diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 51f8215877f5..822679ac90a1 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -2773,14 +2773,16 @@ int __init amd_iommu_init_api(void) int __init amd_iommu_init_dma_ops(void) { - swiotlb = iommu_pass_through ? 1 : 0; + swiotlb = (iommu_pass_through || sme_me_mask) ? 1 : 0; iommu_detected = 1; /* * In case we don't initialize SWIOTLB (actually the common case - * when AMD IOMMU is enabled), make sure there are global - * dma_ops set as a fall-back for devices not handled by this - * driver (for example non-PCI devices). + * when AMD IOMMU is enabled and SME is not active), make sure there + * are global dma_ops set as a fall-back for devices not handled by + * this driver (for example non-PCI devices). When SME is active, + * make sure that swiotlb variable remains set so the global dma_ops + * continue to be SWIOTLB. */ if (!swiotlb) dma_ops = &nommu_dma_ops;