Messages in this thread | | | Date | Fri, 30 Oct 2015 15:13:47 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 8/8] iommu: Move default domain allocation to iommu_group_get_for_dev() |
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Hi Will,
On Thu, Oct 29, 2015 at 06:22:49PM +0000, Will Deacon wrote: > The call to iommu_group_get_for_dev in arm_smmu_add_device will end up > calling __iommu_attach_device, since group->domain will now be initialised > by the code above. This means the SMMU driver will see an ->attach_dev > call for a device that is part-way through an ->add_device callback and > will be missing the initialisation necessary for us to idenfity the SMMU > instance to which is corresponds. In fact, the iommudata for the group > won't be initialised at all, so the whole thing will fail afaict. > > Note that I haven't actually taken this for a spin, so I could be missing > something.
Yeah, I havn't looked at how to convert the ARM-SMMU drivers to default domains yet, so the issue you describe above is totally possible.
But there is no way to trigger it yet, because your domain_alloc function can not yet allocate IOMMU_DOMAIN_DMA domains. While converting the issue must be fixed, of course.
I tested this patch-set on an AMD Seattle system and it worked fine there.
Joerg
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