Re: Oops in during sriov_enable with ixgbe driver

[Jesse Brandeburg <jesse.brandeburg@intel.com>]

On 9/28/2021 4:56 AM, Niklas Schnelle wrote:
> Hi Jesse, Hi Tony,
> 
> Since v5.15-rc1 I've been having problems with enabling SR-IOV VFs on
> my private workstation with an Intel 82599 NIC with the ixgbe driver. I
> haven't had time to bisect or look closer but since it still happens on
> v5.15-rc3 I wanted to at least check if you're aware of the problem as
> I couldn't find anything on the web.

We haven't heard anything of this problem.


> I get below Oops when trying "echo 2 > /sys/bus/pci/.../sriov_numvfs"
> and suspect that the earlier ACPI messages could have something to do
> with that, absolutely not an ACPI expert though. If there is a need I
> could do a bisect.

Hi Niklas, thanks for the report, I added the Intel Driver's list for
more exposure.

I asked the developers working on that driver to take a look and they
tried to reproduce, and were unable to do so. This might be related to
your platform, which strongly suggests that the ACPI stuff may be related.

We have tried to reproduce but everything works fine no call trace in
scenario with creating VF.

This is good in that it doesn't seem to be a general failure, you may
want to file a kernel bugzilla (bugzilla.kernel.org) to track the issue,
and I hope that @Rafael might have some insight.

This issue may be related to changes in acpi_pci_find_companion,
but as I say, we are not able to reproduce this.

commit 59dc33252ee777e02332774fbdf3381b1d5d5f5d
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date:   Tue Aug 24 16:43:55 2021 +0200
    PCI: VMD: ACPI: Make ACPI companion lookup work for VMD bus

At this point maybe a bisect would be helpful, since this seems to be a
corner case that we used to handle but no longer do.

Thanks!
Jesse