The latest VT-d specification states that the PGSNP field in the pasid
table entry should be treated as Reserved(0) for implementations not
supporting Snoop Control (SC=0 in the Extended Capability Register).
This adds a check before setting the field.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
drivers/iommu/intel/pasid.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index f8d215d85695..5cb2daa2b8cb 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -625,8 +625,14 @@ int intel_pasid_setup_first_level(struct intel_iommu
*iommu,
}
}
- if (flags & PASID_FLAG_PAGE_SNOOP)
- pasid_set_pgsnp(pte);
+ if (flags & PASID_FLAG_PAGE_SNOOP) {
+ if (ecap_sc_support(iommu->ecap)) {
+ pasid_set_pgsnp(pte);
+ } else {
+ pasid_clear_entry(pte);
+ return -EINVAL;
+ }
+ }
pasid_set_domain_id(pte, did);
pasid_set_address_width(pte, iommu->agaw);
@@ -710,7 +716,8 @@ int intel_pasid_setup_second_level(struct intel_iommu
*iommu,
pasid_set_fault_enable(pte);
pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
- if (domain->domain.type == IOMMU_DOMAIN_UNMANAGED)
+ if (ecap_sc_support(iommu->ecap) &&
+ domain->domain.type == IOMMU_DOMAIN_UNMANAGED)
pasid_set_pgsnp(pte);
/*
--
2.25.1
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