From: Joerg Roedel <joro@8bytes.org>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mario Limonciello <mario.limonciello@amd.com>,
Alex Deucher <alexander.deucher@amd.com>,
amd-gfx@lists.freedesktop.org,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
Vasant Hegde <vasant.hegde@amd.com>,
Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
"open list:AMD IOMMU (AMD-VI)" <iommu@lists.linux.dev>,
Jatin Kataria <jkataria@netflix.com>,
Boqun Feng <boqunf@netflix.com>,
"Derek J . Clark" <derekjohn.clark@gmail.com>
Subject: Re: [PATCH v2 1/2] iommu/amd: Add PerfOpt IOMMU performance optimization support
Date: Fri, 25 Sep 2026 09:20:02 +0200 [thread overview]
Message-ID: <arYf3iJW7hfTua__@8bytes.org> (raw)
In-Reply-To: <20260924225018.GB16465@ziepe.ca>
On Thu, Sep 24, 2026 at 07:50:18PM -0300, Jason Gunthorpe wrote:
> Why does the GPU driver have to request this? Why can't the iommu
> driver know that this is a special device that can use this magic fast
> path and then auto set it when identity is asked for?
This is a layering violation either way. Either the IOMMU driver needs to poke
into device details and their relations or the device driver needs to poke into
IOMMU details.
This is not perfect but to some degree unavoidable with these highly integrated
SOCs.
-Joerg
next prev parent reply other threads:[~2026-09-25 7:39 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-08 4:12 [PATCH v2 0/2] IOMMU Performance Optimization support Mario Limonciello
2026-09-08 4:12 ` [PATCH v2 1/2] iommu/amd: Add PerfOpt IOMMU performance optimization support Mario Limonciello
2026-09-24 22:50 ` Jason Gunthorpe
2026-09-25 0:03 ` Mario Limonciello
2026-09-25 0:17 ` Jason Gunthorpe
2026-09-25 0:21 ` Mario Limonciello
2026-09-25 7:20 ` Joerg Roedel [this message]
2026-09-25 12:28 ` Jason Gunthorpe
2026-09-25 13:11 ` Mario Limonciello
2026-09-25 22:39 ` Jason Gunthorpe
2026-09-26 0:33 ` Mario Limonciello
2026-09-28 12:08 ` Jason Gunthorpe
2026-09-28 15:32 ` Mario Limonciello
2026-09-28 17:11 ` Jason Gunthorpe
2026-09-28 17:15 ` Mario Limonciello
2026-09-29 2:53 ` Deucher, Alexander
2026-09-28 5:17 ` Christoph Hellwig
2026-09-25 7:30 ` Joerg Roedel
2026-09-08 4:12 ` [PATCH v2 2/2] drm/amdgpu: Enable PerfOpt IOMMU perf optimization when GPU in identity domain Mario Limonciello
2026-09-20 14:10 ` [PATCH v2 0/2] IOMMU Performance Optimization support Mario Limonciello
2026-09-20 16:27 ` Boqun Feng
2026-09-24 11:42 ` Joerg Roedel
2026-09-24 13:01 ` Deucher, Alexander
2026-09-24 13:50 ` Joerg Roedel
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