From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppusw...@linux.intel.com>
As per Intel vt-d specification, Rev 3.0 (section 7.5.1.1, title "Page
Request Descriptor"), Intel IOMMU page request descriptor only uses
bits[63:12] of the page address. Hence Intel IOMMU driver would only
permit devices that advertise they would only send page aligned requests
to participate in ATS service.
Cc: Ashok Raj <ashok....@intel.com>
Cc: Jacob Pan <jacob.jun....@linux.intel.com>
Cc: Keith Busch <keith.bu...@intel.com>
Suggested-by: Ashok Raj <ashok....@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppusw...@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 1457f931218e..6a0b5270cd2e 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1406,6 +1406,7 @@ static void iommu_enable_dev_iotlb(struct
device_domain_info *info)
info->pri_enabled = 1;
#endif
if (!pdev->untrusted && info->ats_supported &&
+ pci_ats_page_aligned(pdev) &&
!pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
info->ats_enabled = 1;
domain_update_iotlb(info->domain);
--
2.20.1
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