Re: [Qemu-devel] [PATCH 23/35] acpi:piix4: make plug/unlug callbacks generic

[Paolo Bonzini]

Il 07/04/2014 11:19, Michael S. Tsirkin ha scritto:
> This means we can't cleanly implement an option for guest to
> disable ACPI and switch to native if supported,
> like the ACPI spec allows.
>
> If we change hotplug code to walk the tree top down
> and invoke all callbacks, then it will be fixed
> in a cleaner way: bridges would just do:
>
>         if (dev->bus != self) {
>                 set_error
>                 return;
>         }
>
> and suddently pci host can trap callbacks and redirect
> to acpi if it wants to.

I think this should be handled by making the q35 PCI host bridge 
implement HotplugHandler itself, possibly overriding the parent's 
implementation.

Paolo