iommu/vt-d: Enable write protect propagation from guest

iommu/vt-d: Enable write protect propagation from guest

Write protect bit, when set, inhibits supervisor writes to the read-only
pages. In guest supervisor shared virtual addressing (SVA), write-protect
should be honored upon guest bind supervisor PASID request.

This patch extends the VT-d portion of the IOMMU UAPI to include WP bit.
WPE bit of the  supervisor PASID entry will be set to match CPU CR0.WP bit.

Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-3-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>