Re: [Qemu-devel] [PATCH RFC 3/3] hw/pci-host: catch acesses to unassigned pci addresses

[Peter Maydell <peter.maydell@linaro.org>]

On 2 September 2013 16:42, Marcel Apfelbaum <marcel.a@redhat.com> wrote:
> On Mon, 2013-09-02 at 15:39 +0100, Peter Maydell wrote:
>> This is happening at the wrong layer -- you want this memory
>> region to be created and managed in the PCI core code so that
>> we get correct PCI-spec behaviour for all our PCI controllers,
>> not just the two x86 ones you've changed here.pci_address_space
> I saw that the memory regions are part of the Host state and
> duplicated for each host type(like pci_address_space).
> Question, why are not pci_address_space and pci_hole present
> in a core layer?
>
> I followed the existing code; from what you are saying
> I understand that also the existing memory regions
> like the one mentioned above should be moved in
> the core layer, right?

Ideally, yes, I think so. However that's not particularly
a requirement for the changes you're trying to make here:
at the moment what happens is that the pci controller
creates the PCI memory and io memory regions (or cheats
by reusing the system memory space[*]), passes them to
the PCI core code (via pci_bus_new) and then they're
the PCI code's responsibility to manage. So in the PCI
code you can ignore where they came from when you're
deciding how to manage these containers (and in this case
what you do is just create your default region and map
it in to the container at a suitable priority).

[*] I'm pretty sure this is a bug in all platforms that do it.

-- PMM