Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses

[Peter Maydell]

On 9 September 2013 13:43, Marcel Apfelbaum <address@hidden> wrote:
> The scenario is covered only for the primary bus and not for buses
> behind the PCI bridge (the later being handled differently.)
> In this case, isn't the Host Bridge always device 00.0?

No. For instance the host controller may pass a nonzero
value of devfn_min to pci_bus_new/pci_register_bus (in
which case the host bridge will end up there; example
hw/pci-host/versatile.c) or it might just pass a nonzero
devfn to pci_create_simple when it creates the host controller
PCI device on the bus (I don't think we have anything that
does it that way, though).

> If not, can we find a way to scan all bus devices and find
> the host bridge so we will not have to manually add it to each
> host bridge?

It would be conceptually nicer not to treat host bridges as
a special case but instead to just report the abort back
to whatever the PCI master was (which might be a device
doing DMA). That might be a lot of effort though.

-- PMM