[PATCH rc v7 0/7] iommu/arm-smmu-v3: Fix device crash on kdump kernel

[Jason Gunthorpe]

On Wed, Jul 01, 2026 at 01:36:29PM +0000, Pranjal Shrivastava wrote:

> However, I agree with the overall problem, i.e. IF an active device
> unmaps the DMA addr after the transaction in the previous kernel, 
> (with the SMMU powered ON) but the TLBI was missed due to a crash/panic,
> Any new DMA in the new kernel may alias onto a memory in the previous 
> (crashed) kernel, not the kdump kernel.

It looks like there is an issue in this series, it isn't doing
anything with the VMIDs.

The VMIDs that are in-used by the adopted stream table have to be
removed from the idr as well (and similarly for ASID if we don't have
VMID HW support).

Then the VMIDs that may be dirtied by the prior kernel remain isolated
and are never re-used by the new kernel. When the new kernel wants to
do DMA it will replace the STE with a new, clean VMID, and there is no
problem.

Jason