On Fri, Mar 12, 2021 at 03:04:10AM -0600, Suravee Suthikulpanit wrote: > To allow specification whether to use v1 or v2 IOMMU pagetable for > DMA remapping when calling kernel DMA-API. > > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com> > --- > Documentation/admin-guide/kernel-parameters.txt | 6 ++++++ > drivers/iommu/amd/init.c | 15 +++++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 04545725f187..466e807369ea 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -319,6 +319,12 @@ > This mode requires kvm-amd.avic=1. > (Default when IOMMU HW support is present.) > > + amd_iommu_pgtable= [HW,X86-64] > + Specifies one of the following AMD IOMMU page table to > + be used for DMA remapping for DMA-API: > + v1 - Use v1 page table (Default) > + v2 - Use v2 page table
Any reason v2 can not be the default when it is supported by the IOMMU?
