> From: Leon Romanovsky <leon@xxxxxxxxxx> > Sent: Wednesday, June 9, 2021 5:02 PM > > On Mon, Jun 07, 2021 at 02:58:18AM +0000, Tian, Kevin wrote: > > Hi, all, > > <...> > > > (Remaining opens in v1) > > <...> > > > - Device-centric (Jason) vs. group-centric (David) uAPI. David is not fully > > convinced yet. Based on discussion v2 will continue to have ioasid uAPI > > being device-centric (but it's fine for vfio to be group-centric). A new > > section will be added to elaborate this part; > > <...> > > > (Adopted suggestions) > > <...> > > > - (Jason) Addition of device label allows per-device capability/format > > check before IOASIDs are created. This leads to another major uAPI > > change in v2 - specify format info when creating an IOASID (mapping > > protocol, nesting, coherent, etc.). User is expected to check per-device > > format and then set proper format for IOASID upon to-be-attached > > device; > > Sorry for my naive question, I still didn't read all v1 thread and maybe > the answer is already written, but will ask anyway. > > Doesn't this adopted suggestion to allow device-specific configuration > actually means that uAPI should be device-centric? > > User already needs to be aware of device, configure it explicitly, maybe > gracefully clean it later, it looks like not so much left to be group-centric. > Yes, this is what v2 will lean toward. /dev/ioasid reports format info and handle IOASID attachment per device. VFIO could still keep its group- centric uAPI, but in the end it needs bind each device in the group to IOASID FD one-by-one. Thanks Kevin
