Re: PCI Passthrough, error: The driver 'pci-stub' is occupying your device 0000:08:06.2

James Neave
2011-02-25T23:03:00Z

On Fri, Feb 25, 2011 at 10:47 PM, James Neave <roboj1m@gmail.com> wrote:
> On Fri, Feb 25, 2011 at 12:06 AM, Chris Wright <chrisw@sous-sol.org> wrote:
>> * James Neave (roboj1m@gmail.com) wrote:
>>> OK, here's my latest dmesg with amd_iommu_dump and debug with no quiet
>>> http://pastebin.com/JxEwvqRA
>>
>> Yeah, that's what I expected:
>>
>> [    0.724403] AMD-Vi:   DEV_ALIAS_RANGE                 devid: 08:00.0 flags: 00 devid_to: 00:14.4
>> [    0.724439] AMD-Vi:   DEV_RANGE_END           devid: 08:1f.7
>>
>> That basically says 08:00.0 - 08:1f.7 will show up as 00:14.4 (and
>> should all go into same iommu domain).
>>
>>> I've just figured out a sequence of "echo DEV > PATH" commands to call
>>> for 14.4 gets me past the "claimed by pci-stub" error and gets me to
>>> the "failed to assign IRQ" error.
>>> I'm going to narrow down the required sequence and then post it.
>>
>> Kind of afraid to ask, but does it include:
>>
>> (assuming 1002 4384 is the pci to pci bridge)
>> echo 1002 4384 > /sys/bus/pci/drivers/pci-stub/new_id
>> echo 0000:00:14.4 > /sys/bus/pci/drivers/pci-stub/unbind
>>
>> (this has the side effect of detaching the bridge from its domain)
>>
>> thanks,
>> -chris
>>
>
> Exact sequence is:
>
> echo "1002 4384" > /sys/bus/pci/drivers/pci-stub/new_id
> echo "0000:00:14.4" > /sys/bus/pci/devices/0000:00:14.4/driver/unbind
>
> I take it this is a bad thing then?
>
>> I assume this means that 00:14.4 is still left claimed by pci-stub?
>
> Yes
>
>> How are you determining this?  The lspci paste above has pci-stub for all
>> of them.  The easiest thing might be to start with manually disabling
>> host driver and reassigning pci-stub to: 00:14.4, 08: 06.2,3 and 0e.0
>> Then giving the guest only 08:06.1.
>
> I determined it by being half asleep and not reading it properly... >.<
> You're right, all 5 devices were using pci-stub
>
>>> libvirtError: this function is not supported by the connection driver:
>>> Unable to reset PCI device 0000:00:14.4: no FLR, PM reset or bus reset
>>> available
>
>> Right, libvirt is more restrictive than qemu-kvm (forgot you were using
>> libvirt here).
>
> What does that libvirt error mean? I can't find a definition.
> Am I limiting myself by using libvirt? Would not using it help and how
> would I go about not using it?
>
>> Trouble now is that
>> with shared IRQ we don't have a good way to handle that right now.
>
> Game over then?
> I've tried assigning the USB devices before, I couldn't do it because
> qemu doesn't support USB2 devices.
> I don't really understand where this IRQ conflict is, the firewire and
> the USB2 device share IRQ22 but I'm assigning them both to the VM?
> Is that still a problem?
> I don't suppose there's any way to change which IRQ they use in the
> BIOS or with a command is there?
>
> I don't know if it means anything but this page:
>
> http://linuxtv.org/wiki/index.php/Hauppauge_WinTV-HVR-2200
>
> Has the lspci output for the HVR-2200 which mentions MSI and IRQ255.
> My knowledge it very limited on this subject so I don't know if that's
> meaningless looking at the output from another person's lspci.
>
> Anything left to try?
>
> Regardless, many thanks for your help,
>
> James.
>

On the off chance I tried disabling the firewire in the BIOS, which
leaves only my tuner card using IRQ 20, 21 and 22.
No difference, still complains about IRQs:

Using raw in/out ioport access (sysfs - Input/output error)
Failed to assign irq for "hostdev0": Operation not permitted
Perhaps you are assigning a device that shares an IRQ with another device?

It does say "Operation not permitted" and that only "perhaps" I am
assigning a device that shares an IRQ.
Perhaps IRQ conflict it not the problem? They really are sitting on
their own. Another permissions problem perhaps?

Regards,

James.