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[v1,2/2] iommu/vt-d: Enable PASID only if device expects PASID in PRG response.

Message ID 5fbcaf70a3686a1355fa81da03157e1e6c9dbf9e.1549479043.git.sathyanarayanan.kuppuswamy@linux.intel.com (mailing list archive)
State Superseded, archived
Headers show
Series Add PGR response PASID requirement check in Intel IOMMU. | expand

Commit Message

Kuppuswamy Sathyanarayanan Feb. 7, 2019, 6:37 p.m. UTC 
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

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 then the device behavior
is undefined. So enable PASID support 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>
---
 drivers/iommu/intel-iommu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 1457f931218e..887847f08746 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1399,7 +1399,8 @@  static void iommu_enable_dev_iotlb(struct device_domain_info *info)
 	   undefined. So always enable PASID support on devices which
 	   have it, even if we can't yet know if we're ever going to
 	   use it. */
-	if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
+	if (info->pasid_supported && pci_pggrp_rsp_need_pasid(pdev) &&
+	    !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))