Re: IGD pass-through failures since 4.10.

[Jan Beulich <jbeulich@xxxxxxxx>]

On 22.02.2022 19:52, Dr. Greg wrote:
> On Fri, Feb 18, 2022 at 08:04:14AM +0100, Jan Beulich wrote:
>> On 17.02.2022 21:15, Dr. Greg wrote:
>>> On Mon, Feb 14, 2022 at 09:56:34AM +0100, Jan Beulich wrote:
>>> In the case of the logs above, the following command sequence is being
>>> executed upon termination of the domain:
>>>
>>> # Unbind devices.
>>> echo 0000:00:14.0 >| /sys/bus/pci/drivers/pciback/unbind
>>> echo 0000:00:02.0 >| /sys/bus/pci/drivers/pciback/unbind
>>>
>>> # Rebind devices.
>>> echo 0000:00:14.0 >| /sys/bus/pci/drivers/xhci_hcd/bind
>>> echo 0000:00:02.0 >| /sys/bus/pci/drivers/i915/bind
> 
>> ... you may still want to try replacing these with
>> "xl pci-assignable-add ..." / "xl pci-assignable-remove ...".
> 
> We tested using the 'xl pci-assignable-add/remove' sequences and we
> believe this may have resulted in the proper return of the devices to
> dom0 but haven't been able to verify that since the Windows VM is now
> throwing the VIDEO_TDR error.
> 
> Unless we are misunderstanding something the 'xl
> pci-assignable-remove' sequence requires the manual re-binding of the
> devices to their dom0 drivers.

Hmm, I thought drivers would be rebound, but I'm not a tool stack person.
Looking at libxl__device_pci_assignable_remove() at least support this
assumption of mine. You did use the command's -r option, didn't you?

Jan