[PATCH 1/3] iommu/vt-d: Set PGSNP bit in pasid table entry for sva binding

[Lu Baolu]

This field make the requests snoop processor caches irrespective of other
attributes in the request or other fields in paging structure entries
used to translate the request. The latest VT-d specification states that
this field is treated as Reserved(0) for implementations not supporting
Snoop Control (SC=0 in the Extended Capability Register). Hence add a
check in the code.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/pasid.c | 2 +-
 drivers/iommu/intel/svm.c   | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index f8d215d85695..9ca3c67a2058 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -625,7 +625,7 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 		}
 	}
 
-	if (flags & PASID_FLAG_PAGE_SNOOP)
+	if ((flags & PASID_FLAG_PAGE_SNOOP) && ecap_sc_support(iommu->ecap))
 		pasid_set_pgsnp(pte);
 
 	pasid_set_domain_id(pte, did);
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 23a38763c1d1..d88af37c20ef 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -394,6 +394,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu,
 	sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ?
 			PASID_FLAG_SUPERVISOR_MODE : 0;
 	sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
+	sflags |= PASID_FLAG_PAGE_SNOOP;
 	spin_lock_irqsave(&iommu->lock, iflags);
 	ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid,
 					    FLPT_DEFAULT_DID, sflags);
-- 
2.25.1