On Thu, Sep 30, 2021 at 7:38 PM Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> wrote: > > On 9/30/2021 7:31 PM, Jesse Brandeburg wrote: > > 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@xxxxxxxxx> > > Date: Tue Aug 24 16:43:55 2021 +0200 > > PCI: VMD: ACPI: Make ACPI companion lookup work for VMD bus > > This change doesn't affect any devices beyond the ones on the VMD bus. The only failing case I can see is when the device is on the VMD bus and its bus pointer is NULL, so the dereference in vmd_acpi_find_companion() crashes. Can anything like that happen? > > 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.
