On Wed, 11 Feb 2026 at 12:28, Mohammadfaiz Bawa <[email protected]> wrote: > > Windows ARM64 guests detect virtio-mmio devices declared in ACPI > tables even when no backend is attached. This causes "Unknown > devices" (ACPI\LNRO0005) to appear in Device Manager. > > Until Windows fixes that by supporting, adding a new machine > property 'virtio-transports' to control the number of > virtio-mmio transports instantiated. The default remains > NUM_VIRTIO_TRANSPORTS (32) for backward compatibility. > Setting it to 0 allows users to disable virtio-mmio entirely. > > Usage: -machine virt,virtio-transports=0 > > Signed-off-by: Mohammadfaiz Bawa <[email protected]>
Applied to target-arm.next, thanks -- but please could you check up with the ACPI spec about whether it says anything about what to report for empty transports? If it says we should or if it's just vague we should probably match the x86 microvm behaviour of not showing empty transports, since they can never be hotplugged after startup. (This might need to be tied to a machine-version, not sure.) Maybe we should also not report them in the dtb? thanks -- PMM
