Re: [PATCH 00/11] Introduce ACPI watchdog for Q35 and arm/virt boards

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 18 Feb 2026 19:10:02 +0000
Peter Maydell <peter.maydell@linaro.org> wrote:

> On Fri, 6 Feb 2026 at 13:14, Igor Mammedov <imammedo@redhat.com> wrote:
> >
> > Windows doesn't ship built-in TCO watchdog driver, and users are
> > forced to install vendor specific driver(s) if such exists.
> > However OS provides a generic watchdog driver that uses
> > ACPI WDAT table [1] to abstract actual hardware behind it.
> > The same applies to ARM version of Windows.
> >
> > This series adds
> >  *  WDAT table tailored for TCO watchdog that Q35 already
> >     has as part of ICH9 chipset and a knob to enable it.
> >  *  SBSA GWDT to arm/vit machine with WDAT table tailored
> >     for it and necessary tweaks to GWDT to make usable
> >     with WDAT driver.  
> 
> > Also CCing SBSA folks to see if they are interested in adding it to their
> > reference machine  
> 
> The sbsa-ref machine already implements an sbsa-gwdt watchdog...

yep, but not exposed as WDAT one. Hence the question.
It also would need clock-frequency tweak if we are expose it via ACPI.

PS:
I don't even see DT mapping for it,
looks like sbsa-gwdt is just wired for the sake of compliance with the spec.
Well sbsa-ref specific firmware could just opencode it's mapping instead
of getting it from QEMU.


> 
> -- PMM
>