On Fri, Sep 22, 2017 at 11:16:34AM +0200, Thomas Huth wrote: > Historically we've marked all devices as hotpluggable by default. However, > most devices are not hotpluggable, and you also need a HotplugHandler to > support these devices. So if the user tries to "device_add" or "device_del" > such a non-hotpluggable device during runtime, either nothing really usable > happens, or QEMU even crashes/aborts unexpectedly (see for example commit > 84ebd3e8c7d4fe955b - "Mark diag288 watchdog as non-hotpluggable"). > So let's change this dangerous default behaviour and mark the devices as > non-hotpluggable by default. Certain parent devices classes which are known > as hotpluggable (e.g. PCI, USB, etc.) are marked with "hotpluggable = true", > so that devices that are derived from these classes continue to work as > expected.
I see that the discussion has moved on, but want to note here that CPU hotplug on pseries breaks with this patch. (qemu) device_add host-spapr-cpu-core,core-id=8,id=core8 Device 'host-powerpc64-cpu' does not support hotplugging (qemu) device_add POWER8E_v2.1-spapr-cpu-core,id=core8,core-id=8 Device 'POWER8E_v2.1-powerpc64-cpu' does not support hotplugging Hope I am not missing anything. Regards, Bharata.
