Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped

[Joerg Roedel]

On Wed, Nov 30, 2016 at 06:23:34PM +0800, Baoquan He wrote:
> OK, talked with Xunlei. The old cache could be entry with present bit
> set.

-EPARSE

Anyway, what I was trying to say is, that the IOMMU TLB is tagged with
domain-ids, and that there is also a context-cache which maps device-ids
to domain-ids.

If we update the context entry then we need to flush only the context
entry, as it will point to a new domain-id then and future IOTLB lookups
in the IOMMU will be using the new domain-id and do not match the old
entries.



	Joerg