Re: [PATCH v2 0/3] KVM: x86: KVM_MEM_PCI_HOLE memory

[Gerd Hoffmann]

  Hi,

> I see a similar ~8k PCI hole reads with a -kernel boot w/ OVMF.  All but 60
> of those are from pcibios_fixup_peer_bridges(), and all are from the kernel.

pcibios_fixup_peer_bridges() looks at pcibios_last_bus, and that in turn
seems to be set according to the mmconfig size (in
arch/x86/pci/mmconfig-shared.c).

So, maybe we just need to declare a smaller mmconfig window in the acpi
tables, depending on the number of pci busses actually used ...

> If all of the above is true, this can be handled by adding "pci=lastbus=0"

... so we don't need manual quirks like this?

take care,
  Gerd