On Thu, 19 Feb 2026 at 12:17, Igor Mammedov <[email protected]> wrote: > > On Wed, 18 Feb 2026 19:08:36 +0000 > Peter Maydell <[email protected]> wrote:
> > Please can you also add support for exposing this device > > in the device tree ? > > It's possible, > but we probably should not enable it if acpi variant was requested, > to avoid confusion on guest side. Why? Almost every other device on this board we advertise via DTB for device tree guests and via ACPI for ACPI guests. (The exceptions are things like the CXL handling that really only has an ACPI representation and can't be described in the DTB.) > For Windows it doesn't really mater, for linux it does. > on x86 linux guest uses a quirk to disable native iTCO watchdog > in favor of WDAT one if later is present. > I assume quirk is not desirable so we should expose only a preferred > variant. For this Arm board there is no watchdog except the one you're adding in this patch, though. > > Can we have a command line option name that isn't ACPI > > specific, please? There's nothing inherent to ACPI about > > "I would like a watchdog device". > > that is specifically asking for ACPI flavor being used/configured. > acpi specific option conflates 2 things: > 1. watchdog device creation (of the board choice) with properties tuned > for WDAT usage > 2. how to expose it on firmware level (in this case ACPI WDAT table) Right, and I think that's the wrong way to approach this, at least for the virt board. We should either always create or allow the user to ask us to create a watchdog device. And then we should do what we do for all the other devices, which is expose it via both the mechanisms that we have for telling the guest about hardware (ACPI and DTB). thanks -- PMM
