On Fri, 7 Aug 2020 13:59:42 +0200 Cornelia Huck <cohuck@redhat.com> wrote:
On Wed, 05 Aug 2020 12:35:01 +0100 Sean Mooney <smooney@redhat.com> wrote:
On Wed, 2020-08-05 at 12:53 +0200, Jiri Pirko wrote:
Wed, Aug 05, 2020 at 11:33:38AM CEST, yan.y.zhao@intel.com wrote:
(...)
software_version: device driver's version. in <major>.<minor>[.bugfix] scheme, where there is no compatibility across major versions, minor versions have forward compatibility (ex. 1-> 2 is ok, 2 -> 1 is not) and bugfix version number indicates some degree of internal improvement that is not visible to the user in terms of features or compatibility,
vendor specific attributes: each vendor may define different attributes device id : device id of a physical devices or mdev's parent pci device. it could be equal to pci id for pci devices aggregator: used together with mdev_type. e.g. aggregator=2 together with i915-GVTg_V5_4 means 2*1/4=1/2 of a gen9 Intel graphics device. remote_url: for a local NVMe VF, it may be configured with a remote url of a remote storage and all data is stored in the remote side specified by the remote url. ... just a minor not that i find ^ much more simmple to understand then the current proposal with self and compatiable. if i have well defiend attibute that i can parse and understand that allow me to calulate the what is and is not compatible that is likely going to more useful as you wont have to keep maintianing a list of other compatible devices every time a new sku is released.
in anycase thank for actully shareing ^ as it make it simpler to reson about what you have previously proposed.
So, what would be the most helpful format? A 'software_version' field that follows the conventions outlined above, and other (possibly optional) fields that have to match?
Just to get a different perspective, I've been trying to come up with what would be useful for a very different kind of device, namely vfio-ccw. (Adding Eric to cc: for that.) software_version makes sense for everybody, so it should be a standard attribute. For the vfio-ccw type, we have only one vendor driver (vfio-ccw_IO). Given a subchannel A, we want to make sure that subchannel B has a reasonable chance of being compatible. I guess that means: - same subchannel type (I/O) - same chpid type (e.g. all FICON; I assume there are no 'mixed' setups -- Eric?) - same number of chpids? Maybe we can live without that and just inject some machine checks, I don't know. Same chpid numbers is something we cannot guarantee, especially if we want to migrate cross-CEC (to another machine.) Other possibly interesting information is not available at the subchannel level (vfio-ccw is a subchannel driver.) So, looking at a concrete subchannel on one of my machines, it would look something like the following: <common> software_version=1.0.0 type=vfio-ccw <-- would be vfio-pci on the example above <vfio-ccw specific> subchannel_type=0 <vfio-ccw_IO specific> chpid_type=0x1a chpid_mask=0xf0 <-- not sure if needed/wanted Does that make sense?