From: Kuppuswamy Sathyanarayanan <[email protected]>
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 <[email protected]> Cc: Jacob Pan <[email protected]> Cc: Keith Busch <[email protected]> Suggested-by: Ashok Raj <[email protected]> Signed-off-by: Kuppuswamy Sathyanarayanan <[email protected]> --- 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
