Hi, comments inline
On 29 November 2016 at 10:58, Christophe Milard < christophe.mil...@linaro.org> wrote: > Hi, > > In our last meeting, yesterday, we agreed on the following objects: > 1) enumerator class > 2) enumerator > 3) enumerated_device > 4) devio > [FF] we have defined two types of devio: devio-nommu, devio-iommu. The devio-nommu can be implemented using uio or vfio-nommu interfaces. devio-nommu abstracts calls to both and ensure it is OS independent. devio-iommu implement full vfio interface with dma and irq remappings. if we consider uio as being deprecated, we may just focus on vfio based devio-nommu and devio-iommu on the first pass and add uio next. 5) driver > > and to come: pktio_interface... > > At registration time, the driver have to tell: > - The enumerator class it expects devices from (string E) > - The devio it intend to use (string D) > > [FF]: 1) the administrator has bound uio or vfio to the device. In that case, the driver have to be compatible with them. 2) the administrator did nothing, then it is the driver duty to ask for a devio-nommu or devio-iommu interface to the enumerator. 3) so I would say that String D is for supported list of devio interfaces and versions. Also, the version of these matters! are we OK with a major/minor > approach?, i.e. the driver will be probed (after registration), only > for objects enumerated by a compatible enumerator E and if a > compatible devio D has been registered: > > By compatible we mean: > At registration time enumerators and devios provide a major/minor > version number > At registration time, driver provides the requested enumerator and > devio name and version. > The register version (of a enumerator or devio) is compatible with the > requested version if: > major(requested) = major(registered) > minor(requested) <= minor(registered) > > Does this make sense for you? any better idea? > > [FF] If we look at operational cases, I think we cannot allow too much flexibility. we should define a "device framework" API version and only allow loaded modules (enumerator classes, drivers...) that have the same API versions. Then a version can be used to identify bug fixes in the implementation. This may allow to update a faulty driver live on a system. Christophe > -- [image: Linaro] <http://www.linaro.org/> François-Frédéric Ozog | *Director Linaro Networking Group* T: +33.67221.6485 francois.o...@linaro.org | Skype: ffozog
