Hi Joerg,

Attachments are console log of normal kernel and kdump kernel on a test
machine at my hand, and the related information of lspci -vt and lspci
-vvv. Before I tried to defer the calling of set_dte_entry() until the
device driver try to call __map_single() to really allocate coherent
memory or do the mapping, seems it didn't work. I am surprised by the
simplicity and effectiveness of Intel IOMMU fix, but can't think of
where I have missed.