Re: [Intel-gfx] [PATCH v3 0/6] Convert the intel iommu driver to the dma-iommu api

From: Lu Baolu
Date: Mon Sep 21 2020 - 20:30:19 EST

Hi Logan,

On 9/21/20 11:48 PM, Logan Gunthorpe wrote:

On 2020-09-20 12:36 a.m., Lu Baolu wrote:
Hi Logan,

On 2020/9/19 4:47, Logan Gunthorpe wrote:
Hi Lu,

On 2020-09-11 9:21 p.m., Lu Baolu wrote:
Tom Murphy has almost done all the work. His latest patch series was
posted here.

Thanks a lot!

This series is a follow-up with below changes:

1. Add a quirk for the i915 driver issue described in Tom's cover
2. Fix several bugs in patch "iommu: Allow the dma-iommu api to use
bounce buffers" to make the bounce buffer work for untrusted devices.
3. Several cleanups in iommu/vt-d driver after the conversion.

I'm trying to test this on an old Sandy Bridge, but found that I get
spammed with warnings on boot. I've put a sample of a few of them below.
They all seem to be related to ioat.

I had the same issue with Tom's v2 but never saw this on his v1.

Have you verified whether this could be reproduced with the lasted
upstream kernel (without this patch series)?


I am sorry. Just want to make sure I understand you correctly. :-) When
you say "yes", do you mean you could reproduce this with pure upstream
kernel (5.9-rc6)?

Also, it's hitting a warning in the dma-iommu code which would not
be hit without this patch set.

Without this series, DMA APIs don't go through dma-iommu. Do you mind
posting the warning message?

Best regards,