From: Jason Gunthorpe <jgg@nvidia.com>
To: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Brost <matthew.brost@intel.com>,
Dave Airlie <airlied@gmail.com>,
dri-devel <dri-devel@lists.freedesktop.org>,
iommu@lists.linux-foundation.org, "Koenig,
Christian" <Christian.Koenig@amd.com>
Subject: Re: iommu/smmu/PCI ATS + TTM unmaps + nouveau best way forward
Date: Wed, 1 Jul 2026 20:34:19 -0300 [thread overview]
Message-ID: <20260701233419.GK7481@nvidia.com> (raw)
In-Reply-To: <akRsELMbwJmUKWek@nvdebian.thelocal>
On Wed, Jul 01, 2026 at 11:30:08AM +1000, Alistair Popple wrote:
> Agree with most of the above and this seems the most likely explaination. ATS
> doesn't change much here - most of our driver still goes via dma_map/unmap to
> access host memory via an IOMMU IOVA so non-present entries there would be fatal
> at the IOMMU level. So even with ATS enabled a non-present DMA mapping should
> still result in noisy IOMMU faults.
AFAIK, the iommu driver does not log ATS non-present replies, those
are considered normal events. The device itself is the only source of
reporting.
Jason
prev parent reply other threads:[~2026-07-01 23:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-30 9:39 iommu/smmu/PCI ATS + TTM unmaps + nouveau best way forward Dave Airlie
2026-06-30 11:24 ` Christian König
2026-06-30 11:51 ` Jason Gunthorpe
2026-06-30 20:45 ` Dave Airlie
2026-06-30 21:00 ` Dave Airlie
2026-07-01 0:17 ` Jason Gunthorpe
2026-07-01 1:22 ` Alistair Popple
2026-06-30 23:59 ` Jason Gunthorpe
2026-06-30 11:39 ` Jason Gunthorpe
2026-06-30 23:21 ` Matthew Brost
2026-07-01 1:30 ` Alistair Popple
2026-07-01 23:34 ` Jason Gunthorpe [this message]
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