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