From 4ed0d3e6c64cfd9ba4ceb2099b10d1cf8ece4320 Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Fri, 24 Apr 2009 17:30:20 -0700 Subject: Intel IOMMU Pass Through Support The patch adds kernel parameter intel_iommu=pt to set up pass through mode in context mapping entry. This disables DMAR in linux kernel; but KVM still runs on VT-d and interrupt remapping still works. In this mode, kernel uses swiotlb for DMA API functions but other VT-d functionalities are enabled for KVM. KVM always uses multi level translation page table in VT-d. By default, pass though mode is disabled in kernel. This is useful when people don't want to enable VT-d DMAR in kernel but still want to use KVM and interrupt remapping for reasons like DMAR performance concern or debug purpose. Signed-off-by: Fenghua Yu Acked-by: Weidong Han Signed-off-by: David Woodhouse --- Documentation/kernel-parameters.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 600cdd72900..fa4faeb7597 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -965,6 +965,7 @@ and is between 256 and 4096 characters. It is defined in the file nomerge forcesac soft + pt [x86, IA64] io7= [HW] IO7 for Marvel based alpha systems See comment before marvel_specify_io7 in -- cgit v1.2.3-18-g5258