iommu/vt-d: Enable QI on all IOMMUs before setting root entry

This seems to be required on some X58 chipsets on systems
with more than one IOMMU. QI does not work until it is
enabled on all IOMMUs in the system.

Reported-by: Dheeraj CVR <cvr.dheeraj@gmail.com>
Tested-by: Dheeraj CVR <cvr.dheeraj@gmail.com>
Fixes: 5f0a7f7614a9 ('iommu/vt-d: Make root entry visible for hardware right after allocation')
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a644d0cec2d8275d202fd3d871673b7787dd258c..10700945994eed2e470c92d267c0bb5723ed0d1a 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3222,11 +3222,6 @@ static int __init init_dmars(void)
                        }
                }
 
-               iommu_flush_write_buffer(iommu);
-               iommu_set_root_entry(iommu);
-               iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
-               iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
-
                if (!ecap_pass_through(iommu->ecap))
                        hw_pass_through = 0;
 #ifdef CONFIG_INTEL_IOMMU_SVM
@@ -3235,6 +3230,18 @@ static int __init init_dmars(void)
 #endif
        }
 
+       /*
+        * Now that qi is enabled on all iommus, set the root entry and flush
+        * caches. This is required on some Intel X58 chipsets, otherwise the
+        * flush_context function will loop forever and the boot hangs.
+        */
+       for_each_active_iommu(iommu, drhd) {
+               iommu_flush_write_buffer(iommu);
+               iommu_set_root_entry(iommu);
+               iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
+               iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
+       }
+
        if (iommu_pass_through)
                iommu_identity_mapping |= IDENTMAP_ALL;