lkml.org 
[lkml]   [2019]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 2/2] iommu/vt-d: Enable ATS only if the device uses page aligned address.
Date
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 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
\
 
 \ /
  Last update: 2019-02-11 22:47    [W:0.035 / U:0.920 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site