Re: [Qemu-devel] [RFC] acpi: add reset register to fadt

[Igor Mammedov]

On Mon, 30 Mar 2015 15:27:26 +0200
Reza Jelveh <address@hidden> wrote:

> On Mon, Mar 30, 2015 at 2:36 PM, Igor Mammedov <address@hidden> wrote:
> 
> > you are extending structure beyond of what specified by ACPI 1.0b spec,
> > that might break guests.
> > We probably can't change revision since Windows ACPI implementation
> > is mostly 1.0b based so we are stuck with it.
> > Patch needs to be tested with Windows guests starting with XP.
> >
> 
> Works fine with XP as long as you don't use q35, but i guess that's
> unsupported by xp by default.
what about other windows versions?

> 
> 
> > related issue,
> > adding fields without changing major version to a corresponding
> > one doesn't look correct.
> >
> 
> What do you suggest? saying we support 2.0a just because of introducing
> reset_reg is not really valid is it?
Try to check whether windows works fine with a newer revision,
if it is, we can create revX FADT structure and use in with new machine types.
In that case we could consider implementing rev5 table so it could be reused
in ARM target.