• Fenghua Yu's avatar
    Intel IOMMU Pass Through Support · 4ed0d3e6
    Fenghua Yu authored
    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: default avatarFenghua Yu <fenghua.yu@intel.com>
    Acked-by: default avatarWeidong Han <weidong@intel.com>
    Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
    4ed0d3e6
iommu.h 364 Bytes