REGRESSION: Re: [patch V2 00/46] x86, PCI, XEN, genirq ...: Prepare for device MSI

[Jason Gunthorpe]

On Wed, Aug 26, 2020 at 01:16:28PM +0200, Thomas Gleixner wrote:
> This is the second version of providing a base to support device MSI (non
> PCI based) and on top of that support for IMS (Interrupt Message Storm)
> based devices in a halfways architecture independent way.

Hi Thomas,

Our test team has been struggling with a regression on bare metal
SRIOV VFs since -rc1 that they were able to bisect to this series

This commit tests good:

5712c3ed549e ("Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc")

This commit tests bad:

981aa1d366bf ("PCI: MSI: Fix Kconfig dependencies for PCI_MSI_ARCH_FALLBACKS")

They were unable to bisect further into the series because some of the
interior commits don't boot :(

When we try to load the mlx5 driver on a bare metal VF it gets this:

[Thu Oct 22 08:54:51 2020] DMAR: DRHD: handling fault status reg 2
[Thu Oct 22 08:54:51 2020] DMAR: [INTR-REMAP] Request device [42:00.2] fault index 1600 [fault reason 37] Blocked a compatibility format interrupt request
[Thu Oct 22 08:55:04 2020] mlx5_core 0000:42:00.1 eth4: Link down
[Thu Oct 22 08:55:11 2020] mlx5_core 0000:42:00.1 eth4: Link up
[Thu Oct 22 08:55:54 2020] mlx5_core 0000:42:00.2: mlx5_cmd_eq_recover:264:(pid 3390): Recovered 1 EQEs on cmd_eq
[Thu Oct 22 08:55:54 2020] mlx5_core 0000:42:00.2: wait_func_handle_exec_timeout:1051:(pid 3390): cmd0: CREATE_EQ(0×301) recovered after timeout
[Thu Oct 22 08:55:54 2020] DMAR: DRHD: handling fault status reg 102
[Thu Oct 22 08:55:54 2020] DMAR: [INTR-REMAP] Request device [42:00.2] fault index 1600 [fault reason 37] Blocked a compatibility format interrupt request

If you have any idea Ziyad and Itay can run any debugging you like.

I suppose it is because this series is handing out compatability
addr/data pairs while the IOMMU is setup to only accept remap ones
from SRIOV VFs?

Thanks,
Jason