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

[Lu Baolu]

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.
> > > >
> > > > https://lore.kernel.org/linux-iommu/20200903201839.7327-1-murphyt7@xxxxxx/
> > > >
> > > > 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
> > > > letter.
> > > > 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)?
>
> Yes.

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,
baolu