Messages in this thread Patch in this message | | | From | sathyanarayanan.kuppuswamy@linux ... | Subject | [PATCH v3 2/2] iommu/vt-d: Enable ATS only if the device uses page aligned address. | Date | Tue, 19 Feb 2019 11:06:10 -0800 |
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From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@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.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Keith Busch <keith.busch@intel.com> Suggested-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@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 78188bf7e90d..bb0e244a0117 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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