[PATCH 0/5] iommu/virtio: Add identity domains

joro at 8bytes.org
Mon, 18 Oct 2021 11:37:55 -0000

On Thu, Oct 14, 2021 at 03:00:38AM +0000, Tian, Kevin
wrote:
> I saw a concept of deferred attach in iommu core. See iommu_is_
> attach_deferred(). Currently this is vendor specific and I haven't
> looked into the exact reason why some vendor sets it now. Just
> be curious whether the same reason might be applied to virtio-iommu.

The reason for attach_deferred is kdump support, where the IOMMU driver
needs to keep the mappings from the old kernel until the device driver
of the new kernel takes over.

Regards,

	Joerg