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

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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: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Lu Baolu 2018-03-16 12:31:36 +08:00 committed by Joerg Roedel
parent bbe4b3af9d
commit 971401015d
1 changed files with 6 additions and 10 deletions
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16
drivers/iommu/intel-svm.c
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@ -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);