> From: Jason Gunthorpe <jgg@xxxxxxxxxx> > Sent: Thursday, June 3, 2021 8:46 PM > > On Thu, Jun 03, 2021 at 04:26:08PM +1000, David Gibson wrote: > > > > There are global properties in the /dev/iommu FD, like what devices > > > are part of it, that are important for group security operations. This > > > becomes confused if it is split to many FDs. > > > > I'm still not seeing those. I'm really not seeing any well-defined > > meaning to devices being attached to the fd, but not to a particular > > IOAS. > > Kevin can you add a section on how group security would have to work > to the RFC? This is the idea you can't attach a device to an IOASID > unless all devices in the IOMMU group are joined to the /dev/iommu FD. > > The basic statement is that userspace must present the entire group > membership to /dev/iommu to prove that it has the security right to > manipulate their DMA translation. > > It is the device centric analog to what the group FD is doing for > security. > Yes, will do. Thanks Kevin
