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>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 271455e5026e73dad6bdab95c6e6aeebf42a9b8b..a341927d95367e80b2e0cc41051e3a77088eea88 100644 (file)
--- 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 &&