Re: [Qemu-devel] [PATCH v3 6/6] hw/pci-bridge: set explicit OFW unit address for TYPE_PXB_HOST

[Laszlo Ersek <lersek@redhat.com>]

On 06/11/15 12:29, Marcel Apfelbaum wrote:
> On 06/11/2015 01:26 PM, Laszlo Ersek wrote:
>> On 06/11/15 12:21, Marcel Apfelbaum wrote:
>>> On 06/11/2015 03:38 AM, Laszlo Ersek wrote:
>>>> The PXB implementation doesn't allow firmware (SeaBIOS or OVMF) to boot
>>>> off devices behind the PXB. This happens because the
>>>> sysbus_get_fw_dev_path() function in "hw/core/sysbus.c" doesn't have
>>>> enough information to format a unique identifier for the PXB in
>>>> question,
>>>> and consequently the OpenFirmware device path passed down to the guest
>>>> firmware in the "bootorder" fw_cfg file is unusable for identifying the
>>>> boot device.
>>>>
>>>> For example, the command line fragment
>>>>
>>>>     -device pxb,id=bridge1,bus_nr=4 \
>>>>     \
>>>>     -netdev user,id=netdev0 \
>>>>     -device e1000,netdev=netdev0,bus=bridge1,addr=2,bootindex=0
>>>>
>>>> results in the following "bootorder" entry:
>>>>
>>>>     /pci/pci-bridge@0/ethernet@2/ethernet-phy@0
>>>>
>>>> The initial "pci" node is formatted by sysbus_get_fw_dev_path(), and
>>>> the
>>>> resultant OpenFirmware device path is independent of bus_nr=4 -- and
>>>> therefore it is useless for identifying the device.
>>>>
>>>> In this patch we change the fw_name device class member of
>>>> TYPE_PXB_HOST
>>>> from "pci" to "pci-root", and set each instance's explicit OFW unit
>>>> address to the PXB bus number. The same command line fragment
>>>> results in
>>>> the following OpenFirmware device path in the "bootorder" fw_cfg file:
>>>>
>>>>     /pci-root@4/pci-bridge@0/ethernet@2/ethernet-phy@0
>>> Hi Laszlo,
>>>
>>> I applied your patches but I still get
>>> /pci@i0cf8/ethernet@5/ethernet-phy@0
>>> in the boot list
>>>
>>> I checked and  the code enters only once in sysbus_get_fw_dev_path
>>> for pci@i0cf8 and goes for pio branch.
>>>
>>> Do you know maybe what I missed?
>>
>> I think so, yes: you added the ...,bootorder=N property to a device that
>> is *not* behind a PXB. :) You forgot the ...,bus=bridgeX property.
> 
> Actually:
> -device pxb,id=bridge1,bus_nr=4 -netdev user,id=u \
> -device
> e1000,id=net2,bus=bridge1,netdev=u,addr=0x5,bootindex=0,romfile=../pc-bios/efi-e1000.rom,bus=pci.0
> 
> 
> Hmm :(

Count the "bus=" substrings on your command line :)

Laszlo