From 1b84778a62ad6d0d97ace457072d93933f306ef5 Mon Sep 17 00:00:00 2001
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Date: Tue, 19 Feb 2019 11:04:52 -0800
Subject: [PATCH] iommu/vt-d: Fix PRI/PASID dependency issue.

In Intel IOMMU, if the Page Request Queue (PRQ) is full, it will
automatically respond to the device with a success message as a keep
alive. And when sending the success message, IOMMU will include PASID in
the Response Message when the Page Request has a PASID in Request
Message and it does not check against the PRG Response PASID requirement
of the device before sending the response. Also, if the device receives
the PRG response with PASID when its not expecting it the device behavior
is undefined. So if PASID is enabled in the device, enable PRI only if
device expects PASID in PRG Response Message.

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>
---
 drivers/iommu/intel-iommu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 271455e5026e7..a341927d95367 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1402,7 +1402,9 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
 	if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
 		info->pasid_enabled = 1;
 
-	if (info->pri_supported && !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32))
+	if (info->pri_supported &&
+	    (info->pasid_enabled ? pci_prg_resp_pasid_required(pdev) : 1)  &&
+	    !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32))
 		info->pri_enabled = 1;
 #endif
 	if (!pdev->untrusted && info->ats_supported &&
-- 
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