When the Q35 machine type(s) of QEMU are used with libvirt, libvirt tends
to place some devices behind PCI bridges. This is then reflected in the
"bootorder" fw_cfg file. For example:
/pci@i0cf8/pci-bridge@1e/pci-bridge@1/scsi@5/disk@0,0
/pci@i0cf8/pci-bridge@1e/pci-bridge@1/scsi@3/channel@0/disk@0,0
As yet QemuBootOrderLib doesn't support such OFW device paths.
Add code that translates a sequence of pci-bridge nodes.
In practice libvirt seems to insert two such nodes (*), hence increment
EXAMINED_OFW_NODES with the same number.
(* Background, paraphrasing Laine Stump's words:
When the machine type is Q35, we create a dmi-to-pci bridge coming off of
the pcie root controller, and a pci-to-pci bridge coming off of that, then
attach most devices to the pci-to-pci bridge. This is done because you
can't hotplug into pcie-root, can't (or at least shouldn't) plug a
pci-to-pci bridge into pcie-root (so the next one has to be
dmi-to-pci-bridge), and can't hotplug into dmi-to-pci-bridge (so you need
to have a pci-to-pci bridge).)
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17385 6f19259b-4bc3-4df7-8a09-765794883524
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