Il 22/07/2013 17:04, Peter Maydell ha scritto: > On 22 July 2013 15:36, Paolo Bonzini <pbonz...@redhat.com> wrote: >> Il 22/07/2013 16:32, Peter Maydell ha scritto: >>> In the long term it would be good to identify which boards >>> were using isa_mmio purely for the benefit of old_portio >>> (which I think is basically "boards where the CPU has no >>> concept of port I/O instructions"). >> >> All of them. Only i386/x86_64 has I/O space, as far as I know. > > Sounds plausible. I had wondered if our ISA bus infrastructure > assumed that ISA device IO ports live in the system IO space, > but it doesn't.
No, luckily it doesn't, and neither should the PCI-to-ISA bridges as you found out---they do not after these patches. PReP is an exception, but I think it could be rewritten to use an IOMMU memory region. > Side question: should the ICH9 emulation ich9_lpc_initfn() > really put its ISA bus in the system IO space rather than > in the pci_address_space_io() ? No, I think it should use pci_address_space_io(). PCI devices (the ISA bridge is one) should not know that a system IO space exists, only the PCI host bridge has that knowledge. Paolo
