Hi Jason, On 2/3/23 13:51, Jason Gunthorpe wrote: > 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? where does the requirement come from? Thanks Eric > > Jason >
