Re: [PATCH-for-5.0 1/2] hw/acpi/piix4: Add 'system-hotplug-support' property

[Paolo Bonzini]

On 18/03/20 23:15, Philippe Mathieu-Daudé wrote:
> The I/O ranges registered by the piix4_acpi_system_hot_add_init()
> function are not documented in the PIIX4 datasheet.
> This appears to be a PC-only feature added in commit 5e3cb5347e
> ("initialize hot add system / acpi gpe") which was then moved
> to the PIIX4 device model in commit 9d5e77a22f ("make
> qemu_system_device_hot_add piix independent")
> Add a property (default enabled, to not modify the current
> behavior) to allow machines wanting to model a simple PIIX4
> to disable this feature.

Yes, all hotplug stuff (PCI/memory/CPU) are custom additions by QEMU.

> +    DEFINE_PROP_BOOL("system-hotplug-support", PIIX4PMState,
> +                     use_acpi_system_hotplug, true),

Why not cpu-hotplug-support?

Paolo