From: Joerg Roedel <joro@8bytes.org>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>,
Alex Williamson <alex.williamson@redhat.com>,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@infradead.org>,
Kevin Tian <kevin.tian@intel.com>,
Ashok Raj <ashok.raj@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Will Deacon <will@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
rafael@kernel.org, Diana Craciun <diana.craciun@oss.nxp.com>,
Cornelia Huck <cohuck@redhat.com>,
Eric Auger <eric.auger@redhat.com>, Liu Yi L <yi.l.liu@intel.com>,
Jacob jun Pan <jacob.jun.pan@intel.com>,
Chaitanya Kulkarni <kch@nvidia.com>,
Stuart Yoder <stuyoder@gmail.com>,
Laurentiu Tudor <laurentiu.tudor@nxp.com>,
Thierry Reding <thierry.reding@gmail.com>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Jonathan Hunter <jonathanh@nvidia.com>,
Li Yang <leoyang.li@nxp.com>, Dmitry Osipenko <digetx@gmail.com>,
iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 5/8] iommu/amd: Use iommu_attach/detach_device()
Date: Mon, 14 Feb 2022 15:23:07 +0100 [thread overview]
Message-ID: <YgplyyjofwlM+1tc@8bytes.org> (raw)
In-Reply-To: <20220214140236.GC929467@nvidia.com>
On Mon, Feb 14, 2022 at 10:02:36AM -0400, Jason Gunthorpe wrote:
> That works for VFIO, but it doesn't work for other in-kernel
> drivers.. Is there something ensuring the group is only the GPU and
> sound device? Is the GPU never an addin card?
GPUs supporting this functionality are always iGPUs, AFAIK.
> I'd say the right way to code this after Lu's series to have both the
> GPU and sound driver call iommu_attach_device() during their probe()'s
> and specify the identity domain as the attaching domain.
>
> That would be quite similar to how the Tegra drivers got arranged.
>
> And then maybe someone could better guess what the "sound driver" is
> since it would be marked with an iommu_attach_device() call.
Device drivers calling into iommu_attach_device() is seldom a good
idea. In this case the sound device has some generic hardware
interface so that an existing sound driver can be re-used. Making this
driver call iommu-specific functions for some devices is something hard
to justify.
With sub-groups on the other hand it would be a no-brainer, because the
sound device would be in a separate sub-group. Basically any device in
the same group as the GPU would be in a separate sub-group.
Regards,
Joerg
next prev parent reply other threads:[~2022-02-14 14:23 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-06 2:20 [PATCH v1 0/8] Scrap iommu_attach/detach_group() interfaces Lu Baolu
2022-01-06 2:20 ` [PATCH v1 1/8] iommu: Add iommu_group_replace_domain() Lu Baolu
2022-01-06 17:06 ` Jason Gunthorpe
2022-01-07 0:26 ` Lu Baolu
2022-02-14 12:09 ` Robin Murphy
2022-02-14 12:45 ` Jason Gunthorpe
2022-02-14 14:10 ` Robin Murphy
2022-02-14 14:56 ` Jason Gunthorpe
2022-02-14 16:38 ` Robin Murphy
2022-02-14 17:25 ` Jason Gunthorpe
2022-01-06 2:20 ` [PATCH v1 2/8] vfio/type1: Use iommu_group_replace_domain() Lu Baolu
2022-01-06 2:20 ` [PATCH v1 3/8] iommu: Extend iommu_at[de]tach_device() for multi-device groups Lu Baolu
2022-01-06 17:22 ` Jason Gunthorpe
2022-01-07 1:14 ` Lu Baolu
2022-01-07 1:19 ` Jason Gunthorpe
2022-02-14 11:39 ` Joerg Roedel
2022-02-14 13:03 ` Jason Gunthorpe
2022-02-14 14:39 ` Joerg Roedel
2022-02-14 15:18 ` Robin Murphy
2022-02-14 15:46 ` Jason Gunthorpe
2022-02-15 8:58 ` Joerg Roedel
2022-02-15 13:47 ` Jason Gunthorpe
2022-02-16 6:28 ` Lu Baolu
2022-02-16 13:54 ` Jason Gunthorpe
2022-01-06 2:20 ` [PATCH v1 4/8] drm/tegra: Use iommu_attach/detatch_device() Lu Baolu
2022-01-06 2:20 ` [PATCH v1 5/8] iommu/amd: Use iommu_attach/detach_device() Lu Baolu
2022-01-06 14:33 ` Jason Gunthorpe
2022-01-07 0:23 ` Lu Baolu
2022-02-14 11:27 ` Joerg Roedel
2022-02-14 13:15 ` Jason Gunthorpe
2022-02-14 13:40 ` Joerg Roedel
2022-02-14 14:02 ` Jason Gunthorpe
2022-02-14 14:23 ` Joerg Roedel [this message]
2022-02-14 15:00 ` Jason Gunthorpe
2022-02-15 9:11 ` Joerg Roedel
2022-02-15 13:02 ` Robin Murphy
2022-02-15 14:37 ` Jason Gunthorpe
2022-01-06 2:20 ` [PATCH v1 6/8] gpu/host1x: " Lu Baolu
2022-01-06 15:35 ` Jason Gunthorpe
2022-01-07 0:35 ` Lu Baolu
2022-01-07 0:48 ` Jason Gunthorpe
2022-01-07 1:19 ` Lu Baolu
2022-01-06 2:20 ` [PATCH v1 7/8] media: staging: media: tegra-vde: " Lu Baolu
2022-01-06 2:20 ` [PATCH v1 8/8] iommu: Remove iommu_attach/detach_group() Lu Baolu
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