hpet_fw_cfg;
> 
> Could this field belong to the (yet unexisting) HPETClass?

Several instances would share the same class, so HPETClass could manage
multiple HPETState info.

But in fw_cfg.c, do you have idea about how to get the HPETClass?

Regards,
Zhao