iommu/vt-d: Enable ATS only if the device uses page aligned address.

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]>
Signed-off-by: Joerg Roedel <[email protected]>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a341927d95367e80b2e0cc41051e3a77088eea88..00f46021d6908c27aaf2a5e1d41f3eca02b8d6b3 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1408,6 +1408,7 @@ 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);