From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Date: Tue, 19 Feb 2019 19:06:10 +0000 (-0800)
Subject: iommu/vt-d: Enable ATS only if the device uses page aligned address.
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=61363c1474b146114fb4c5e5af2908c8afcf1c5e;p=linux.git

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 <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>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a341927d95367..00f46021d6908 100644
--- 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);