iommu/vt-d: Use second level for GPA->HPA translation

iommu/vt-d: Use second level for GPA->HPA translation

The IOMMU VT-d implementation uses the first level for GPA->HPA translation
by default. Although both the first level and the second level could handle
the DMA translation, they're different in some way. For example, the second
level translation has separate controls for the Access/Dirty page tracking.
With the first level translation, there's no such control. On the other
hand, the second level translation has the page-level control for forcing
snoop, but the first level only has global control with pasid granularity.

This uses the second level for GPA->HPA translation so that we can provide
a consistent hardware interface for use cases like dirty page tracking for
live migration.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210926114535.923263-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20211014053839.727419-6-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>