Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 97140101 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu/vt-d: Use real PASID for flush in caching mode 



If caching mode is supported, the hardware will cache
none-present or erroneous translation entries. Hence,
software should explicitly invalidate the PASID cache
after a PASID table entry becomes present. We should
issue such invalidation with the PASID value that we
have changed. PASID 0 is not reserved for this case.

Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Sankaran Rajesh <rajesh.sankaran@intel.com>
Suggested-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarLiu Yi L <yi.l.liu@intel.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent bbe4b3af

drivers/iommu/intel-svm.c

+6 −10
Original line number Diff line number Diff line
@@ -423,17 +423,13 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ 
		iommu->pasid_table[svm->pasid].val = pasid_entry_val;



		wmb();

		/* In caching mode, we still have to flush with PASID 0 when

		 * a PASID table entry becomes present. Not entirely clear

		 * *why* that would be the case — surely we could just issue

		 * a flush with the PASID value that we've changed? The PASID

		 * is the index into the table, after all. It's not like domain

		 * IDs in the case of the equivalent context-entry change in

		 * caching mode. And for that matter it's not entirely clear why

		 * a VMM would be in the business of caching the PASID table

		 * anyway. Surely that can be left entirely to the guest? */



		/*

		 * Flush PASID cache when a PASID table entry becomes

		 * present.

		 */

		if (cap_caching_mode(iommu->cap))

			intel_flush_pasid_dev(svm, sdev, 0);

			intel_flush_pasid_dev(svm, sdev, svm->pasid);

	}

	list_add_rcu(&sdev->list, &svm->devs);