[PATCH 3.16 076/132] iommu/vt-d: Set intel_iommu_gfx_mapped correctly

[Ben Hutchings]

3.16.74-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

commit cf1ec4539a50bdfe688caad4615ca47646884316 upstream.

The intel_iommu_gfx_mapped flag is exported by the Intel
IOMMU driver to indicate whether an IOMMU is used for the
graphic device. In a virtualized IOMMU environment (e.g.
QEMU), an include-all IOMMU is used for graphic device.
This flag is found to be clear even the IOMMU is used.

Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
Reported-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Fixes: c0771df8d5297 ("intel-iommu: Export a flag indicating that the IOMMU is used for iGFX.")
Suggested-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel-iommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3578,9 +3578,7 @@ static void __init init_no_remapping_dev
 
 		/* This IOMMU has *only* gfx devices. Either bypass it or
 		   set the gfx_mapped flag, as appropriate */
-		if (dmar_map_gfx) {
-			intel_iommu_gfx_mapped = 1;
-		} else {
+		if (!dmar_map_gfx) {
 			drhd->ignored = 1;
 			for_each_active_dev_scope(drhd->devices,
 						  drhd->devices_cnt, i, dev)
@@ -4074,6 +4072,9 @@ int __init intel_iommu_init(void)
 		goto out_free_reserved_range;
 	}
 
+	if (dmar_map_gfx)
+		intel_iommu_gfx_mapped = 1;
+
 	init_no_remapping_devices();
 
 	ret = init_dmars();