On Tue, Jan 31, 2023 at 09:53:05PM +0100, Eric Auger wrote: > Now we support two types of iommu backends, let's add the capability > to select one of them. This depends on whether an iommufd object has > been linked with the vfio-pci device: > > if the user wants to use the legacy backend, it shall not > link the vfio-pci device with any iommufd object: > > -device vfio-pci,host=0000:02:00.0 > > This is called the legacy mode/backend. > > If the user wants to use the iommufd backend (/dev/iommu) it > shall pass an iommufd object id in the vfio-pci device options: > > -object iommufd,id=iommufd0 > -device vfio-pci,host=0000:02:00.0,iommufd=iommufd0 > > Note the /dev/iommu device may have been pre-opened by a > management tool such as libvirt. This mode is no more considered > for the legacy backend. So let's remove the "TODO" comment. The vfio cdev should also be pre-openable like iommufd? Jason
