> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Tuesday, August 27, 2024 11:52 PM > > From: Nicolin Chen <nicolinc@xxxxxxxxxx> > > For virtualization cases the IDR/IIDR/AIDR values of the actual SMMU > instance need to be available to the VMM so it can construct an > appropriate vSMMUv3 that reflects the correct HW capabilities. > > For userspace page tables these values are required to constrain the valid > values within the CD table and the IOPTEs. > > The kernel does not sanitize these values. If building a VMM then > userspace is required to only forward bits into a VM that it knows it can > implement. Some bits will also require a VMM to detect if appropriate > kernel support is available such as for ATS and BTM. > > Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx> > Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
