When the dmar translation fault happens, the kernel prints a single line
fault reason with corresponding hexadecimal code defined in the Intel VT-d
specification.

Currently, when user wants to debug the translation fault in detail,
debugfs is used for dumping the dmar_translation_struct, which is not
available when the kernel failed to boot.

Dump the DMAR translation structure, pagewalk the IO page table and print
the page table entry when the fault happens.

This takes effect only when CONFIG_DMAR_DEBUG is enabled.
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Link: https://lore.kernel.org/r/20210815203845.31287-1-kyung.min.park@intel.comSigned-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20211014053839.727419-3-baolu.lu@linux.intel.comSigned-off-by: Joerg Roedel <jroedel@suse.de>