Re: [PATCH for-4.6 0/5] xen: arm: Parse PCI DT nodes' ranges and interrupt-map

[Suravee Suthikulanit <suravee.suthikulpanit@amd.com>]

On 2/17/2015 4:35 PM, Suravee Suthikulanit wrote:
> On 2/17/2015 7:50 AM, Andrew Cooper wrote:
>> On 17/02/15 13:43, Julien Grall wrote:
>>> (CC Jan and Andrew)
>>>
>>> Hi Suravee,
>>>
>>> On 17/02/15 03:04, Suravee Suthikulanit wrote:
>>>> By the way, looking at the output of "xl dmesg", I saw the following
>>>> message:
>>>>
>>>> (XEN) DOM0: PCI host bridge /smb/pcie@f0000000 ranges:
>>>> (XEN) DOM0:    IO 0xefff0000..0xefffffff -> 0x00000000
>>>> (XEN) DOM0:   MEM 0x40000000..0xbfffffff -> 0x40000000
>>>> (XEN) DOM0:   MEM 0x100000000..0x7fffffffff -> 0x100000000
>>>> (XEN) DOM0: pci-host-generic f0000000.pcie: PCI host bridge to bus
>>>> 0000:00
>>>> (XEN) DOM0: pci_bus 0000:00: root bus resource [bus 00-7f]
>>>> (XEN) DOM0: pci_bus 0000:00: root bus resource [io  0x0000-0xffff]
>>>> (XEN) DOM0: pci_bus 0000:00: root bus resource [mem
>>>> 0x40000000-0xbfffffff]
>>>> (XEN) DOM0: pci_bus 0000:00: root bus resource [mem
>>>> 0x100000000-0x7fffffffff]
>>>> (XEN) DOM0: pci 0000:00:00.0: of_irq_parse_pci() failed with rc=-19
>>>> (XEN) do_physdev_op 16 cmd=25: not implemented yet
>>>> (XEN) do_physdev_op 16 cmd=15: not implemented yet
>>>> (XEN) DOM0: pci 0000:00:00.0: Failed to add - passthrough or MSI/MSI-X
>>>> might fail!
>>>> (XEN) DOM0: pci 0000:00:02.0: of_irq_parse_pci() failed with rc=-19
>>>> (XEN) do_physdev_op 16 cmd=15: not implemented yet
>>>> (XEN) DOM0: pci 0000:00:02.0: Failed to add - passthrough or MSI/MSI-X
>>>> might fail!
>>>> (XEN) do_physdev_op 16 cmd=15: not implemented yet
>>>> (XEN) DOM0: pci 0000:00:02.1: Failed to add - passthrough or MSI/MSI-X
>>>> might fail!
>>>> (XEN) do_physdev_op 16 cmd=15: not implemented yet
>>>> (XEN) DOM0: pci 0000:01:00.0: Failed to add - passthrough or MSI/MSI-X
>>>> might fail!
>>>> (XEN) DOM0: pci 0000:01:00.1: of_irq_parse_pci() failed with rc=-22
>>>> (XEN) do_physdev_op 16 cmd=15: not implemented yet
>>>> (XEN) DOM0: pci 0000:01:00.1: Failed to add - passthrough or MSI/MSI-X
>>>> might fail!
>>>>
>>>> IIUC, This is because xen_add_device() failed, and it seems to be
>>>> related to some hyper call not implemented. Not sure what is "cmd=15".
>>>> Any ideas?
>>> There is 2 commands not implemented in the log:
>>>     * cmd 15: PHYSDEVOP_manage_pci_add
>>>     * cmd 25: PHYSDEVOP_pci_device_add
>>>
>>> Linux fallbacks on the former because the later is not implemented.
>>>
>>> AFAICT, PHYSDEVOP_manage_pci_add should not be implemented for ARM
>>> because it doesn't support segment. I suspect that it's kept for legacy
>>> on older Xen x86. Maybe Jan or Andrew have more input on this?
>>
>> It needs to be kept for backwards compatibility in x86.
>>
>> All new code should use PHYSDEVOP_pci_device_add.
>>
>> ~Andrew
>>
>
> Ok, now that I look at the arch/arm/physdev.c, I don't think the code
> for supporting any of the PHYSDEVOP_xxx is there.  That's probably why
> Xen complains. In contrast, arch/x86/physdev.c has most PHYSDEVOP_xxx
> already supported.
>
> My question is, are we supposed to be adding code to put the support in
> here?
>
> Thanks,
>
> Suravee.

My guess is yes, and that would mean we need to enable building 
drivers/pci.c when building arm code, which then open up a can of worms 
with re-factoring MSI support code from x86 and etc.

Suravee