iommu/vt-d: Calculate and set flags for handle_mm_fault

iommu/vt-d: Calculate and set flags for handle_mm_fault

Page requests are originated from the user page fault. Therefore, we
shall set FAULT_FLAG_USER. 

FAULT_FLAG_REMOTE indicates that we are walking an mm which is not
guaranteed to be the same as the current->mm and should not be subject
to protection key enforcement. Therefore, we should set FAULT_FLAG_REMOTE
to avoid faults when both SVM and PKEY are used.

References: commit 1b2ee1266ea6 ("mm/core: Do not enforce PKEY permissions on remote mm access")
Reviewed-by: Raj Ashok <ashok.raj@intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-5-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>