From a4c34ff1c029e90e7d5f8dd8d29b0a93b31c3cb2 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 17 Jun 2016 11:29:48 +0200 Subject: [PATCH] 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 Tested-by: Dheeraj CVR Fixes: 5f0a7f7614a9 ('iommu/vt-d: Make root entry visible for hardware right after allocation') Cc: stable@vger.kernel.org Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index a644d0cec2d8..10700945994e 100644 --- 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; -- 2.30.2