Messages in this thread Patch in this message | | | From | Jacob Pan <> | Subject | [PATCH v3 3/7] iommu/vt-d: Fix PASID devTLB invalidation | Date | Wed, 1 Jul 2020 08:33:52 -0700 |
| |
DevTLB flush can be used for both DMA request with and without PASIDs. The former uses PASID#0 (RID2PASID), latter uses non-zero PASID for SVA usage.
This patch adds a check for PASID value such that devTLB flush with PASID is used for SVA case. This is more efficient in that multiple PASIDs can be used by a single device, when tearing down a PASID entry we shall flush only the devTLB specific to a PASID.
Fixes: 6f7db75e1c46 ("iommu/vt-d: Add second level page table") Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> --- drivers/iommu/intel/pasid.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c index c81f0f17c6ba..fa0154cce537 100644 --- a/drivers/iommu/intel/pasid.c +++ b/drivers/iommu/intel/pasid.c @@ -486,7 +486,16 @@ devtlb_invalidation_with_pasid(struct intel_iommu *iommu, qdep = info->ats_qdep; pfsid = info->pfsid; - qi_flush_dev_iotlb(iommu, sid, pfsid, qdep, 0, 64 - VTD_PAGE_SHIFT); + /* + * When PASID 0 is used, it indicates RID2PASID(DMA request w/o PASID), + * devTLB flush w/o PASID should be used. For non-zero PASID under + * SVA usage, device could do DMA with multiple PASIDs. It is more + * efficient to flush devTLB specific to the PASID. + */ + if (pasid == PASID_RID2PASID) + qi_flush_dev_iotlb(iommu, sid, pfsid, qdep, 0, 64 - VTD_PAGE_SHIFT); + else + qi_flush_dev_iotlb_pasid(iommu, sid, pfsid, pasid, qdep, 0, 64 - VTD_PAGE_SHIFT); } void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev, -- 2.7.4
| |